’Tis the Season for Swine Respiratory Diseases: Tips for Diagnosis

( SDSU Extension )

Severe weather changes can often trigger disease outbreaks in swine. To aid in determining a diagnosis, Dale Miskimins, DVM, a pathologist in the South Dakota State University Veterinary and Biomedical Sciences Department, offers a few tips to help producers get to the root of the problem.

When it comes time to send in diagnostic samples, choose animals, both live and dead acutely affected pigs, that are untreated whenever possible. If animals can’t be submitted, he suggests choosing these tissue samples: tonsil, trachea-affected lung and mediastinal lymph nodes. If lung lesions vary, include several pieces of lung. Put duplicate pieces in 10% formalin. 

Filling out the correct diagnostic laboratory forms will help lab diagnosticians and speed up the process. Always identify tissue containers, especially if they are from different ages, pens or barns, he advises.

“Respiratory disease is often a combination of viral and bacterial agents,” Miskimins says. “The laboratory will do appropriate testing to sort out problems. The workup will most likely include necropsy by a veterinary pathologist, histopathology, bacteriology, virology and molecular diagnostics (PCR testing).”

Common Viral Agents
The most common viral agents include:
•    Porcine reproductive and respiratory syndrome virus (PRRSV)
•    Swine influenza virus (SIV)
•    Type 2 circovirus (PCV 2)

Common Bacterial Agents
The most common bacterial agents include:
•    Pasteurella multocida
•    Streptococcus suis
•    Haemophilus parasuis
•    Mycoplasma hyopneumoniae
•    Mycoplasma hyorhinis

“A complete investigation will help both you and your veterinarian identify causes of respiratory disease, limit losses and return your operation to better health,” Miskimins says.

If you have questions on sampling, contact your local diagnostic laboratory.

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