Term
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Definition
| 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 |
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| A 2-year old Brown Swiss with an abomasal torsion is likely to have which electrolyte abnormalities? |
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Definition
| 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. |
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Definition
along the outer membrane of red blood cells.
Anaplasma marginale is an obligate intracellular bacterium. It is the most prevalent tick-borne pathogen of cattle worldwide and is endemic in tropical and sub-tropical regions. Canada is Anaplasma-free.
Infection causes large scale destruction of red blood cells and fever, weight loss, respiratory distress, abortion, and often death.
Although some cattle recover, they can become lifetime carriers as reservoirs. Anaplasma ovis can occur in sheep and goats.
Anaplasma can often be treated successfully with a single injection of long acting tetracycline (20 mg/kg). When the PCV is below 12%, a blood transfusion may also be needed. In addition, the animal should be given ready access to feed and water.
Even with treatment, animals may remain carriers after all clinical signs resolve. |
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Term
| A dairy farmer asks you to examine a 5-year old Holstein cow because he has noticed that her eyes appear strange (see photo). You find normal TPR, but there is bilateral swelling of the conjunctivae and prescapular and prefemoral lymph nodes are enlarged bilaterally. You suspect bovine leukosis virus (BLV) is causing adult bovine lymphoma. Of the following, which test would give you the best positive predictive value in making the correct diagnosis? |
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Definition
Sera from cattle with lymphoma generally have a high titer to gp51. ELISA is more sensitive than AGID.
All of these tests can sometimes be helpful. There is a paper indicating that fine needle aspiration was better than biopsy, but each of them can sometimes be confused with inflammatory lymph node reactions unless immunohistochemistry is available and most labs do not have that capability. The ELISA is the herd test standard for detecting subclinically infected cattle as well. |
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Term
| You are in the process of giving a cow a blood transfusion and begin to notice tachycardia, dyspnea, ptyalism, and rough lung sounds. |
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Definition
| The clinical signs that are described are those of an anaphylactic reaction to the transfusion.Epinephrine, antihistamines, dexamethasone, IV fluids and oxygen are all possible treatment options. |
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Term
| The dairy cow in the picture presents to you with mild signs of ataxia, a right eye droop, and right ear droop. Physical examination also reveals that she is also febrile and does not have a palpebral response on the right side. You are suspicious of Listeriosis and perform a CSF tap; you expect to find ________ on the cytology. |
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Definition
| 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. |
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Term
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Definition
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. |
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Definition
Unlike the bitch, who shows overt signs, including polydypsia, polyuria, inappetence, and sometimes high fever and diarrhea, the cow shows very few external signs of pyometra.
Cows localize the problem to the uterine lumen. Diagnosis in cows is obtained by transrectal palpation or transrectal ultrasonography. |
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Term
| You are performing health checks on a beef ranch after an E. coli O157:H7 outbreak was detected due to contaminated crops in a nearby vegetable farm. Which of the following is an appropriate way to identify and test suspected carriers? |
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Definition
E. coli O157:H7 is an enterohemorrhagic strain of E. coli that produces "Shiga-like toxins" which cause illness in humans. The bacteria can exist in the intestines of healthy, normal cattle without causing signs or symptoms; therefore, there are no specific signs to look for when trying to identify suspects.
A stool culture can detect the bacterium, but must be specifically requested. The sample is usually cultured on sorbitol-MacConkey (SMAC) agar. On SMAC agar, O157 colonies appear clear due to their inability (unlike other E. coli serotypes) to ferment sorbitol. Non-sorbitol fermenting colonies are tested for the somatic O157 antigen before being confirmed as E. coli O157.
Like all cultures, diagnosis is slow using this method, and swifter diagnosis is possible using PCR techniques. A PCR to detect Shiga-like toxin specific to O157-H7 would be an equally good choice. You would pick culture or PCR based on speed and cost.
