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Flashcards in BOVINE Deck (156)
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1

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?

a. Free gas bloat, failure to eructate

b. Frothy bloat

c. Type 3 vagal indigestion

d. Cecal dilation

e. Left displaced abomasum

a. Free gas bloat, failure to eructate

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.

2

You examine several dairy calves which have developed areas of hair loss and thick grayish skin (see image). It is winter, and these are 2-month old housed calves. They appear to be otherwise healthy and growing normally, but the owner would like a diagnosis and treatment.

a. Ringworm

b. Lumpy skin disease

c. Lice

d. Mange

e. Warts (papillomatosis)

 

a. Ringworm

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.

3

An outbreak of psoroptic mange is identified in a herd of cattle .  What is the treatment of choice?

a. Ivermectin

b. Pyrethrin

c. Levamisole

d. Albendazole

a. Ivermectin

Albendazole and levamisole are used to treat worms. Ivermectin is more effective than pyrethrin

4

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?

a. Sarcophaga

b. Simulium

c. CUlicoides

d. Anopheles

e. Hypoderma

e. Hypoderma

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.

5

Each year, hide damage due to this organism results in tremendous economic loss in cattle.

a. Hypoderma bovis

b. Sarcopetes scabiei

c. Chochliomyia hominivorax

d. Ornithodoros coriaceus

 

 

a. 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.

6

A 5-year old cow presents with skin lesions confined to the nonpigmented areas (see image). The affected skin is dry and raised at the periphery. The skin of the teats appears dry. Which of the following could result in this presentation?

a. Ingestion of Pteridum aquilinum (bracken fern)

b. Ingestion of Quercus spp.

c. Ingestion of lupine

d. Ingestion of moldy feed containing aflatoxins

d. Ingestion of moldy feed containing aflatoxins

This is a case of photosensitization based on the skin lesions confined to the nonpigmented areas. Primary photosensitization can occur when photodynamic agents are absorbed from the G.I. tract such as Hypericum perforatum (St. John's wort), Fagopyrum esculentum (buckwheat), Ammi majus (bishop's weed), and Cymopterus watsonii (spring parsley). Secondary (hepatogenous) photosensitization occurs when the liver's excretion of phylloerythrin is impaired due to liver damage. Phylloerythrin is derived from the breakdown of chlorophyll by rumen microbes. The best answer in this question is aflatoxins because they are known to cause liver damage.

Bracken fern toxicity causes acute hemorrhagic syndrome in cattle. Lupine toxicity primarily causes birth defects. Quercus (oak) toxicity causes GI and renal dysfunction.

7

You are presented with a Longhorn steer with a large bloody sore on its left side just behind the scapula (see image). There is pus and serum mixed with blood. Once you clean away this material, there appears to be a large open superficial sore, slightly raised (excoriated granuloma). The impression smear you make is full of intracellular pleomorphic gram positive rods. What organism is causing this lesion?

a. Onchocerca cervicalis

b. Staphylococcus aureus

c. Streptococcus bovis

d. Corynebacterium pseudotuberculosis

e. Corynebacterium bovis

d. Corynebacterium pseudotuberculosis

The lesions of C. pseudotuberculosis in cattle, horses, sheep and goats are all rather different by species. In horses one sees pectoral and ventral abscesses, or even internal abscesses. In sheep and goats, the organism causes caseous lymphadenitis.

In cattle, as seen here, the lesions tend to be on the sides, perhaps initiated by a skin scratch from a fence. Most lesions heal spontaneously in 3 to 4 weeks and, although they attract flies, they are not a significant disease in cattle.

8

The owner of a nearby dairy calls to have a wound on his heifer inspected. The wound is located ventrally, on the brisket, and there are larvae feeding on the tissue. The wound is approximately 5cm in diameter and has now become 6 cm deep as a result of larval feeding. As you approach the cow, you see a large, metallic blue-green colored fly leaving the wound. What is your diagnosis?

a. Chrysops

b. Cochliomyia hominivorax

c. Stomoxys calcitrans

d. Tabanus

b. Cochliomyia hominivorax

This fly is also known as the screwworm. Females lay hundreds of eggs at the edge of fresh wounds on the cow; the larvae hatch in approximately 24 hours. As the larvae eat the living tissue, they create a huge wound. Screwworm larvae then fall off and pupate, completing their life cycle in approximately 21 days. This fly is reportable!

