imtiaz's notes

Bovines

49 min read

  • Reproductive Problems:
  • Campylobacter fetus subsp venerealis usually causes early embryonic death. Campylobacter is a cause of early embryonic death but does not usually result in pyometra.
  • Tritrichomonas fetus abortions usually occur in the first half of gestation but does have placentitis and pneumonia in the fetus as does Brucella.  Tritrichomonas foetus is associated with a post-coital pyometra in addition to causing early embryonic death.  The mature bull is commonly the reservoir of infection for a herd.  Trichomoniasis, caused by the protozoan Tritrichomonas foetus, is typically a temporary infection in the female. She characteristically eliminates the infection in 2-4 months. The bull, however, becomes a chronic carrier as he ages, since aging is associated with increased depth of epithelial crypts of a bull’s glans penis and prepuce, thus increasing the availability of the “niche” where the organism thrives.
    • Once infected, a cow typically clears the infection from the reproductive tract in 2-4 months and regains her fertility.
    • Young bulls are rarely infected chronically, probably because they have shallow penile and preputial crypts, which are thought to provide poor niches for chronic infection.  Trichomoniasis typically manifests no visible signs in either the male or female.
  • **Neospora **abortions are usually mid gestation and cause necrosis of the cotyledons, with fetal lesions including myocarditis, hepatitis, myositis and encephalitis.
    • Neospora abortions usually occur around 4-6 months, but can occur throughout gestation. Calves with neurologic deficits may also result. Dogs ingest infected tissues from fetus or placenta and pass oocysts in feces, which are ingested by cows.
    • Other causes of abortion tend to occur later in gestation (such as Brucella, Listeria, and leptospirosis). A confirmed diagnosis of N caninum is based on histologic lesions which are found in the brain (and also other organs) and consist of scattered foci of nonsuppurative cellular infiltrates with occasional foci of necrosis
  • Leptospirosis is a cause of mid- to late-gestation abortions and not post-coital pyometras.
  • Brucellosis You should be most suspicious of Brucellosis based on the assortment of signs (abortions, retained placenta, metritis and lack of signs in younger animals), the timing of abortions (last half of pregnancy), and the relatively normal appearance of the examined fetuses. Plus the cattle are not tattooed as they should be if they were given calfhood brucella vaccine.  Brucella will result in late term abortion.
  • The correct answer is tritrichomonas foetus. This organism is commonly associated with a post-coital pyometra in addition to causing early embryonic death. Campylobacter is a cause of early embryonic death but does not usually result in pyometra.Brucellosis will result in late term abortion. Leptospirosis is a cause of mid- to late-gestation abortions and not post-coital pyometras.
  • Breeding Soundness Examination
  • The correct answer is 70% normal. To be a satisfactory potential breeder, a bull must meet certain requirements including a normal physical exam, adequate scrotal circumference, sperm motility of at least 30% motile, and sperm morphology of at least 70% normal.
  • You are called out to a dairy herd that has recently been experiencing reproductive problems. The cows were all acquired 1 year ago from an unknown source and have no known vaccinations or tattoos. The dairyman reports that several cows have had late abortions (6-7 months gestation) and weak or stillborn calves in the past year and he’s never had this problem before. Several of the cows that had abortions developed placental retention and/or metritis. None of the younger pre-pubescent heifers are displaying any clinical signs. You perform a necropsy on two recently aborted fetuses and find lung consolidation in one but no other obvious abnormalities. Which of the following should you recommend?
  • Serologic testing for Brucellosis
  •  Serologic testing for Neospora
  •  Test for Campylobacter fetus subsp venerealis
  •  Test for Trichomoniasis
  • Explanation
    • You should be most suspicious of Brucellosis based on the assortment of signs (abortions, retained placenta, metritis and lack of signs in younger animals), the timing of abortions (last half of pregnancy), and the relatively normal appearance of the examined fetuses. Plus the cattle are not tattooed as they should be if they were given calfhood brucella vaccine. Tritrichomonas fetus abortions usually occur in the first half of gestation but do have placentitis and pneumonia in the fetus as does Brucella. Campylobacter fetus subsp venerealis usually causes early embryonic death. Neospora abortions are usually mid gestation and cause necrosis of the cotyledons, with fetal lesions including myocarditis, hepatitis, myositis and encephalitis.
    • Hormones
    • Q. A 4-year old dairy cow in her third lactation presents after calving normally about 95 days ago. No one has observed her in estrus since calving. On physical exam, you find a non-pregnant heavy, fluid-filled uterus, and an apparent corpus luteum on one ovary. Assuming treatment is successful, which of the following is the most significant therapeutic effect of a single intra-muscular injection of PGF2-alpha in this patient?
      • Explanation:  PGF2-alpha will lyse her corpus luteum, increase uterine motility, evacuate her uterus, and bring her into estrus
      • PGF2-alpha has many effects, but chief among them is its luteolytic action. Lysis of the corpus luteum will immediately reduce circulating progesterone levels, allow the final development of an ovarian follicle, and bring the cow into estrus, which is accompanied by increased uterine motility, and in this case, drainage.
      • PGF2-alpha will not likely stimulate the cow’s appetite and would not do so by a direct therapeutic effect.
      • PGF2-alpha will not decrease uterine contractility. PGF2-alpha will probably increase uterine contractility, both directly (utero-tonic effects) and indirectly, through the rise of estrogen that follows PGF2-alpha-induced luteolysis.
      • PGF2-alpha is an inflammatory mediator. It will NOT directly suppress uterine inflammation. This cow needs an effective immune/inflammatory response to “clean up” her uterus. Anti-inflammatory therapy is not indicated.
      • PGF2-alpha will NOT cause the maturation and ovulation of multiple follicles (i.e., superovulation). That is achieved by an altogether different class of hormones, the gonadotropins.
    • ** Penile warts** in young bulls are quite common and are caused by bovine papilloma virus-1 (BPV-1) which can also cause warts on the nose or teats. Warts are very contagious and primarily spread by contamination of facility equipment but also spread directly from bull to bull. BPV-1 infection is not associated with other health problems. The treatment of choice for penile warts is surgical removal. Surgical damage to the warts frequently stimulates an immune response against BPV-1. Healing is usually complete within 2-3 weeks.
    • Autogenous vaccines have been used to treat penile warts but this is rarely practiced now due to cost and risk of severe reactions and relatively little benefit compared to surgical removal. It is not necessary to wait 6 months before breeding.
    • Bull BSE: Bulls typically reach puberty at 9-11 months of age depending on breed. Scrotal circumference of a 1 year-old bull also varies by breed but >30 cm is typically recommended for breeding at this age.
    • Normal Fetal Position:
    • What is the normal presentation and position at birth of a calf?