In humans, common signs of infection are severe, acute hemorrhagic diarrhea and abdominal cramps, usually without fever. In most cases, the illness resolves in 5 to 10 days. |
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Term
| Mucosal disease, or alternatively, chronic Bovine Virus Diarrhea (BVD) occurs in cattle when: |
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Definition
| A 5-month old calf which was persistently infected as a fetus with a non cytopathic (nonCPE) biotype of BVD virus is superinfected with a cytopathic (CPE) biotype of BVD due to rearranging of the parent non-CPE viral RNA. |
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| A two year old Hereford western range cow presents for anorexia, depression, and ataxia of two day's duration. Recently, the cow has become more aggressive, is bellowing and charging people across fences. She is put into a squeeze chute and found to have normal rectal temperature and pink mucous membranes. Because of your differentials, you elect not to examine her oral cavity. What is your top differential at this point? |
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Definition
The correct answer is rabies. Although the clinical signs are not highly specific, rabies should be your top differential until you obtain more information. In cattle, most cases of rabies are the paralytic type, but these aggressive cases do occur. In livestock, the incubation period for rabies may range between 2 weeks and up to 6 months depending on the site of inoculation.
Anemia due to anaplasmosis can sometimes cause cattle to become wild and aggressive, but the pink mucous membranes rule that out in this case. |
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Term
| A 3-year old Holstein dairy cow, 3 weeks post partum, is presented with the complaint that she has dropped in milk production over the last several days. You perform a physical exam and the only abnormality you note is a large amount of ketone bodies in the milk and urine. You decide to administer glucose IV and insulin SQ. What else should this cow be administered? |
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Definition
| The oral propylene glycol will serve as a precursor for glucose production, and will help with the demands of lactation that are causing increased fat mobilization and ketosis. A fourth treatment that is sometimes used is corticosteroids, as they decrease milk production and increase gluconeogenesis. |
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Term
| What is the significance of xanthochromia on a CSF tap? |
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Definition
| The correct answer is evidence of prior hemorrhage. This is that yellow discoloration that can be seen for at least a week after bleeding in the CSF. A black discoloration would be diagnostic for melanoma. |
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Term
| A 2-year old nonlactating dairy cow in California has a sudden onset of head tilt and drooling. The owner also reports that she appears less active and less interested in feed than normal, and today is circling in one direction in the pen. You examine her and find T=105F (40.6 C), HR=96, and RR=32. There is ptosis, drooped ear, and weakness of the lips on the affected side. You take a lumbosacral spinal tap (see photo), and submit the CSF to your lab. The results show elevated protein and WBCs, with the cell type being mainly monocytes. The lab reports seeing some gram positive bacteria in the monocytes of the CSF. Based on these findings what is the best treatment for this condition? |
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Definition
| The diagnosis is Listeriosis. Listeria monocytogenes can effectively be treated in the early stages of the disease with penicillin, ampicillin, or tetracycline. Intramuscular procaine penicillin for example has a withdrawal of 10 days for slaughter (meat) and 48 hours for milk if the animal is lactating. Other choices of approved antimicrobials would also likely be effective since L. monocytogenes is susceptible to most antimicrobials. For a list of approved animal drugs see www.farad.org/vetgram. FARAD is the United States Food Animal Residue Avoidance Databank which gives withdrawal information as well as a list of prohibited drugs. The other drugs listed as choices here are prohibited and cannot be legally used in food animals in the USA |
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| 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, to 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? |
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Definition
| 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. |
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Term
| After you make a diagnosis of Hypoderma lineatum in a herd of beef cattle, the owner asks how the warble got there and what its life cycle. You explain the difference between Hypoderma lineatum and Hypoderma bovis. What is the difference in life cycle between the two? |
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Definition
| L3 larvae of both H. lineatum and H. bovis are on the subcutaneous tissue of the back (L2 larvae migrated there and then molted to L3 larvae), where they drill an air hole and then grow before falling out on to the ground, pupating for 1 to 3 months before becoming a short-lived fly. |
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Definition
| Free gas bloat in young animals is often secondary to bacterial bronchopneumonia, and mediastinal lymph node inflammation that affects the thoracic vagus nerve. Once the gas accumulates, it stops motility and decreases appetite. Treat the pneumonia with antimicrobials. The gas can also be relieved by creating a small temporary rumen fistula. |
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Term
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Definition
| 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. |
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Term
| Which of the following medications has the shortest meat withdrawal time in beef cattle? |
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Definition
| The correct answer is ceftiofur. Ceftiofur or Naxcel has a 4 day withdrawal time in meat. Chloramphenicol use is not allowed in food animals. Oxytetracline (LA200) has a 28 day meat withdrawal time. Sulfadimethoxine has a meat withdrawal time of 7 days. Penicillin G has a meat withdrawal time of 10 days. |
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Term
