Why Does My Dog Have Sores On Their Upper Lip?

Photo by Steve Baker on Flickr

Dogs can get sores on their lips just like humans. 

Dogs are far more vulnerable to contracting certain diseases in their mouth because they use their mouths as hands. 

Like picking up objects, eating food, and licking random surfaces, including their favorite human friend. 

So if you ever noticed a sore, lesion, bump, or pink spot on your dog’s upper lip or around the mouth area, chances are it could be linked to some periodontal or autoimmune disease. 

To start with, let’s take a look at the main type of sores that might be found on their lips.

Four types of sores that dogs can get on their lips

  • Oral Tumors cause abnormal growth of cells. A dog is made up of many different cells, such as skin cells, bone cells, fibrous cells, and many other cells. However, there are some types of tumors  that are benign, meaning they are not cancerous. Malignant tumors will grow and spread aggressively. Not to mention different types of cancers are prominent in specific breeds of dogs. The oral tumors can look really darker and or sometimes no color.  
  • Oral warts are caused by oral papillomavirus found in dogs. These lumps are located on a dog’s upper lip or inside of its mouth. Viral papillomas are warts that flare up in the mouth. The small wart-like growth can show up in the tongue, roof of mouth, cheeks, and on a dog’s lips. 
  • Canine Ulcerative Paradental Stomatitis (CUPS); It’s a very tedious condition to treat because outbreaks are reoccurring. CUPS is classified as a periodontal disease because it affects the gums, causes  inflamed gums, teeth loss, and can damage the jawbone. The warts are described as whitish,  greyish,  fleshy, lesions on the mouth. These lumps can flare up on the lips, mouth, tongue and throat.
  • Pemphigus is a disease that attacks the immune system; it’s most common in older dogs. There are three different types.
  • Pemphigus Foliaceus causes ulcers and sores that can over time cover various parts of the dog’s body, including the mouth area. 
  • Pemphigus Erythematosus only affects certain breeds of dogs as listed below and isn’t as bad.
  •  Pemphigus Vulgaris is more aggressive, attacking the deepest layer of epithelium (tissue that forms the body’s outer layer)—causing blisters, vesicles that often rupture, and lesions on the dog’s body. 

What causes sores on a dog’s lip?

Like, the papillomavirus (HPV); affects humans.

However, there is a canine version.

Oral warts are caused by papillomavirus, which causes warts in or around a dog’s mouth. 

A virus causes the outbreak.

The virus is harmless to humans and only affects dogs.

Papillomavirus can affect newborn puppies as young as 2 years old and younger.

These pups are more predisposed to contracting the virus because of a weak immune system.

On the bright side, the more these young pups grow, the more antibodies their body will produce to help destroy the virus permanently. 

Canine Stomatitis is also known as Chronic Ulcerative Paradental (CCUP), a chronic disorder that affects the lining of the mouth.

These are painful bumps caused by a continued reaction to plaque build-up on a dog’s teeth, higher concentration of antibodies fighting off tissue and bacterial film, and sometimes the causes are just unknown. 

Sometimes, much like how humans get cancer, it may seem like it came out of nowhere is the same phenomenon in dogs a lot of the time, due to hereditary or unknown factors.

However, some of the causes of oral tumors may be due to environmental factors.

Oddly enough, male dogs are way more likely to get cancer than female dogs.

Signs of oral cancer depend on the location of the tumor and size and if it’s spreading.

The bump has no color, cauliflower-shaped, small swollen lumps, and inflamed gums. 

How can they be treated?

For oral tumors, surgical removal is the best option.

First, the veterinarian will do a simple CT scan of the head and neck to pinpoint the extent and source of the disease.

On the plus side, this exam also helps locate any lymph nodes, and the doctor will remove those as well.

Surgical removal of oral tumors is the best treatment plan to prevent the spreading of cancer. 

Some oral warts will go away after a few months without treatment, resulting in the dog developing immunity against the virus.

But, if it’s a large number of bumps, the dog will develop other symptoms like lameness: the dog will move slowly and sometimes limp. 

If warts do not go away within 3-5 months, they can become cancerous and more challenging to eradicate.

When Oral warts become a cause for concern, the best treatment option is to remove them surgically.

Warts can be removed with a scalpel, laser, and cryosurgery–the use of intense cold to destroy the wart. 

In addition, other treatment plans like the use of medication are only used when there is a large number of lumps.

