SWINE Flashcards
At what age are piglets normally weaned on North American commercial swine farms?
a. 16 to 21 days of age
b. 64 to 68 days of age
c. 52 to 56 days of age
d. 40 to 44 days of age
e. 28 to 32 days of age
a. 16 to 21 days of age
The range throughout the world tends to be slightly greater at 14 to 28 days.
Which of the following is a method of control to prevent infection of Metastrongylus lung worms in pigs?
a. Supply a clean water supply
b. Raise pigs strictly on soil pasture
c. Prevent access to soil containing snails
d. Prevent access to soil containing earthworms
d. Prevent access to soil containing earthworms
The correct answer is to prevent access to soil containing earthworms. Earthworms are the intermediate host often involved in transmission of Metastrongylus lungworms in pigs. Direct transmission without the intermediate host can occur as well. Clinical signs include coughing and unthriftiness. If a secondary pneumonia occurs, dyspnea and abdominal breathing or “thumps” may occur. Affected pigs that are raised on pastures are often affected with both lungworms as well as ascarids.
You arrive at a farm where the farmer has lost 2 pigs in the past 2 days. He has 450 pigs which are currently weighing 200 lbs. The pigs seemed to be doing quite well and all appear to be eating. They all look healthy (no respiratory or enteric signs noted) and there has not been a diet change for at least 2 weeks. On arrival to the farm you find the latest mortality. The pig just died over night and is in excellent body condition. It seems to be one of the biggest pigs from the group. The abdomen is quite distended. As you perform the necropsy you find the following gross lesions (photo). No intestinal torsion/volvulus is noted. What should you do next?
a. Check intestinal content for clotted blood
b. Treat all pigs with tylosin in the water
c. Collect two feed samples (one from affected group and one from non-affected group)
d. Immediately treat all remaining pigs with ceftiofur
e. Immediately vaccinate remaining pigs for salmonella
a. Check intestinal content for clotted blood
Your next step should be to check intestinal content for clotted blood. Your top two differentials at this time are acute ileitis or hemorrhagic bowel syndrome. Both present as sudden death and on necropsy both appear grossly as distended intestines with diffuse hemorrhagic tissue. In the case of acute ileitis, the intestinal content will be hemorrhagic and clotted. For hemorrhagic bowel syndrome (HBS) or intestinal volvulus, the intestinal content will be hemorrhagic and liquid; non-clotted. Making the correct diagnosis is critical as in the case of acute ileitis, immediate treatment of all pigs with tylosin would be warranted. For HBS, the etiology is unknown, and there are no effective treatments.
The pot bellied pig in the picture is infected with Trichinella spiralis. How is this parasite in pigs transmitted?
a. Ingestion of snails, the intermediate host
b. Ingestion of encysted larvae in muscle
c. Ingestion of earthworms, the intermediate host
d. Ingestion of encysted larvae in urine
e. Ingestion of encysted larvae in feces
b. Ingestion of encysted larvae in muscle
The correct answer is ingestion of encysted larvae in muscle. Trichinella spiralis is a worm that can infect most mammals. It commonly affects wildlife, including bears, horses, rats, marine mammals, and of course, pigs. Infection in pigs is often due to ingestion of rodents, raw garbage, or cannibalism of meat infected with the cysts. Humans can get the infection by eating inadequately cooked pork. Control in pigs is to prevent them from cannibalizing the dead, prevent them from eating rodents, and by cooking the garbage that is fed to them.
Which of the following is true about hernias in swine?
a. Inguinal hernias in pigs is heritable
b. Inguinal hernias are always bilateral
c. Inguinal hernias in pigs occur more commonly in females than males
d. Umbilical hernias in pigs occur more commonly in males than females
a. Inguinal hernias in pigs is heritable
The correct answer is inguinal hernias in pigs is heritable. Both inguinal and umbilical hernias occur commonly in pigs. Inguinal hernias occur more commonly in males than females, particularly after castration. They can be unilateral or bilateral and occur more commonly on the left side. Umbilical hernias occur in both sexes but are slightly more common in females.
Which of the following cells is the primary target for porcine reproductive and respiratory syndrome (PRRS) virus infection?
a. Alveolar macrophages
b. Ciliary epithelium
c. Type II pneumocytes
d. Type I pneumocytes
a. Alveolar macrophages
The correct answer is alveolar macrophages. PRRS virus has a high affinity for macrophages especially those in the lung. This is part of the reason the porcine immune system is compromised when infected with PRRS making them more susceptible to other pathogens.
