Types of Cysts on Dogs

Dogs love to get belly rubs, back scratches, or simply the feel of running your fingers through their skin. While you and your pet enjoy these bonding moments, you might notice something like a lump or bump under your dog’s skin. Often, this can cause every loving pet owner to worry as these lumps or bumps called cysts can cause your beloved pet’s life if left unattended.

What are cysts?

Before knowing the types of cysts on dogs, let us first find out what a cyst is. A cyst on a dog is like a sack. It consists of hollow spaces inside the tissues. These spaces, in turn, can either have a solidified or liquid material. These materials can also be an abnormal breakdown product or something the body secrets.

There are times when cysts will grow within a cancerous lump, classifying them as malignant. But most of the lumps and bumps present in a dog’s skin are benign.

The importance of early detection of growths in dogs

As with other health issues, what is important is early detection of the cysts so that your dog can receive appropriate and immediate treatment before cancer progresses. The earlier the diagnosis is the more chances of getting better medication and the higher the chance of survival.

Early detection will save your dog from further troubles and give you peace of mind. As a responsible and loving pet owner, you sure want your dog to have the best and appropriate treatment at the earliest time possible. 

Types of cysts on dogs

First off, you should learn about the most basic classification of cysts. Cysts can be cancerous (malignant) and non-cancerous (benign).

A. Non-cancerous (benign)

These kinds of cysts cannot attack other tissues. They are incapable of spreading beyond their location. While benign lumps may not reach other areas, they may continue to grow in size and sometimes restrict your dog’s breathing and movement. 

These lumps can also make your dog uncomfortable, leaving them with no choice but to scratch the area. Should the scenario be like this, the best way to prevent further complications is to remove the lump through an operation.

Here are some of the known and most common types of non-cancerous or benign lumps or growths in dogs:

1. Lipomas (Fatty Tumors)

Lipomas are a natural part of aging in dogs. These are more commonly visible in older dogs. Some middle-aged dogs also have lipomas. These fat-filled tumors are the most common benign lumps in dogs and grow beneath the skin.

2. Follicular Cysts

As the name implies, this type of cyst starts from the hair follicles. Another name for these is epidermoid cysts. These appear as large nodules or bumps on your dog’s skin.

Follicular cysts are usually thick dark brown. Sometimes, they are yellowish or whitish in color. They may be found in younger dogs or senior dogs. Multiple cysts can also develop in dogs. Although these are benign growths, they can be bothersome to your dogs because they can become painful and itchy as they grow in size.

To properly diagnose this condition, vets will conduct fine needle aspiration (FNA). A fine needle called the fine needle aspirate is used to take out samples from the mass. 

3. Sebaceous Cysts

The most visible bumps on your pet’s skin are these sebaceous cysts. These are also known as tumors in the oil glands. A sebaceous cyst appears like an overgrowing pimple filled with sebum. 

These kinds of cysts may be left untreated. While there is a possibility that it will go away on its own, there is also a change of recurring. 

Once it bursts, you may notice a white substance coming out of these bumps. It looks like cottage cheese. 

Most sebaceous cysts are harmless, but pet owners cannot say there is nothing to worry about as it is just a sebaceous cyst. If your dog has this cyst, it may be prone to secondary bacterial infection, which can cause soreness and redness. Thus, it is best to take your pooch to the vet and get the necessary help.

4. Histiocytomas

Common to young dogs below six years of age, histiocytomas appear like red, button-like lumps (ulcerated nodules). Many would think these are dog leg tumors because of their massive growth and look like those dangerous cancers in dogs.

Usually, they disappear on their own without the need for medical intervention. But should you find these on your dog, you might want to have it verified by the vet first to rule out the possibility of cancer.

5. Urticaria (Hives)

Very similar to those found in humans, urticarial or hives appear as reddish welts on the body. These can be uncomfortable to your dogs because aside from being swollen, they are itchy.

Hives are a result of allergic reactions to bee stings. It could also be from certain pollens and plants.

In the case of mild hives, this may not be too alarming as they usually disappear or heal on their own. There are times, however, when the vet would recommend some steroids or antihistamines.

6. False Cysts

The most common false cysts in dogs are those that develop from trauma and look like a hematoma. There are also times when these skin cysts develop due to reactions to injections. These blood-filled structures have no secretory lining and are dark.

