Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Can Dogs Get Cold Sores? Vet-Verified Facts & FAQ

young veterinarian woman examining teeth and mouth of cute lovely pomeranian dog at veterinary clinic

Many people have experienced a cold sore or fever blister sometime during their life. For humans, it’s often a painful condition that may come on suddenly. It may also accompany a cold or fever, usually occurring around the mouth. Cold sores result from a viral infection, most often herpes simplex virus type 1 (HSV-1). However, it’s a different story with dogs.

First, canines don’t get HSV-1, and you can’t transmit your condition to your pet. Canines have their own herpes virus but it doesn’t cause mouth sores.1 There are, however, several conditions that can cause mouth sores in dogs.

divider single dog paw oct 2024

Causes of Canine Mouth Sores

Canine Stomatitis

Canine stomatitis or chronic ulcerative paradental stomatitis (CUPS) is inflammation of the mouth, mucous membranes, and gums. Gingivitis and mouth sores are often associated with this painful condition. Drooling, bad breath, and feeding avoidance are classic signs.

Susceptible dog breeds include the following:

Trauma

Injuries around the face and lips can look like cold sores. Dogs love to chew and play bite, so every now and then they might get a wound around their lips. If they have had some rough play or a fight recently, they may have had their lip bitten or accidentally bit their own lip. Things like thorns and grass awns can be embedded in the lips causing inflammation, infections, and lumps.

woman-and-sick-old-german-shepherd-at-veterinarian
Image Credit: Beach Creatives, Shutterstock

Warts and Tumors

Abnormal growths often pop up around the lips and mouth. Skin cancers like mast cell tumors and benign growths like histiocytomas often start as small lumps that can be ulcerated. A papillomavirus can cause warts to appear in and around the mouth, which can look like cold sores.

Eosinophilic Granuloma Complex

The words “eosinophilic” and “granuloma” describe the type of inflammation seen in eosinophilic granuloma complex. The lesions are inflammatory and occur secondary to insect bites or other allergic reactions. Eosinophilic granuloma has the appearance of lumps or sores as a break in the mucous membrane. However, they don’t just occur in the mouth and on the lips. You may also see them on your pup’s thighs or anywhere else on your pooch’s body. Terriers and long-nosed large breeds are particularly susceptible.

Seek veterinary advice if you’re concerned about your pet’s well-being.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's our online service where you can talk to a vet online and get the advice you need for your dog — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

divider dog paws oct 2024

Treatment of Mouth Sores

The treatment depends on what’s causing the cold sore. Remember that they aren’t diagnostic of themselves. Your vet may need to biopsy the lesions or assess the response to a preliminary treatment plan.

Skin cancers usually need surgical removal, but other growths like histiocytomas and viral warts can sometimes resolve on their own.

Treatment for CUPS can be challenging, depending on the extent of the disease and infection. Excellent oral hygiene and care are at the crux of recovery. It also involves antibiotics to control secondary bacterial infections and other complications and pain relief. The owner’s compliance with home care is imperative. Your vet may also prescribe prednisone, a corticosteroid. It brings its own trials.

Treatment for eosinophilic granuloma begins with managing the signs and effects of the sore. It also involves identifying the trigger. If it’s stinging insects, your plan will extend to containing that problem. A local beekeeper can help if honeybees are the problem. They may remove them for free if you let them take the insects away.

Brown Spanish Water Dog opening her big mouth like yawning and lying on the sofa
Image Credit: Lucia Romero, Shutterstock

Dogster divider_v1_NEW_MAY_24_

Frequently Asked Questions (FAQ)

What Diet is Best for a Dog With Mouth Sores?

Mouth sores are often painful. They may put your dog off their feed because it hurts to eat. Your vet may suggest a canned diet that is easier to eat than kibble.

What Else Can I Do to Treat These Sores?

Your vet may suggest putting an Elizabethan or e-collar on your dog if they are pawing at the wound site. We recommend using a clear one to prevent your pet from running into walls or furniture.

Are Mouth Sores Preventable?

Prevention depends on the cause. For example, good oral hygiene can help prevent CUPS. Regular veterinary care can go a long way toward early detection and less stressful treatment. We suggest getting your dog used to having their mouth touched and examined. It’ll make brushing your pet’s teeth easier, which is the most effective way to maintain good dental health.

divider dog paws 3 oct 2024

Final Thoughts

Dogs can’t get cold sores from herpesvirus but they can get other mouth sores. Different disease processes are at work in each case. While they are sometimes self-limiting in people, that’s not always the case with canines. It all rests with the cause of the problem. It can run the gamut from a benign issue to something more challenging to treat. It makes a strong case for regular veterinary care.


