Term
| (6) Neonatal vaccination with IBR and BVD modified live viruses has been proven to provide a measurable protective response despite presence of protective colostral antibody. What is the immunologic basis of the protective response and how is it measured? |
|
Definition
| The response is a cell-mediated immune response (not a humoral response. It can be measured by a number of laboratory techniques such as lymphocyte blastogenesis or gamma-interferon assays but more simply can be measured by carefully controlled challenge experiments. |
|
|
Term
| (3) What is the essential requirement before one can vaccinate pregnant cows with a modified-live BVD vaccine that is licensed for such use? |
|
Definition
| The pregnant cow essentially has to have been vaccinated with the identical vaccine prior to being bred. In essence she has to be immune to the vaccine virus. |
|
|
Term
(10) Match the clinical Adiseases@ below with the stage of gestation at which each is most likely to occur with BVD infection in cattle:
0 to 125 days
120 to 170 days
150 days to term
a. Persistent infection
b. Increased stillbirths or premature births
c. Abortion
d. Congenital anomalies
e. Fetal death |
|
Definition
_a, c, e___ 0 to 125 days
__d______ 120 to 170 days
__b______ 150 days to term
a. Persistent infection
b. Increased stillbirths or premature births
c. Abortion
d. Congenital anomalies
e. Fetal death |
|
|
Term
| (4) Vaccination during a bovine shipping fever outbreak has been demonstrated to work reasonably well to help control the outbreak and in some cases has led to a rapid decrease in morbidity. What is the immunological basis for the success of vaccination in the face of an outbreak? |
|
Definition
| Some of the viral agents such as IBR go through a herd relatively slowly and vaccination can head them off in naïve population. Also, one might just be boostering a previous vaccination or exposure such that the levels of immunity in the herd rise dramatically. Also one is most likely stimulating an interferon response. |
|
|
Term
| (6) Why would a Johne=s-infected herd not be allowed to be vaccinated? In what situations is vaccination permitted? |
|
Definition
| Vaccination will interfere with the ability to test and remove infected animals. If a control program is underway, it might not be in the best interests of the producer to vaccinate unless he/she is willing to ignore positives in the vaccinated group. Vaccination is restricted to infected herds. |
|
|
Term
| (6) Briefly outline the main elements of the Voluntary Johne=s Disease Eradication Program. |
|
Definition
Each state must have a Johne’s Disease Coordinator (responsible for coordination of that state’s program
Johne’s Certified Veterinarians (accredited veterinarians that have completed training by the JDC) evaluate herd risk for Johne’s (rank herds as 1, 2, 3, or 4 for test-negative herds and A, B, C, or D for test-positive herds).
The Johne’s Veterinarian develops a plan for each farm. Plans include manure and waste handling, calf management, herd additions and high-risk animals, biosecurity, and strategies for handling infected animals. Individual animal identification is important. |
|
|
Term
| (4) The 7-way (or greater) clostridial vaccines are used to immunize feeder cattle against which main disease problem(s)? |
|
Definition
|
|
Term
| (4) What are the two major problems with the killed Anaplasma marginale vaccine? |
|
Definition
They are not highly protective and animals can be readily infected.
Neonatal isoerythrolysis has been a problem due to the fact that the vaccines contain cattle RBC antigens. |
|
|
Term
| (4) List the two most important components of a good program to prevent coccidiosis in feeder cattle. |
|
Definition
Feeding a coccidiostat such as Rumensin or Bovatec
Sanitation |
|
|
Term
| (8) List three methods for preventing metabolic acidosis when starting beef cattle on feed in the feedlot? Why does one need to avoid metabolic acidosis? |
|
Definition
Restrict silage feeding, especially if the calves are not used to it.
Be careful with feeding concentrates to avoid rumen acidosis.
Feeding an ionophore will help smooth out any ration transitions.
