Pigs Flashcards
Testing for Classical Swine Fever can be complicated by the presence of which of the following viruses in swine?
- Vesicular Stomatitis virus
- Influenza type A virus
- Bovine Viral Diarrhea (BVD)
- Porcine Reproductive and Respiratory
Syndrome virus (PRRS) - Porcine Circovirus Type 2 (PCV2)
Answer: Bovine Viral Diarrhea
Explanation
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 CS is considered a foreign animal disease in the U.S.
***PowerLecture: Foreign Animal Diseases
As an international consultant, you are called to examine a group of feeder pigs on a farm in West Africa. The pigs have high fever, inappetence, and hemorrhages in the skin of the ears. Several have died acutely, and you find petechial hemorrhages on internal organs. The clinical signs and lesions look like classical swine fever or erysipelas, but there is one other disease you need to rule out which also has similar signs. What is this other disease?
- Porcine parvovirus
- Swine influenza
- Leptospirosis
- African swine fever
- Swine dysentery
Answer: African swine fever.
Explanation
AS acts in a similar manner to classical swine fever. It is highly virulent, carried by bush pigs and warthogs, and can also be transmitted by soft ticks.
***PowerLecture: Foreign Animal Diseases
Two weeks ago, the owner of a small swine farm performed castrations on several litters of unvaccinated piglets. Now he calls you with the complaint that a number of pigs are walking very stiffly and two are unable to stand. On examination, you note erect ears, tail held straight out, elevated head, and a visible nictitating membrane on the stiff pigs. There are similar signs plus muscle rigidity in the down pigs. When touched, the pigs worsen and muscle spasms occur. What disease is this most likely to be?
- Hypomagnesemia
- Cerebellar hypoplasia
- Selenium deficiency
- Clostridium tetani infection
- Aspergillus infection
Answer: Clostridium tetani infection
Explanation
The best prevention for all Clostridial diseases is vaccination. These pigs should be treated with penicillin, muscle relaxants, tranquilizers, tetanus antitoxin and vaccinated with tetanus toxoid. If the owner has the time, feeding these pigs orally with glucose solutions may also help survival (this is rarely done on commercial pig farms). Those surviving will need to be revaccinated in 4 weeks. You should also advise this owner on ways to castrate more effectively to avoid this problem.
Which of the following is one of the most common causes for diarrhea in a nursing piglet?
- E. coli
- Brachyspira hyodysenteriae
- Lawsonia intracellularis
- Trichuris suis
- Salmonella
Answer: E. coli.
Explanation
The correct answer is E. coli. Enterotoxogenic strains of E. coli cause enteric colibacillosis. It occurs commonly in nursing and weanling piglets and causes watery diarrhea, dehydration, acidosis, and death. Salmonellosis, swine dysentery (Brachyspira hyodysenteriae), proliferative enteropathies (Lawsonia intracellularis), and whipworm infections (Trichuris suis) cause diarrhea most commonly in growing, finishing, or breeding pigs.
***PowerLecture: Gastrointestinal Diseases
You identify a pig with skin lesions characteristic of Pityriasis rosea. What should you do next?
- Do nothing
- Euthanize the pig
- Give it an injection of avermectin
- Segregate the pig from others
- Give it an injection of penicillin
Answer: Do nothing
Explanation
The correct answer is to do nothing. Pityriasis rosea is a skin condition in pigs of unknown etiology. It is not a contagious condition and therefore pigs do not need to be separated from the rest of the herd. It is non-pruritic and resolves on itself with time. Almost all pigs fully recover with no effects on health or growth performance.
***PowerLecture: Dermatology
A 2-month old pig is presented for evaluation of lesions on the ventrum. You find multiple raised circular lesions. You tell the farmer that you suspect the lesions will resolve without further treatment. 3 weeks later, he returns, thankful that his pig has gotten all better. What condition did the pig have?
- Sporothrix schenckii
- Microsporum nanum
- Erysipelothrix rhusiopathiae
- Pityriasis rosea
Answer: Pityriasis rosea
Explanation
The correct answer is pityriasis rosea, a disease of unknown cause. Pityriasis rosea occurs in pigs 3-14 weeks of age and is characterized by raised circular lesions on the ventral abdomen. Pityriasis rosea resolves on its own in a few weeks without any treatment.
