Todayโs path rounds are on ๐ซ๐๐๐๐จ๐จ๐ง ๐ซ๐จ๐ฎ๐ง๐๐ฐ๐จ๐ซ๐ฆ๐ฌ, otherwise known as ๐๐๐ฒ๐ฅ๐ข๐ฌ๐๐ฌ๐๐๐ซ๐ข๐ฌ ๐ฉ๐ซ๐จ๐๐ฒ๐จ๐ง๐ข๐ฌ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐๐ฒ๐ฅ๐ข๐ฌ๐๐ฌ๐๐๐ซ๐ข๐ฌ ๐ฉ๐ซ๐จ๐๐ฒ๐จ๐ง๐ข๐ฌ is a type of roundworm that uses raccoons as part of its lifecycle. These roundworms are specifically studied because they produce ๐ฅ๐๐ซ๐ฏ๐๐ฅ ๐ฆ๐ข๐ ๐ซ๐๐ง๐ฌ in species other than raccoons, which is what weโre going to talk about today!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
Obviously raccoons are the typical species infected by the roundworm, hence the name. However, rodents, rabbits, primates (including humans) and birds most commonly get the larval migrans form of this disease.
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Baylisascaris eggs are shed into the feces of an infected raccoon, causing contamination of the environment. From there, other mammals ingest the eggs and become an ๐๐๐๐ซ๐ซ๐๐ง๐ญ ๐ก๐จ๐ฌ๐ญ, meaning the larvae doesnโt really know what to do when inside that species. This results in the larvae ๐ฆ๐ข๐ ๐ซ๐๐ญ๐ข๐ง๐ around the aberrant host, burrowing through various tissues and producing a lot of inflammation. In particular, these wandering larvae seem to really like the brain of their new friends!
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Well, your brain isnโt supposed to have larvae wandering around in it, for one. Having larvae in your brain results in ๐ง๐๐ฎ๐ซ๐จ๐ฅ๐จ๐ ๐ข๐ ๐ฌ๐ข๐ ๐ง๐ฌ like tremors, head tilt, circling, falling, inability to get up, blindness, ๐๐ญ๐๐ฑ๐ข๐ (wobbly gait), coma and even death. Even if the animal does not die directly from the larvae, they often will have difficulty carrying out their daily functions like eating, so they are often euthanized.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
In the raccoon, roundworm infection can be diagnosed by a ๐๐๐๐๐ฅ ๐๐ง๐๐ฅ๐ฒ๐ฌ๐ข๐ฌ to look for the eggs.
In species with larval migrans, diagnosis becomes much more difficult. Usually, a sample of the ๐๐๐ซ๐๐๐ซ๐จ๐ฌ๐ฉ๐ข๐ง๐๐ฅ ๐๐ฅ๐ฎ๐ข๐ is taken to identify immune cells that indicate a parasitic infection. While this doesnโt specifically point to Baylisascaris, it usually provides the veterinarian enough context to figure out whatโs going on.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
Raccoons can be treated with typical anti-parasitic drugs to clear the infection. In the aberrant hosts, treatment is generally not feasible, and the animals are often euthanized.
๐๐ก๐จ๐ญ๐จ๐ฌ
1) Roundworms in the intestine of a raccoon!
2-4) Cross-sections of roundworms in the brain, as seen under the microscope. I hope you enjoy your brain larvae nightmare tonight 
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Stringfield CE. Baylisascaris Neural Larva Migrans in Zoo Animals. Zoo and Wild Animal Medicine, Sixth Edition. 2008.
Photos 1-4 ยฉ Noahโs Arkive contributor King, Ossiboff licensed under CC BY-SA 4.0.