Metabolic acidosis can lead to immunosuppression and the development of more severe shipping fever pneumonia. |
|
|
Term
| (4) Explain on an immunologic basis why vaccination against Histophilus somni is included as part of many preconditioning programs despite the fact that the available bacterin products do not protect well against shipping fever pneumonias. |
|
Definition
| The killed bacterins can stimulate an IgM and an IgG response that protects against thrombotic meningoencephalitis.but which is not especially protective against respiratory disease because of the lack of efficacy of those immunoglobulins in the lung. |
|
|
Term
| (3) Briefly list the main clinical signs of rinderpest in cattle. |
|
Definition
| Explosive outbreak. High fevers initially. Rumenal atony, reddened oral mucosa. Feces are initially dry and coated with mucus or blood and later become fluid. Fetid breath due largely to the oral lesions. High mortality, especially in European breeds of cattle. |
|
|
Term
| (6) The J5 vaccine was originally developed to help prevent salmonellosis in dairy calves. However it never gained wide acceptance for that purpose. Based on your knowledge of salmonellosis in dairy calves and the immune response to the J5 vaccine, list two main reasons why the vaccine is not commonly used in calves. |
|
Definition
| It is a rough core mutant and the core antigen stimulates primarily an IgM response. Serum IgM cannot protect well against enteric infections very well because it stays in the intravascular space and has a short half-life. Also, it would need to be given to calves almost at birth in order to stimulate an immune response in time to cover the period when salmonellosis is most likely to cause problems. |
|
|
Term
| (6) What is an SRP vaccine and why is it supposed to be better at protecting against salmonellosis? |
|
Definition
| SRP stands for “Siderophore Receptor Protein”. The siderophore receptor proteins are relatively conserved between salmonella serovars and immunity against this protein has been demonstrated to provide protection against a variety of serovars. |
|
|
Term
| T or F States are accredited bovine tuberculosis free when no evidence of tuberculosis is found for 5 consecutive years. |
|
Definition
|
|
Term
| T or F Tuberculosis reactor cattle must either be slaughtered at an approved plant or be destroyed. |
|
Definition
|
|
Term
| T or F Most beef herds in the U.S. are tested for tuberculosis at least every three years. |
|
Definition
|
|
Term
| T or F The single cervical test for cattle tuberculosis diagnosis is more sensitive than the caudal fold test and that is the reason it is preferred for testing infected herds. |
|
Definition
|
|
Term
| T or F Most tuberculosis reactor cattle have extensive gross pulmonary lesions. |
|
Definition
|
|
Term
| T or F Infections with Coxiella burnetii in cattle are almost always clinically severe and require rapid diagnosis and treatment. |
|
Definition
|
|
Term
| T or F Vaccination against infectious bovine keratoconjunctivitis usually provides solid immunity against clinical disease. |
|
Definition
|
|
Term
| T or F According to the Iowa State University Veterinary Diagnostic Laboratory, Listeria monocytogenes is one of the leading bacterial causes of bovine abortion. |
|
Definition
|
|
Term
| T or F Otitis media in cattle can be caused by a number of organisms but Pasteurella multocida and Mycoplasma bovis are two of the most common ones. |
|
Definition
|
|
Term
| T or F Treatment of otitis media needs to be long-term |
|
Definition
|
|
Term
| T or F Unlike other enteric diseases, the link between sanitation and salmonellosis is not as strong. |
|
Definition
|
|
Term
26. Rift valley fever:
a. Is readily spread by contact with nasal discharges of infected cattle.
b. Is limited in host range to cattle and other ruminants.
c. Affects most species with the exception of sheep and goats.
d. Characteristically produces acute hepatitis, fever, vomiting and abortions in sheep and goats.
e. Has a relatively low mortality rate for young ruminants but kills almost 100% of adult animals. |
|
Definition
| d. Characteristically produces acute hepatitis, fever, vomiting and abortions in sheep and goats. |
|
|
Term
Heartwater disease:
a. Was eradicated from the U.S. in the late 1800's.
b. Is largely confined to Africa.
c. Could easily be brought into the U.S. with infected ticks.
d. Is transovarially transmitted in ticks.
e. None of the above. |
|
Definition
| c. Could easily be brought into the U.S. with infected ticks. |
|
|
Term
Which of the following is NOT a clinical sign of rabies in cattle?
a. Abnormal vocalization (bellowing).
b. Abrupt cessation of eating and drinking.