***PowerLecture: Dermatology
A swine herd with excellent biosecurity has experienced some abortions in new replacement gilts they purchased which are bred and gestating in an on off-site facility just for P1 females (parity segregation). You have diagnosed Leptospira pomona as the serovar responsible. Which of the following is the best course of action to effectively control this disease?
- Vaccinate all sows at both the off-site (parity segregation farm) and main farm against L. pomona
- Cull replacement gilts (parity segregation farm) and vaccinate sows on main farm
- Treat affected pigs with chloramphenicol for 5 days
- Depopulate and repopulate both the gilt farm (parity segregation farm) and sow farm (main farm)
- Treat all pigs with oxytetracycline in the feed for 3 days
Answer: Cull replacement gilts (parity segregation farm) and vaccinate sows on main farm
Explanation
Since the disease causes reproductive problems including abortions and is maintained in a herd by renal carriers, the best thing to do if economically feasible would be to cull the entire group of replacement gilts involved. Additionally it is important to maintain strict isolation and vaccinate the rest of the sows on the main farm. There is also the possibility of treating the affected group with long term use of antibiotics (several weeks of tylosin, tetracycline, or erythromycin). Chloramphenicol use in food animals is specifically prohibited in the US.
Which of the following is a method of control to prevent infection of Metastrongylus lung worms in pigs?
- Supply a clean water supply
- Prevent access to soil containing snails
- Raise pigs strictly on soil pasture
- Prevent access to soil containing earthworms
Answer: Prevent access to soil containing earthworms
Explanation
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 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?
- Test 10 random sows for PRRS antibodies via ELISA
- Collect 6 aborted fetuses to test for PRRS virus via PCR
- Collect 6 aborted fetuses to test for PRRS antibodies via ELISA
- Test 10 random sows for PRRS antibodies virus IFA
Answer: Collect 6 aborted fetuses to test for PRRS virus via PCR
Explanation
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 herd of pigs is presented for multiple 1-2 cm round papules, pustules, vesicles, and scabs on their ventral abdomens. Young and growing pigs are most severely affected. What is the most likely diagnosis?
- Pseudorabies
- Swine pox
- Greasy pig disease
- Erysipelas
Answer: Swine pox
Explanation
The correct answer is swine pox. The disease is caused by a poxvirus that causes the skin lesions described in the question. All ages can be affected, but it is more commonly seen in young and growing pigs. The disease is often transmitted by biting insects, particularly lice. The disease usually does not require treatment, unless the lesions become secondarily infected. Broad-spectrum antibiotics may be helpful in this situation. Hog lice and insect vectors should be investigated and eliminated to help control swine pox. Erysipelas causes diamond-shaped skin lesions and necrosis of the ears and tail. Greasy pig disease or exudative epidermitis is caused by Staphylococcus hyicus. It causes dark, greasy, brown skin lesions in the axilla, groin, head, and face.
Pseudorabies affects the CNS, respiratory system, and causes reproductive failure.
***PowerLecture: Dermatology
Which of the following E. coli is most commonly found in post-weaning diarrhea in pigs?
- 0157:H7
- F4 (K88)
- F6 (987P)
- F5 (K99)
- F41
Answer: F4 (K88)
Explanation
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. O157:7 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.
***PowerPage: Swine Diarrhea
Which of the following external parasites is considered to be the most economically important in swine?
- Haematopinus suis
- Demodex phylloides
- Stomoxys calcitrans
- Pulex irritans
- Sarcoptes scabei
Answer: Sarcoptes scabei
Explanation
Sarcoptic mange can cause pruritus in sows (mainly hyperkeratotic ear lesions) and growing pigs, resulting in reduced weight gains and feed efficiency.
***PowerLecture: Dermatology
Which of the following mycotoxins can cause hyperestrogenism and pseudopregnancy in pigs?
- Ergot
- Zearalenone
- Ochratoxin
- Aflatoxin
- Fumonisin
Answer: Zearalenone
Explanation
Zearalenone is a potent estrogenic metabolite produced by some Fusarium species. Young gilts will be most affected. Young boars will also have reduced libido.
