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Gnat Bites on Dogs: Our Vet Shares Pictures & Home Remedies

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closeup picture of a gnat on grass

This article was updated on March 8th, 2024

Gnats are small flies that tend to fly in swarms. Some are non-biting, but it is the biting ones that cause our dogs problems. They are most prevalent in the Spring months and like to live near long grass and bodies of water.

The bites they inflict can look quite nasty and many owners come to my clinic worried that their dog has a serious skin issue. Thankfully, for most they cause little irritation and resolve quickly. Let’s take a closer look at gnat bites on pet dogs.

Example pictures of gnat bites on dogs

The classic gnat bite causes red, circular lesions which are sometimes mistaken for ringworm. Initially they are a bright or dark red but soon fade to a paler color. They can get quite large, especially if the dog has been licking, chewing or scratching at them.

red, circular lesions due to gnat bites

If you know your dog has been near gnats, you can be quite confident that lesions which look like these are gnat bites.

lesions on a dog's belly as a result of gnat bites
Dog with multiple gnat bites on belly

However, red circular lesions like this can also be seen with infections like Ringworm or Staphylococcus bacterial infections, so always have a veterinarian confirm the diagnosis if you’re unsure.

Skin issues caused by gnats

When dogs are bitten a number of times, they may become quite itchy and this can lead to secondary skin infections. This can become uncomfortable and, if not treated promptly, could lead to a skin infection that becomes difficult to manage.

Most dogs cope well with gnat bites and they just cause mild discomfort.

For dogs who are very itchy or seem to have secondary skin infections, a routine vet appointment should be scheduled. Uncommonly, a dog may have an immediate allergic reaction to a gnat bite. Signs could include facial swelling, trouble breathing, widespread hives and weakness. In this instance, you would need to seek immediate vet care.

Top symptoms

After a gnat bite, your dog may develop the following signs:

  • Red lesions that form a ring (like a ‘bullseye’)
  • Mild itching
  • Slight crusting

Bites often occur in clusters and we tend to see them on the furless areas of skin. If there is a secondary skin infection, we may also notice ooze, a bad smell and redness which is spreading. View pictures of skin infections.

What to do to help your dog at home

1. Bathing your dog

I recommend that my patients gently bathe the skin in an oatmeal wash, medicated wash or salt water. A shampoo like this one below is a good idea, to soothe the skin and remove surface yeast and bacteria. This makes infections less likely to set in. The oatmeal in this shampoo helps to calm any itchy or inflamed skin:

Vet's Best Allergy Itch Relief Dog Shampoo |...
  • RELIEF FOR ITCHY SKIN - Vet’s Best Allergy Itch Relief Dog Shampoo is a soothing, natural remedy for dogs with itchy skin due to allergies or sensitivity.
dog taking bath

2. Distractions!

Lick Mats and Kongs help your dog to stay calm while itchy and they will appreciate a distraction from the itch, making it less likely for them to lick their own skin. I’m a big fan of food puzzles as they are easy for dogs to use, even when wearing a buster collar.

Always monitor your pooch when using these products, to ensure they are not chewed apart or ingested.

MateeyLife 3PCS Small Lick Mat for Dogs and...
  • REDUCES ANXIETY & DESTRUCTIVE BEHAVIOR: These lick mats for dogs, lick mat for cats and dog lick mat with suction cups help release endorphins through the process of licking, which can calm and soothe your pets well. Our cat lick mat and dog licking mat is a safe alternative for your dog to lick when facing stressful times such as grooming, bath time, nail clipping, injury recovery, and fireworks.
KONG Classic Stuffable Dog Toy - Fetch & Chew...
  • Satisfy Instinctual Needs: The KONG Classic red rubber toy helps satisfy dogs' instinctual needs and provides mental stimulation; toy helps solve chewing, teething, boredom, crate training, digging, barking and more

3. Collars

Thankfully, gnat bites are not known for causing pain and the itch tends to be mild. However, if your dog has many gnat bites or their skin is infected, they are likely to have some discomfort. To protect the skin, use a buster collar or loose pet t-shirt, as excess licking and chewing will introduce infection.

BENCMATE Protective Inflatable Collar for...
  • ✅ 【COMFORTABLE FOR YOUR PET】 - While wearing the BENCMATE Collar, the inflatable function and the soft outside material will let your dog wear it comfortably and it does not block your pet’s vision, they can eat, drink, sleep and play at ease while staying protected.

Your vet may also discuss the use of an antihistamine from home. These are sometimes continued for several days. If your dog seems uncomfortable or the gnat bites are not improving, it is a good idea to schedule a vet visit.

Is it a gnat bite or it is something else?

I always want my owners to be aware that several issues can mimic gnat bites. The most common would include fungal infections, bacterial infections and lesions that occur with flea allergy dermatitis.

ringworm on dog with closeup view
Ringworm or skin infections can be mistaken for gnat bites

Your vet can often determine if a lesion is a gnat bite by simply looking at it, given their experience. If unsure, they may discuss some tests such as a skin swab, flea comb and skin scrape.

If you’ve not seen gnats near your dog and it is the wrong time of the year, we should question if there could be more going on than gnat bites.

Tip: email photos to your vet

It is always a great idea to email photos to your vet (or to an online vet service), so they can let you know if they agree that we are dealing with gnat bites. The vet will also be able to spot signs of a secondary infection and can advise on the best treatment plan going forward.

Signs that you need to call the veterinarian

Never hesitate to contact your vet if concerned. It may be that your dog is very unsettled by the bites, they are not healing quickly or that your dog is showing signs of illness (for example as a result of an allergic reaction). Your vet will be happy to advise and may suggest you bring your dog in for an assessment if they are concerned.


  • Dr. Linda Simon, Veterinarian

    Dr Linda Simon (MVB MRCVS) has 10 years of experience as a veterinarian. She is a veterinary surgeon with a special interest in geriatric patient care, dermatology and endocrinology. She is a member of the British Royal College of Veterinary Surgeons. She graduated top of her class from UCD School of Veterinary Medicine in Dublin in 2013. Linda has also worked as a locum vet in a range of clinics, including 24 hour emergency clinics and busy charity clinics.

    View all posts MVB MRCVS

Disclaimer: This website's content is not a substitute for veterinary care. Always consult with your veterinarian for healthcare decisions. Read More.

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