c. Straining to defecate or urinate.
d. Knuckling over at the hind fetlock.
e. Abnormal swelling in the esophagus. |
|
Definition
| e. Abnormal swelling in the esophagus. |
|
|
Term
Hemorrhagic bowel syndrome in dairy cattle has been most closely associated with:
a. Lack of long-stemmed roughage in the diet.
b. Overgrowth of Clostridium botulinum in the intestinal tract.
c. The presence of low levels of mycotoxins in the feed.
d. All the above.
e. Only a and b above. |
|
Definition
| a. Lack of long-stemmed roughage in the diet. |
|
|
Term
Winter dysentery in cattle:
a. Is caused by infection with Brachyspira hyodysenteriae
b. Is usually a relatively mild disease.
c. Is usually more clinically obvious in younger cows.
d. Frequently occurs simultaneously in clusters of several farms.
e. All the above.
f. Only b through d above. |
|
Definition
| f. Only b through d above. |
|
|
Term
Malignant catarrhal fever virus:
a. Most commonly causes explosive outbreaks of severe disease.
b. Most commonly affects only one or a few animals at a time.
c. Is readily isolated from lambs.
d. Is a foreign animal disease.
e. Transmits slowly from animal to animal in a group of cattle, thus giving time to vaccinate in the face of an outbreak. |
|
Definition
| b. Most commonly affects only one or a few animals at a time. |
|
|
Term
Vaccination against which of the following has been most commonly associated with reported adverse reactions?
a. Mannheimia haemolytica
b. Pasteurella multocida
c. Mycoplasma bovis
d. Bovine Respiratory Syncytial Virus
e. Clostridium tetani |
|
Definition
| d. Bovine Respiratory Syncytial Virus |
|
|
Term
| (6) What are the three most important elements of any preconditioning program for feeder cattle? |
|
Definition
a. Weaning well ahead of sale or shipment (30 to 45 days)________________________________
b. _ Adequate vaccination_(minimum of 2 weeks prior to shipping and 2-3 weeks between if 2X)
c. _Starting on feed ____ |
|
|
Term
| (6) List three major program responsibilities of a Johne=s Certified Veterinarian. |
|
Definition
a. _Producer education____________________________
b. _Risk assessment for each herd______________________
c. _Develop a management plan for each herd |
|
|
Term
| (6) List three of the most important problems that are adversely affecting the Texas Cattle Fever Tick Eradication Program. |
|
Definition
a. _ The ticks (especially R. microplus) are rapidly becoming resistant to the coumaphos dips.
b. Ranchers are financially unwilling to invest approx. $257/cow to dip cows every 2 wks for 6 to 9 months.
c. When the ranchers abandon the pastures, white-tailed deer graze there and can spread the ticks outside of the quarantine zone. |
|
|
Term
| (6) The herd of one of your cow-calf producers (300 cows) is going through an outbreak of infectious keratoconjunctivitis and wants some suggestions on how to prevent further clinical cases this year. It is currently late July, the pastures are understocked by about 25% (he could have placed about 75 more cows on the pastures), the pastures are mostly open (few trees, stumps, rocks or other obstructions). The weather is hot, sunny, and there are no buildings available for the cattle to get into. List three things that this owner could do that would be most likely to help control the outbreak. |
|
Definition
a. Mow the pastures if there is a lot of long stemmy grass and weeds.
b. __Immunization is a possibility but probably not worth as much in late July.
