Todayโs path rounds are on ๐๐ฒ๐ณ๐ณ๐๐ซ’๐ฌ ๐๐ข๐ฌ๐๐๐ฌ๐!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ฒ๐ณ๐ณ๐๐ซ’๐ฌ ๐๐ข๐ฌ๐๐๐ฌ๐ is a bacterial infection of the liver that leads to ๐ก๐๐ฉ๐๐ญ๐ข๐ ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ, or death of the liver cells.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
We most commonly see this disease in foals and rodents, however it can also be seen in calves, kittens and puppies!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Tyzzerโs disease is caused by ๐๐ฅ๐จ๐ฌ๐ญ๐ซ๐ข๐๐ข๐ฎ๐ฆ ๐ฉ๐ข๐ฅ๐ข๐๐จ๐ซ๐ฆ๐, a spore forming bacteria that is considered ๐จ๐๐ฅ๐ข๐ ๐๐ญ๐ ๐ข๐ง๐ญ๐ซ๐๐๐๐ฅ๐ฅ๐ฎ๐ฅ๐๐ซ, meaning it must live within host cells. The bacteriaโs spores are shed in the feces of sick or ๐๐๐ซ๐ซ๐ข๐๐ซ (unaffected) animals, which contaminates the environment and provides a source for other animals to get sick.
Animals will ingest the spores when they explore their environment, and from there the bacteria gains access to the intestine. From there, it enters the ๐ฉ๐จ๐ซ๐ญ๐๐ฅ ๐๐ข๐ซ๐๐ฎ๐ฅ๐๐ญ๐ข๐จ๐ง, the vessels that lead from the gut to the liver. Once in the liver, the bacteria sets up shop in the liver cells, causing ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ (cell death).
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
With a large amount of the liver cells dying, these animals often show signs of ๐๐๐ฎ๐ญ๐ ๐ฅ๐ข๐ฏ๐๐ซ ๐๐๐ข๐ฅ๐ฎ๐ซ๐, including depression, fever, ๐ข๐๐ญ๐๐ซ๐ฎ๐ฌ (yellowing of the tissue) which progresses to seizures, coma and ultimately death. Depending on the extent of the gut infection, they may also develop ๐๐ข๐๐ซ๐ซ๐ก๐๐ due to death of intestinal cells.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Diagnosis is typically based on necropsy, showing multiple areas of liver necrosis and visualizing the bacteria under the microscope using special stains. It can also be detected in fecal samples of live animals using ๐๐๐, which detects the bacterial DNA.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Clostridium piliforme is susceptible to some antibiotics, however the prognosis is extremely poor, even with treatment. This is particularly true in foals, where the disease is considered almost 100% fatal! To prevent the disease, environments where previously sick animals lived should be thoroughly cleaned to try and remove spores. Animals should also have their stress minimized to keep their immune system in tip-top shape!
๐๐ก๐จ๐ญ๐จ๐ฌ
1-3) Examples of the ๐ฆ๐ฎ๐ฅ๐ญ๐ข๐๐จ๐๐๐ฅ (many affected areas) liver necrosis in Tyzzerโs. Itโs almost kinda pretty!
4) A regular ๐&๐ ๐ฌ๐ญ๐๐ข๐ง of an affected liver. Kinda hard to see the bacteria!
5) A ๐๐๐ซ๐ญ๐ก๐ข๐ง-๐๐ญ๐๐ซ๐ซ๐ฒ ๐ฌ๐ญ๐๐ข๐ง that highlights the bacteria. Much easier to see!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 2. Sixth Edition.
Uzal F. Tyzzer Disease in Animals. Merck Veterinary Manual 2021.
Photos 1-3 ยฉ Noahโs Arkive contributors Williams, Arp, Mosier licensed under CC BY-SA 4.0.
Photos 4-5 ยฉ University of Calgary Diagnostic Services Unit.