| You examine a 3-year old dairy cow (see image) with severe acute diarrhea on a hot summer day. She freshened 3 days ago, and her appetite and milk production are now markedly decreased. The watery green/brown feces are foul and fetid smelling. The cow has a rectal temperature of 106F (41.1 C), HR=90, and rapid respiratory rate but no cough. There is scleral injection and one weak rumen contraction per minute. You take lab samples to make what preliminary diagnosis? |
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Definition
| This cow is in the most susceptible fresh cow group, and has all the clinical signs of an invasive bacterial diarrhea; the foul smell of the feces indicates serum proteins in the feces that make it smell like it was produced by a meat eater. The effects of absorbed endotoxins (LPS) create fever, decreased appetite, decreased rumen activity, and scleral injection (enlarged and dark scleral vessels). |
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Term
| What cardiac abnormality is commonly associated with hypocalcemia and milk fever in the cow? |
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Definition
| The correct answer is tachycardia. Calcium administration may cause all the other abnormalities if you give too much too fast. You may also see a sinus node arrest. Calcium administration will cause the heart to beat more slowly and more strongly. |
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Term
| How soon after administration of a dose of dexamethasone for induction of parturition in a cow do you expect parturition? |
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Definition
| The correct answer is 48 hours. Parturition may occur anytime between 2 and 7 days but on average it occurs on the second day. A dose of 25-30 mg IM is sufficient. |
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Term
| During a necropsy of a 3-year old cow with a history of weight loss and diarrhea, you notice thickened mucosal folds in the abomasum (with less shiny mucous than normal), and thousands of larvae are detected when you digest and stain the abomasal mucosa. What did this cow potentially die from? |
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Definition
| The correct answer is Type II Ostertagiasis. This is a classic description of postmortem findings. Type I Ostertagiasis is found in naive calves and is not associated with large numbers of larvae with few adult worms in the abomasum. Type II Haemonchus contortus is possible, but it mainly causes anemia, as it is a blood sucker. Also, H. contortus most commonly severely affects sheep and goats. Coccidiosis and giardiasis are mainly calf diseases. |
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Term
| Which of the following is not a dietary deficiency associated with a neurologic disorder in livestock? |
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Definition
| 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. |
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Term
| 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? |
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Definition
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. |
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Term
| A dairyman's favorite cow was bred by a new bull a few weeks ago and now his cow has pyometra. What agent is most likely responsible for causing the cow's pyometra? |
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Definition
| 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. Brucella will result in late term abortion. Leptospirosis is a cause of mid- to late-gestation abortions and not post-coital pyometras. |
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Term
| A 4 month old Holstein heifer has a loud cough, tachypnea, diarrhea, and ill thrift of 8 days duration. However, there are no signs of sepsis, depression, or loss of appetite. On physical exam, you could hear crackles and wheezes over the lung fields and a harsh bronchial tone cranioventrally. Given this presentation what is the most likely diagnosis? |
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Definition
| The correct answer is enzootic pneumonia. This disease is multifactorial but is mainly a result of poor housing and environment (poor sanitation and ventilation). Calves with enzootic pneumonia will have cranioventral consolidation and many times they have diarrhea as a result of being infected with Eimeria bovis (like this one). Shipping fever (fibrinous pleuropneumonia) will most likely present with more systemic signs, which is key in differentiating the two diseases. Aspiration pneumonia will probably not result in diffuse lung pathology without also causing systemic signs. Moldy sweet potato poisoning is a good differential and will result in respiratory disease followed by death, but there was no history of exposure here. However, these animals will typically present with more acute respiratory distress and will probably not survive for 8 days, as death usually ensues 2-5 days after exposure. The principal toxin is ipomeanol which is produced by sweet potatoes infected with Fusarium javanicum or F. solani. Ipomeanol will destroy clara cells and type I pneumocytes. |
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Term
| A 3 week old Holstein calf presents for diarrhea, fever, and anorexia. On physical exam the calf appears to have a very stiff neck and hyperesthesia. Blood work shows an increased WBC and neutrophilia. A CSF tap is performed which shows a turbid fluid, protein of 120 mg/dl, and 420 WBCs/uL which are mainly neutrophils. What is the most likely diagnosis? |
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Definition
Meningitis
This conclusion can be made by examining the CSF. An elevated CSF protein and CSF neutrophilia indicates a bacterial infection. Listeriosis tends to be associated with monocytosis of the CSF. |
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Term
| The genetic disorder bovine leukocyte adhesion deficiency (BLAD) appeared in Holstein dairy cattle some years ago. If it is like most animal genetic disorders, which of the following modes of inheritance is it likely to be? |
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Definition
Autosomal recessive
Bovine leukocyte adhesion deficiency (BLAD) in Holsteins is an autosomal recessive congenital disease. The most common inheritance pattern of genetic disease in cattle is a simple recessive trait. The defective calf receives a recessive gene from its sire and dam. An autosomal recessive disorder means two copies of an abnormal gene must be present for the disease or trait to occur. |
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Term
While performing a routine pregnancy exam on a cow, it is noted that placentomes and bilateral uterine artery fremitus are present. At what point in gestation is the fetus?