      • Anterior presentation, dorso-sacral position, front limbs extended HIGHLIGHTS
      • The correct answer is anterior presentation, dorso-sacral presentation, front limbs extended. Anterior means the face is coming out first. Dorso-sacral means that the dorsum of the fetus is up against the sacrum of the mama. Legs extended implies the legs are in front and will be the first thing visible. This is the normal presentation.
    • Infectious Diseases
    • Clostridium
      • The clinical signs and history are all very characteristic for a cow with tetanus. The causative agent is Clostridium tetani.
      • C. botulinum is responsible for a flaccid paralysis and rapid death, not the hyper-alert signs shown here.
      • C. difficile is notorious for bowel infections, especially in horses.
      • Systemic infection with C. septicum will result in massive necrosis of damaged tissues, but would not show the hyper-excitability seen in the cow in question.
    • A uterine infection with Trueperella pyogenes would result in endometritis or at worst, pyometra, but would not cause any overt signs as seen in this question.
    • Actinomyces bovis or Lumpy jaw
    • A 6-year old Friesian cow presents to you with a mass on the left mandible (see image). The farmer reports that the mass has developed over the last several weeks and the cow has recently had some difficulty eating and lost weight. On examination, the mass is firm, immobile, and painful on manipulation. You note a thick discharge with small granular particles. Based on the most likely diagnosis, what should you tell the farmer?
    •  The most effective treatment is oral sodium iodide
    •  Treatment with sodium iodide intravenously is likely curative but the cow’s milk and meat will not be suitable for human consumption for 120 days
    •  Intravenous penicillins are likely to be effective
    • Treatment is unlikely to be successful and the cow should be culled
    • Explanation
      • This is a case of Actinomyces bovis or “lumpy jaw”. The keys to the diagnosis are the firm mass that is immobile over the mandible. The presence of “sulfur granules” in the discharge is also a characteristic finding with this disease. Unfortunately, simply making the diagnosis is not sufficient to answer this question correctly. All of the answer choices are potential treatments for lumpy jaw but this represents a moderate to severe case which is unlikely to respond to treatment due to difficulty in achieving the necessary antibiotic concentration over a sustained period. Therefore, the best answer choice in this case is to cull the cow.
      • Bovine Viral Diarrhoea
      • Anaplasmosis
      • Ostertagia Ostertagii - ostertagiasis
      • Free Gas Bloat
        • A 6-month old feedlot steer, which entered the feedlot 4 weeks ago, has lost weight and is now showing an enlarged left flank as shown in the image below. On exam, you find the left side of the abdomen to be gas-filled under moderate pressure, and the rumen to be otherwise poorly filled and with poor motility. Based on percussion and auscultation, the animal also appears to have chronic bronchopneumonia. What is the most likely cause of the rumen malfunction?
        • Explanation
          • This is sometimes called Type 1 vagal indigestion, or free gas bloat. It is frequently associated with swollen mediastinal lymph nodes caused by pneumonia. The signals to or from dorsal rumen receptors, which detect gas pressure and open the cardia, are compromised such that eructation does not occur normally and free gas bloat occurs. This in turn causes the calf to feel full and it eats poorly and loses weight. One needs to treat the pneumonia and perhaps create a temporary rumen fistula to allow the escape of gas until eructation returns to normal
        • Pinkeye
        • The correct answer is pinkeye (infectious bovine keratoconjunctivitis). This image is a typical representation of what you are likely to observe. Usually, initial symptoms are blepharospasm, chemosis, and photophobia. This is due to the centrally located ulcer from the infection. The ulcer usually runs its course over a few weeks, however sometimes you may observe corneal descemetoceles and corneal perforation. Therefore, you will probably want to treat these conditions also. Additionally, it is very painful and stressful for the animals, and they will decrease their productivity.
        • IBR and Thelazia (eyeworm) can also cause ocular signs.
        • **Ringworm **is a dermatomycosis that tends to occur most commonly in housed, crowded calves in winter when there is little UV light present. The most common dermatophyte in cattle tends to be Tricophyton verrucosum, with T. mentagrophytes second most common. Therapy includes such topical treatments as captan, diluted bleach, lime sulfur, or miconazol shampoos. Systemic treatment is rarely needed.
        • Q. A group of 30 housed 4-6 month-old Friesian heifer calves presents with multifocal several-centimeter skin lesions like the ones seen in the image. The lesions are primarily located around the head and neck but are also seen more sparsely in other areas. The lesions are superficial, dry, scaly and do not appear pruritic. The underlying skin is not thickened. The cows are eating and behaving otherwise normally. Which of the following tests will help confirm your presumptive diagnosis?
        •     Microscopic examination of a hair/skin scraping from edge of the lesions
        • You should be most suspicious of ringworm based on the lesion appearance and distribution. Microscopic examination from the periphery of the lesions is likely to reveal fungal hyphae of Trichophyton spp. Dermatophyte culture would also be a good option. Ringworm will typically regress over many months without treatment but untreated lesions may present risk of transmission including zoonotic transmission. Topical treatments including 4% lime sulfur, 0.5% sodium hypochlorite (1:10 household bleach), 0.5% chlorhexidine, 1% povidone-iodine, natamycin, and enilconazole may be options and likely work best if any crusts are removed prior to application.
        • Q. The correct answer is a mononuclear pleocytosis. CSF tap is most important for distinguishing Listeriosis from thromboembolic meningoencephalitis (TEME), in which you will see a neutrophilic pleocytosis on CSF cytologic examination. Remember with Listeria, you will often observe CNS signs, an increased number of monocytes and macrophages. Also remember that Listeria is usually contracted from ingesting silage that has been stored at a pH > 5.0.
        • Q. A 4 year old Ayrshire cow presents with a two day history of depression, anorexia, fever, conscious proprioceptive deficits, right sided head tilt, and head-pressing. A neurologic exam identified cranial nerve deficits. Particularly, the right ear is drooping, the right eye appears “dropped”, and she is drooling from the right side of her mouth. Where is the lesion?
        • The correct answer is Hypoderma bovis. H bovis is also known as the cattle grub, heel fly, or warble fly. The life cycle starts with the female attaching up to 500 eggs to the hairs around the hocks and lower portions of the cow. First-stage larvae will hatch in just a few days and burrow into the skin. At this point, they migrate towards the epidural fat in the spinal canal (H bovis) or via the esophagus (H lineatum). After several months, they become L2s and migrate to the subcutaneous tissues of the back where they will reach puberty, molt once more, and become L3s. Once they are L3s, swellings on the cows’ backs can be felt. After 5-11 weeks, the L3s mature and burst through the skin, dropping on the ground where they will become adults in another 1-3 months.
        • Cochliomyia hominivorax (aka screwworm) lays its eggs on skin wounds. The developing maggots feed on the flesh and can lead to multiple infestations from additional screwworms and other flies.
