Cytauxzoonosis

Todayโ€™s path rounds are on ๐œ๐ฒ๐ญ๐š๐ฎ๐ฑ๐ณ๐จ๐จ๐ง๐จ๐ฌ๐ข๐ฌ!

๐–๐ก๐š๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐‚๐ฒ๐ญ๐š๐ฎ๐ฑ๐ณ๐จ๐จ๐ง๐จ๐ฌ๐ข๐ฌ is a parasitic disease caused by the protozoa ๐‚๐ฒ๐ญ๐š๐ฎ๐ฑ๐ณ๐จ๐จ๐ง. The protozoan can be found in wild felids throughout North America!

๐–๐ก๐จ ๐ ๐ž๐ญ๐ฌ ๐ข๐ญ?
As mentioned, this disease most commonly affects felids in North America, including our domestic cats.

๐–๐ก๐š๐ญ ๐œ๐š๐ฎ๐ฌ๐ž๐ฌ ๐ข๐ญ?
Cytauxzoon is transmitted by ๐ญ๐ข๐œ๐ค๐ฌ, who generally acquire the protozoan by feeding on ๐๐จ๐ซ๐ญ๐ก ๐€๐ฆ๐ž๐ซ๐ข๐œ๐š๐ง ๐›๐จ๐›๐œ๐š๐ญ๐ฌ. Bobcats generally do not become sick with this protozoal infection, allowing them to act as a ๐ซ๐ž๐ฌ๐ž๐ซ๐ฏ๐จ๐ข๐ซ for the parasite. These ticks then feed on a domestic cat, transferring the protozoan.

๐–๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐š ๐ฉ๐ซ๐จ๐›๐ฅ๐ž๐ฆ?
Cytauxzoon often infects the ๐ซ๐ž๐ ๐›๐ฅ๐จ๐จ๐ ๐œ๐ž๐ฅ๐ฅ๐ฌ of cats, which targets them for destruction by the immune system. This can result in ๐š๐ง๐ž๐ฆ๐ข๐š (low RBCs). When RBCs are destroyed, ๐›๐ข๐ฅ๐ข๐ซ๐ฎ๐›๐ข๐ง is released, and overwhelms the liverโ€™s ability to process it for excretion in the bile. Bilirubin begins to accumulate in the animal, staining tissues yellow, which is called ๐ข๐œ๐ญ๐ž๐ซ๐ฎ๐ฌ.

The parasite can also infect ๐ง๐ž๐ฎ๐ญ๐ซ๐จ๐ฉ๐ก๐ข๐ฅ๐ฌ (major clean-up cell of the immune system) and ๐ฉ๐ฅ๐š๐ญ๐ž๐ฅ๐ž๐ญ๐ฌ (major blood clotting cell), resulting in increased susceptibility to infection and poor clotting. ๐Œ๐š๐œ๐ซ๐จ๐ฉ๐ก๐š๐ ๐ž๐ฌ (another clean-up cell) can also eat the protozoan and become very large, to the point where they begin to obstruct blood flow in vessels. This can lead to ๐œ๐จ๐ง๐ ๐ž๐ฌ๐ญ๐ข๐จ๐ง (lack of blood flow) and ๐ž๐๐ž๐ฆ๐š (fluid leaking from vessels), particularly in the lungs.

๐‡๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐š๐ ๐ง๐จ๐ฌ๐ž๐?
Cytauxzoon can be diagnosed on a ๐›๐ฅ๐จ๐จ๐ ๐ฌ๐ฆ๐ž๐š๐ซ, where the blood is examined under a microscope. The parasite has a characteristic ๐ฌ๐ข๐ ๐ง๐ž๐ญ ๐ซ๐ข๐ง๐  shape that can be identified in red blood cells.

๐‡๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐ž๐š๐ญ๐ž๐? ๐‡๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐ž๐ฏ๐ž๐ง๐ญ๐ž๐?
Unfortunately, most antiparasitic drugs are poorly effective in treating cytauxzoonosis. However, with adequate ๐ฌ๐ฎ๐ฉ๐ฉ๐จ๐ซ๐ญ๐ข๐ฏ๐ž ๐œ๐š๐ซ๐ž including fluids, oxygen, blood transfusions and pain medications, these animals are often able to survive long enough for the antiparasitics to work, and resolve their infection. Prevention for this disease is key, so make sure you use a tick preventative!

๐๐ก๐จ๐ญ๐จ๐ฌ
1) What Cytauxzoon looks like in a blood smear.
2-4) Examples of cells harbouring lots of little dit-dot protozoans!
5) A cat with icterus and lung congestion and edema from Cytauxzoon.

๐’๐จ๐ฎ๐ซ๐œ๐ž๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโ€™s Pathology of Domestic Animals, Volume 3. Sixth Edition.

Photos 1-5 ยฉ Noahโ€™s Arkive contributors Doster, Rech, Camus, French licensed under CC BY-SA 4.0.

Leave a Reply