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Definition
at least 7 months
The correct answer is at least 7 months. Placentomes will be palpable starting between 75-90 days of gestation. The fetus itself will be palpable beginning at approximately 60 days gestation, but may be out of reach between months 4-7 of gestation. Uterine artery fremitus will be evident on the ipsilateral pregnant horn at about 120 days of gestation. From 7 months on, the fremitus can be felt bilaterally. |
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Term
| Post-milking teat dips are not effective at preventing this type of mastitis in cows. |
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Definition
| The correct answer is Escherichia coli. This is an environmental contaminant and not a contagious organism. Pre-milking teat dips are useful for preventing such noncontagious diseases as E. coli, enterocoocus, and Streptococcus sp. other than S. agalactiae. Post-milking teat dips help prevent the spread of contagious pathogens such as Strep agalactiae from the skin into the streak canal and gland. |
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Term
| A herd of beef cows has been presented to you with an increase in lameness, diarrhea, poor body condition and infertility. You note achromotrichosis among several of the cows and decide to measure copper levels. What is the most sensitive way to measure copper levels? |
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Definition
| A liver biopsy is needed. Copper is stored in the liver, and the liver is very good at maintaining copper homeostasis until the very end. Therefore, the blood levels might look good, but in reality, the liver may have very little copper left to share with the rest of the body. |
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Term
| A 1-month old Charolais calf presents as a result of exercise intolerance and collapse. The only abnormality is elevated AST, CK, and LDH. Selenium and vitamin E levels were submitted for analysis and are normal. CSF collected by lumbosacral puncture is normal. What is your most likely diagnosis? |
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Definition
| The correct answer is myophosphorylase deficiency. This is a genetic disease that has been identified in Charolais cattle. Affected cattle are born with a deficiency in the enzyme phosphorylase. Your other main differential would have been white muscle disease, but vitamin E and selenium levels are normal. Tetanus would present differently (rigid paralysis), and a brain abscess is highly unlikely as there are no neurological deficits mentioned. |
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Term
| A 7-day old calf presents for further evaluation and supportive care due to an acute onset of watery diarrhea. On physical examination, the calf is markedly depressed, floppy, nonresponsive, and 10% dehydrated. Which of the following best describes this calf`s state? |
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Definition
| No matter what the causative agent, calves of this age with severe diarrhea develop hypovolemia, severe metabolic acidosis, which results in potassium leaving cells, and the calf becomes hyperkalemic (in plasma). The floppy calf is typical of an animal with severe metabolic acidosis (base deficit of 15 meq or more) and may also be hypoglycemic. This calf is also possibly septic, as bacterial translocation across the gut often occurs in very ill calves. |
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Term
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Definition
The plant is bracken fern and it contains a toxic glycoside (ptaquiloside) plus thiaminase. In cattle, chronic bracken fern ingestion (consumption of the animal's body weight over several months) can result in bone marrow suppression, as well as alkylation of DNA leading to tumors. The problem will manifest as hemorrhages, hematuria, and/or cancers in the bladder or other organs. The bone marrow suppression leads to anemia and neutropenia.
The thiaminase seems to affect horses more than cattle. Horses develop thiamine deficiency manifested as weight loss, ataxia, lethargy, tremors, recumbency, and death. |
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Term
| You recently helped deliver twins on a dairy farm where one of the twins was male and one was female. Which of the following is the common outcome of mixed sex twins in cattle? |
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Definition
The heifer is intersex, infertile with masculinized behavior, non-functioning ovaries, and is genetically chimeric (XX/XY); the bull is phenotypically normal
Freemartinism is the normal result of mixed-sex twins in cattle. This occurs due to shared circulation of chorionic blood vessels in utero. This allows antimullerian duct hormone and testosterone from the male fetus to inhibit development of the female tract resulting in a short vagina that ends blindly without communication to the uterus. The heifer also frequently shows masculinized behavior. Cytogenetic examination of freemartins reveals both XX and XY chromosome patterns.