A group of 20 farm pigs are being raised because the owner has extra barley and he is feeding the pigs from weaning to finish mainly on barley and table scraps. The pigs are housed outside and now approaching 150 lbs. He calls you because this week several pigs have not been able to get up. You examine three down pigs and find that they have a normal TPR but all appear to have pelvic and femoral fractures. What is the most likely diagnosis, based on this history and findings?
- Botulism
- Bone fractures due to nutritional imbalance
- Mycoplasma arthritis
- Bone fractures due to Vitamin D deficiency
- White muscle disease due to selenium deficiency
Answer: Bone fractures due to nutritional imbalance
Explanation
The high dietary phosphorus and lack of calcium can result in bone resorption and spontaneous fractures.
Vitamin D3 could also be inadequate, but this is less likely if the animals are housed where they can get some sunlight.
***PowerLecture: Musculoskeletal Diseases
This 2-year old pot belly pig in the picture presents for eating a box of cooking salt. It is very thirsty at presentation, but otherwise clinically normal. Its blood sodium concentration is 175 mEq/dl. What is the best treatment for this pig?
- Send the pig home and have the owner bring the pig back if it starts to show neurologic signs
- Give Normosol R IV slowly to decrease the blood sodium concentration
- Give IV diazepam to suppress seizures and wait for the excess salt to be excreted by the kidneys
- Give unlimited amounts of drinking water
- Give a bolus of 50ml/kg of D5W (5% dextrose in sterile water) as an intravenous infusion to quickly lower the blood sodium concentration
Answer: Give Normosol R IV slowly to decrease the blood sodium concentration
Explanation
The correct answer is to administer Normosol R IV slowly to decrease the blood sodium concentration. Salt poisoning in pigs occurs as a consequence of water deprivation (reduced amount of free water in the animal), or too much salt intake. When the blood sodium concentration is too high, water from the brain diffuses into the vasculature. The brain responds by forming hyperosmolar (idiogenic osmoles) particles to draw water back into the brain to prevent dehydration of its cells. Giving large amounts of free water in the form of drinking water or as a bolus of D5W intravenously will quickly drop the blood sodium concentration, causing a large amount of water to diffuse into the brain cells due to the hyperosmolar particles formed. Cerebral edema then ensues and neurologic signs result. Treatment should be aimed at slowly decreasing blood sodium concentration by about 1 meq/hr to prevent cerebral edema. This is best done by using a replacement fluid that approximates normal levels of sodium so as to not create too large of an osmotic gradient. Pigs showing clinical signs of brain disease usually die despite treatment.
***PowerLecture: Neurologic Diseases
A herd of pigs is presented for various reasons; some pigs have been found suddenly dead with no other apparent clinical signs. Some animals are febrile, lethargic, unable to rise, and have multifocal diamond-shaped skin lesions over their bodies. Some animals have swollen, painful hocks and carpi. What is the most likely causative agent/diagnosis?
- Swine pox
- Erysipelothrix rhusiopathiae
- Lawsonia intracellularis
- E. coli
- Mycoplasma hyosynoviae
Answer: Erysipelothrix rhusiopathiae
Explanation
The correct answer is Erysipelothrix rhusiopathiae. There are 3 forms of erysipelas. In the peracute form, pigs are found suddenly dead with no other clinical signs. In the acute form, the pigs become lethargic, painful in their joints, anorexic, and develop diamond-shaped skin lesions. In the chronic form, the arthritis progresses to the vertebral joints and the limb joints may fuse. All three forms of the disease can appear in a herd, particularly if there is noncompliance of vaccination of the herd and if treatment is delayed. The diamond-shaped skin lesions are pathognomonic for the disease.
***PowerLecture: Multisystemic Diseases
A litter of 2-week old piglets is presented for incoordination, salivation, opisthotonos, and seizures. You suspect pseudorabies and perform virus isolation to confirm your diagnosis. How will you treat these piglets?