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You are called to an organic swine farm to address a problem with piglet performance. The owner reports he is losing a large number of pigs due to wasting. The pigs seem to do fine for about 3 weeks and then will start losing weight. Pigs are left on the sow for 4-5 weeks before they are weaned. Many of the pigs are in such bad shape by the time they are weaned they are not able to recover in the nursery phase. As you visit the farm you find one dead piglet. It appears to weigh just over 10 lbs. You perform a necropsy and notice the small intestines to be extremely thickened. The owner thinks the pig is about 4 weeks old. As you look for other pigs you find 40% of them are thinner than expected. Several of them have a loose stool. No blood is noted on any stools. Sows seem to be eating well. All pigs are vaccinated for ileitis. What question should you ask the owner?
a. Do you remove all antibiotics from the feed 3 days before and 3 days after vaccinating for ileitis?
b. Are pigs vaccinated against PCV2?
c. When are pigs vaccinated for ileitis?
d. Have there been any new additions to the herd in the past 3 months?
e. What is the PRRS status of the herd?
c. When are pigs vaccinated for ileitis?
Your next question for the farmer should be “When are pigs vaccinated for ileitis?” The clinical presentation of diarrhea, extremely thickened small intestines, and wasting pigs is highly suggestive of Lawsonia intracellularis infection, commonly called ileitis. In modern pig production, ileitis vaccine is usually administered in the mid-to-late nursery stage (6 - 8 weeks of age) as clinically the disease becomes apparent when pigs are >12 weeks of age. In this case, because the farmer raised the pigs without antibiotics and most likely they are outdoors (organic production), these pigs are exposed to heavy doses of Lawsonia intracellularis organisms very early in life. This results in clinically affected pigs even as early as 3 weeks of age. Since the farmer is using a vaccine it is important to know right away if the timing of the vaccine is appropriate (at least 3 weeks before clinical signs are noted).
In this case, there is no need to ask about antibiotic use around vaccination as the farmer produces organic pigs and thus no antibiotics are allowed. PRRS does not cause thickening of intestines. PCV2 can cause wasting of pigs, but clinically affects pigs in the finishing phase (usually > 12 weeks of age). Ileitis is endemic in most, if not all, farms and therefore herd additions would not be a significant contributor to an acute outbreak.
How many teats does a sow usually have?
a. 4
b. 8
c. 10
d. 2
e. 14
e. 14
The correct answer is 14. Dogs have 10, cats 8, cows 4, sheep, goats, and horses have 2.
Testing for Classical Swine Fever can be complicated by the presence of which of the following viruses in swine?
a. Bovine Viral Diarrhea (BVD)
b. Influenza type A virus
c. Porcine Reproductive and Respiratory Syndrome virus (PRRS)
d. Porcine Circovirus Type (PCV 2)
e. Vesicular Stomatitis virus
a. Bovine Viral Diarrhea (BVD)
The correct answer is Bovine Viral Diarrhea (BVD). Although BVD virus does not usually cause disease in pigs, pigs do get exposed to the virus and seroconvert. Both BVD and CSF are Pestiviruses from the family Flaviviridae. Antibody production in pigs to BVD can cross react with some CSF assays. This can create some problems because CSF is considered a foreign animal disease in the U.S.
Several litters of 2 to 3 day old pigs have recently died rapidly with hemorrhagic enteritis. Post mortem lesions include mucosal hemorrhage, necrosis and emphysema in the small intestines. What pathogen is most likely to cause these signs?
a. Clostridium perfringens type C
b. Enterotoxigenic E. coli
c. Haemophilus parasuis
d. Salmonella choleraesuis
e. Erysipelothrix rhusiopathiae
a. Clostridium perfringens type C
The age of these affected pigs along with the rapid course of hemorrhagic and necrotic enteritis help you come to this conclusion. As with many Clostridial diseases, vaccination is the most effective means of control. Other important clostridial diseases of swine include C. perfringens type A, C. difficile, C. tetani, C. botulinum, C. novyi, C. septicum, and C. chauvoei.
