What is Fly strike dermatitis?

Fly strike dermatitis can occur at the tip and folds of a dog’s ear and is caused by a fly named Stomoxys calcitrans. The common name for this fly is Stable Fly and it likes to feed on the blood of dogs by biting the ears. Fly strike is the name for the irritation caused by these bites.

Dogs at risk for fly strike dermatitis

Dog fly dermatitis is chiefly a problem for dogs that are confined to the outdoors during summer and fall. It is much less common in pet dogs that spend a lot of time indoors between walks.

In many cases, the flies have been attracted to your dog for a reason. You dog might for instance have a minor cut or an ongoing ear infection. This will alert the flies, and they will start biting. This naturally creates a very painful cycle where the bites cause more sores and infections, and even more flies are attracted to your dog. The dog might also attempt to get rid of the flies by excessive scratching and this can cause even more ear irritation. 

Symptoms of fly strike dermatitis in dogs

Flies can be extremely irritating for the dog and the bites can cause red and bleeding sores along the edges of the dog’s ears. These sores are very painful for the dog and can look crusty. Fly strike sores often become infected. If your dog has erect ears, the bites will most likely be located at the ear tips. If your dog has floppy ears, look for bites along the front edge of each ear. Some dogs are also bitten across the face.

Fly strike diagnosis

Fly strike can be hard to diagnose since a lot of different problems can cause ear sores and infection. Fly strike is for instance sometimes mistaken for vasculitis, atopy, or mange. The vet will therefore normally do culture to check for bacteria and fungi, and a skin biopsy can also be necessary. Some veterinarians also carry out urine analysis and blood count to make sure that the rest of the dog’s body is okay.

Fly strike dermatitis treatment for dogs

The skin wounds caused by fly bites can be treated with topical antibiotics and topical corticosteroids. This will not only reduce inflammation and infection; it can also create a barrier for the flies. Keeping the ear clean is very important.  

Preventing future fly bites is naturally a very important aspect of successful fly strike treatment. A topical fly repellent can be used to keep the flies away. Make sure that you pick a repellent that is specifically produced to keep flies away, and that the product is safe for dogs. In some cases, it is better to keep the dog indoors. This is especially true if the fly repellent causes skin irritation for an already irritated ear. As mentioned above, dogs confined to the outdoors are much more likely to suffer from fly strike dermatitis and dogs that only venture outside a few times a day for their walks are much less susceptible to this problem. Keeping your dog inside except for a few walks a day is therefore one way of preventing fly strike, especially while the ear is still healing.

Ear problems in dogs: (click for more info)
Deafness in dogs
Ear infections in dogs
Fly strike dermatitis in dogs