Swine Infectious Diseases Flashcards
- Herpes virus
- Young neonates: CNS sings, anorexia, tremors,in coordination, blindness, paddling.
- Morbidity, mortality: 100%.
- Weaned pigs: Respiratory: coughing, dyspnea. Mortality much lower.
- Grower and Finisher: Coughing, sneezing, nasal discharge.
- Older: respiratory signs, reproductive failure. No CNS signs.
- No treatment. Older can recover. Vaccines available.
Pseudorabies
Aujesky’s disease
- Control: Vaccination
- Control also air quality, ambient temperature, and ventilation
- No cell walls and penicillin is not effective
- Feeder pigs, and sows. Fevers, inapetente
- Post mortem: purple to gray areas of consolidation in the cranio-ventral lungs, with catarrhal exudate in the airways and enlarged regional lymph nodes.
- Attach to and disrupt the pulmonary mucociliary apparatus preventing from functioning properly = lungs more susceptible to other bacterial infection
- Coughing in the feeder pigs and few sows.
- Fevers, inappetence,most remain normal in appearance.
- Weight gains slowed.
- Post-mortem: Purple to gray areas of consolidation in cranio-ventral lungs. Catarrhal exudate in the airways and n larger regional lymph nodes
Mycoplasma hyopeumoniae
A post-weaned piglet presents with sudden onset of fever, ataxia, and lateral recumbency. Neurological examination reveals nystagmus and paddling movements. The piglet was previously healthy, and other piglets in the same cohort have shown similar signs, with some experiencing sudden death. What is the most likely diagnosis, and which diagnostic method would confirm this condition?
A. Streptococcus suis infection; confirm by bacterial culture of cerebrospinal fluid.
B. Haemophilus parasuis infection; confirm by PCR of nasal swabs.
C. Erysipelothrix rhusiopathiae infection; confirm by culture of skin lesions.
D. Mycoplasma hyorhinis infection; confirm by serology.
Answer: A. Streptococcus suis infection; confirm by bacterial culture of cerebrospinal fluid.
Explanation: The clinical signs of fever, ataxia, lateral recumbency, nystagmus, and paddling movements in a post-weaned piglet are indicative of meningitis, commonly caused by Streptococcus suis. This pathogen is a significant cause of bacterial mortality in post-weaned piglets, leading to septicemia, meningitis, arthritis, and endocarditis. Diagnosis is confirmed by isolating the bacterium through bacterial culture of cerebrospinal fluid or other affected tissues.
In a swine herd, several piglets exhibit swollen joints, lameness, and reluctance to move. Some piglets also show signs of fever and depression. Upon necropsy of a deceased piglet, fibrinopurulent exudate is observed in the joints. Which pathogen is most likely responsible for these clinical signs, and what is the typical treatment approach?
A. Streptococcus suis; treat with beta-lactam antimicrobials such as penicillin or amoxicillin.
B. Mycoplasma hyosynoviae; treat with tetracyclines.
C. Erysipelothrix rhusiopathiae; treat with antiserum and penicillin.
D. Haemophilus parasuis; treat with ceftiofur.
Answer: A. Streptococcus suis; treat with beta-lactam antimicrobials such as penicillin or amoxicillin.
Explanation:
The presentation of swollen joints, lameness, fever, and fibrinopurulent exudate in the joints is consistent with arthritis caused by Streptococcus suis. This bacterium can lead to septicemia, meningitis, arthritis, and endocarditis in pigs. S. suis is usually susceptible to beta-lactam antimicrobials, with penicillin and amoxicillin being the treatments of choice. Early intervention is crucial for effective management.
A pig farmer reports sudden deaths in recently weaned piglets. Affected piglets had exhibited signs of depression and high fever shortly before death. Post-mortem examination reveals hemorrhages on multiple organs and splenomegaly. Considering the clinical presentation and post-mortem findings, which disease should be suspected, and what preventive measures can be implemented to control its spread?