c. Fly control might help. Possibly placing the herd on aureomycin but this would require setting up feeders and feeding sufficient grain or protein/molasses supplement to kill the taste and ensure sufficient intake. |
|
|
Term
| (3) Why is bacteriologic culture of the small intestine not very rewarding as a diagnostic tool for identification of neonatal colibacillosis of calves? |
|
Definition
| Because E. coli is in the small intestine anyway and one really needs to identify whether the F5 antigen is present on the organisms. |
|
|
Term
| (2) What is the most obvious, non-acute, clinical sign of adult lymphosarcoma (leukosis) in cattle? |
|
Definition
| Markedly swollen lymph nodes are classic. |
|
|
Term
| (6) List the three most useful methods for prevention of salmonellosis in calves. |
|
Definition
a. _Sanitation (especially of feeding equipment, bottles, calf hutches, creep feeders)__
b. _Vaccination (the SRP vaccine may help)______________________________________________
c. Non-stressful environment for calves (comfortable, well-bedded, good ventilation, not crowded, etc.) |
|
|
Term
| (4) The two most effective methods for prevention of coccidiosis in cattle are: |
|
Definition
a. _Feeding a coccidiostat such as Rumensin or Bovatec
b. _Improve sanitation, decrease crowding |
|
|
Term
| (4) Briefly describe the two most salient clinical signs of winter dysentery in cattle. |
|
Definition
a. _Blood in the feces_(usually in small amounts)
b. _Animals off-feed, lowered milk production, depressed (all more common/severe in heifers)___ |
|
|
Term
| (4) The AVMA Compendium on Rabies lists what two reasons for vaccinating livestock in the U.S. against rabies. |
|
Definition
a. _ If the animals have high dollar value . Also required for interstate shipment of some animals._
b. If the animals are going to be around people a lot (fairs, shows, petting zoos, racetracks, kids riding ponies, etc.) |
|
|
Term
| (4) Calves infected with BVD virus between approximately 120 and 180 days of gestation may be born with congenital anomalies. List two of the most obvious congenital anomalies of these calves. |
|
Definition
a. Cerebellar hypoplasia_________________________________________________
b. _Hydrocephaly________________________________________________________________________ |
|
|
Term
| (4) Name and briefly describe the test most commonly used to identify persistently infected (BVD virus) calves. |
|
Definition
| IHC on an ear notch. A full thickness notch or plug of the external ear is removed and sent to the lab. The lab prepares a thin section of the ear tissue and uses an immunohistochemical stain to visualize and quantitate the amount of BVD viral antigen present. |
|
|
Term
Which of the following is not routinely observed in Heartwater (Ehrlichia ruminantium) infection?
a. Pneumonia
b. Hemoglobinuria
c. Hydropericardium
d. Hydrothorax
e. High case fatality rate |
|
Definition
|
|
Term
The clinical picture of Tritrichomonas foetus infection in a cattle herd is due to:
a. The fact that the breeding season in many of these herds is extended because bulls are allowed to run with the cow herd for much of the year.
b. The females can remain infected for 3 to 20 weeks before clearing the organism and finally allowing an embryo to implant.
c. Occasional cases of pyometra and late-term abortions throw off the calving and breeding schedule.
d. All the above.
e. Only b and c above. |
|
Definition
|
|
Term
Rapid diagnosis of anaplasmosis by practicing veterinarians can be accomplished using:
a. Rapid Slide Agglutination
b. Complement fixation
c. Agar gel immunodiffusion
d. Demonstration of the organisms in stained blood smears.
e. Only a and d above
f. Only b and d above. |
|
Definition
|
|
Term
Which of the following is true of the Iowa Gold Tag Preconditioning Program:
a. All calves must be at least 4 months of age before the first required immunizations.
b. The second immunization must be performed at least 14 days following the initial immunization.
c. The second immunization must be performed at least 14 days before the calves are sold.
d. The name of the vaccine must be listed on the form.
e. All the above.
f. Only a and d above. |
|
Definition
|
|
Term
Which of the following is true if abscesses are observed in the lungs of a feeder calf that died of shipping fever pneumonia 3 days after arriving in the lot?
a. The calf must have been infected with Mycoplasma bovis.
b. The calf was peracutely infected with BRSV.
c. The calf was Astale@ (had been in transit, sale barns, trader cattle pens, etc., for 9 to 11 days before purchase by the present owner.
d. This is probably the second bout of respiratory disease for this calf.
e. Only b and c above.
f. Only c and/or d above. |
|
Definition
| d. This is probably the second bout of respiratory disease for this calf. |
|
|
Term
Immunization against Histophilus somni:
a. Is generally regarded as giving reasonably good protection against thrombotic meningoencephalitis.
b. Tends to stimulate an IgM response due to the oligosaccharide outer surface antigens.
