Todayโs path rounds are on ๐ญ๐ฎ๐ฅ๐๐ซ๐๐ฆ๐ข๐!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ฎ๐ฅ๐๐ซ๐๐ฆ๐ข๐ is a bacterial disease caused by ๐
๐ซ๐๐ง๐๐ข๐ฌ๐๐ฅ๐ฅ๐ ๐ญ๐ฎ๐ฅ๐๐ซ๐๐ง๐ฌ๐ข๐ฌ. It was first described in the county of Tulare in California, hence the name!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This disease affects numerous species, including humans. We most commonly see this disease in cats, rabbits and wild rodents like beavers and muskrats.
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Francisella tularensis can be spread in many different ways, including ๐๐๐ซ๐จ๐ฌ๐จ๐ฅ (particles in the air), direct contact, ingestion and biting insects and ticks. For herbivores and people, the most common route of infection is being bitten by an infected tick. Carnivores tend to acquire the bacteria from eating carcasses of infected animals.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Tularemia causes a ๐ฌ๐๐ฉ๐ญ๐ข๐๐๐ฆ๐ข๐ ๐๐ข๐ฌ๐๐๐ฌ๐, meaning that the bacteria is present in the bloodstream and showers multiple different organs. When the bacteria lodge in an organ, they cause areas of ๐ง๐๐๐ซ๐จ๐ฌ๐ข๐ฌ (cell death). This large amount of necrosis can lead to organ failure, and in some cases may lead to death of the animal. In particular, tularemia seems to like the liver, spleen, lungs and lymph nodes. The bacteria also stimulates a potent immune response, leading to high fever.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Tularemia can be diagnosed based on ๐๐๐๐ญ๐๐ซ๐ข๐๐ฅ ๐๐ฎ๐ฅ๐ญ๐ฎ๐ซ๐, where the organism is grown on a culture plate, or by ๐๐๐, where the DNA of the bacteria is identified directly.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
If caught early, antibiotics can be effective at treating the disease. However, later stages of the disease are very difficult to treat! Preventative anti-tick medications and preventing your carnivorous pets from eating wildlife carcasses are the best methods of keeping animals safe from tularemia. Also, if you are eating a wildlife species yourself, make sure it is adequately cooked!
๐๐ก๐จ๐ญ๐จ๐ฌ
1-4) Multiple organs including the liver, spleen, and intestinal tract showing white areas of necrosis scattered throughout!
5-6) What those white areas look like under the microscope. You can see the bacteria pretty easily under our usual H and E stain (the pink one), but a ๐๐ซ๐๐ฆ ๐ฌ๐ญ๐๐ข๐ง specific for bacteria highlights them even better!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 3. Sixth Edition.
Foley JE. Tularemia in Animals. Merck Veterinary Manual 2020.
Photos 1-5 ยฉ Noahโs Arkive contributors Doster, Daoust, Leighton, King, Williams licensed under CC BY-SA 4.0.