        • Ornithodoros coriaceus (aka Pajahuello tick) is a soft tick that feeds on many different mammals and birds. This tick has become somewhat famous because it appears to transmit epizootic bovine abortion.
        • Sarcoptes scabiei (aka scabies mange mite) causes mechanical and chemical irritation and intense pruritus, leading to loss of milk production and damage of hides due to scratching. Although this is a possible answer, the economic impact of Sarcoptes scabies is not as worrisome as with Hypoderma bovis
        • This is a cattle warble called Hypoderma. The 2 species are H. bovis and H. lineatum. They undergo a long migration in tissues and only emerge from the back of the animal in spring. The crucial treatment time is early fall when larvae are just beginning to migrate in tissues. Organophosphates or one of the macrocyclic lactones (ivermectin, doramectin, eprinomectin or moxidectin) are effective.
        • When formulating late gestation anionic diets for dairy cows to help prevent hypocalcemia in the last 2 to 3 weeks prior to calving, what formula is used?   DCAD = (Na + K) - (Cl + S)
        • DCAD stands for Dietary Cation Anion Difference. Na=sodium, K=potassium, Cl=chloride, and S=sulfur. These are the 4 most important strong ions to be considered. When the diet is optimal the urine pH of Holstein cows should range between 6.2 and 6.8 for cows on the ration.
        • The owner of a new beef ranch on poor volcanic soil asks you to evaluate 2 steers. They are representative of an ongoing herd problem of chronic diarrhea and respiratory disease that is unresponsive to antibiotic treatment. On physical exam, you notice achromotrichia, ill thrift, and a temperature of 103F (39.4 C) in both steers. You perform a transtracheal wash in one of the steers and it comes back positive for Pasteurella multocida. What is your diagnosis?
        • The correct answer is copper deficiency. The giveaway is achromotrichia or loss of hair color. Dilution of the coat color is due to dysfunction of tyrosinase which converts L-tyrosine to melanin. In addition, copper deficient animals will have spontaneous fractures, secondary respiratory disease, diarrhea, ill thrift, decreased immunity, anemia, and poor reproduction. Selenium deficiency and BVD are actually pretty good differentials and if achromotrichia was not present either of those two are reasonable choices. Molybdenum deficiency would not result in achromotrichia. On the other hand, if there had been excess molybdenum, then the Cu:Mo ratio would be off and copper deficiency could be observed.
        • The diagnosis is endometritis. This is based on the involuting post partum uterus and the normal vital signs (TPR). Intrauterine penicillin (after 30 days) or tetracycline or ceftiofur can be beneficial. The negative impact can be antibiotic residues in milk (up to 80 hours for penicillin and 96 hours for tetracycline in milk) and in tissues ( up to 12 days for penicillin), so some prefer to use dilute povidone iodine, or uterine lavage with saline. Systemic ceftiofur achieves adequate intrauterine levels and is thus the safest and best of the options listed.
        • Prostaglandins can also be given to “short cycle” the cow which will aid in treating the endometritis. The other drugs listed are not legal for use in the USA, and could cause harmful residues to appear in milk.
        • Brucellosis:
        • You are vaccinating a herd of heifers for protection against brucellosis with the RB51 strain of vaccine. You inadvertently puncture your index finger with a vaccine syringe. Which of the following measures should you take?
          • The RB51 strain of vaccine is the vaccine that is most widely used currently for Brucellosis. Exposure is associated with local and systemic adverse events. The RB51 vaccine is considered much safer than the previous vaccine (known as Strain 19) to humans who are accidentally stuck or have spray exposure to the conjunctiva or open wounds. It remains undetermined if the RB51 vaccine can cause systemic brucellosis in humans. Therefore, it is recommended that individuals receive a 3-week course of doxycycline after suspected exposure. Rifampin was recommended in addition to doxycycline for exposure to the Strain 19 vaccine but RB51 is rifampin and penicillin resistant.
        • Diagnosis can be made from viral isolation of nasal or ocular swabs from live animals or from bronchial lymph nodes or tracheal tissue in deceased animals. Serology 2-3 weeks apart can also confirm a diagnosis of IBR.
        • The different strains of IBR tend to produce different syndromes; in this case there are both respiratory and vaginal signs, a likely result of two or more strains being present since the calves recently came from multiple sources.
        • A typical TPN mixture for a calf this size would be 1L of 10% amino acids, 1L of 50% glucose and 500 ml of 10% lipids per day. HIGHLIGHTS
        • Mastitis:
        • You are at a dairy trying to solve a mastitis problem. You perform a physical exam on a cow with mastitis and notice serum-like secretion with clots from two of the teats, and the affected quarters are hot and swollen. The cow has a fever of 104 F , rapid HR of 100 bpm, and is not eating well. What can you tell the dairyman with a fair degree of confidence about the type of mastitis this is likely to be?
        • Exp
        • The correct answer is this cow is infected with a coliform. This is a typical secretion and other clinical signs with coliform mastitis, although coliform mastitis can also present with mild clinical signs. Trueperella pyogenes mastitis is usually thick pus and the the cow is not so ill. Staph aureus can also cause systemic signs of illness , or gangrenous mastitis when severe. It is usually found in a herd without a comprehensive mastitis prevention and control program. Mycoplasma bovis and a few other species can cause mastitis in cows, but M mycoides is mainly a problem of mastitis in does and systemic illness and arthritis in young goats.
        • Histophilus somni (Hemophilus somnus)-  thromboembolic meningoencephalitis (TEME)
        • A rancher has several yearling cattle which were shipped to his place a few days ago and are showing ataxia (see photo). You observe three to be coughing and breathing hard, two have marked gait abnormalities including staggering, circumducting, knuckling, and one has a slight head tilt. All three have fevers of 104 to 105.5 F (40 to 40.8 C) and appear slightly depressed. They have no rumen motility. One has hypopyon and one has hyphema. Based on the CNS signs you take CSF samples from the 3 in a squeeze chute and find xanthochromia, increased protein, and an increased number of neutrophils. What is your diagnosis?
        • Histophilus somni (Hemophilus somnus)
        • Also known as thromboembolic meningoencephalitis (TEME) and caused by Histophilus somni, this systemic infection may start in the respiratory tract in young stressed, often transported, cattle. Early treatment with antimicrobial drugs such as tetracycline, penicillin, erythromycin, or sulfonamides can be effective.
        • A 6-month old calf presents with a head tilt towards the right side and spontaneous horizontal nystagmus with the fast phase directed towards the left side. Ventral strabismus (eye drop) is present on the right side. There is drooping of the right upper eyelid and drooping of the right ear (see image). Which of the following is the best list of differential diagnoses?