9

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?

a. Cecal displacement or volvulus

b. Gas in the spiral colon

c. Abomasal torsion

d. Intussusception

c. Abomasal torsion

he clinical signs described are classic for an abomasal torsion. These are much less common than left or right displaced abomasum. However, the risk factors for developing abomasal torsion appear to be the same. This finding is a surgical emergency and must be corrected before cows go into shock. Another factor is that many times you may be able to palpate abomasal torsion rectally, but not always (esp difficult in large Holstein cows).
Cecal displacement and cecal volvulus can be ruled out because you would likely be able to palpate these disease processes via rectal examination as a soft loaf of bread that you can get all the way around. The ping is usually high in the right flank and does not extend to the 9th rib on a line from hip to elbow. Animals with intussusception are very colicky and have scant dark red feces. The intussusception can be found sometimes by rectal palpation as a firm painful mass. Gas in the spiral colon is a frequent finding in any sick cow with poor GI motility and is not a primary disease problem. It is diagnosed by finding an 8-inch circular ping high on the last rib or just behind it.

10

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?

a. Rabies

b. Salt poisoning

c. Pseudorabies

d. Polioencephalomalacia

e. Hypomagnesemia

c. 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.

11

You visit a dairy that has ongoing problems with mastitis. They ask you for advice on proper milking and maintenance of equipment. Which of the following statements is INCORRECT?

a. Replace the liner every 25 milkings

b. Post dip all teats

c. Shut off vacuum before removing the claw

d. Pre dip all teats

e. Fore strip each quarter

a. Replace the liner every 25 milkings

This is the best answer because the liner will last for at least 500 milkings. There are three types of liners: synthetic rubber, natural rubber, and silicone. These are designed to last anywhere between 500 and 10,000 milkings. Post-milking teat disinfection is probably the most effective way of reducing the rate of contagious mastitis. Pre-milking dip will help control environmental mastitis.

12

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. What can you tell the dairyman with a fair degree of confidence about the type of mastitis this is likely to be?

a. This cow is infected with a fungus

b. This cow is infected with Arcanobacterium pyogenes

c. This cow is infected with a coliform

d. This cow is infected with a contagious pathogen

c. This cow is infected with a coliform

This is a typical secretion with coliform mastitis.

13

A dairy farmer brings you a 6-week old calf for postmortem exam on a nice warm spring day. He has had three 5- to 7-week old calves die in the last week and this one just died an hour ago. They show depressed appetite, fever, and rapid labored breathing before collapsing within a day from the time the first signs are noticed. The calves were born on his farm and have been in good well-ventilated individual hutches with shade. They are fed 12% of their body weight per day in whole milk, plus a calf starter grain, alfalfa hay and free choice water. The major lesions are serosal and subcutaneous petechial hemorrhages and heavy wet red lungs (see image). Based on these pathologic findings, which of the following is the most likely cause of death?

a. E. coli septicemia

b. Bovine virus diarrhea (BVD)

c. Mannhemia hemolytica bronchopneumonia

d. Salmonella dublin

e. Malignant catarrhal fever (MCF)

d. Salmonella dublin

S. dublin tends to cause septicemia in dairy calves 4 to 8 weeks of age, and the lesions described are typical. The organism can be transmitted by carrier cows to neonates at birth or via their milk. The most effective control measures are to cull carriers and vaccinate calves using a modified live S. dublin vaccine.

14

Which of the following medications has the shortest meat withdrawal time in beef cattle?

a. Sulfadimethoxine

b. Oxytetracycline

c. Penicillin G

d. Chloramphenicol

e. Ceftiofur

e. Ceftiofur

 

15

One cold December morning you are presented with a 5-year old Holstein dairy cow which freshened the day before. This morning she was found down in the corral and unable to rise. On physical examination you find T=98F, 36.7C, HR=90 (and the heart is difficult to hear), and RR=10. She has her neck turned back toward her thorax, and it has an "S" shaped curve in it. Her nose is dry, she is non-responsive to being handled, and her rumen motility is absent. The rectal exam shows that her bladder is full. The mammary glands and the uterine lochia appear normal.

Based on these findings, which of the following disorders is most likely?

a. Coliform mastitis

b. Milk fever

c. Left displaced abomasum (LDA)

d. Hypothyroidism

e. Spinal lymphoma

b. Milk fever

A cow with a history of recent parturition with clinical signs such as these should be considered as having hypocalcemia until proven otherwise. The cow needs treatment to restore normal calcium levels.