- Treat the piglets with penicillin for secondary bacterial infections and wait for the viral infection to clear
- Vaccinate the piglets and then repeat vaccinations again 3 weeks later
- There is no treatment for these piglets; herd needs to be depopulated.
- No treatment is needed; the piglets will clear the infection on their own in about a week
Answer: There is no treatment for these piglets; herd needs to be depopulated.
Explanation
The correct answer is there is no treatment for these piglets. Currently, all commercial US swine production is free of pseudorabies and therefore a confirmed diagnosis would require the immediate depopulation of the herd. Mortality in piglets this young with pseudorabies is near 100%. Piglets less than 3 weeks of age infected with pseudorabies often die in 1-3 days. Clinical signs include fever, anorexia, vomiting, blindness, convulsions, and neurologic signs. Pigs 3-9 weeks old have similar signs but their mortality rate is much lower. They also commonly show respiratory signs such as sneezing, nasal discharge, and coughing. Pigs older than 10 weeks infected with pseudorabies are more commonly affected with respiratory signs but may show CNS signs. Most of these pigs will recover in 7-10 days. Pregnant sows infected with the virus have reproductive failure including abortion, fetal resorption, and fetal mummification.
**PowerPage Pseudorabies
**PowerLecture: Multisystemic Diseases
Which of the following statements is true about pseudorabies in pigs?
- Older pigs with the disease show respiratory clinical signs such as sneezing, nasal discharge, and coughing
- Neonatal piglets affected with pseudorabies do not show neurologic signs
- Older pigs with the disease usually show neurologic signs such as prostration, paddling, and convulsions
- Pseudorabies does not affect pregnant sows
Answer: Older pigs with the disease show respiratory clinical signs such as sneezing, nasal discharge, and coughing
Explanation
The correct answer is older pigs with the disease show respiratory clinical signs such as sneezing, nasal discharge, and coughing. Pseudorabies in young nursing piglets tends to cause neurologic signs such as incoordination, tremors, blindness, paddling, coma, and death. Weaned pigs may have both neurologic signs and respiratory signs such as sneezing, nasal discharge, and coughing. Older pigs tend to only have respiratory signs. Pregnant sows affected with the virus often have reproductive failure.
**PowerPage: Pseudorabies
**PowerLecture: Multisystemic Diseases
A local farmer calls you because they are having reproductive problems in their 600 head sow farm. For the past month they have been having trouble with sows not becoming pregnant. The heat cycles in about 20% of the sows have been quite unusual. These sows seem to be in heat for 5-6 days. They have been breeding them once a day as long as they are in heat. Their semen costs are getting out of hand and their 30 day pregnancy check for the past 2 weeks has only been 60%. Gilts appear to be affected more severely. Some gilts even seem to be in heat all the time.
The farmer knows they had been busy emptying the manure pit and spreading manure on nearby fields most of last week which has changed their usual time for heat checking sows. This week they went back to their normal breeding schedule but are still having problems. What would you recommend they do next?
- Collect nasal swabs from 10 affected sows for influenza virus testing
- Collect gestation and lactation feed samples for mycotoxin testing
- Collect blood samples for 20 sows (10 affected and 10 non-affected) for parvovirus testing
- Collect a water sample for nitrogen testing
- Collect a urine sample for leptospirosis testing
Answer: Collect gestation and lactation feed samples for mycotoxin testing
Explanation
The correct answer is to collect gestation and lactation feed samples for mycotoxin testing; specifically zearalenone testing. The indications of a prolonged heat cycle suggest high estrogens. This is a case of cystic ovarian disease. High levels of zearalenone mycotoxins in the feed are the most common cause of cystic ovaries in swine. Although, parvovirus causes reproductive problems, it usually causes a high incidence of mummies. Leptospirosis manifests as late term abortions. Influenza virus infections cause an acute respiratory outbreak with high fevers and abortions. Clinical signs associated with nitrate poisoning include high respiration rate, increased incidence of diarrhea, reduced feed intake, poor growth, and increased abortions.