Interestingly, although some bulls born as mixed-sex twins show the presence of XX cells, they have normal conformation and external genitalia and are fertile. |
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Term
| Which type of urolith occurs most commonly in feedlot cattle receiving large amounts of grain and is shown in the photo below? |
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Definition
| Struvite is composed of magnesium ammonium phosphate. The alkaline urine in cattle along with high dietary phosphate and magnesium levels favors formation of struvite stones. Feedlot animals can also develop apatite stones composed of calcium phosphate. |
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Term
| Persistent infection of a bovine fetus with Bovine Viral Diarrhea (BVD) virus is most likely to occur when the non-immune dam is viremic with a non-cytopathic biotype of BVD at what stage of gestation? |
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Definition
| At 50 to 150 days gestation, the fetal immune system does not recognize the BVD virus as foreign and becomes persistently infected. |
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Term
| Mycotoxins found in feed are important problems in cattle. Which of the following is an important mycotoxin? |
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Definition
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Term
| At what day in gestation can pregnancy be first confirmed via ultrasound in cattle? |
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Definition
28 days
Veterinarians can determine the fetal gender at approximately 58-90 days of gestation. |
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Term
| Treatment for woodent tongue |
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Definition
| Sodium iodide and antibiotics are effective. Given the presentation and clinical signs these animals have probably begun to ingest very rough and stemmed (scabrous) feed items which have injured their mouths. Upon injury, the normal inhabitant Actinobacillus lignieresii invades the soft tissues and causes the characteristic woody tongue granulomatous inflammation. |
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Term
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Definition
| associated with cyclops in sheep |
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Term
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Definition
| abortion from 3-8 months gestation and typically results in an autolyzed fetus; there are usually no retained fetal membranes or metritis. |
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Term
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Definition
| It causes microabscesses in the brain resulting most commonly in unilateral cranial nerve signs such as facial nerve paralysis, vestibular signs (circling), head tilt, and dysphagia. CN V-XII may be involved. Head pressing may be seen in some cases. It is also a cause of abortions. Treatment is with tetracyclines or high levels of penicillin. |
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Term
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Definition
| in young calves can affect some animals with otitis interna, so the calf shows ( uni or bilateral) facial paralysis, ear droop, and vestibular signs such as head tilt , nystagmus, and ataxia. There may be purulent discharge from the aural canal. M bovis can also cause pneumonia, polyarthritis and tenosynovitis. This condition can be difficult to treat and result in many animals with chronic illness. |
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Term
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Definition
| can commonly be a cause of respiratory disease and septicemia , as well as TEME (thromboembolic meningoecephalitis) or otitis media /interna in young feedlot animals where they exhibit head tilt, nystagmus, circling and stumbling. They may also develop ipsilateral facial paralysis. So in this case the main differential is the age of the animal and the fact that this is often a feedlot animal, plus H somni tends to be a more fulminant systemic disorder. |
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Term
| A valuable bull that has been heavily grain fed for show for over 3 months is found bleeding from the nose. You examine the animal and note a fever of 104 F(40 C), rapid respiratory rate, and HR of 90 beats/min. You tell the owner that this bull may have developed rumen acidosis in the past, a resulting liver abscess and has now developed ___________. |
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Definition
| vena caval thrombosis and metastatic pneumonia. By chance a liver abscess in a few animals that develop rumen acidosis may form near the posterior vena cava and cause infected thrombi to break off and move down pulmonary arteries into the lung until they lodge and form an abscess. Pulmonary embolic abscesses then create tracts from affected arteries to an airway, which results in pulmonary bleeding. This condition is extremely difficult to treat successfully and animals usually die within months of a massive bleed. |
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Term
| Tag 10169, 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? |
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Definition
| cecal displacement or torsion |
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Term
| A goat herd is diagnosed with having Mycoplasma mycoides ssp. mycoides (caprine or large colony type). What should you tell the owner to do? |
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Definition
The correct answer is to culture milk from all does and cull positive culture animals and affected kids. There is no effective therapy for Mycoplasma mycoides ssp. mycoides that can assure that some animals, even treated kids, do not remain carriers after treatment. Thus treatment is controversial and depends on the circumstances, herd size and owner`s wishes. Keeping the kids in the face of an outbreak is not recommended because they may become carriers. Isolating for six months may not solve the problem because there may be carriers.If the owner wishes, then kids can be treated, then isolated and raised on known mycoplasma free milk or milk replacer.
