Yersinia Infection in Guinea Pigs

By PetMD Editorial on Jul. 22, 2010

Yersiniosis in Guinea Pigs

Yersiniosis is the term used for an infectious condition that arises when a guinea pig has been exposed to the bacteria Yersinia pseudotuberculosis. Transmission of the yersinia infection can occur through contact with contaminated food, bedding and other materials, though contact or incidental ingestion of infected urine or feces, through inhalation of airborne yersinia cells, or the bacteria can enter the body through otherwise minor cuts or scrapes in the skin. From the time of the initial infection to the full blown disease condition, the illness may take several courses. Once the infection has taken a strong hold, the general outcome of Yersinia infection in guinea pigs is poor.

Yersinia infection can spread quickly and diagnosis can be quite difficult as the guinea pig exhibits no specific signs early in the disease process, and blood tests would be needed to confirm that the guinea pig is indeed suffering from yersiniosis. Without symptoms, there is often no reason to suspect a problem requiring veterinary treatment, allowing the bacteria the opportunity to spread throughout the body. Often, once the infection has been found and diagnosed conclusively, treatment is not a viable option. It is therefore important to tale steps to preventing yersiniosis from arising in the first place.

Symptoms and Types

In some cases, an infected guinea pig will be infected without showing symptoms of yersinia infection. Other times the guinea pig will display signs and symptoms such as:

  • Swollen lymph nodes in the neck or shoulder
  • Diarrhea
  • Weight loss
  • Bacteria in the bloodstream (bacteremia) and cause sudden death (if not treated quickly) 


Infection with Yersinia pseudotuberculosis bacteria may come about through contaminated food, bedding, or water. The Yersinia bacteria can also enter a guinea pig's body through cuts or scrapes in the skin, or through inhalation of airborne yersinia cells.


A complete blood profile, urinalysis, and physical examination will be conducted. Your veterinarian may be able to make an initial diagnosis based on the outward symptoms your guinea pig is showing. If the infection became apparent at too late a stage, and your guinea pig suffers a sudden death, postmortem observations can be made on the physical manifestations (like swollen lymph nodes), so that your veterinarian can determine whether the death was the result of yersiniosis. Further postmortem tests will determine if you need to take immediate preventative actions with your surviving guinea pigs.


Oral or injectable antibiotics, along with other supportive therapy, may be administered but the outcome is usually not good. Treatment for yersiniosis is not a viable option in many guinea pigs.

Living and Management

Though the general outcome of guinea pigs infected with yersiniosis is poor, all recovering guinea pigs must be placed in a clean environment. Clean and disinfect the cages before allowing the guinea pig to go back inside them. Make sure to provide fresh and clean drinking water and fresh, balanced foods. Do not allow the recovering guinea pig to come into contact with other animals, and follow the supportive care as advised by your veterinarian.



Yersinia infection is recognized as a relatively common infection in small animals such as guinea pigs, so it is important to take steps to prevent the infection from occurring in the first place. To prevent yersinia infection, improved general guinea pig husbandry and sanitation are required. Disinfection practices should be intensified to eliminate all bacteria from the cage flooring, bedding materials, food dishes, and anything else your guinea pigs come into contact with. Most owners are advised to have all the infected guinea pigs euthanized, as well as those that have been in contact with the infected guinea pigs, to prevent spread of Yersinia infection.

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