        • Otitis media/interna, middle ear trauma, listeriosis
        • Expl: The calf’s signs are most consistent with dysfunction of the peripheral vestibular system (although one cannot rule out central vestibular) and facial nerve dysfunction. Middle/inner ear infection or trauma are likely and listeria is a reasonable differential as well. Most of the other choices listed are not typically associated with vestibular signs as described in this case.
        • Q. It is the middle of winter and this adult Holstein cow in the picture has just presented after developing neurologic signs including ataxia, head-pressing, nystagmus, and star-gazing. There were no significant clinical exam findings besides the neurologic signs described. The owner was questioned about the housing situation this cow was in because this cow is representing 7 other individuals who are similarly affected. The owner said that nothing has changed in the diet and they are fed a complete mixed ration. Additionally, they are provided water with automatic water feeders. Initial blood work is as follows: Sodium 164 mEq/L (normal 132-152), Chloride 115 mEq/L (normal 97-111), Potassium 4.6 mEq/L (normal 3.9-5.8), Calcium 11.9 mg/dl (normal 9.7-12.4) , Glucose 78mg/dl (normal 45-75), and Protein 7.9mg/dl (6.7-7.46). Which of the following is the most likely diagnosis?
        • The correct answer is salt poisoning. Notice the markedly elevated blood sodium level. A sodium value that high is diagnostic for salt poisoning. If for some reason you are still not sure, you could perform a CSF tap and check the sodium levels and be completely certain. What probably happened to these animals is that the water pipes froze (occurs in northern US with cold winters). As a result, the cows were deprived of water for a certain period of time. During that time, their bodies began to accumulate sodium in the cells of the brain and produce these intracellular proteins to draw water in and maintain normal function. The cows then drink lots of water at the first chance they get, and the hyperosmolar environment in the brain causes water to rush into the cells and destroy them. Ingestion of blue-green algae results in a peracute intoxication which usually results in convulsions, ataxia, bloody diarrhea, and death. Leukoencephalomalacia is a disease which affects horses as a result of ingesting corn infested by the fungus Fusarium moniliforme. Lead poisoning is less likely because the history, clinical signs, and findings are not consistent with exposure to lead.
        • Q.
        • A rancher raises purebred animals and is always concerned about reputation and selling only healthy animals. He calls you to examine a cow (see image) that has been out in a back pasture unobserved for over 2 months, and you suspect bovine leukosis (BLV, bovine lymphosarcoma) based upon the fact that she has multiple large lymph nodes. You aspirate a node and it contains only lymphocytes, further enhancing your suspicions. What test can you now use to confirm that this individual has BLV and also utilize to examine the 200 individuals in his herd for BLV?
        • ELISA to detect antibodies to BLV
        • Explanation
        • ELISA to detect antibodies has been found to have the best sensitivity and specificity of all tests on a herd basis. If the individual with multiple enlarged lymph nodes is also ELISA positive, a necropsy should be performed.
        • PCR can be negative in infected individuals with low numbers of circulating infected lymphocytes, even when they are ELISA antibody-positive. Few infected cows that are still asymptomatic have elevated blood lymphocyte counts. Performing biopsies on 200 cows is not practical when there are other better tests.
        • Blackleg:
        • A 1-year old unvaccinated Angus steer presents as a result of acute lameness and depression. He has historically been healthy and one of the best animals in the group. On physical exam, there are no signs of trauma and the steer is febrile. A crepitant, edematous swelling is seen on the muscles of the left shoulder. It is hot and painful to the touch. Assuming there are no signs of trauma, what is the most likely diagnosis?
        • The correct answer is Clostridium chauvoei (blackleg). Clostridium chauvoei results in infection after gaining access to the blood stream via the alimentary tract and then depositing in muscle. This is a serious disease, and animals will die if left untreated. Cattle should be vaccinated at 3 to 4 months of age against this and other Clostridial diseases. Clostridium hemolyticum causes liver lesions, and the toxin results in acute hemolysis and often in death. Clostridium difficile usually results in gastrointestinal disease in horses. Corynebacterium pseudotuberculosis results in large external bleeding sores on the skin of cattle and boils and internal abscesses in sheep and goats.
        • Blackleg is caused by Clostridium chauvoei, but can also be seen with Cl. septicum or Cl. sordellii (often called malignant edema). Vaccines containing up to 8 different Clostridia are often used. Calves under one year old are most susceptible. On high-risk farms it may be necessary to start vaccination at a younger age or also vaccinate cows to maintain high colostral levels of antibody, and/or to give a booster (second) dose 4 to 8 weeks following the initial dose to calves. Annual revaccination of at least yearlings is also recommended.
        • Mycoplasma bovis can cause sepsis, joint infections and mastitis.
        • BRD is defined as a “disease complex”:
          • It usually is caused by a variety of pathogens, both viral (Bovine Respiratory Syncytial Virus (BRSV), ParaInfluenza 3 (PI3), Adenovirus, Bovine Viral Diarrhea Virus (BVDV), and Infectious Bovine Rhinotracheitis (IBR)) and bacterial (Pasteurella multocida, Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis).
          • Parasitic (lungworm) and fungal (Aspergillus) agents are also pathogens.
          • These pathogens  interact with one another and the animal’s immune system to produce full-blown disease.
          • Bacterial pathogens apparently cause the acute syndrome by invading the bovine respiratory tract that has been compromised by viral infections, environmental conditions and/or other stress factors.
        • Listeriosis
        • Mastitis
        • A cow presents to you as a result of decreased milk production. On physical exam you determine the cow has a much stronger pulse on expiration than she does on inspiration. What is this pulse associated with?
        • A 3-month old Holstein female calf has severe unilateral corneal ulceration, opacity and melting, along with mild conjunctivitis and marked neovascularization. The calf also exhibits photophobia, blepharospasm, and lacrimation. What is the most likely cause of this?
          • The most common bacteria causing this is Moraxella bovis, although other organisms including Neisseria species and Moraxella ovis can also induce similar lesions in cattle. Also, IBR and mycoplasma seem to be risk factors that may increase the risk of developing IBK.
        • Metabolic/Colic
          • Rumen Gas filled This dairy cow in the picture presents for a decrease in appetite and milk production. You systematically do your physical exam and as you percuss and auscultate you hear a monotone “boink” on the left side, dorsally, approximately between rib spaces 9-13 and extending to the hip. What gas-filled organ are you hearing?
        • The location extending up to the hip and the monotone “boink” (not ping) are indicative of the rumen. A cow with LDA would have a variable-pitched ping heard to only just in back of the last rib (not to the hip). It is variable because the rumen is usually still contracting medial to the displaced abomasum, and the changing gas pressures result in a pitch that changes during percussion and auscultatio
        • abomasal torsion/volvulus
        • The photo shows a 3-year old dairy cow which has suddenly developed an enlarged abdomen, is acutely down on milk production, and is not eating. She freshened one month ago, and was a high producing cow. On physical exam, you find a large ping on the right side from just behind the last rib to the 10th rib, and note a large amount of fluid in both the right and left sides of the abdomen on ballottement. T=101 F (38.3 C), HR=120, and RR=42. You diagnose abomasal torsion/volvulus and prepare her for surgery. What fluid should she be treated with?
