Can Dogs Get Cold Sores?

Some dogs just love giving face kisses, whether the person on the receiving end wants them or not. While most people’s main concern is about where the dog’s mouth has been, some may worry if their active cold sores can infect dogs. No one wants to spread their cold sores to others, including their pup. So, are dogs at risk of getting cold sores?

Can dogs get cold sores like humans?

Dogs don’t get cold sores like people. Some dogs can get ulcers or other lesions on their lips for other reasons, but generally not due to a viral infection. Dogs can get infected with a different, canine-specific variant of herpesvirus, but this virus has symptoms that differ from human variants. 

Why dogs do not get human cold sores

Cold sores in people are caused by herpes simplex virus (HSV-1 and HSV-2). Herpesviruses tend to be shared among a limited number of species, and human herpes does not spread to dogs. This means that human cold sores can’t be transmitted to dogs, no matter how much they lick.

As an aside, HSV-1 can spread to some small mammals such as rabbits and chinchillas. The virus can cause severe neurological symptoms that may result in death. For safety, avoid contact with these species if you have an active herpesvirus infection.

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Canine herpesvirus

Canine herpesvirus (also known as CHV-1, canine alphaherpesvirus-1, and CaHV-1) causes herpes infections in dogs. It can be transmitted from direct contact with an infected dog or from mother to puppy before, during, or after birth. Similar to human herpesviruses, infections with canine herpesvirus persist throughout life.

Lifelong infection doesn’t mean lifelong symptoms, though. Most dogs will overcome the active infection, and the virus will stay latent in the facial nerves. Recurrence of active infections can happen during times of stress, with immunosuppression, or with other health issues. Dogs may shed the virus intermittently throughout their lives.

How common is dog herpes?

Canine herpesvirus is seen in dogs worldwide. The prevalence of the virus varies by region and environment. Blood tests show infection rates up to 86 percent in some populations. Because of its effects on developing and newborn puppies, the virus has mostly been tracked in dogs used for breeding. Infection rates seem to be higher in dogs who live in shared facilities (such as kennels) than among household pets.

Symptoms of dog herpes in puppies

Newborn puppies are most susceptible to the worst effects of canine herpesvirus. Neonates rely on their mother and littermates for warmth and maintain a lower body temperature than adult dogs. Canine herpesvirus replicates most readily in the 95 to 97 degrees Fahrenheit (or 35 to 36 degree Celcius) range, which is the normal body temperature for very young puppies. In puppies less than three weeks old, the effects of herpesvirus can be devastating.

Symptoms of herpesvirus infection in newborn (less than three weeks old) puppies include:

• Decreased or absent nursing

• Weight loss

• Diarrhea

• Abdominal pain

• Mental dullness

• Difficulty breathing

• Nasal discharge

• Seizures

• Bruising

• Hypothermia

Unfortunately, most puppies infected with herpesvirus — in the womb or shortly after birth — die within days. Puppies who survive may be left with lifelong neurological conditions such as blindness and difficulty walking.

Puppies infected after three weeks of age can show similar signs to newborns, but usually have milder symptoms and a higher chance of survival. Their primary symptoms may appear as those of an upper respiratory infection: coughing, sneezing, and discharge from the eyes and nose.

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Symptoms of canine herpes in adult dogs

In contrast to puppies, healthy adult dogs infected with CHV-1 may not show any signs at all. If symptoms develop, they’re usually consistent with an upper respiratory infection. In fact, canine herpesvirus is part of the canine infectious respiratory-disease complex commonly known as kennel cough. Dogs can show signs of genital herpesvirus infections as well, with the development of vesicles (small, fluid-filled bumps) or redness around the penis or vagina.

Some infected dogs will develop ocular problems, including ulcerative lesions around or on the surface of the eyes. Immunocompromised adult dogs may have trouble fighting off a herpesvirus infection, which may spread systemically and result in severe illness or death due to pneumonia, liver or kidney issues, or neurological disease.

Breeding female dogs infected with herpesvirus have more trouble getting pregnant and produce smaller litters. Active infections during pregnancy can result in abortions and stillbirths.

How to tell the difference between canine herpes and other infections

Herpesvirus infections can be detected in a number of ways. For newborn puppies who die unexpectedly, a post-mortem examination can reveal tissue death and abnormal bleeding that raises the suspicion of a herpesvirus infection. This can be confirmed by sending tissues to a pathologist for confirmatory testing.