You are called to a sow farm to investigate an abortion outbreak. The owner has 600 sows and is concerned because 5 sows aborted overnight. Upon arrival you find that all 5 sows that aborted were at least 95 days pregnant. Everyone seemed fine 2 days ago but yesterday a few sows started to cough and were off feed. Today there are a lot more sows coughing. The aborted sows all have temperatures of 105.0 - 106.5F (40.6-41.4 C). Which of the following samples is most important in helping you confirm your diagnosis?
a. Collect a random sample of blood samples from sows (aborted and not aborted)
b. Collect 2 aborted fetuses from each sow
c. Collect blood samples from aborted sows only
d. Collect nasal swabs from all aborted sows
e. Euthanize a sow and collect a complete set of tissues
d. Collect nasal swabs from all aborted sows
The correct answer is collect nasal swabs from all aborted sows. In this case, the sudden onset of coughing that is highly contagious is highly suggestive of swine influenza virus. Swine influenza virus does not go systemic. It causes abortion by creating a systemic illness (fever), but the virus does not spread via the blood. The virus is not found in the blood or the aborted fetuses. A necropsy of an affected sow is not necessary to confirm the diagnosis as nasal swabs of acutely affected animals are great diagnostic specimens.
A 3 month old pig is presented for an abnormal gait and lameness of both pelvic limbs. Your history reveals the pig has been gaining weight quickly and is on a high-energy diet. There is no history of trauma, although the pig is usually unsupervised outside. What is the most likely diagnosis?
a. Pelvic fracture
b. Hip dysplasia
c. Immune medicated polyarthritis
d. Osteochondrosis
d. Osteochondrosis
The correct answer is osteochondrosis. Osteochondrosis is a common disease in young, rapidly-growing pigs. Lesions include ulcerations or defects in articular cartilage. Lesions are often bilateral and symmetric. Common sites of the disease in pigs include the medial femoral condyle, humeral condyle, humeral head, glenoid of the scapula, distal ulna, and lumbar vertebrae.
Which of the following E. coli is most commonly found in post-weaning diarrhea in pigs?
a. O157:H7
b. F4 (K88)
c. F5 (K99)
d. F41
e. F6 (987P)
b. F4 (K88)
The correct answer is F4 (K88). Susceptibility to the different pili is dependent on the presence of receptors. These receptors change as enterocytes mature in piglets. O157:H7 is not known to be pathogenic in swine and is rarely found. F4, F5, F6, and F41 can all cause diarrhea in pre-weaning piglets (<3 weeks of age) but only F4 (K88) continues to be a problem into the post-weaning phase.
You have just been called to a small outdoor swine farm. The farmer just found what appear to be 3 different litters of aborted fetuses. The sows are roaming around the pasture and it is difficult to identify which animals have aborted (there are some pregnant and non-pregnant animals in the group). There are no noticeable respiratory signs on any of the sows either. The farmer is concerned the herd is undergoing an outbreak of porcine reproductive and respiratory syndrome (PRRS) virus. What should you do next?
a. Test 10 random sows for PRRS virus via PCR
b. Test 10 random sows for PRRs antibodies
c. Collect 6 aborted fetuses to test for PRRS virus via PCR
d. Collect 6 aborted fetuses to test for PRRs antibodies
c. Collect 6 aborted fetuses to test for PRRS virus via PCR
The correct answer is to collect 6 aborted fetuses to test for PRRS virus via PCR. Because the outbreak appears to be just beginning, you are more likely to find the actual virus on any sample tested rather than antibodies. It takes 10 - 14 days after exposure for antibodies to be detected. Research has shown that during a PRRS abortion outbreak, approximately 50% of aborted fetuses will test positive for virus (i.e. 50% chance of detection). Entire fetuses or just thoracic fluid are appropriate samples for submission. By including 6 aborted fetuses you will have a 98.5% chance of finding the virus if it is there. At the start of an outbreak, disease prevalence will be very low and therefore a very large sampling size would be needed to find a single positive animal.
A client with a pet pot belly pig carries it into your clinic one day, cradling it lovingly against her body. The complaint is pruritus and skin lesions; she mentions that she and her boyfriend also have similar lesions. You do a skin scraping on the pig and find Sarcoptes scabiei. What treatment should you now recommend?
a. No treatment is necessary, as Sarcoptes spontaneously die after 3 weeks and the animal heals
b. Treat hte pig for mange
c. Use corticosteroids to stop the itching, as all the skin damage is due to scratching
d. Dip the pig daily in toxaphene
e. Treat pig for lice
b. Treat hte pig for mange
The best treatment drugs are the avermectins; two doses at 2-week intervals will be required. The mange mite completes its entire life cycle on the pig. Also advise her to see her physician for herself and boyfriend. Finally, tell her this can spread to other species of animals, and the pig must be quarantined away from all other pets and livestock.
