10/29/2026
New world screwworm has arrived in Arizona and it is all going to be ok. This is not the world of 50 years ago when there was no internet and ranchers and people didn’t have access to information or help. Screwworm was a terrible thing back then because people just didn’t know anything about it or what to do to prevent it other than mix together some transmission grease and a bit of oil and whatever other grimy stuff one could find to mix in a can and smear it all over your critter if it had a wound or you castrated it or branded it.
When I moved to Arizona almost 30 years ago the old timers were still smearing that stuff on their cattle even though screwworm had been eradicated for a few decades. Fear ruled back then and it is ruling now and it doesn’t have to. We know so much more and we have access to so much more information. Drugs are a lot more readily available and it is all going to be ok.
The most important thing you need to know is- pay attention to your animals! Do NOT just spray your favorite colored spray on the wound and walk away. You are going to have to keep an eye on it. If you are castrating your horses or cattle or sheep, use some ivermectin or some exzolt at the time of the procedure and then look at it every day! Invest the time in looking over your animals every day. There is treatment that is very effective and very readily available.
If your dog gets in a fight, pay attention. If your cat comes up with an abscess, pay attention. We have easy treatment for screwworm and if you find maggots on one of your animals do not panic but give us a call or bring the animal in so we can collect some maggots and treat them accordingly and everything will be good.
The biggest thing being a positive state changes is that health certificate regulations are going to change and you are going to have to be more prepared before you leave the state with your horses or cattle. You are going to need to shorten your window for your health papers and the veterinarian is going to have to inspect them right before you leave and write a statement on the papers.
If you are in the infested zone you will need your horse examined by the livestock inspector or a veterinarian and proper paper work filled out as well as oral treatment of LIQUID ivermectin EVERY FIVE DAYS if you are leaving the infested zone. If you are traveling within the infested zone you do not need anything extra.
Does it suck that NWSW is in Arizona? Yes it does but we all knew it was coming. It is not going to eat your dog or cat or cow or horse alive unless you choose to remain ignorant and do not take care of their wounds.
If you are worried about your dogs and cats call and make an appointment for an exam and a prescription for Bravecto and then your dog will be safe for three months with each treatment and your cat for a month.
It is all going to be ok and we are here to help you help your animals.
*Current as of October 29,2026 of all cases and the species. Save the link and keep up to date and let's not spread heresy or false information.
https://www.aphis.usda.gov/animals/animal-health/livestock-and-poultry-disease/stop-screwworm/current-status/confirmed