        •  IV 50% glucose, 1 liter
        •  IV lactated Ringer`s solution
        •  IV sodium bicarbonate

        •  IV saline with 20 meq/L added potassium

        •  Oral saline plus 40 meq/L added potassium
        • A cow with abomasal torsion is accumulating chloride in the forestomachs, which results in hypochloremia and metabolic alkalosis. This in turn leads to hypokalemia as potassium rushes into cells when all available hydrogen ions leave the cells. The treatment of choice is thus IV saline (154 meq/L Na and 154 meq/L Cl) plus potassium. A good rule of thumb for rate of IV administration of potassium is not to exceed 0.5 meq/Kg /hour. So a 500 Kg cow can receive 250 meq/hr safely (which is 12 liters/hr of the fluid described). Oral fluids will simply add to the fluid-filled rumen.
        • Ketosis
        • Q.  A 4-year old Holstein dairy cow in mid-lactation has developed acute onset illness and is colicky (kicking at abdomen, switching her tail, repeatedly lying down and getting up). Her temperature is 102.0 F (38.9 C), HR is 100/min, her scant feces are sticky and dark blackberry jam-colored, her abdomen is distended, and there is no rumen motility. No pings are audible. Her PCV= 30% (24-46%). A blood gas and electrolyte panel reveals Na=140 mEq/L (136-144 mEq/L), K=2.5 meq/L (3.6-4.9 mEq/L), Cl=80meq/L (99-107 mEq/L), and HCO3= 40meq/L (20-30 mEq/L). Based on these clinical signs and lab values, which of the following is most likely to be the correct diagnosis?
        •  Cecal dilation      Intussusception          Abomasal ulcer      Salmonellosis       LDA
  • LDA
  • A 3-year old Holstein dairy cow is one month fresh and the milker has noted that her production has dropped in the last week. On physical exam you find normal TPR, a gaunt abdomen, scant but normal-appearing feces, and no abnormalities on rectal exam. She has a prominent ping with variable changing pitch on the left side of the abdomen between the 10th and 13th ribs when simultaneous auscultation and percussion are used. The image shows a model of her abdominal organs viewed from the left side. What is the correct diagnosis?
  • The gas-filled abomasum has moved from its normal position near the ventral midline to the left of the rumen, where it is trapped (see image). As gas bubbles in and out, it sounds like the end of a toilet flush. When percussed and auscultated, the changing gas pressures yield a variable high-pitched ping.
  • A recently freshened cow presents for decreased appetite and milk production. On physical exam, a left sided variable pitch ping is heard using simultaneous auscultation and percussion from the last rib and then diagonally downward to the 8th rib. Which is the most likely differential?
  • LDAs occur most commonly after parturition and should be considered. The ping described is classic for a left displaced abomasum. You can rule out a right displaced abomasum because the ping is described on the left side. Right displaced abomasum is much less common than LDA. There is no mention of stiff gait or xiphoid pain that would indicate a diagnosis of hardware disease. Free gas in the rumen is likely to be heard from the hip to the 8th rib and be a monotone ping.
  • Traumatic Reticulopertonitis
  • cow with fever, inappetence, scant but normal-appearing feces, and decreased rumen motility shows the presence of abdominal fluid and fibrin. Analysis also shows the fluid to have 5 gm/dL protein, and a WBC count of 200,000/uL, most of which are neutrophils.
  • The fluid is obviously inflammatory in origin, as judged by the presence of a large amount of fibrin. Other possibilities would be trauma to another part of the GI tract or the reproductive tract.
  • A cow with** abomasal torsion** is accumulating chloride in the forestomachs, which results in hypochloremia and metabolic alkalosis. This in turn leads to hypokalemia as potassium rushes into cells when all available hydrogen ions leave the cells. The treatment of choice is thus IV saline (154 meq/L Na and 154 meq/L Cl) plus potassium. A good rule of thumb for rate of IV administration of potassium is not to exceed 0.5 meq/Kg /hour. So a 500 Kg cow can receive 250 meq/hr safely (which is 12 liters/hr of the fluid described). Oral fluids will simply add to the fluid-filled rumen
  • The correct answer is left displaced abomasum. LDAs occur most commonly after parturition and should always be considered. The other answer choices are not as common in ruminants, especially after parturition
  • The 3 most common causes of colic are intussusception, cecal dilation with or without torsion, and abomasal volvulus. You can quickly rule out the torsion of the omasum and abomasum and the RDA, as the ping would be lower on the right and in front of the last rib, plus you would not have palpated the “loaf of bread” rectally. Cattle with intussusception usually have scant dark blackberry jam-colored feces and on rectal exam, sometimes have a palpable hard and painful mass on the right
  • At what period in production does displaced abomasum most commonly occur in dairy cows? First 4 weeks postpartum . This occurs for multiple reasons. Due to the increased metabolic demands from lactation, the diet changes drastically, and more gas is produced in the abomasum. Dairy cows often undergo a period of clinical or subclinical hypocalcemia. Hypocalcemia predisposes to decreased abomasal motility and may be a factor contributing to displacement (especially since there is more gas to move)
  • Q. A 2-year old Holstein heifer presents for depression and decreased milk production over the previous week. On physical exam, it is noted her posterior shape is “papple” and she is slightly dehydrated. T=100.2 (37.9 C), P=62, R=28. She does not have episcleral injection. Rumen contractions are not present. Xiphoid pain response is negative and you are able to hear a monotone ping in the rumen on the left side from the 11th rib to the hip. On ballottement and rectal exam a large fluid-filled rumen is palpable. Which of the following is the most likely diagnosis?
  • Failure of omasal transport
  • Abomasal torsion or volvulus
  •  Grain overload (rumen acidosis)
  • Left displaced abomasum (LDA)
  • The correct answer is failure of omasal transport, a form of vagal indigestion, which leads to an accumulation of fluid and some dorsal gas in the rumen, lack of motility, and inappetance. TRP is a common cause of vagal indigestion; the negative grunt test for xiphoid pain is the result of chronicity and formed adhesions that are no longer acutely painful. It is difficult to clinically distinguish between omasal transport failure and pyloric outflow failure, except that the latter usually has more profound acid-base and electrolyte disturbances, and the cow will appear sicker as a result.
