With an average lifespan of 10 – 13 years, it is not uncommon for our pets to develop lumps and bumps at some point in their life. Skin growths come in many shapes and sizes, and some are of more concern than others. But can dogs get skin tags? Like us humans, dogs sometimes grow skin tags. So, what exactly are these, and should you be concerned about them if your pet gets them?

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Understanding the layers of the skin in dogs

Skin makes up the largest organ of the body and contains multiple layers. Dogs and humans have the same layers in the skin, but they vary in hair cover and thickness. Given the variety in appearance of our many companion dog breeds, several of which have folds around the face, body or tail region, the amount of skin proportional to a dog’s weight can vary. This variety means that a dog’s skin can account for between 12 – 24% of the overall body weight depending on the breed.

The surface of the skin that we see with our eyes, is the epidermis

The epidermis acts as a barrier, preventing our body from losing moisture and blocking the particles that we come into daily contact with. It is made up of several cell types, the most common of which are keratinocytes. These replenish themselves from the bottom up, producing a compact top layer of older, dead cells which form a barrier locking in moisture and salts. Other cells in the epidermis are responsible for pigment (melanin) production, immune response, and sensory (touch) reception.

Below the epidermis is a thin basement membrane which supports the living basal cells which multiply to replace the dead ones above them as they are shed.

The next layer is the dermis, which is much thicker

The dermis contains hair follicles, and the oil-producing glands associated with these follicles. Both the hair (fur) and glands open through the epidermis to the skin surface. The density of both these depends on the part of the body, and the breed of the dog. Blood vessels and nerves run through the dermis to support the epidermis, and collagen is produced in this layer also. Just as the epidermis has immune cells, so does the dermis. Collectively, both layers act to prevent external pathogens from invading the body through the skin.

Under the dermis is the subcutaneous fat layer

Combined with the outer hair coat, this acts as an insulator to regulate body temperature. The thickness of this layer is affected by the weight and health of the animal. This layer also stores energy and fluids, and acts as a shock absorber.

What are skin tags on dogs?

Skin tags develop as an outgrowth of the epidermis. The epidermis of the skin tag may be thinner than normal but contains the same cells; meaning the colour (pigment) of the skin tag usually matches the surrounding skin. The dermis underneath brings blood vessels, collagen and fibrous tissue along with it; however, skin tags don’t usually grow hair as the cell structure within the tag’s dermis differs slightly from the surrounding skin.

From the surface, they usually look like a firm but flat patch of skin or an out-pouch of skin on a narrow stalk and can appear to hang off the skin like a pendulum. These more pendulous ones can feel soft and squishy to touch and are non-painful to your dog when you touch them. For the most part, skin tags are usually small, just millimetres in diameter; however, some of the more pendulous ones may be much longer in length despite a very narrow stalk attachment.

Why do skin tags form on dogs?

The exact cause for skin tags has not been determined. They can occur in any breed of dog and at any age. They are also just as likely in males or females. There may be some genetic involvement however, as cocker spaniels, poodles, miniature schnauzers, and English bulldogs have a slightly higher likelihood to develop them.

Skin tags can develop anywhere on the body. But they are more often seen on the torso, along the sternum, on the face or where there is a bony protrusion such as at the elbow or ankle joints. Lifestyle and size of the dog may also have an impact; middle-aged and older dogs of the large and giant breeds can be a bit more prone to developing them.

What is widely believed to be a trigger though is repetitive friction or trauma to the epidermis in a region of skin. Friction occurs where skin folds rub against each other. This includes normal anatomical skin folds, such as in the armpits, or can be folds created by rolls of skin in certain breeds or where an animal is very overweight.

Skin trauma can also occur with poorly-fitted harnesses and dog clothing. The fabric of some collars or harnesses are more likely to trap grit, dirt, fur and dead skin cells. This can dry into the fabric and then rub against the skin over time. If your dog has allergies, their skin can be more fragile, and may have a less robust epidermis. This may make their skin more likely to be damaged through friction; and definitely makes your dog more likely to self-traumatise their skin when scratching.