Testing for canine herpesvirus may be recommended in cases of spontaneous abortion, stillbirths, or when breeding females have trouble conceiving. A respiratory panel can be done for adult dogs with upper respiratory symptoms. This test includes screening for canine herpesvirus and many other causes of respiratory disease.

Differences between human and canine herpes viruses

Symptoms of an active herpes infection in people tend to be limited to ulcer-like sores around the mouth and genitals. Some people may have eye irritation as well. Except for some uncommon, but similar-ish symptoms of genital herpes, herpesvirus infections in adult dogs are quite different from those in adult humans. 

How cold sores in dogs are diagnosed

Dogs don’t really get cold sores like people do because of the differences in how herpesvirus infections manifest. Other diseases can cause dogs to have lesions in or around their mouths that look like cold sores. Some possible causes include autoimmune disorders, ulcers secondary to dental disease, licking a caustic substance, skin infections, and cancer.

If you notice areas on your dog’s lips that look like cold sores, get them checked out by your veterinarian. Depending on their appearance, your vet may want to take surface samples to look for bacteria or yeast, aspirate cells from the lesion, or take a small biopsy. Figuring out the cause of the lesion will help to guide treatment.

Treatment for cold sores in dogs

Don’t bother putting antiviral ointments or zinc creams (which can be toxic to dogs) on a pup’s oral lesions: They won’t help get rid of them. The treatment for lesions around a dog’s mouth will vary based on the cause. Sometimes a dental cleaning is needed to get rid of the plaque that’s contacting the lips. Topical or systemic antibiotics may be needed for infected wounds, and steroids could be recommended for autoimmune conditions. If there is suspicion that the lesion is a tumor, surgical removal is usually recommended.

Natural remedies for dog cold sores

Because dogs don’t get cold sores, there isn’t a need for natural remedies for them. Keep any wounds around your dog’s mouth clean and free of debris.

How to prevent cold sores in dogs

Cold sores aren’t a big worry in dogs due to the different strain of herpesvirus they get infected with. Keeping up to date with vaccinations is important for both puppies and adult dogs to help control bacteria and other viruses involved in upper respiratory infections in dogs.

Brush your dog’s teeth and pursue regular dental care as recommended by your vet. This can help prevent lip ulcers and a host of other diseases. Other causes of oral sores in dogs may not be preventable, but can be kept in control with medication.

When to see a vet for cold sores in dogs

Always check with your vet if you notice any new wounds or lesions around your dog’s mouth. Even though it’s not a cold sore, it could still indicate a problem for your dog. Getting mouth lesions taken care of quickly can prevent pain and discomfort for your dog.

Bottom line

Dogs cannot get cold sores. Cold sores in people are caused by herpes simplex virus, which is a different type of herpesvirus than the one that dogs get. Cold sores cannot be transmitted from people to dogs. Sores around a dog’s mouth could indicate another health problem and should be checked out by a veterinarian.

FAQs

Can dogs transmit herpes to humans?

Canine herpesvirus is not transmissible to people. 

Can dogs get cold sores from humans?

Dogs cannot get cold sores from people. Humans get cold sores due to a strain of herpesvirus that does not infect dogs.

Is there a vaccine for CHV?

There is no vaccine available for canine herpesvirus in the United States. However, there is a vaccine available in the UK and Europe that can be used in breeding dogs.

How do I know if my dog has a cold sore?

Dogs don’t get cold sores as people do. This means an ulcer or other abnormality on their lips isn’t due to a herpes infection. A vet can help determine the cause of oral lesions.

References

• Grest, P et al. “Herpes simplex encephalitis in a domestic rabbit (Oryctolagus cuniculus).” Journal of comparative pathology vol. 126,4 (2002): 308-11. https://pubmed.ncbi.nlm.nih.gov/12056779.

• Opstelten, Wim et al. “Treatment and prevention of herpes labialis.” Canadian family physician vol. 54,12 (2008): 1683-7. https://pmc.ncbi.nlm.nih.gov/articles/PMC2602638.

• Samies, Nicole L, and Scott H James. “Prevention and treatment of neonatal herpes simplex virus infection.” Antiviral research vol. 176 (2020): 104721. https://pubmed.ncbi.nlm.nih.gov/32044154.

• Wohlsein, P et al. “Spontaneous human herpes virus type 1 infection in a chinchilla (Chinchilla lanigera f. dom.).” Acta neuropathologica vol. 104,6 (2002): 674-8. https://link.springer.com/article/10.1007/s00401-002-0597-6.