c. Has been linked to possible type I hypersensitivity responses due to the presence of histamine in the killed bacterins.
d. Is required for the Iowa Green Tag and Gold Tag preconditioning programs.
e. All the above.
f. Only a and c above. |
|
Definition
|
|
Term
Immunization with killed bacterins in the face of an outbreak of shipping fever pneumonia is contraindicated because:
a. Killed bacterin products usually take 10 days to over two weeks to stimulate a reasonably strong immune response and this is too late to do much good.
b. Killed bacterins are highly specific for the parent organism and do not stimulate broad protection against other bacteria and viruses.
c. Killed bacterin products frequently stimulate an IgG or sometimes only an IgM response which is not very protective on the respiratory mucosae.
d. All the above.
e. Only a and b above. |
|
Definition
|
|
Term
Ehrlichia ruminantium is transmitted by:
a. Respiratory route
b. Rhiphicephalus sp. ticks
c. Any species of Amblyomma ticks
d. Mosquitoes
e. All the above |
|
Definition
| c. Any species of Amblyomma ticks |
|
|
Term
Which of the following induces the fusion of epithelial cells to form multinucleate giant cells?
a. IBR virus
b. BVD virus
c. PI3 virus
d. BRSV
e. Attaching-Effacing E. coli. |
|
Definition
|
|
Term
Which of the following is least likely to be associated with Mycoplasma bovis infection in cattle?
a. Diarrhea
b. Lameness
c. Pulmonary abscesses
d. Otitis media (ear droop)
e. Mastitis |
|
Definition
|
|
Term
The Single Radial Immunodiffusion Test (SRID) is used for diagnosis of:
a. BVD infection
b. Rotavirus infection
c. Failure of passive transfer
d. Neonatal isoerythrolysis
e. None of the above. |
|
Definition
| c. Failure of passive transfer |
|
|
Term
The modified live oral rotavirus-coronavirus vaccine:
a. Must only be given to adult cows that are not pregnant.
b. Needs to be given to calves shortly after birth, preferably before colostrum intake.
c. Needs to be given to calves between 3 to 5 days of age in order to occupy mucosal epithelium attachment sites and thereby block infection with virulent virus.
d. None of the above. |
|
Definition
| b. Needs to be given to calves shortly after birth, preferably before colostrum intake. |
|
|
Term
| T or F Lumpy skin disease is occasionally seen as large epidemics in southern and eastern Africa and occasionally the Middle East. |
|
Definition
|
|
Term
| T or F Once tuberculosis is found in a herd of cattle, deer, elk or bison in the U.S. the only option available is to depopulate the herd. |
|
Definition
|
|
Term
| T or F The single cervical test for tuberculosis may lack specificity but it is still used as the sole test for identifying reactors in a herd that has been quarantined. |
|
Definition
|
|
Term
| T or F Most preconditioning programs specify the use of modified live virus vaccines rather than killed products. |
|
Definition
|
|
Term
| T or F The Iowa preconditioning programs require that cattle have to be owned at least 60 days prior to sale in order to prevent trader cattle from meeting the requirements. |
|
Definition
|
|
Term
| T or F Bibersteinia trehalosi produces the same leukotoxin as Mannheimia haemolytica and causes very similar pulmonary lesions. |
|
Definition
|
|
Term
| T or F IBR and BVD modified live vaccines are safe to use in pregnant cows only if the cows are already relatively immune to the vaccine viruses. |
|
Definition
|
|
Term
| T or F Intranasal IBR vaccines generally give a longer lasting immune response compared to the subcutaneous MLV vaccines. |
|
Definition
|
|
Term
| T or F BRSV is one of the easier viruses to grow in tissue culture and was one of the first viral immunizing products developed against bovine respiratory disease. |
|
Definition
|
|
Term