  • Abomasal torsion can be immediately ruled out because there is no abomasal ping on the right. In addition, if it were a right displaced abomasum, the cow would be showing more signs of distress and systemic disease such as episcleral injection and an elevated heart rate. Left displaced abomasum can be ruled out because the ping is monotone (LDA ping is variable in pitch) and the ping extends all the way back to the hip. Further, the large fluid filled rumen is rectally palpable, whereas a cow with LDA would have an empty rumen. Grain overload (rumen acidosis) would have a large fluid filled rumen, but the cow would be very sick with scleral injection and rapid heart rate.
  • TPN for a calve with severe diarrhoea, and weight loss
  • A typical TPN mixture for a calf this size would be 1L of 10% amino acids, 1L of 50% glucose and 500 ml of 10% lipids per day.
  • Diagnosing Colic

  • The correct answer is rumen. The location extending up to the hip and the monotone “boink” (not ping) are indicative of the rumen. A cow with LDA would have a variable-pitched ping heard to only just in back of the last rib (not to the hip). It is variable because the rumen is usually still contracting medial to the displaced abomasum, and the changing gas pressures result in a pitch that changes during percussion and auscultation.

  • Malignant Catarrhal Fever
  • You have submitted tissues from a dead dairy cow near a sheep feedlot that died in 7 days after exhibiting clinical signs of corneal opacity, high fever, lymphadenopathy, and CNS signs. The lab reports that the brain has lymphocytic perivasculitis. Which of the following disorders is the most likely diagnosis?
  • You are called to a small beef and sheep ranch where the owner is concerned about a 1-year old steer which has cloudy eyes, mucoid nasal discharge, thickened and cracked skin, and diarrhea. You examine the animal and find T=107F or 41.7 C, HR=105, RR=40, corneal opacity and thick white nasal discharge (see photo), thick cracked skin all over the animal, enlarged prescapular lymph nodes, and diarrhea with small amounts of blood in it. There are also some oral erosions.
  • Based on the PE you tentatively diagnose this condition.
  • MCF in North America is caused by sheep associated ovine herpes virus-2. A very high percentage of sheep and goats in North America are infected with OHV-2 and can transmit the virus to susceptible cattle, bison, deer and other related species, even when in close proximity and not in direct contact. The virus causes lymphocytic vasculitis and can be fatal.
  • BVD could result in corneal opacity in some cases, although not usual, and does cause fever, but the marked lymphadenopathy and lymphocytic vasculitis would not occur with BVD.
  • Fusobacterium necrophorum, calf diphtheria
  • A 6 month old Brown Swiss presents for respiratory distress of 1 day duration. She has a moist, painful cough and a loud inspiratory stridor. On physical exam, it is noticed that the head and neck are extended, there is a swelling around the larynx, and ozena. She also has a temperature of 104.6F and episcleral injection. On palpation of the larynx, a cough is easily elicited along with pain and increased stridor. What is the most likely organism causing this and diagnosis?
  • The correct answer is Fusobacterium necrophorum (aka calf diphtheria or necrotic laryngitis). Clinical signs are seen between 3-18 months of age. The signs are usually acute, and the animals may die within the week if they are not treated. Actinomyces bovis is the cause of lumpy jaw. Trueperella pyogenes may cause laryngeal abscesses, however affected animals are not febrile and septic. Laryngeal papillomatosis is fairly common in feedlot cattle and is caused by a papovavirus. Clinical signs are usually stertorous respiration and a cough. Again, there are no systemic signs as there are with calf diphtheria.
  • It is November and one of a group of 6 to 7-month old calves that entered a feedlot 50 days ago is sick. He has been observed coughing and open-mouth breathing with his head extended, and has a nasal discharge. You examine him and find his vitals to be T=105F 40.6 C, RR=70 (27-36 breaths/min), HR= 100 (60-70 beats/min). His breath is necrotic-smelling, and his larynx is swollen and painful on palpation (see image). There is inspiratory dyspnea and stertor. Based on the history and clinical signs you diagnose necrotic laryngitis (calf diphtheria), believed to be initiated by Histophilus somni, after which Fusobacterium necrophorum proliferates where the mucosa is damaged. This causes necrosis of the laryngeal cartilages. Knowing that the disease is commonly fatal, you elect to treat aggressively. Which of the following would be the best course of therapy?
  • Ans  IV tetracycline followed by SC long acting tetracycline, plus NSAIDS
  • The laryngeal cartilages (particularly the arytenoids) can become necrotic (see image), toxemia and bacteremia can develop, and death can ensue. Treatment must be aggressive. Start with a high blood level by giving IV tetracycline, then follow up with long acting tetracycline. Repeat as needed. Penicillin is also a good choice against Fusobacterium necrophorum, but it is more difficult to achieve high levels long-term using penicillin than it is with tetracycline. When edema, inflammation, and dyspnea are very severe, a tracheostomy may be needed, and a dose of corticosteroids may help shrink the swollen larynx. NSAIDS are also indicated. Good nursing care is also essential to recovery.
  • Chloramphenicol cannot legally be used in animals intended for meat or milk in the USA. Dexamethasone could be used in conjunction with antimicrobials but not alone against Calf Diphtheria. Sprays would not cure this calf.
  • Malignant Catarrhal Fever is caused by a herpes virus carried by sheep in North America and called ovine herpesvirus type 2. The virus affects lymphocytes and allows the animal`s own killer cells to attack blood vessels, resulting in arteritis. Arteritis results in multisystemic signs, high fever, and enlarged lymph nodes. The acute severe form such as described here is usually fatal. While a small number of cattle with Bovine Viral Diarrhoea may develop corneal opacity, they do not usually have the enlarged lymph nodes and the combination of other signs seen with MCF.
  • Anaplasmosis  Nine out of 100 adult cattle are found weak, depressed, and staring into space. On physical exam, they are found to be pale, icteric, and febrile. None of them have hemoglobinuria. The nine cattle all arrived at the ranch approximately one month ago. What is your most likely diagnosis?
  • Explanation The correct answer is Anaplasmosis. The causative agent is Anaplasma marginale. The clinical signs are fairly straight forward, and you need to pick up on a couple key features. The fact that new adults are sick is one feature because cattle are resistant to clinical Anaplasmosis as calves. Also, it should be remembered that hemoglobinuria with Anaplasmosis is never seen because it is all extravascular hemolysis. Since there is no hemoglobinuria, leptospirosis, bacillary hemoglobinuria, and anthrax can be ruled out. Additionally, icterus with anthrax is not seen.
    • **Nutritional Deficiencies / Toxicosis **
    • Selenium and Vitamin E deficiency - White Muscle Disease
    • Copper Deficiency, animals may suffer from achromotrichosis (pale hair coat) as a result of this enzyme not working properly. What is the enzyme?
    • The correct answer is tyrosinase. This enzyme converts L-tyrosine to melanin.
    • Lysyl oxidase is involved with synthesis of collagen in connective tissue and it is also dependent on adequate copper levels.
    • Glutathione peroxidase is involved in free radical protection, and selenium is necessary to keep this enzyme going.
