08/01/2026
GRAPHIC IMAGE! (This image was taken from the internet... this is not a dog that we have and we don't know the outcome of this dog.)
What is Cochliomyia Hominivorax aka "screwworm"?
By: Casey Jo
(Some of this information was taken directly from the internet... )
Cochliomyia hominivorax or the new world screwworm fly causes a dangerous parasitic infection with larvae from the fly that feed on living flesh. Gross, right? The screwworm dates back to the 1800’s and carried through to the 1920’s. During this time this fly created massive widespread livestock devastation in South America, Mexico and the south. By the 1930’s farmers and livestock owners were educated on how to identify and treat open wounds in livestock to help keep this fly away. Through the years many studies were done and by 2000 a biological barrier of sterile flies was successfully maintained down through Mexico and Central America to Panama. Between 2023-2025 the barrier was broken and the parasite started moving north. THIS YEAR, federal authorities confirmed cases in Texas and New Mexico livestock and pets, prompting regional transport restrictions and emergency state protections.
Knowing that this parasite infection has been confirmed in domestic pets, what should you know to help protect your pet? There are some physical signs to look for. Ensure your pet has no open wounds and if they do, call your veterinarian office to make an appointment for further investigation of the wound. If a wound is present, it may put out a foul smell, have watery-bloody discharge, it might grow and/or there could be larvae movement in and around the wound. The wound will be irritating to your pet, they could pace or be uncomfortable, they may become weak, depressed or detached. Your pet may also lose their appetite. Advanced symptoms are fever, swelling or even septic shock which could lead to death!
What treatment should you be aware of? The FDA has approved specific oral and topical medications. There are flea and tick medications with specific ingredients that are authorized. Anything containing Nitenpyram, which is found in Capstar (or a generic equivalent), will kill the larvae and is fast acting. It would need to be repeated 6 hours later. It's safe to repeat daily until the infestation is eradicated. It's also important to keep your pet on a monthly preventive. Don't buy over the counter - speak with your vet!
If your pet does have an infestation, the worms do need to be extracted and PLEASE ALWAYS consult with your veterinarian about ANY treatment before beginning. Your veterinarian will talk with you about any treatments, wound care and supportive therapy.
If you suspect an active infestation, do not transport the animal directly to a clinic without calling first, as transport can risk spreading the parasite to new regions. Contact your veterinarian immediately so they can prepare a secure isolation space for arrival. Remember to always contact your veterinarian with any concerns or questions.
The articles are meant to be informative and a guideline of sorts in caring for pets. We know many of you out there are experienced and responsible pet owners, maybe you will learn something new or be able to help someone else who is reading the article. Please be kind in your comments, we will not tolerate any negative or rude comments.
