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Bump on Dogs’ Back: What They Are & What to Do

Bumps on dogs’ backs can be cancer, benign tumors, mange, allergies, insect bites, ticks, sebaceous cyst, abscesses, post-injection nodules, or warts. Bumps on the backs are not as common as in other areas of the body. Contact the vet if your dog has one or more bumps on its back.

Most dog owners quickly think of the worst possible scenarios when discovering bumps and lumps.

But there’s no need to panic if you feel a bump on your dog’s back. Most skin bumps are harmless, and in some cases, it is just a tick.

What you can do is carefully inspect the bump. Do not pull or scratch but contact the vet and describe it to them. Only they are able to make a correct diagnosis and administer the appropriate treatment.

In this article, you will learn why dogs develop bumps on their backs, what you should do, and more.

Why Does My Dog Have a Bump on Its Back?

Dogs develop bumps and lumps on their back for many reasons. The most common are allergies, insect bites, folliculitis, parasitic infections, and others. Less common causes are skin cancers, both malignant and benign, abscesses, or sebaceous cysts. 

Depending on the cause, bumps on dogs’ backs can be of all sizes and colors:

  • Cutaneous or subcutaneous
  • Red, pink, black, white, or gray
  • Single or multiple
  • Big or small
  • Smooth or rough
  • Round, oval, or irregular
  • Movable or immovable
  • Ulcerated or not
  • Infected or not

Most of the bumps that occur on your dog’s back are harmless. They can appear in any breed and age, but old dogs and certain breeds are generally more prone.

Why Does My Dog Have a Bump on Its Back
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Sometimes benign tumors become cancerous (malign). If they are discovered and treated in time, your dog has greater chances of recovery.

In any case, go to the veterinarian when you find one or more bumps on your pet’s back.

Here are the most common reasons why dogs develop bumps on their backs:

  • Clogged sebaceous glands
  • Papillomavirus
  • Injections
  • Skin infections
  • Parasites
  • Allergies

Bumps on dogs’ backs can also be benign or cancerous tumors.

1. Clogged Sebaceous Glands

Clogged Sebaceous Glands

Cysts form when the sebaceous glands clog. These cysts contain sebum: a thick and oily substance that has a role in protecting the skin.

Sebaceous cysts appear as small white bumps in areas where these glands are found.

In some cases, these cysts become infected and fill with pus.

Treatment of sebaceous cysts includes drainage or surgical removal of the cyst and application of local creams. 

In cases where they are infected, the vet can also prescribe oral antibiotics for your dog.[1]

2. Papillomavirus

Viral Papilloma

Papillomavirus is a DNA virus with an incubation period of 1-2 months. This virus leads to the development of warts on dogs’ skin. They are pink, white, or gray harmless (benign) tumors with an irregular shape.

They can appear on any area of the body, including the back. They are usually solitary, but can also form in groups.

Papillomatosis is a contagious disease that is transmitted from dog to dog and through contaminated objects:

  • Toys
  • Accessories
  • Food bowls
  • Bedding

Warts usually disappear on their own over time, but you can also choose to have them surgically removed.[2]

3. Injections

Injections on dog

Sometimes subcutaneous injections lead to the formation of nodules or bumps under the skin. These bumps are a local inflammatory reaction and appear a few weeks after the injection/vaccination. It is not an allergic reaction.

These bumps can become infected and turn into abscesses.

Nodules following injections mostly disappear by themselves. Drainage and oral antibiotics may be needed, if they do become infected.

The vet may also recommend surgical removal if the nodule has not disappeared within three months of its appearance.[3]

4. Skin Infections

Skin Infections That Cause Black Spots and Hair Loss

Folliculitis and acne are two most common skin infections that lead to the development of bumps on dogs’ backs.


Folliculitis occurs all over the body, including dogs’ backs, due to infections, parasites, trauma, and certain systemic diseases.[4]

It affects hair follicles and is manifested through:

  • Red bumps full of pus (papules)
  • Redness
  • Itchiness
  • Excessive scratching
  • Pain
  • Hair loss


Acne generally occurs in young dogs and manifests with white or black small bumps on their skin. Bumps can appear anywhere on the body, including the back. It is more frequent on dogs’ faces. 

It is not recommended to pop the pimples until you talk to a vet.[5]

Treatments for folliculitis and acne generally include the application of antibiotic creams. In severe cases, they can also prescribe steroid treatments.

5. Parasites

Sarcoptic Mange in Dogs
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Ringworms and sarcoptic mange can cause bumps to appear on dogs’ backs or anywhere on their bodies. Bumps can also be embedded ticks.


In some cases, bumps on dogs are nothing more than embedded ticks. If this is the case, remove it and monitor your dog for one or two weeks for tick-borne disease symptoms.

Related: Hard Lump on Dog After Tick Bite

Sarcoptic Mange

Dogs with mange have small red bumps on their skin, intense itching, and sores.[6] Infected dogs often end up self-mutilating due to itching, making the situation worse.

This type of mange is extremely contagious, transmitted to both humans and other animals.

Treatment of mange includes bathing with special shampoos and the use of external antiparasitics.


Although they sound like parasites, ringworms are actually fungi (Microsporum canis). This fungus affects the skin and hair follicles, causing crusts, redness, and characteristic spots all over dogs’ skin, including the back.

Ringworms can also be transmitted to humans and other animals.[7]

Treatment consists of the administration of antifungal creams and oral drugs.

6. Allergies

Flea Bite Pet Allergies

Irritants (e.g. pollen, food, insect bites, or drugs) can cause allergies and the appearance of small red bumps (i.e. hives) on dogs’ skin, including their backs. Allergies mainly manifest through intense itching, scratching, and hair loss.

Depending on the factor that caused the allergy, the treatment consists of the following:

  • Changing your dog’s diet
  • Administration of antihistamine drugs
  • Ointments application

7. Benign and Malignant Tumors

Benign Tumors on dog
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Benign tumors, unlike malignant ones, are considered harmless. In some cases, they can become cancerous.

Skin tumors are of two types:

  • Benign (harmless)
  • Malignant (harmful)

Benign tumors of the skin can be:

  • Melanocytoma
  • Histiocytoma
  • Mastocytom
  • Hemangioma

Malignant tumors of the skin include:

  • Malignant melanoma
  • Squamous cell carcinoma
  • Cutaneous hemangiosarcoma

Benign and malignant tumors appear as growths (bumps or nodules) of different sizes and shapes, red, pink or black. They can only be differentiated through pathological examination.

Malignant tumors often ulcerate, causing pain and bleeding. Benign bumps do not.

Treatment commonly consists of the surgical removal of the tumor. 

When it comes to malignant tumors, chemotherapy, radiotherapy, or other adjuvant treatments are also recommended.


Bumps on dogs’ backs have many causes. Many of these bumps are harmless, and you do not need to panic if you find a growth on your dog’s back.

Take your dog to the vet as soon as you discover one or more bumps on its back or skin, and always ensure proper hygiene. Most of these medical conditions can be avoided in this way.

About Iulia Mihai (DVM)

Dr. Iulia is a certified veterinarian with more than 10 years of experience in the field. With extensive knowledge of diet, care, and medication, she helps Misfit Animals provide readers with accurate knowledge on technical topics.

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