It is, however, challenging to tell how effective this treatment option is since most bumps go away on their own. Below are the various types of treatment plans. 

  • Interferon- is an oral injection that helps restore the dog’s defense system. 
  • Imiquimod- is a combination of antiviral medication and antitumors.
  • Cimetidine- oral treatment could negatively affect the immune system. 
  • Azithromycin- oral medication 
  • Autogenous vaccination- a vaccine made out of the wart virus to help strengthen the immune system to fight off the virus.
  • Reduce immunosuppression- a drug that suppresses the immune system to fight the sickness harder. 

Papillomavirus is asymptomatic in dogs.

Therefore, no treatment is necessary unless the n red sores on your dog’s upper lip become infected.

Furthermore, if the lesions on your dog’s upper lip become infected, antibodies will help clear up the infection. 

  • Canine Stomatitis is difficult to treat sometimes. Lesions can appear on your dog’s lip and around the tooth. The veterinarian will take out the infected tooth and remove the plaque buildup. 
  • Removal of plaque and decaying tooth.
  • Tooth sealant to protect against plaque build-up. 
  • Consistent dental care at home using  toothbrush, antibacterial wipes, and gel.
  • Antibacterial medication to help fight off bacteria in the mouth. 
  • Medication to reduce inflammation.
  • Pain relief medication to help your dog feel comfortable. 

Are any breeds more susceptible to mouth sores than other breeds?

  • Oral warts are more commonly linked to breeds like Boerboel, Great Dean, and Mastiff. 
  • Oral tumors are more likely to affect breeds like Chow Chows, Boxer Dogs, German Shepherd, German Shorthaired Pointers, Weimaraners, Golden Setters, Minister Poodles, and Golden Retrievers.
  • Dogs that are more susceptible to getting Canine Stomatitis are dachshunds, pugs, Cavalier Kings Charles, petite fully white dogs, Havanese, Eskimo dogs.
  • Pemphigus Erythematosus commonly found more in German Shepherds, Collies, and Shetland Sheepdogs. This type of illness is mild in appearance. 

Why has my dog got sores on his lips?

Much like there are different forms of many trends of the herpes virus that humans can contract. Unfortunately, dogs can get herpes too.

These kinds of cold sores are called canine herpesvirus (CHV). Luckily CHV is not fatal.

Dogs can get on their upper lip from contact with a human’s bodily fluids or an infected dog; they can also get cold sores through normal doggy behaviors such as licking, and nosing.

Newborn puppies can also be born with the virus, sadly this can be life-threatening. However, sores on a dog’s lip or nose are a more serious underlying condition of your dog’s  overall health.  

  • These are the signs and symptoms your dog has cold sores, such as consent licking of the sore. 
  •  change of color in tongue
  •  No appetite, chewing unnaturally
  • touching the area of the sores their paws

What are the best home remedies for these sores?

Although you can cure cold sores, and if the blisters on your dog’s upper lip get infected,  seek veterinary help! There are a few at-home treatments that you can use to relieve your dog’s symptoms. 

  • Protect yourself and put a muzzle on your dog’s mouth because if your dog is in pain, he may bite you. 
  •  Use an antibacterial soap to wash the bumps on the dog’s upper lip. Trim down the hair on your dog if needed so you can see the pink spots on your dog’s upper lip. 
  • Instead of antibiotics, use apple cider and vinegar and apply to the area 3 to 4 times a day.
  •  Make a homemade saline solution placing a teaspoon of salt and a cup of water to disband. Then put the solution on the sores 3 to 4 times a day. 
  • Damp tea bags placed directly on the infected sore on your dog’s upper lip to  help reduce redness.
  •  Make wormwood oil. It’s a pretty decent remedy that can treat swollen bumps on a dog’s upper lip. A combination of thyme oil and olive oil may help a great deal. You can even add yeast to the mixture for faster healing.

There are many different reasons dogs get cold sores on their upper lip. The simplest explanation may not always be enough. However, simple home remedies can help control the blister on your dog’s upper lip. Be cautious because your dog may be in pain when touching the infected area.  The best possible answer is to take your dog to the veterinarian for a proper examination because it’s better to stay on the safe side, and your best pal will thank you! 


James Grayston

My name is James and I love dogs. have owned four Golden Retrievers in the past 15 years. Currently I own two "Goldies"- a five year old and a seven month old. The photo shows me with our youngest when she was about 7 weeks old!