Featured Image Credit: Josep Suria, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.


How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Nulo Dog Food Review: Recalls, Pros & Cons

Review Summary Nulo was created with quality care for dogs in mind. Its founder realized that there weren’t enough care options available for...

Can Dogs Eat Limes? Vet-Approved Facts & FAQ

Disclaimer: Before changing your dog’s/ cat’s diet or introducing new ingredients or supplements that they haven’t eaten before, especially when it comes to...

Can You Unspay a Dog? Vet-Verified Health Facts

Spaying is a procedure that removes a female dog’s reproductive organs. It is a highly recommended surgery for many health reasons. Also, if...

How Many Puppies Are Born in a Litter? Vet-Verified Average Sizes & Influential Factors

If your dog is expecting puppies soon, you are probably anticipating how many pups you should expect. This can be a very thrilling...

More related

Kuvasz Dog: Breed Info, Pictures, Facts, & Traits

The Kuvasz is part of a group of ancient Hungarian dog breeds, and the plural for Kuvasz in Hungarian is Kuvaszok. They’re an...

Can Dogs Eat Duck? Vet-Verified Health Benefits

It’s hard to resist when your dog is begging for a scrap or two from your dinner plate. But before giving your pet...

Wowauzer Dog Breed: Info, Pictures, Care Guide & More

Combining the hunting prowess of the Miniature Schnauzer and Welsh Terrier, the Wowauzer is an adorable designer dog that’s known for being charming,...

9 Best Bark Collars for Large Dogs in 2026 – Reviews & Top Picks

Training your dog is a complicated but necessary part of ownership. Some dogs respond very well to two general commands, while others need...

Keep reading

7 Best Wet Dog Foods to Mix With Dry in 2026 – Reviews & Top Picks

Wet and dry food has benefits and drawbacks, prompting many dog owners to mix the two to get the best of both worlds. Your dogs get the fun mix of textures that stave off food boredom, and you get the...

dry and wet cat food on white background

Whole Earth Farms Dog Food Review 2026: Recalls, Pros & Cons

Review Summary If you’re a pet parent, then you’ve probably already heard of Whole Earth Farms dog food just because of their tagline, “Goodness from the Earth.” Whole Earth Farms is dedicated to providing pets everywhere, whether they’re dogs or...

Dogster_Whole Earth Farms Dog Food Review

What Is Crude Fiber in Dog Food? Vet-Verified Nutrition Facts & FAQ

Finding good dog food can certainly be an uphill battle in many ways. Whether the problem is finding food that has the right nutritional components or if you have a picky dog who may not want to eat food, it...

Ginger dog eating

Can Dogs Eat Jolly Ranchers? Vet Approved Facts & FAQ

Do you have a candy jar on the coffee table or the counter? Does your dog enjoy stealing food when you’re not looking? You are not alone! With dogs, this is a common situation. You might be curious if Jolly...

Can Dogs Eat Jolly Ranchers

Pedialyte for Dogs: Is It Safe? Vet-Approved Health & Safety Guide

The most common way to treat dehydration in children and adults is with Pedialyte. It’s an over-the-counter, drinkable electrolyte solution that replaces electrolytes and minerals lost by dehydration. In small quantities, unflavored Pedialyte is safe for most dogs, but it’s...

electrolyte beverage in bottles

8 Dog Birthday Cookie Recipes to Treat Your Pup With

This article has been reviewed by a veterinarian for safety. The recipes included in this article will be suitable for most dogs however, it does not take your dog’s circumstances and health status into account. It is your responsibility to...

Dog Birthday Cookie Recipes to Treat Your Pup With

Apple Cider Vinegar for Dogs: Vet-Approved Uses, Safety & Effectiveness

Apple cider vinegar and home remedies are extremely popular right now, and for good reason. They’re usually affordable, and some have actually been proven to work. And who wants to miss out on affordable preventative medicine? However, some remedies are...

Apple Cider

Is Corn in Dog Food Bad? Vet Approved Ingredient Guide

Corn is a controversial ingredient that is used in a lot of commercial dog foods. It is very much a normal dog food ingredient in grain-inclusive diets and has been for quite some time. In fact, according to The Institute...

lots of corn