    • Myophosphorylase is a muscle enzyme that is associated with a genetic disease of Charolais cattle.
    • Mineral deficiency:
    • Achromotrichia means an absence of pigment in the hair, so a black animal would develop reddish hair. Other clinical signs of copper deficiency can include diarrhea, poor body condition, lameness, anemia, and infertility. Dermatophilus congolensis results in crusty lesions, usually along the spine, which are usually due to and exacerbated by damp conditions. Cheyletiella, also called “walking dandruff”, is caused by a mite and is usually seen in dogs and cats. Vitamin C deficiency is very rare in ruminants and may cause crusting, alopecia, and pruritus. Lead toxicity will lead to neurological clinical signs.
    • Copper Deficiency can be primary (due to low copper intake) or secondary (due to high molybdenum, sulfur, iron, selenium, zinc, or other factors which inhibit absorption and promote excretion of copper). Copper deficiency can cause a number of signs including microcytic anemia, decreased production, faded hair, heart failure, infertility, swollen joints, gastric ulcers, and diarrhea. The two neurologic diseases that are specific to copper deficiency are enzootic ataxia (seen in lambs 1 to 2 months old) and swayback (seen congenitally or in very young lambs and kids). Clinical signs of progressive ascending paralysis are incoordination, muscle atrophy, and weakness. Copper deficiency leads to less myelin formation and to demyelinization.
    • The correct answer is vitamin D deficiency. Vitamin D deficiency will manifest with bone abnormalities (rickets). Vitamin A deficiency may produce an encephalopathy in which convulsions and blindness are common clinical signs. Copper deficiency may result in demyelination and pathologic fractures of the vertebrae. Thiamine deficiency produces polioencephalomalacia.
    • Hypomagnesemic tetany  It is March and you are called to a beef ranch because several beef cows on lush pasture have been found dead and another is staggering, according to the rancher. By the time you arrive this cow is down on her side with her legs paddling. The HR=140 and is pounding, while T=103F (39.4 C). The eyelids are fluttering, there is nystagmus, and champing of the jaws. Which of the following disorders fits these signs best?
    • Hypomagnesemic tetany (grass tetany) can cause all of these signs. It usually occurs in cold or cool weather in pastured lactating beef or dairy cows. Lush pastures that are high in potassium and nitrogen and low in magnesium and sodium are most often involved. Hypocalcemia may cause similar signs in periparturient cows (milk fever).
    • ECG/Heart
    • In this type of arrhythmia, the P-R interval progressively gets larger until there is a dropped QRS complex (P wave without a QRS complex).
    • The correct answer is Second degree Mobitz type I heart block, also known as the Wenckebach beat. In a Mobitz type II block, the P-R interval duration is unchanged and occasionally you will observe a P wave without a QRS complex. These blocks are thought to be caused by a refractory AV node which is not responding to a delayed atrial depolarization. In a 1st degree heart block, you will observe an increased P-R interval and no dropped QRS. In 3rd degree heart blocks, the P waves are unassociated from the QRS complex.
    • Toxicity
    • A group of yearling steers were recently fed moldy sweet potatoes two days ago. Yesterday, they began to exhibit tachypnea, dyspnea, grunting, frothing at the mouth, deep cough, and respiratory distress. Today there are several dead. The lungs are wet, firm, and fail to collapse. Lobules are dark red and firm, with hemorrhages, edema, emphysema and bullae throughout the interstitial pneumonia. What is the cause of this disorder?
    • A metabolite of 4-ipomeanol is a pneumotoxic compound that is produced by the fungus Fusarium solani acting on the sweet potato compound called 4-hydroxymyoporone. This metabolite is toxic to pulmonary tissues. Lesions are similar to those found with acute bovine pulmonary edema and emphysema (ABPE) caused by conversion of ingested L-tryptophan in lush pastures to pneumotoxic 3-methylindole.
    • A rancher has called you to diagnose and treat several nursing beef calves in a group which have suddenly developed blindness and dullness. One is down and unable to rise (see photo). Another is vocalizing ceaselessly, and all the affected calves appear dull and unaware of your presence. The affected animals have normal TPR. You pass a stomach tube and wash out some rumen contents, noting an oil sheen on the water in the bucket where the contents have been caught. You then go into the nearby barn and find an open drum half filled with used motor oil. Based on these findings, which of the following conditions do you need to treat these calves for?
    • Used motor oil contains tetraethyl lead when leaded gasoline was used. Cattle are sometimes curious and will actually drink used motor oil, resulting in acute lead poisoning. Treatment involves chelation therapy with calcium disodium EDTA. Thiamine has also proven useful, as well as several other adjunct therapies. Removal of the oil from the rumen and GI tract may also prove beneficial.
    • Eye
    • A 5-day old dairy calf has decreased appetite and is depressed. On physical exam, you note that she has a temperature of 104F (40 C), HR 120, scleral injection, and one eye has cloudy material in the anterior chamber. Pending lab results, you make a tentative diagnosis of what condition?
    • The history of a neonate with these signs and an elevated temperature, scleral injection and hypopyon are indicative of bacterial sepsis, a result of FPT.
    • Euthanasia
    • On a visit to a feedlot, the rancher asks you what method she should use to euthanize sick cattle. Which of the following is considered an acceptable method of euthanasia for conscious cattle, according to the AVMA?
    • According to the AVMA Guidelines for the Euthanasia of Animals, gunshot is the most common method used for on-farm euthanasia of cattle. The anatomic landmarks used for the point of entry should be the intersection of two imaginary lines drawn from the outside corner of the eye to the center of the base of the opposite horn (or equivalent position). The person euthanizing the animal should have sufficient training and experience with the firearm for a safe and accurate procedure. Although one well-placed bullet usually results in immediate loss of consciousness with little likelihood of return to consciousness, one should always be prepared to deliver a second or even a third shot if necessary.
    • Unacceptable methods for euthanasia of conscious animals include injection of chemical agents (disinfectants, electrolytes including potassium chloride, and nonanesthetic pharmacologic agents), drowning, air embolism, electrocution, and exsanguination. Administration of xylazine or other alpha-2 agonists followed by intravenous potassium chloride or magnesium sulfate is also considered unacceptable because alpha-2 agonists alone are recognized as being unreliable for producing generalized anesthesia although they can produce a state resembling it.
    • Ref: AVMA Guidelines for the Euthanasia of Animals: 2013 Edition
  • Parasitic
  • Illness in young calves caused by Eimeria sp. is best treated with which of the following?  Amprolium
  • A number of drugs can be used to treat or prevent coccidiosis. The treatment dosage is generally higher but for fewer days than the preventive dosage. Monensin- and sulfa-containing drugs are also frequently used as treatments.