You receive a call from a local farmer who is having trouble with a gilt farrowing. This is a small producer with just 20 sows. This is the last gilt to farrow in the group. No other gilts have had any problems. The gilt started farrowing 3 hours ago. So far she has had 8 pigs born alive and 1 stillborn. The gilt seems to be straining for the past 15-30 minutes but nothing has come out. He performed a vaginal exam and “armed” her and is not able to feel anything in the birth canal. No fetal membranes have been passed. What should you tell the farmer to do next?
- Do nothing
- Give prostaglandins and recheck in 10 minutes
- Go to the farm and manually extract pigs from birth canal
- Go to the farm and perform a C-section
- Give oxytocin and recheck the gilt in 20 minutes
Answer: Give oxytocin and recheck the gilt in 20 minutes
Explanation
The correct answer is to give oxytocin and recheck the gilt in 20 minutes. The normal duration of farrowing ranges from 1.5 - 4.5 hours with an average interval between pigs of 15 - 20 min.
In this case the fact that the farmer did a vaginal exam and “armed” her tells you there are no pigs in the birth canal and thus manual extraction is not possible at this time.
Prostaglandins causes luteolysis of the corpora lutea and release of relaxin, which causes relaxation of the birth canal and cervix and is primarily used to induce parturition, not to assist in dystocia. The indications that the gilt has been straining with no fetal membranes passed suggest she is not done.
Gilts traditionally have smaller litter sizes than sows. Her current numbers of 8 born alive and 1 stillborn make it difficult to know if there are any more pigs left in her or not. On average sows today will have 11 -13 pigs born alive per farrowing. The gilt has been farrowing for only 3 hours and there are no pigs stuck in the birth canal so there are no indications that a C-section is necessary at this time. Oxytocin is very effective in creating uterine contractions. The best option at this time is to administer the oxytocin and recheck the gilt in 20 minutes.
You have been called to a farm to fix several rectal prolapses in a group of 60 lb pigs. The pigs are not coughing and you notice that several of the gilts in the group also have reddened and enlarged vulvas. What could be causing both problems?
- Zearalenone
- Salmonellosis
- Low Ca to P ratio in the feed
- Genetic predisposition
- Aflatoxins
Answer: Zearalenone
Explanation
The correct answer is zearalenone. The estrogenic effect of this mycotoxin causes edema of the vulva and sometimes edema of the rectum, predisposing to rectal prolapses. While some have suggested a genetic predisposition for rectal prolapse, there is not yet substantial evidence to prove this; additionally, genetic factors would not explain the enlarged reddened vulvas.
Calcium and phosphorus balance has no effect on either of the clinical presentations described. Severe diarrhea caused by salmonellosis can lead to rectal prolapses, but systemic manifestations such as diarrhea or coughing would likely be present as well.
Which of the following mycotoxins can cause hyperestrogenism and pseudopregnancy in pigs?
- Zearalenone
- Ochratoxin
- Aflatoxin
- Fumonisin
- Ergot
Answer: Zearalenone
Explanation
Zearalenone is a potent estrogenic metabolite produced by some Fusarium species. Young gilts will be most affected. Young boars will also have reduced libido.
You receive a report from your diagnostic submission on a pig with diarrhea that reveals serotype B Salmonella. Which of the following Salmonella would you be concern of?
- Salmonella typhimurium
- Salmonella choleraesuis
- Salmonella enteritidis
- Salmonella dublin
- Salmonella newport
Answer: Salmonella typhimurium
Explanation
The correct answer is Salmonella typhimurium. It is important to know serotypes as actual speciation of Salmonella usually requires submission to the national veterinary laboratory and takes several weeks to complete. Knowing serotypes allows you to start considering the possible significance of the isolate. The serotypes for the other Salmonella are as follows: Dublin and Enteritidis (D), Choleraesuis (C1), and Newport (C2). Salmonella enteritidis is specific to poultry.
Which of the following is true about eperythrozoonosis in pigs?
- It is often associated with anemia, fever, icterus, and reproductive failure
- Transmission of the disease is by direct contact and aerosol
- Clinical signs in adult pigs are more severe than in younger pigs
- Vaccinations in piglets are effective in preventing the disease
- Affected animals should be culled from the herd and slaughtered
Answer: It is often associated with anemia, fever, icterus, and reproductive failure
Explanation
The correct answer is it is often associated with anemia, fever, icterus, and reproductive failure.