| T or F Ceftiofur is preferred for treatment of Mycoplasma bovis infection in cattle because the organism has never developed resistance to it. |
|
Definition
|
|
Term
| T or F BVD-MD, Rinderpest and Malignant Catarrhal Fever all produce similar lesions on the mucosa of the alimentary tract. |
|
Definition
|
|
Term
| T or F Malignant Catarrhal Fever virus attacks the vascular endothelium and can result in sloughing of hooves. |
|
Definition
|
|
Term
| T or F Bison in Yellowstone National Park are known carriers of Pasteurella multocida Type B and occasionally develop hemorrhagic septicemia. |
|
Definition
|
|
Term
| T or F Rotavirus infection in calves results in a marked thickening of the mucosa of the small intestine. |
|
Definition
|
|
Term
| T or F Gradual increases in the incidence of Neospora caninum infections in cattle herds are best explained by continual exposure to feces of infected canines. |
|
Definition
|
|
Term
| T or F Early embryonic death and infertility occur with both Tritrichomonas foetus and Campylobacter fetus subspecies venerealis infections but the former increases in incidence over 2 to 5 years in an infected cow herd. |
|
Definition
|
|
Term
40. ____ F5 Escherichia coli
41. ____ Clostridium perfringens
42. ____ Rotavirus
43. ____ Cryptosporidium
44. ____ Salmonellosis
A. >14 days of age
B. 3 to 30 days of age
C. >35 days of age
D. 5 to 35 days of age
E. 1 to 3 days of age
F. <3 to 5 days of age
G. None of the above |
|
Definition
40. __F__ F5 Escherichia coli
41. __E__ Clostridium perfringens
42. __G__ Rotavirus
43. __D__ Cryptosporidium
44. __A__ Salmonellosis |
|
|
Term
| Preconditioning programs are becoming more common but there are still some major obstacles that prevent many cow-calf operations from wanting to adopt some type of preconditioning. List two major factors that limit preconditioning programs, especially in the Western states. |
|
Definition
a. Economics. In most of the western states where calves are sold at auction, the premium on preconditioned calves is often not enough to offset the costs of the vacciation and handling.
b. It takes feeed. There isn't usually enough feed for holding the calves during the preconditioning period |
|
|
Term
| On strictly an immunological basis what are the major reasons that it is unwise to give the first dose of a killed bacterin to feeder calves on arrival at a feedlot or within a few days of arrival? |
|
Definition
a. There isn't sufficient time to develop a good immune response. When these are used, they typically require a booster (after initial vaccination)
b. They can be immunosuppressive and have other adverse effects |
|
|
Term
| One of your major feedlots has used the following plan for treatment of respiratory disease. Basically, any calf off feed or having abnormal respiration is sorted off and tagged and has its rectal temp taken. If the rectal temp is 103.5 or higher, the calf is treated with Tilmicosin. It is placed in a sick pen and observed twice daily. The rectal temp is recorded and if significant improvement doesn't occur in three days, the calf is given a three day course of Naxel. Recently a higher percentage of these calves have died following completion of the Naxel therapy (some of the deaths occured in poor-doers that apparently didn't respond to therapy. You have posted several of them and your culture results indicate that P. multocida has been the dominant organism recovered from the lungs. Antimicrobial susceptibility testing indicates that all of the P. multocida you recovered are susceptible to Naxel. Explain possible reasons for these findings and suggest possible methods for control/prevention of the repiratory dx problem at this feedlot. |
|
Definition
a. The Tilmicosin apparently wasn't working against the P. multocida and allowing the organism time to damage the lungs and the formation of self protective abcesses.