Mycoplasma mycoides small colony type is the cause of contagious bovine pleuropneumonia and is a reportable agent in the United States as it no longer exists in the USA (eradicated in 1892). |
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Term
| IBR intramuscular vaccine not indicated? |
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Definition
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Term
| Recently, there has been an outbreak of several cows with an acute onset of ataxia, nystagmus, circling, strabismus, and depression followed by strange behavior, vocalization, convulsions, and death in just two days. A few cows appear to be initially less severely affected and have intense pruritus and alopecia which is then followed by similar clinical signs as above. The only recent change in environment is the acquisition of fifty pigs that are housed close by. What is the most likely diagnosis? |
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Definition
| The correct answer is pseudorabies. This question is kind of tough because all the choices are great differentials. The key here is the history of introducing new pigs and the pruritus with alopecia. Pigs are the primary host of pseudorabies and are usually asymptomatic. Some of these pigs were probably infected and being in close proximity somehow the disease has been introduced to the cattle. Even though there is an outbreak going on, it is probably not going to be self-perpetuating among the cattle since they don't shed virus for long periods of time. In cases that are not as peracute to acute the first clinical signs are often paresthesia hence the name "Mad Itch". However, you must be careful because sites of rabies virus inoculation are also pruritic and result in alopecia from scratching. Unfortunately, there is no treatment and most affected animals die. The best thing to do is remove the pigs. |
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Term
| Malignant Catarrhal fever |
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Definition
MCF 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 BVD may develop corneal opacity, they do not usually have the enlarged lymph nodes and the combination of other signs seen with MCF. |
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Term
| Left atrial enlargement on an ECG is known as |
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Definition
| P mitrale - increase in duration of p waves |
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Term
| Typical TPN mixture for calf |
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Definition
| would be 1L of 10% amino acids, 1L of 50% glucose and 500 ml of 10% lipids per day. |
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| When is a chorioallantoic membrane slip first palpable in a heifer? |
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| This is a hereditary disease which produces a continuous stiffness of the hocks. There could be bilateral or unilateral involvement. It is a recessive disease; therefore, affected animals should not be bred. Treatment involves a tibial neurectomy or gastrocnemius tenectomy. |
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| Hyponatremia, hypochloremia, hyperphosphatemia |
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| Bovine spongiform encephalopathy (BSE or mad cow disease) is not only a health concern for the management of cattle but also has potential public health implications if bovine nervous tissue from infected cows is consumed by humans. BSE has been implicated in a condition that mimics which of the following human diseases? |
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Definition
BSE is a transmissible spongiform encephalopathy suspected to be caused by a prion.
True Creutzfeldt-Jakob disease (CJD) is a rare disorder that can occur due to a genetic mutation or may occur sporadically. Patients may experience psychiatric symptoms such as depression or a schizophrenia-like psychosis. Unusual sensory symptoms may also occur. Neurological signs progress to difficulty walking and involuntary movements, and, by the time of death, patients become completely immobile and mute.
Variant Creutzfeldt-Jakob disease (vCJD) typically affects younger people and has been strongly linked to exposure, probably through food, to cattle BSE. |
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| treatment for nitrate poisoning |
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Definition
Nitate toxicosis causes methemoglobinemia, in which the blood appears chocolate brown. As a result the oxygen carrying capacity and delivery is greatly reduced and the animal may die. Methylene blue is usually administered IV as a 1% to 4% solution, with a total dose of 4 to 15 mg.Kg body weight to cattle, for treating nitrate toxicosis.
Nitrates are found in high levels in many plants and some water sources. The nitrate is converted in the rumen to nitrite, absorbed into blood, which causes oxidation of the heme iron to the +3 ferrous state (Called methemoglobin). Methylene blue restores the iron in hemoglobin to its normal (reduced) oxygen-carrying state. This is achieved by providing an artificial electron acceptor for NADPH methemoglobin reductase (RBCs usually don't have one; the presence of methylene blue allows the enzyme to function at 5A? normal levels). The NADPH is generated via the hexose monophosphate shunt. |
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| What is the main vector of Trypanosomiasis (Nagana in cattle or African sleeping sickness in man)? |
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