Eperythrozoonosis in pigs is caused by Mycoplasma suis (previously called Eperythrozoon suis), a disease vectored by biting insects. Clinical signs include anorexia, weakness, anemia, icterus, and reproductive failure.
Younger pigs are more severely affected than older pigs.
The treatment of choice for the disease is tetracycline antibiotics.
Vaccines are not available for the disease.
***PowerLecture: Miscellaneous Diseases of Pigs.
A litter of 3-week old piglets is presented for shifting leg lameness. They have warm swollen joints in all legs, a temperature of 107.OF (41.7 C), and are dyspneic. Necropsy of one dead animal shows fibrinopurulent pleuritis and peritonitis. What is the most likely diagnosis?
- Erysipelothrix rhusiopathiae
- Mycoplasma hyosynoviae
- Osteochondrosis
- Glaesserella parasuis
Answer: Glaesserella parasuis
Explanation
Glasserella parasuis (formerly named Haemophilus parasuis) causes Glasser’s disease, which is usually characterized by sudden death but can often also lead to painful joints, pneumonia, and occasionally neurologic signs. Lesions show fibrinopurulent pleuritis, pericarditis, and peritonitis. Meningitis is usually responsible for the cause of neurologic signs and seizures. This disease most commonly affects piglets from 2 weeks to 4 months of age. Morbidity rate can reach up to 50-75% and mortality rate up to 10%.
Erysipelas typically occurs in grower and finisher pigs and does not result in pneumonia. Diamond-shaped skin lesions (thus the name “diamond skin disease”) are pathognomonic for erysipelas. Mycoplasma hyosynoviae and osteochondrosis do not cause fever, pneumonia, or neurologic signs, and occur mainly in growers and finishers.
***PowerLecture: Multisystemic Diseases
A large swine herd has recently been experiencing coughing in the feeder pigs and a few sows. A few have fevers and inappetence but most remain normal in appearance, however the weight gains in the feeder pigs have slowed and the owner is concerned. A post-mortem reveals purple to gray areas of consolidation in the cranio-ventral lungs, with a catarrhal exudate in the airways and enlarged regional lymph nodes. You identify Mycoplasma hyopneumoniae in the lungs. What is the most cost effective approach to controlling this agent?
- Vaccination against M. hyopneumoniae
- Improve biosecurity, as this agent is brought in by rodents
- Cull all pigs and start over with specific pathogen free pigs
- Eliminate carriers by test and slaughter
- Treat all pigs with procaine penicillin for 3 days
Answer: Vaccination against M. hyopneumoniae
Explanation
Vaccines are effective and widely used in the US to control this disease. Air quality, ambient temperature, and ventilation must also be addressed. Because mycoplasmas do not have cell walls, treatment with penicillin is not effective.
***PowerLecture: Respiratory Diseases
What is the causative agent of blue eye in swine?
- Paramyxovirus
- Adenovirus
- Picornavirus
- Rotavirus
Answer: ** Paramyxovirus**
Explanation
The correct answer is blue eye paramyxovirus or rubulavirus.
A herd of pigs is presented for a sudden onset of respiratory distress with open mouthed breathing and frothy, pink, oral and nasal discharge. The pigs are lethargic, anorexic, and have a temperature of 106.OF (41.1 C). Pigs less than 6 months of age are mainly affected, but a few adults are showing clinical signs as well. What is the most likely diagnosis?
- Swine influenza
- Mycoplasma pneumonia
- Atrophic rhinitis
- Pleuropneumonia
Answer: Pleuropneumonia
Explanation
The correct answer is pleuropneumonia. Pleuropneumonia in pigs is caused by Actinobacillus pleuropneumoniae, a gram negative coccobacillus. The clinical signs described in the question are typical of pleuropneumonia. The disease has a rapid onset and primarily affects young pigs. The pneumonia is characterized by fibrinonecrotic and hemorrhagic lung lesions. Concurrent infections with Mycoplasma, Pasteurella, porcine reproductive and respiratory syndrome virus, or swine influenza virus are common.
