By the Pethocyn editorial team. Published October 31, 2026. Updated November 1, 2026. Sources are listed at the end of the article.

Bite wounds are a common reason dogs and cats need a vet, and pets that go outdoors on their own get into more fights [2]. A bite can leave only small marks on the skin while the real damage sits deeper [3][5]. This guide explains what studies tell us about bite wounds in dogs and cats and why a vet must check every one.

Have your vet check any bite wound, even if you see only small marks.

For first steps at home and the signs of an infected bite, see minor wound care for dogs and cats.

Cat bites

A cat’s mouth normally carries bacteria such as Pasteurella, and these germs are often found in the pus of abscesses under the skin of cats [1]. A cat’s tooth makes a small, deep hole, so germs get pushed in while the skin on top can close over them. An abscess is a pocket of infection under the skin, and your vet decides how to treat it.

In a large US study of cats seen for bite wounds or abscesses, about one in five tested positive for feline leukemia virus or feline immunodeficiency virus, and outdoor access was one of the links [2]. Your vet may suggest testing your cat for these viruses after a fight, and again some weeks later [2].

Dog bites

Dog bites vary a lot. A dog can grip and shake, which tears tissue under skin that looks almost whole. In one study of dogs bitten on the chest, broken ribs and air leaking around the lungs pointed to injury inside the chest, and some of these dogs needed surgery on the chest [3]. In another study, about one in five pets that were breathing normally still had changes on chest X-rays after a bite [5].

Cats bitten by dogs often have injuries in more than one part of the body [4]. Most of these cats survive with treatment, but deep wounds and injuries to many areas carry more risk [4].

What your vet does first

Your vet checks and steadies your pet’s overall condition first, because shock, breathing trouble or bleeding matter more than the skin wound. X-rays may be taken, especially after a bite to the chest [3][5].

The vet then cleans the wound and may probe or open it to follow the damage to its full depth before deciding on repair [3]. In one study of cats bitten by dogs, half were treated without surgery, about a third needed the wounds cleaned and trimmed, and some needed a larger operation to look inside [4].

Why vets may not close a bite wound right away

A bite pushes germs from the mouth into the wound [1]. For this reason your vet may leave a bite wound partly open, place a drain, close it later, or let it heal on its own, depending on how much tissue is hurt. For how vets choose, see stitched or left open wounds in dogs and cats. For how an open wound fills in, see how wounds heal in dogs and cats.

Treatment

Your vet will advise on treatment for your pet’s bite wound.

At home, as directed by a vet:

  • keep your pet from licking, chewing or scratching the wound;
  • care for any drain or bandage only in the way your vet shows you;
  • go back for every recheck your vet books.

When to see your vet

See your vet if your dog or cat:

  • has been bitten by another animal, or you think it may have been;
  • has small puncture marks or bruising after a fight [3][5];
  • has a warm, painful swelling some days after a fight, which can be an abscess [1];
  • breathes fast or with effort after a bite to the chest [3].

The bottom line

A bite wound can look small while the damage lies under the skin. Only a vet can find out how far a bite goes, so have your vet check any bite.

This article is for general information only and does not replace advice from your veterinarian. If your pet has been bitten, see your vet.

Sources

  1. Lloret A, Egberink H, Addie D, et al. Pasteurella multocida infection in cats: ABCD guidelines on prevention and management. J Feline Med Surg. 2013;15(7):570-572. PubMed abstract. https://pubmed.ncbi.nlm.nih.gov/23813817/
  2. Goldkamp CE, Levy JK, Edinboro CH, Lachtara JL. Seroprevalences of feline leukemia virus and feline immunodeficiency virus in cats with abscesses or bite wounds. J Am Vet Med Assoc. 2008;232(8):1152-1158. PubMed abstract. https://pubmed.ncbi.nlm.nih.gov/18412524/
  3. Frykfors von Hekkel AK, Pegram C, Halfacree ZJ. Thoracic dog bite wounds in dogs: a retrospective study of 123 cases (2003-2016). Vet Surg. 2020;49(4):694-703. PubMed abstract. https://pubmed.ncbi.nlm.nih.gov/32077513/
  4. Klainbart S, Shipov A, Madhala O, et al. Dog bite wounds in cats: a retrospective study of 72 cases. J Feline Med Surg. 2022;24(2):107-115. PubMed abstract. https://pubmed.ncbi.nlm.nih.gov/33980052/
  5. Cabon Q, Deroy C, Ferrand FX, et al. Thoracic bite trauma in dogs and cats: a retrospective study of 65 cases. Vet Comp Orthop Traumatol. 2015;28(6):448-454. PubMed abstract. https://pubmed.ncbi.nlm.nih.gov/26383037/