How to Treat Black Fly Bites on Dogs

Fly bites are annoying, but black fly bites on dogs are painful and itchy! Fortunately, they can usually be treated at home with some basic care. The best way to protect your dog from these nasty insects is to know when and where they swarm and avoid them.

What Are Black Flies?

Black flies, also called buffalo gnats, are small dark flies that travel in swarms. They breed in running water, but prefer still air in the morning, late afternoon, and evening. Hot, humid spring and summer months are considered “black fly season” because this is when these airborne biters are most active.

Only the female flies bite, but those bites hurt. Unlike mosquitos, black flies do not specifically target blood vessels. Instead, the black fly’s bite creates a tiny wound in the skin, and then the fly drinks the blood.

Identifying Black Fly Bites on Dogs

The flies usually target parts of your dog’s body that have less hair, such as the face, ears, belly, and inner thighs.

Black fly bites develop a characteristic “bullseye” appearance with a red spot of blood in the center, swelling around the puncture, and then a red ring of irritation. Since black flies usually travel in swarms, your dog will likely have many of these bites in one area or across the body.

You might notice your dog cry out when he is bitten by a black fly or attacked by a swarm, but you will definitely notice the chewing and scratching when the bites start to itch. If your dog has been bitten on his face, he may repeatedly rub his face against the ground or you.

Allergic reactions to black fly bites are rare. If your dog does show signs of an anaphylactic reaction such as facial swelling, difficulty breathing, vomiting, or hives, seek veterinary care immediately.

How to Treat Black Fly Bites on Dogs

Most black fly bites heal on their own. To ease the discomfort, ice swollen areas for 5 to 10 minutes. You can also apply hydrocortisone cream or aloe vera, but don’t let your dog lick it.

If your dog has many bites, ask your veterinarian for an appropriate dose of diphenhydramine (Benadryl). This can help relieve both itching and swelling.

The bites can get infected if your dog chews and scratches at them. If you notice your dog bothering the bitten areas, use an Elizabethan collar or another device that prevents the dog from chewing. You may be able to put your dog in an old T-shirt or the light shirt to block your dog’s access to the itchy. If any of the bites become infected (increased swelling and redness, oozing pus), your dog will require veterinary care and antibiotics.

How to Prevent Black Fly Bites on Dogs

Dog-safe bug sprays may help deter black flies, but the best strategy is to avoid areas likely to have swarms.

Remember that black flies reproduce in running water and are most active during the spring and summer when it is warm and humid. They are also generally most active in the morning and in the hours before sunset. Avoid walking your dog in the woods or near running water during these times of day during black fly season.