Atrophic rhinitis is characterized by sneezing, coughing, lacrimation, and occurs most commonly in pigs 3-8 weeks of age. Mycoplasma pneumonia or enzootic pneumonia is characterized by a persistent dry cough.
Swine influenza can be differentiated from pleuropneumonia because swine influenza affects pigs of all ages in the herd and does not result in discharge of blood-tinged oral and nasal froth.
***PowerLecture: Respiratory Diseases
Which of the following causes reproductive failure in pigs by an ascending infection of the reproductive tract?
- Leptospira interrogans
- Parvovirus
- Toxoplasma
- E. coli
- Eperythrozoon suis
Answer: E. coli
Explanation
The correct answer is E. coli. Other infectious agents that ascend the reproductive tract causing metritis and reproductive failure in pigs include Streptococci, Staphylococci, Actinomyces spp., Pseudomonas spp., etc. The other answer choices listed cause reproductive failure via systemic infections. Other systemic agents causing reproductive failure include PRRS, pseudorabies, brucellosis, etc.
***PowerLecture: Reproduction
Farrowing crates do not allow females of which species below to engage in nesting behaviors:
- Cattle
- Rats
- Poultry
- Horses
- Pigs
Answer: Pigs
Explanation
Farrowing crates are utilized in pig production.
You receive a report from your diagnostic submission on a pig with diarrhea that reveals serotype B Salmonella. Which of the following Salmonella would you be concern of?
- Salmonella dublin
- Salmonella newport
- Salmonella choleraesuis
- Salmonella enteritidis
- Salmonella typhimurium
Answer: Salmonella typhimurium
Explanation
The correct answer is Salmonella typhimurium. It is important to know serotypes as actual speciation of Salmonella usually requires submission to the national veterinary laboratory and takes several weeks to complete. Knowing serotypes allows you to start considering the possible significance of the isolate. The serotypes for the other Salmonella are as follows: Dublin and Enteritidis (D), Choleraesuis (C1), and Newport (C2). Salmonella enteritidis is specific to poultry.
A pig infected with Trichuris suis will show which of the following clinical signs?
- Dyspnea
- Head tilt
- Evidence of liver disease
- Mucoid diarrhea
- Productive cough
Answer: Mucoid diarrhea
Explanation
The correct answer is mucoid diarrhea. Trichuris suis is the whipworm of pigs. It typically affects older, weaned pigs. It penetrates the mucosa and submucosa of the cecum and colon, causing a large bowel diarrhea, sometimes with blood. Diagnosis can be made by finding the worms on necropsy or by finding the ova on fecal flotation. The disease can be controlled well by keeping pigs off pasture, or by avoiding exposure to contaminated pastures. Anthelmintic drugs are effective.
**PowerLecture: Gastrointestinal Diseases
You are called to a farm that is experiencing sudden death in a group of pigs that are scheduled to go to market in 10 days. Upon performing a necropsy, you find large amounts of blood in the small intestine and spiral colon. The blood is red and clotted. There is no gross thickening of the intestinal mucosa. Your diagnosis is which of the following?
- Hemorrhagic bowel syndrome
- Stomach ulcer
- Erysipelas rhusiopathiae
- Acute ileitis
- Intestinal torsion
Answer: Acute ileitis
Explanation
The correct answer is Acute ileitis or proliferative hemorrhagic enteropathy or PHE caused by Lawsonia intracellularis. The name PHE can be deceiving as its acute nature does not always allow for gross evidence of proliferation. Lesion location in the small intestines as well as indications of red clotted blood is almost pathognomonic for the condition. Hemorrhagic bowel syndrome and intestinal torsion are not associated with intraluminal coagulated blood on necropsy. Digested blood is a sequelae to stomach ulcers. Erysipelas does not cause enteric pathology.
While visiting a porcine operation, the managers ask you about several pigs that have been sporadically dying. You examine several live pigs in the group and notice no immediate abnormalities other than occasional coughing. At that point, you tell them you are unsure of the cause of sporadic death and you would like them to give you a pig for necropsy next time one of them dies. As it happens, you are delivered a pig for necropsy a week later. At the time of necropsy the most significant findings were white spots on the liver and an intestinal obstruction of large 20-40cm worms in the small intestine which were likely the cause of death (see image). With what medication should you treat the rest of the pigs?