A. Streptococcus suis septicemia; implement strict biosecurity measures and consider autogenous vaccination.
B. Actinobacillus pleuropneumoniae infection; improve ventilation and reduce stocking density.
C. Salmonella choleraesuis infection; administer in-feed antibiotics and enhance hygiene.
D. Haemophilus parasuis infection; provide prophylactic antibiotics and minimize stress.
Answer: A. Streptococcus suis septicemia; implement strict biosecurity measures and consider autogenous vaccination.
Explanation:
The sudden deaths of recently weaned piglets, preceded by depression and high fever, along with post-mortem findings of hemorrhages and splenomegaly, suggest septicemia caused by Streptococcus suis. To control the spread, strict biosecurity measures should be enforced, including isolating affected animals, sanitizing equipment, and controlling human traffic. There is no universal commercial vaccine available; however, autogenous vaccines, prepared from isolates obtained from the affected herd, have been used with varying success.
A swine farm reports multiple pigs exhibiting high fever, lethargy, and yellowish diarrhea. Some pigs show purple discoloration of the ears and lower abdomen. Neurological signs such as ataxia and convulsions are also observed. Several sows have experienced abortions recently. What is the most likely diagnosis, and which diagnostic tests are appropriate to confirm this disease?
A. African Swine Fever; confirm with PCR and virus isolation.
B. Classical Swine Fever; confirm with RT-qPCR assay and virus isolation.
C. Porcine Reproductive and Respiratory Syndrome; confirm with ELISA and virus isolation.
D. Swine Influenza; confirm with RT-PCR and hemagglutination inhibition assay.
Answer: B. Classical Swine Fever; confirm with RT-qPCR assay and virus isolation.
Explanation:
The clinical signs of high fever, lethargy, yellowish diarrhea, purple skin discoloration, neurological manifestations, and reproductive failures are indicative of Classical Swine Fever (CSF).
CSF is a highly infectious viral disease caused by the Classical Swine Fever Virus (CSFV), affecting domestic and wild pigs. Diagnostic confirmation involves detecting the virus using reverse transcription quantitative PCR (RT-qPCR) assays and virus isolation techniques. Serological tests such as ELISA can detect antibodies against CSFV, but molecular methods are preferred for early detection.
In a region previously free from Classical Swine Fever, a sudden outbreak occurs with pigs showing signs of fever, hemorrhages, and high mortality. Investigation reveals that the farm recently incorporated uncooked pork products into the swine feed. What is the most likely source of the outbreak, and what control measures should be implemented to prevent further spread?
A. Introduction of infected live pigs; implement quarantine and culling.
B. Contaminated water supply; ensure water purification and sanitation.
C. Feeding uncooked pork products; cease feeding swill and enforce proper cooking of feed.
D. Airborne transmission from neighboring farms; establish air filtration systems.
Answer: C. Feeding uncooked pork products; cease feeding swill and enforce proper cooking of feed.
Explanation:
Classical Swine Fever Virus (CSFV) can survive in uncooked pork products, and feeding swine with contaminated swill is a common route of transmission.
To prevent outbreaks, it is crucial to prohibit the feeding of uncooked pork products to pigs. Implementing strict biosecurity measures, including proper cooking of swill and monitoring feed sources, is essential to control the spread of CSF. In regions free from CSF, vaccination is not typically practiced; instead, rapid detection, quarantine, and depopulation of affected herds are standard control measures.
A pig farm in an area where Classical Swine Fever is endemic reports pigs with chronic diarrhea, weight loss, and poor reproductive performance. Some piglets are born with congenital tremors. Considering the endemic nature of the disease, what preventive strategy is most appropriate to manage and control Classical Swine Fever in this scenario?
A. Implement strict biosecurity measures and avoid vaccination.
B. Regularly vaccinate the herd with live attenuated vaccines.
C. Administer antibiotics to prevent secondary infections.
D. Cull all affected animals and refrain from restocking.
Answer: B. Regularly vaccinate the herd with live attenuated vaccines.
Explanation:
In regions where Classical Swine Fever (CSF) is endemic, vaccination with live attenuated vaccines is a common preventive strategy to control the disease.
