Bot fly larvae on squirrels, other animals - Mary Cummins, Animal Advocates
During the late summer and fall months you will see animals with what appear to be large infected swellings on their backs, around their necks or areas which are not easy for them to reach to clean. These are most likely bot fly larvae. The photo above from the Squirrel Board shows some bot fly larvae attached under the skin of a squirrel. Some larvae have already left the host. You will see large holes in the skin after the larvae emerge.
"Bot flies: The Oestridae are a family of flies variously known as bot flies, warble flies, heel flies, gadflies, and similar names. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut."
"The word "bot" in this sense means a maggot. A warble is a skin lump or callus such as might be caused by the presence of a warble fly maggot under the skin."
The fly lays an egg on the animal's skin. The egg hatches and the larva emerges. The larva burrows into the skin and attaches to the animal. It will live off the host until it is ready to drop off and continue the pupal stage in the soil. Then it turns into a fly. More from wiki below.
http://en.wikipedia.org/wiki/Bot_fly
"The tree squirrel bot fly, Cuterebra emasculator Fitch, is an obligate parasite of tree squirrels and chipmunks throughout most of eastern North America. The adult and other life stages are seldom seen; instead, what is usually observed from July through September or October is the outcome of infestation, namely the relatively large, fluid-draining swellings (รข€˜warbles') in a host's hide caused by the subcutaneous larvae."
Treatment from the Squirrel Board:
"If the bot fly larva is not in an area that restricts movement or other functions, it can be left intact and will drop off at maturity. The sight on your animal is gruesome, but in many cases they only cause mild irritation for the animal. Once the warble drops out, clean the wound with an antiseptic and apply topical ointment if needed. On very small mammals such as mice, the warble can be life threatening -- it may need to be surgically removed. If the bot fly is killed while it is living under the skin of the mammal, it can release a toxin which can cause anaphylactic shock (this is one reason why we don't try to kill it while it is still there). Oral antibiotic treatment may be indicated if a secondary infection develops in the warble. A mature bot fly larva is large enough to be carefully removed using tweezers or forceps. Sometimes slow, steady pressure AT THE BASE of the warble can push the larva out thru the opening. Be sure not to kill the larva in the process. The warble pore can then be flushed with chlorhexiderm@ or saline solution and a topical antibiotic applied if needed."
I personally would only trap the squirrel, chipmunk, mouse and remove the larvae if it's a small animal, very young animal, very old animal, lactating/weak/skinn, injured, infected or the animal appears weak. Otherwise they will drop off. Trapping and treating wild animals can cause more stress than the bot fly larvae. If you trap a lactating female, you must instantly treat and return to the exact place where found so she can nurse her young.
I spoke with my vet. He said Capstar or Ivermectin might help. Squirrel dosage is similar to cat by weight. Adult fox squirrels weigh about 2 lbs.
Here's a great article about US bot fly larva that affect squirrels, chipmunks, mice, hares and rabbits.
http://entnemdept.ufl.edu/creatures/misc/flies/squirrel_bot_fly.htm
Howler monkey with bot fly larvae being removed. This species of bot fly is larger than the ones on squirrels in the US. The monkey is sedated. He's not dead. The vet is pulling live larvae out of the warble. The hole you see is how the larva breaths. The larva is attached to the host by it's mouth so it can feed off the host. If you do remove them, grab the larva firmly with tweezers. Try not to squish it. You want to slowly, gently pull it out whole. Some put vaseline or tape over the hole to first suffocate the larvae which makes them easier to remove.
Mary Cummins of Animal Advocates is a wildlife rehabilitator licensed by the California Department of Fish and Game and the USDA. Mary Cummins is also a licensed real estate appraiser in Los Angeles, California.
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Mary Cummins of Animal Advocates is a wildlife rehabilitator licensed by the California Department of Fish and Game and the USDA. Mary Cummins is also a licensed real estate appraiser in Los Angeles, California.
- Mary Cummins LinkedIn
- Mary Cummins Meet up
- Animal Advocates custom Facebook name
- Mary Cummins Real Estate blog
- Animal Advocates on Google maps
- Mary Cummins of Animal Advocates
- Mary Cummins biography resume short
- Mary Cummins Real Estate Services
- Animal Advocates fan page at Facebook.com
- Mary Cummins Animal Advocates Squirrel Rescue
- Mary Cummins Animal Advocates on Flickr photos
- Mary Cummins Animal Advocates on Twitter.com
- Mary Cummins on Picasa web photo albums
- Mary Cummins on MySpace.com
- Mary Cummins on Google Blogger Blogspot
- Mary Cummins on YouTube.com videos
- Mary Cummins of Animal Advocates on Classmates
- Mary Cummins on VK
- Mary Cummins of Animal Advocates on Google+