- Metronidazole
- Fenbendazole
- Flumazenil
- Sulfamethazine
- Fluconazole
Answer: Fenbendazole
Explanation
The necropsy findings are consistent with an infection of Ascaris suum. This is the roundworm of pigs. These little worms have the ability to occasionally cause intestinal obstruction in large infestations. They can also migrate into the bile ducts and liver, causing characteristic “milk spots” on the liver.
In the A. suum life cycle, the pig ingests an egg with an L2 larva inside, which then undergoes hepatic migration (milk spots), migrates to the lungs and becomes an L3 larva, enters the alveoli and finally gets coughed up. The larval migration can sometimes cause rapid shallow breathing that many refer to as “thumps”.
Diagnosis is by fecal flotation and clinical signs for the most part. Treatment options are wide and include ivermectin, fenbendazole, pyrantel, levamisole and other ascaracides.
Fenbendazole is a benzimidazole anthelmintic with a broad spectrum against many gastrointestinal parasites such as roundworms, hookworms, whipworms, pinworms, and strongyles.
Metronidazole is an antibiotic with a mainly anaerobic spectrum. It is also useful in the treatment of certain parasites such as giardia. Fluconazole is an antifungal and commonly used to treat coccidiodomycosis in small animals. Flumazenil is a reversal for benzodiazepines. Sulfamethazine is an antibiotic that has been used in the treatment of coccidiosis in pigs.
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?
- Dip the pig daily in toxaphene
- Use corticosteroids to stop the itching, as all the skin damage is due to scratching
- No treatment is necessary, as Sarcoptes spontaneously die after 3 weeks and the animal heals
- Treat pig for lice
- Treat the pig for mange
Answer: Treat the pig for mange
Explanation
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.
***PowerLecture: Dermatology
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?
- Immediately vaccinate remaining pigs for salmonella
- Immediately treat all remaining pigs with ceftiofur
- Treat all pigs with tylosin in the water
- Check intestinal content for clotted blood
- Collect two feed samples (one from affected group and one from non-affected group)
Answer: Check intestinal content for clotted blood
Explanation
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.
You have arrived at an lowa farm with an acute outbreak. The farmer has lost 25 pigs in the last two days. The pigs are all from the same building and are from a group of 950 four-week old pigs. The pigs arrived on the farm approximately 8 days ago. Upon arrival to the farm, you perform a necropsy on 8 out of the 20 dead pigs available. Seven of the first eight pigs you necropsy have lesions similar to those seen on the attached photo. You then perform a quick walkthrough of the building and do not identify any other sick pigs. What should you do next?
- Have the feed company add 400g per ton of chlortetracycline to the next batch of feed
- Have the owner inject all remaining pigs in the building with ceftiour
- Select five non-treated, acute live pigs from the rest of the group to euthanize and collect samples for a diagnostic workup
- Continue performing a necropsy on the remaining 12 dead pigs
Answer: **
Explanation
The correct answer is to have the owner inject all remaining pigs in the building with ceftiofur. The photograph depicts a classical presentation for polyserositis. The top two differentials for polyserositis in four week old pigs would be Streptococcus suis and Glasserella parasuis. Because of the high mortality in only two days, Glasserella parasuis would be your top differential and suggests a true emergency situation. As seen in the case history, many times the rest of the pigs appear to be normal. The only way to try and stop the outbreak is to inject all pigs ASAP. Although adding 400g per ton of chlortetracycline may be effective in preventing an outbreak, it is not the correct choice at the time of an outbreak. Feed delivery may be a week away, and even if feed could be delivered that same day, it would take three or four days before the pigs would get enough antibiotic via the feed. Immediate action is critical. There is no need to necropsy additional pigs, as a pattern has already been established. It is practically impossible to find an acute live pig in cases of Glasserella parasuis outbreaks; pigs are usually just found dead.
Note: ceftiofur is not as commonly used in Canada and should be used following confirmatory results on a bacterial culture/sensitivity.
***PowerLecture: Multisystemic Diseases