Managing skin tags on dogs

Regardless of the cause, skin tags may occur as a single entity or could occur in clusters. If there is a large area of skin affected by a cluster, the skin tag is on a limb or bony protrusion, or if it is the pendulous form, they are at greater risk of being traumatised. Because the epidermis may be thinner in a skin tag, it may take less force to damage the surface, which could cause discomfort. They may bleed or become infected.

Are canine skin tags dangerous?

True skin tags are benign. This means that they are a local issue only, and are not at risk of spreading (metastasising) to other parts of the body. Due to the characteristic appearance of skin tags, they can often be deemed to be one from appearance alone. Your vet may discuss this likelihood with you if they find one. That being said, a definitive diagnosis is only possible if the tissue is removed and assessed by a pathologist (known as histology). 

Surgical removal is unnecessary for the vast majority of skin tags. Where your vet recommends it, either because it is problematic or there is a suspicion that it could be something else, removal requires either a sedation or a general anaesthetic. The choice between these depends on the size and location of the skin tag or tags, and the temperament of your dog. A small skin tag on a lower limb for example, may be amenable to removal under sedation with the use of local anaesthetic. A larger area with a cluster, or a dog that is anxious at the vet clinic, may be best done under general anaesthetic.

Different types of dog skin tags

Based on histology, a skin tag may be given a descriptive name such as a fibrovascular papilloma or a collagenous hamartoma. These terms are used as a descriptor for the cellular make-up of the skin tag. Histology is also used to confirm that the growth has been completely removed on a cellular level. The surgical removal of a skin tag is expected to be curative.

For skin tags that are left in place, taking photographs can be a good way to monitor them over time. With any lump that isn’t being removed, it is important to monitor its characteristics for changes. These include the size and shape of the growth itself; and the colour of the surface and the skin around it. Where there are any doubts about whether a lump is a skin tag, or where you feel your dog’s skin tag has changed characteristics, it is important to get your vet to take a look.

When is a Skin Tag Not a Skin Tag?

There are other growths which can occasionally mimic a skin tag, and histology can differentiate these. If a skin tag has a pigmented surface when the surrounding skin doesn’t, it could instead be a melanoma which is a type of skin cancer. The papilloma virus, a disease more typically associated with warts, can occasionally trigger a skin tag-like growth instead of a wart. Papilloma-induced skin tags will typically disappear on their own (regress); as the body’s immune system mounts an antibody response to the virus.

Ticks, a blood-feeding external parasite, can sometimes be mistaken for a skin tag. Depending on the tick species and whether they have fed when spotted, they can range from a grey to brown colour. If you look closely, you may spot 8 little legs close to the skin surface. Ticks can carry diseases, so should be removed when found. It is important to remove a tick completely though, as they burrow their mouthpiece into the dermis to reach the blood vessels. Your veterinary team can assist with tick removals or give advice on how best to safely remove these at home.

How to prevent of skin tags on dogs

The formation of skin tags can only be prevented where there is an obvious source of friction or trauma that can be identified and corrected. For animals with allergies, management of the underlying allergic trigger, as well as skin barrier support, can limit the likelihood of self-trauma. For dogs with breed-related skin folds, it is important to have a regular cleaning regime. This will prevent build-up and irritation between the folds. For weight-related skin folds, your veterinary team can help create a weight loss programme to help your dog lose weight.

Dogs that are less mobile or are older may need extra padding under their body while they rest and sleep to prevent surface friction and the creation of pressure sores. For any dog, it is important that collars, harnesses and clothing are correctly fitted and regularly cleaned to prevent skin irritation.

Can dogs get skin tags – final word

Skin tags can affect any dog breed of any age and sex. As benign growths, they are more of an issue of appearance, than a concern to the health of your dog. However, some skin tags can be easily damaged, especially if they are pendulous. Although intervention is not often needed, removal may be warranted if they are being aggravated or there is a concern that it could be some other kind of growth. Your vet can advise if any management or prevention strategies are required to deal with your dog’s skin tags.

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