16

One 3-week old calf in a group of young calves being fed milk replacer has been depressed, growing poorly and appears unthrift with a rough hair coat. She recently began kicking at her flank, teeth grinding, and vocalizing with an arched back. She has developed white, putty-like feces and is dehydrated. Which of the following is the most likely underlying cause of the problem?

a. Excessive carbohydrate in the milk replacer

b. Intussusception of the small intestine

c. Congenital rumen stasis

d. Dysfunction of the esophageal groove

e. Atresia coli

d. Dysfunction of the esophageal groove

This is a typical description of esophageal groove dysfunction in a calf resulting in rumen acidosis.

To review normal physiology, the esophageal groove (also known as reticular groove) is a specialized part of the ruminant stomach that closes in response to drinking milk, directing it directly to the abomasum. When dysfunctional, milk goes to the rumen where it is fermented by rumen microbes and converted to volatile fatty acids and lactic acid. The resulting rumen acidosis leads to the clinical signs described in this case. For this reason, this phenomenon is sometimes referred to as rumen drinking.

For this reason, this phenomenon is sometimes referred to as rumen drinking.

17

A three-year old Jersey cow presents for decreased milk production and weight loss. On physical exam, a hard, non-painful swelling of the mandible is identified. Radiographs of this region show lysis and productive bone lesions, with distortion of the teeth in the area. What is the most likely cause for these findings?

a. Osteosarcoma

b. Vesicular stomatitis

c. Actinomycosis

d. Actinobacillus lignieresii

c. Actinomycosis

This cow has become infected with Actinomyces bovis (lumpy jaw) as a result of sustaining an injury in the mucous membranes, often from eating hard scabrous feeds. Actinomyces bovis is part of the normal oral and rumen flora and can become a source of infection when cows consume items that traumatize their mouths. The lesion classically causes a hard non-painful swelling of the mandible or maxilla along with productive and destructive bony changes. Teeth may be lost. Osteosarcoma is very uncommon in cattle and is therefore a poor answer choice. Vesicular stomatitis will not cause a hard non-painful swelling. Instead, you may see oral ulceration as a result of ruptured vesicles along the tongue. This virus can also cause lesions of the feet and teats. Cows infected with vesicular stomatitis will most likely be salivating, not eating, depressed, and febrile. Actinobacillus lignieresii is the causative agent of woody tongue. In this case, you would expect to see a large firm tongue on physical exam. Sodium iodide has been used to treat lumpy jaw, but this will only arrest the lesion.

18

You are called by a beef rancher located in the northern California oak foothills one day in March after an unusual spring snowstorm that dumped a foot of wet snow two days earlier. You are asked to diagnose and treat several calves in the 3- to 5- month old age range which are listless and weak. You do a physical exam and find elevated heart and respiratory rates, but normal rectal temperatures. The most remarkable finding is marked edema of the perineum and vulva of the calves (see image).
What is the best diagnosis based on these signs and history?

a. Acute oak toxicosis

b. Clostridium hemolyticum infection (redwater)

c. Bovine virus diarrhea

d. Malignant catarrhal fever

e. Lead toxicity

a. Acute oak toxicosis

The reason that oak toxicosis may occur in this scenario is as follows: the snow knocks down the budding oak limbs which are eaten by curious calves who cannot reach the grass. The calves develop both renal and GI signs as the tannins damage the mucosa. Many develop hemorrhagic diarrhea and renal tubular necrosis. Some tannins are hydrolyzed in the rumen to gallic acid and pyrogallol, which are both very toxic to the renal tubules. Treatment is aimed at flushing out the toxins (intravenous fluids) and protecting the gastrointestinal tract. Prevention is best; and the animals will avoid eating the oak if they are offered hay immediately during the storm.

19

Pick the ideal suture pattern for a uterus after a Caesarian section in a cow.

a. Horizontal mattress

b. Simple interrupted

c. Utrecht pattern

d. Near-far-far-near

c. Utrecht pattern

This pattern achieves a nice mucosal and serosal seal when done correctly. Additionally, the exposure of suture to the serosa is minimized with this type of pattern, so adhesions of uterus to surrounding structures is minimized.