b. Once the Naxel was finally used, it was too late to save the animals
c. ...also, occasionally there are more virulent strains of P.multocida... |
|
|
Term
| How long does colostrol immunity against IBR virus last in calves assuming a proper amount of good quality colostrum in a cow vaccinated with MLV IBR virus? |
|
Definition
| At least 4 months and maybe as long as 7 months |
|
|
Term
| Disease caused by BRSV used to be known as "silage disease" by some cattlemen and vets. What is/was the role of silage in BRSV? |
|
Definition
| Immunosuppression occurs from the ruminal acidosis from grain overload |
|
|
Term
| Vaccines against BRSV have a high rate of complaints for adverse reactions. What is thought to be the basis for most of these adverse reactions? |
|
Definition
| Type 1 or immediate hypersensitivity reactions |
|
|
Term
| You are called to a farm that has a very sick 14month old steer. There are 180 other steers on this fram and none of the others seem to be ill. This steer is breathing hard, has diarrhea, nasal and ocular discharge, a ropy saliva, is off feed, reluctant to move and has a fetid breath. ON examination you find the epithelium of the oral cavity to have several ulcerated areas and the rectal temp is 99.5F. List four differential diagnoses, circle the top two and discuss recommendations to prevent the spread of your most likely two infectious diseases. |
|
Definition
1. MCF*
2. BVD-MD*
3. Rinderpest - not likely, would see many more sick, would explain the breath
4. FMD - not likely, would see many more sick along with vesicles, lameness
answers probably based on age of animal, systemic lesions, oral epithelial ulceration
Why not IBR? |
|
|
Term
| Vaccination against contagious bovine pleuropneumonia is practiced in areas where the organism is endemic. Treatment is also commonly used. Why are vaccination and treatment not very wise practices to used against this disease? |
|
Definition
| Vaccinated and treated animals remain carriers |
|
|
Term
| What are the major problems associated with the efficacy and use of the modified live oral rotavirus-coronavirus vaccine? |
|
Definition
a. It has to be given within 24hours of birth and this is often difficult, especially with beef calves
b. There are numerous rotovirus serotype variants which a commercial product makes less efficacious. |
|
|
Term
| With a group of calves 3-4weeks old that have broke with a respiratory disease, a total serum protein is taken. There is a finding of 5.3mg/dl, is failure of passive transfer the most likely cause? |
|
Definition
| No, it is unlikely that FPT played a role here |
|
|
Term
| Outline the major clinical signs of rabies in cattle |
|
Definition
| Drooling, excited (sometimes), fixed look, straining to defecate/urinate, sucking air into rectum. Dramatic drop in lactation. May resemble indigestion. |
|
|
Term
| Why is the vaccine against Neospora caninum being promoted for use in feedlot calves as well as for replacement heifers? |
|
Definition
| Apparently infection with N. caninum causes a decrease in average daily gain and a marked decrease in feed efficiency |
|
|
Term
| List 3 common agents involved in middle ear infections in cattle and discuss how to prevent middle ear infections caused by all three. |
|
Definition
1. M. bovis
2. Manheimia haemolytica
3. Pasturella
Prevent respiratory disease
Utilize pasteurized milk for dairy calves to prevent M. bovis |
|
|
Term
| Why has bovine anaplasmosis traditionally been a more severe problem in southern areas of the US and tropical or semitropical areas of the world in general? |
|
Definition
a. Hematophagous insects that contribute to the spread of A. marginale are much more common
b. The insects are able to overwinter, and do not require transovarial transmission |
|
|
Term
| Leptospirosis seems to be recognized as being more of a problem in dairy cattle than it is in beef cows. Why would dairy cattle be more likely to be effected. |
|
Definition
| a. more crowded conditions and greater possibility of urine contamination of food and water |
|
|
Term
| Modified-live BVD virus vaccines have been used in young dairy calves (especially bulls) despite the presence of protective maternal antibody titers. Whatis the immunologic basis for th eprotection these vaccines provide in the face of colostral immunity? |
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Definition
| Stimulation of CMI reponse |
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Term
| Briefly outline an effective program to decrease the economic impact of Johne's disease on a dairy herd. |
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Definition
Test all adult cattle in herd on a routine basis using the available ELISA test or other suitable test
Test all adult cattle showing clinical signs
Cull immediately all positives and any of their offspring that are currently in the herd
If Johne's is prevalent in the herd, one could vaccinate the calves at 1 month of age and use these as replacement heifers
Rear replacement heifer claves in totally separate area and prevent cross-contamination with fecal material as much as possible
Do not spread cattle manure on hay or pasture ground |
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Term
| Outline the procedure one should use to establish a herd that is negative for bovine lymphosarcoma (leukosis). Why would one want to establish a negative herd in this country? |
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Definition
| Test and cull the positives. The most likely reason for establishing a negative herd would be to allow export of cattle, semen, or embryos to a country requiring cattle from a herd that is negative. |
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