  • Amprolium is an anti-protozoal drug and in chemical structure analogue to thiamine (vitamin B1). It inhibits the use of thiamine by the protozoal parasites.
  • Coccidia are a subclass of microscopic, spore-forming, single-celled obligate intracellular parasites belonging to the apicomplexan class Conoidasida.
  • Coccidiosis is usually an acute invasion and destruction of intestinal mucosa by protozoa of the genera Eimeria or Isospora. Clinical signs include diarrhea, fever, inappetence, weight loss, emaciation, and in extreme cases, death. However, many infections are subclinical.
  • Thelazia
  • The correct answer is to remove them manually. After removal it is recommended to treat with 10% levamisole drops. This is actually a photo of thelazia in a canine, but the appearance is very similar in cattle. The eye-worm can also be treated with ivermectin.
  • Babesiosis - Babesia bigemina and Babesia bovis are red cell parasites of cattle found in the Americas and spread mainly by Boophilus ticks. Other species of Babesia can infect man and other animals and are found on most continents. The disease they cause is characterized by hemolytic anemia, hemoglobinuria (which differentiates it from anaplasmosis), icterus, and death. Bovine babesiosis is also called piroplasmosis, red water, Texas fever, or tick fever. Eradication of Boophilus ticks has been an effective means of control in the United States.
  • Hypoderma bovis or H lineatum
  • During a visit to a dairy, several cows are noted to have 1-3 cm cysts on their backs with small holes at the center resembling breathing pores created by larvae. If these are breathing pores, what organism are the cows infected with?
  • The correct answer is Hypoderma bovis or H lineatum. Hypoderma is also known as the cattle grub, heel fly, or warble fly. The life cycle begins with the female attaching up to 500 eggs to the hairs around the hocks and lower portions of the cow. First-stage larvae will hatch in just a few days and burrow into the skin. At this point, they begin their tour de cow and migrate towards the epidural fat in the spinal canal(H bovis) or via the esophagus (H lineatum). After several months in this beautiful location, they become L2s and migrate to the subcutaneous tissues of the back where they will molt once more, and become L3s. Once they are L3s, the swelling on the cows’ backs can be felt. After 5-11 weeks, the L3s mature and burst through the skin, dropping on the ground where they will become adults in another 1-3 months. Sarcophaga spp are known as the flesh flies. An adult female will deposit her eggs in wounds and ulcers; the larvae then feed off the wounds. Eventually, they mature into L3s and fall off to pupate on the ground.
  • Simulium flies are also known as buffalo gnats or black flies. Adult females are the key problem with these flies because they suck blood! They prefer the legs, abdomen, head, and ears. Additionally, they will only eat during daytime. Female flies are an annoyance to cows and cause decreased productivity.
  • Anopheles are just mosquitoes; however, they are the most important vectors of human malaria and spread West Nile Virus.
  • Culicoides are also known as no-see-ums, biting midges, and punkies. They are a great annoyance to cows and have the potential to transmit bluetongue and Onchocerca. In horses, they are thought to be the cause of sweet itch, a Type I hypersensitivity to their saliva
  • Sacrocystosis
  • A 3-year old Jersey dairy cow presents 8 days after parturition with decreased milk production, anorexia, teeth grinding, episcleral injection, and colicky behavior. On physical exam, you observe distention of the right flank, a wide region of right sided monotone pinging from the 9th rib to behind the 13th rib and extending down in a line from the hip to the elbow at the 9th rib, and no rumen contractions. On rectal exam, you note normal-appearing feces and a large turgid structure palpable to the right of midline and as far forward as you can reach. The cow is negative for xiphoid pain. Temperature is 103.3F (39.6 C) degrees, HR=98, and respiration is 44. What is the most likely diagnosis?
  • The only choices likely to cause colic are intussusception, cecal dilation, and abomasal ulcer. Of those 3, only intussusception would cause scant, sticky, dark feces. The intussusception usually occurs in the jejunum or ileum, and results in a backed-up GI tract. This causes chloride to be sequestered in the abomasum, as well as internally vomited into the rumen, resulting in hypochloremia, hypokalemia, and metabolic alkalosis. A PCV of 30% is normal for a cow, so a bleeding ulcer is unlikely; the HR of 100/min in this case is likely due to pain rather than anemia
  • Q. A 2.5-year old Guernsey, presents for clinical signs of colic. There is a history of very little feces being passed over the last 24 hours. On rectal exam, a distended structure can be palpated just cranial to the pelvis. The structure feels like a loaf of bread. Additionally, there is a right sided ping heard from the last rib to the pelvis, high up. The rest of the physical was unremarkable. What is your top differential?
  • The 3 most common causes of colic are intussusception, cecal dilation with or without torsion, and abomasal volvulus. You can quickly rule out the torsion of the omasum and abomasum and the RDA, as the ping would be lower on the right and in front of the last rib, plus you would not have palpated the “loaf of bread” rectally. Cattle with intussusception usually have scant dark blackberry jam-colored feces and on rectal exam, sometimes have a palpable hard and painful mass on the right.
  • Q. You are called to examine and treat a cow which has eaten green chop alfalfa and has bloat. You first pass a stomach tube but little or no gas escapes, and the cow is in respiratory distress due to the tremendous abdominal pressure. You next insert a trocar into the rumen from the left flank and froth exits as shown in the photo. The pH of the froth is 6.2. You should now treat this cow with what drug to further relieve the bloat?
  • You need to treat with a substance to reduce the surface tension and destabilize the froth. The pH is within normal limits for rumen contents; therefore, oral bicarbonate is not beneficial. In a pinch, one could also use cooking oil to attempt to break down the foam.
  • Poloxalene orally (44 mg/kg
  • A 2-year old Brown Swiss with an abomasal torsion is likely to have which electrolyte abnormalities?
  • The correct answer is hypochloremia, metabolic alkalosis, and hypokalemia. As a result of torsion, affected animals sequester HCl in the abomasum, get hypochloremia and metabolic alkalosis. Additionally, animals become dehydrated and try to maintain adequate blood pressure by conserving sodium through renal mechanisms. Because there is an alkalosis, potassium is sequestered even more than usual in cells leading to hypokalemia. Normally the kidney excretes some potassium because of the need to maintain an equal number of anions and cations in the urine. But when there is insufficient potassium available, in order to reabsorb sodium to maintain blood pressure, hydrogen ions are excreted rather than potassium. This results in acidic urine at the same time as metabolic alkalosis, a condition known as paradoxic aciduria.
  • Reproductive Problems:
  • Breeding Soundness Examination
  • LDA
  • Traumatic Reticulopertonitis
  • Diagnosing Colic
  • Malignant Catarrhal Fever
  • Parasitic
  • Thelazia
  • Hypoderma bovis or H lineatum
  • Sacrocystosis
  • Poloxalene orally (44 mg/kg

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