20

A beef cattle farm in the mountains of California is experiencing an abortion storm affecting about 50% of heifers. The abortions are occurring primarily in the last trimester. The cows appear healthy; some of the aborted fetuses have hepatosplenomegaly and generalized lymphadenopathy. A necropsy on one of the aborted fetuses shows lymphoid hyperplasia in the spleen and granulomatous inflammation in the liver. In the thymus, extensive macrophage infiltration into the medulla was seen as well as loss of cortical thymoctes. Fetal IgG was markedly elevated. Based on the likely diagnosis, which of the following measures would decrease the future incidence of this problem?

a. Control of Ponderosa pine trees

b. Vaccinate heifers against bovine herpesvirus

c. Avoid feeding silage to heifers

d. Expose heifers to endemic areas before breeding age

e. Control of mosquitoes

d. Expose heifers to endemic areas before breeding age

This is the typical presentation for epizootic bovine abortion (EBA), also known as foothill abortion. The agent causing foothill abortion remains a subject of some investigation but a 2005 molecular study identified a novel deltaproteobacterium as being present in the Ornithodoros coriaceus tick vector and in DNA from fetal thymuses. With EBA, cows usually do not experience abortions again in later pregnancies and exposure to endemic areas before breeding age can also prevent abortions. Other control options may include control of the tick vector or prophylactic antibiotic use.

You can lower your index of suspicion for bovine herpesvirus (Infectious bovine rhinotracheitis virus) because there is no respiratory disease seen in this case; abortions from herpesvirus occur throughout pregnancy and fetuses are typically autolyzed with foci of necrosis in the liver or no gross lesions.

Ponderosa pine needle abortions occur in the last trimester but cows are often moribund after delivery and hemorrhage. There are usually no specific fetal lesions.

21

A cow about one month from term goes off feed and rapidly develops an enlarged, rounded, abdominal shape. She is now uncomfortable and reluctant to move. You examine the cow and note marked accumulation of watery fluid in the uterus. You perform a brief ultrasound and confirm the large volume of fluid in the uterus and a thickened placenta. What should you tell the farmer about this condition?

a. Hydrops amnion (hydramnios) is a disorder of the fetus and although the fetus is unlikely to survive, the cow should be okay

b. Hydrops allantois (hydroallantois) is a disorder of the fetus and can be treated by induction of parturition or Caecarian section and in most cases if the fetus is close to term, the calf will survive and the cow will be fertile

c. Hyprops amnion (hydramnios) is a disorder of the placenta and the fetus is likely to survive but the cow will likely be infertile

d. Hydrops allantois (hydroallantois) is a disorder of the placenta and the prognosis for life of the fetus and fertility of the cow is poor

d. Hydrops allantois (hydroallantois) is a disorder of the placenta and the prognosis for life of the fetus and fertility of the cow is poor

The clinical description is most consistent with hydroallantois because of the rapid accumulation of fluid and the clinical signs of the cow. Hydramnios is a reasonable differential although it more typically involves gradual accumulation of fluid and the cow is usually clinically unaffected.

Hydroallantois is a disorder of the placenta (chorio-allantois) that results in rapid accumulation of 100-200 liters of watery, clear fluid during the last trimester. The cow develops a rounded appearance to the abdomen and it is usually not possible to palpate the fetus or placentomes. The cow often becomes sick with anorexia, decreased rumen motility, dehydration and weakness. She may go down or rupture the prepubic tendon. The prognosis for the fetus is guarded and even with treatment, the cow will likely be infertile. Induction of parturition or C-section are treatment options but the majority of calves are not viable and the dam rarely has normal colostrum. If the pregnancy is terminated, it is unlikely that the cow will have a productive milk cycle. Usually salvage for slaughter is the preferred option unless the fetus is considered valuable and the cow is near term.

Hydramnios is a disorder of the fetus, and the placenta itself is normal. The condition is typically characterized by gradual accumulation of thick viscous fluid during the later part of gestation. The cow develops a pear shaped caudal view. The fetus and placentomes are usually palpable and the cow is usually clinically well. Pregnancy usually goes to term and a small, deformed fetus is delivered. The cow has a fair to good prognosis for life and fertility. The cow may be induced or allowed to go to term depending on her condition.

22

Which immunoglobulin predominates in bovine colostrum?

a. IgG

b. IgE

c. IgA

d. IgM

a. IgG

The correct answer is IgG. It makes up about 85%.

23

About 1 hour after a difficult labor where the calf had to be pulled out with force, the cow goes down. She is pale and her heart rate is 100/min. What happened?

a. Obturator paralysis

b. Pelvic fracture

c. Hypocalcemia

d. Uterine tear

d. Uterine tear

With a traumatic fracture or damage to nerves, the cow would have gone down right away rather than an hour later. Hypocalcemia is possible but less likely in this case where the calf had to be forcibly extracted which can result in a uterine tear, and would be unlikely to make her pale and tachycardic.