Systematic vaccination can lead to the elimination of CSFV from swine herds by reducing virus circulation and preventing clinical disease. In addition to vaccination, maintaining strict biosecurity measures is essential to prevent the introduction and spread of the virus. In countries free from CSF, vaccination is not practiced; instead, control relies on rapid detection, quarantine, and depopulation of affected herds.
A group of 12-week-old pigs presents with sudden onset of diarrhea. The feces are loose to watery and have a reddish-brown tint. Some pigs exhibit weight loss and poor body condition. Upon necropsy, the ileum shows marked thickening of the intestinal wall with a corrugated appearance. What is the most likely diagnosis, and which diagnostic method would confirm this condition?
A. Swine Dysentery; confirm with culture and PCR for Brachyspira hyodysenteriae.
B. Porcine Proliferative Enteropathy; confirm with histopathology and PCR for Lawsonia intracellularis.
C. Salmonellosis; confirm with bacterial culture and serotyping.
D. Trichuriasis; confirm with fecal flotation for Trichuris suis eggs.
Answer: B. Porcine Proliferative Enteropathy; confirm with histopathology and PCR for Lawsonia intracellularis.
Explanation:
The clinical signs of sudden onset diarrhea with reddish-brown feces, weight loss, and poor body condition in 12-week-old pigs are indicative of Porcine Proliferative Enteropathy (PPE), also known as ileitis. Necropsy findings of thickened and corrugated ileal mucosa further support this diagnosis. PPE is caused by Lawsonia intracellularis, an intracellular, gram-negative bacterium. Definitive diagnosis is achieved through histopathologic examination revealing characteristic mucosal hyperplasia and detection of the organism via PCR or immunohistochemistry.
Several finishing pigs exhibit sudden death without prior clinical signs. On necropsy, the small intestine, particularly the ileum, displays marked thickening with a fibrinonecrotic membrane and clotted blood within the lumen. Which form of Porcine Proliferative Enteropathy is most likely responsible for these findings, and what is the typical age group affected?
A. Nonhemorrhagic form; pigs weighing 18–36 kg (40–80 lb).
B. Hemorrhagic form; pigs weighing 18–36 kg (40–80 lb).
C. Nonhemorrhagic form; pigs weighing over 70 kg (154 lb).
D. Hemorrhagic form; pigs weighing over 70 kg (154 lb).
Answer: D. Hemorrhagic form; pigs weighing over 70 kg (154 lb).
Explanation:
The hemorrhagic form of Porcine Proliferative Enteropathy (PPE) is characterized by sudden death, often without prior clinical signs. Necropsy findings include thickened intestinal walls with fibrinonecrotic membranes and clotted blood within the lumen, particularly in the ileum. This form typically affects older pigs, usually those weighing over 70 kg (154 lb). In contrast, the nonhemorrhagic form commonly affects younger pigs weighing 18–36 kg (40–80 lb) and presents with diarrhea and poor growth.
A swine herd experiences an outbreak of diarrhea among growing pigs. The attending veterinarian suspects Porcine Proliferative Enteropathy and considers treatment options. Which antimicrobial therapy is appropriate for managing this condition, and what additional control measure can enhance herd immunity?
A. Tetracyclines; implement strict biosecurity measures.
B. Macrolides; administer a commercial vaccine against Lawsonia intracellularis.
C. Aminoglycosides; improve sanitation and hygiene.
D. Fluoroquinolones; provide supportive care and electrolytes.
Answer: B. Macrolides; administer a commercial vaccine against Lawsonia intracellularis.
Explanation:
Porcine Proliferative Enteropathy (PPE) is commonly treated with antimicrobials effective against Lawsonia intracellularis, such as macrolides (e.g., tylosin) or pleuromutilins (e.g., tiamulin). In addition to antimicrobial therapy, vaccination with a commercial vaccine against L. intracellularis can enhance herd immunity and reduce the incidence and severity of the disease. Implementing both treatment and preventive measures is crucial for effective control of PPE in swine herds.