24

You are in the process of auscultating a cow that presented for respiratory distress and you hear no breath sounds in the dorsal chest. What is your tentative diagnosis?

a. Pulmonary contusion

b. Aspiration pneumonia

c. Fibrinous pleuropneumonia

d. Pneumothorax

d. Pneumothorax

Since there is free air in the chest, the lung has lost its vacuum and is collapsed. The free air moves dorsally and you are unable to hear any lung sounds. Fibrinous pleuropneumonia will have lung sounds associated with it. Aspiration pneumonia is usually cranioventral in location. Pulmonary contusion is a differential, but given the location, a pneumothorax is more likely.

25

What is the definitive host of Sarcocystis cruzi?

a. Sheep

b. Horse

c. Goat

d. Cat

e. Dog

e. Dog

The ruminant is an intermediate host. Sarcocystis hirsuta involves the cat as the definitive host. Primates are the definitive host for Sarcocystis hominis. The life cycle involves a carnivore eating an infected cow which has cysts in the muscle. Then the cyst eventually forms sporocysts which are shed in feces and subsequently eaten by more cows. The sporocysts then hatch and penetrate artery walls and hang out in the endothelium to develop into sporozoites and eventually become merozoites at which time they invade muscle and encyst as sarcocysts. It takes about 10 weeks for the entire maturation process to occur. Clinical signs are non-specific such as fever, anorexia, salivation, weakness, muscle fasciculations, and weight loss. Diagnosis is likely to be at necropsy; so, prevent carnivore feces from contaminating the area.

The definitive host of Sarcocystis hirsuta is the cat and for Sarcocystis hominis, it is the human.

26

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?

a. Intravenous injection of xylazine followed by intravenous injection of potassium chloride

b. Air embolism (intravascular injection of air)

c. Exsanguination

d. Intravenous injection of bleach (sodium hypochlorite)

e. Gunshot

 

e. Gunshot

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

27

A dairy is having difficulties because many of the lactating cows are developing hairy foot warts as seen in the picture (papillomatous digital dermatitis) and are becoming lame. The owner plans to have all cows evaluated and the feet trimmed on those that need it. What other treatment would be effective?

a. Topical daily spraying of all lesions with oxytetracycline, plus installation of properly designed and managed foot baths

b. IM procaine penicillin daily for 5 days, plus properly designed and managed foot baths

c. Use of a commercial Treponema vaccine in all cows

d. Ceftiofur SQ for 3 days

e. Commercial wart vaccine two times SQ at 4 week intervals

a. Topical daily spraying of all lesions with oxytetracycline, plus installation of properly designed and managed foot baths

Both topical tetracycline and topical lincomycin have been found effective against the Treponema spirochete that causes this lesion. Foot baths can also be effective but difficult to manage on large dairies. A commercial vaccine is likely ineffective based on a published study finding no benefit. Systemic treatments with penicillin or ceftiofur are not recommended as effective, and penicillin use would require discarding the milk. The commercial Treponema vaccine has not been shown to be effective. Ceftiofur may not be used extra label.

28

Which of the following is less likely to be elevated in white muscle disease (WMD)?

a. Lactate dehydrogenase (LDH)

b. Aspartate aminotransferase (AST)

c. Sorbitol dehydrogenase (SDH)

d. Creatine kinase (CK)

 

c. Sorbitol dehydrogenase (SDH)

SDH is specific for the liver and white muscle disease involves skeletal or cardiac muscle. To review, WMD is a result of a selenium and/or vitamin E deficiency. This results in a myodegeneration of muscle which causes release of muscle enzymes into the serum. AST, CK, and LDH are all released with muscle damage.

29

Guillian-Barre syndrome is an acute inflammatory demyelinating polyneuropathy of humans that has been associated with a foodborne illness. Which of the following agents has been associated with Guillian-Barre syndrome?

a. Clostridium perfringens

b. Campylobacter jejuni

c. Listeria monocytogenes

d. Yersinia enterocolitica

e. Salmonella

b. Campylobacter jejuni

Guillian-Barre syndrome appears to be an autoimmune disease that is triggered after certain respiratory and gastrointestinal infections. 40% or more cases of the syndrome are seen after Campylobacter jejuni infections. Other agents that have been associated with Guillain-Barre syndrome include cytomegalovirus and Epstein-Barr virus.

30

Copper deficiency in ruminants is most often secondary and mainly associated with marginal copper levels and high levels of _______.

a. Molybdenum

b. Iron

c. ZInc

d. Cadnium

a. Molybdenum

The correct answer is molybdenum. This question is sort of tricky because the other answer choices also interfere with copper absorption but to a lesser degree. Sulfates are another contributing factor.