7. Abscesses

Often called a “pocket of pus”, an abscess is usually caused by a bite of another animal or insect. That wound gets infected.

Another cause of abscesses is grass awns, sticks, or other sharp objects that may leave a cut into your dog’s skin. Beneath the skin layer, it may appear like a water balloon, and it can feel firm.

In cleaning, vets would drain and flush the fluid out of the swollen area using an antibacterial solution. The veterinarian usually prescribes oral anti-inflammatory medicines or antibiotics.

8. Dermoid Cysts

Although very rare, this type of cyst is formed even before a dog’s birth. In other words, they are congenital.

9. Perianal Adenomas

Common to dogs who have not been de-sexed (neutered or spayed), perianal adenomas are benign tumors that grow around the anal area. It is usually not painful.

As to its growth pace, it is usually slow. However, it may become ulcerated and infected. If you find any bump or lump in your pet’s anus, take your dog to the vet because the malignant tumor can be common in this area. 

10. True Cysts

Also called real cysts, this type of cyst originates in the glands like the sweat glands. True cysts are formed when the ducts get blocked. Unlike a false cyst, this has a secretory lining.

This produces secretions even after draining the cyst. For that, vets need to remove the entire cyst wall to prevent the structure from coming back.

11. Sebaceous Adenomas

Bichon Frise, Maltese, Poodles, and their crossbreed dogs commonly have wart-like growths forming like clusters in their sebaceous glands. These wooly-haired dog breeds are more prone to sebaceous adenomas than other breeds.

Aside from those canine breeds, these are also common conditions among older dogs. These tumors grow slowly. It is easy for vets to identify this type of tumor by examining its appearance.

There are times, however, when a biopsy is required. Although these are mostly benign, there may be a need to remove them when it causes problems for your dog as when it gets ulcerated or puts your dog at risk of irritation.  

12. Melanomas

Canine melanomas appear as dark lumps on your dog’s skin. Melanomas can either be benign or malignant and are slow-growing.

If you think melanoma in dogs is a product of exposure to sunlight, then that is wrong. Unlike melanomas in humans, canine melanomas are tumors linked to melanocytes – the pigment-carrying cells. 

There are even more aggressive types that grow on a dog’s legs and mouth. In this case, surgery is required for its removal, but there is no guarantee that it will not recur.

13. Warts (Papillomas)

You probably heard about dog warts countless times. Papillomas, as vets call them, are caused by the virus known as papillomavirus and are highly contagious.

Canine warts are common among puppies. Aside from puppies, immunocompromised dogs and other older dogs are also prone to warts.

If you notice your puppy or older dog having a small cauliflower-like growth on its mouth, eyelids, head, or face, that could be a wart. Warts can also grow on your pet’s feet (in between toes or on the footpads), lower legs, and even on its genital area.

Whenever your dog has warts, no treatment is required. They usually fall off by themselves in a couple of months. These can also be troublesome for your dog when they get irritated. Thus, the need for it to be surgically removed.

14. Skin Tags

As humans get older, they develop skin tags. The same is true with dogs. As they get older, some fibrous growths manifest on the skin’s surface – face, chest, armpits, back, legs, and some other areas. Sometimes, many would think they are warts.

Whether you have a small breed dog or a large breed dog, they can be prone to skin tags, although the latter can be at greater risk.

15. Granulomas 

Firm to touch, these granulomas can be found underneath the skin. They look like red lumps, and the surface appears to be crusted.

As most of these look malignant, veterinarians highly recommend surgical removal or biopsy to check whether the tumors are malignant or benign.

16. Hemangiomas

Made up of skin tissues or blood vessels, these tumors may have been caused by exposure to sunlight. But there are some other factors too that might have caused hemangiomas. Vets recommend surgical removal or biopsy to check whether these are benign or malignant, as some hemangiomas become malignant over time.

B. Cancerous (malignant)

What makes malignant cysts dangerous is their ability to perform metastasis. That means that it is capable of spreading from its present site to another within your dog’s body. It can enter the lymphoid system as well as the bloodstream.

Cancerous growths can also spread quickly to your dog’s organs like the brain, lungs, liver, and bones. The cancer cells spread and growth rate can become faster than usual, and they may destroy those nearby tissues. 

Once your dog gets a confirmation that the cysts are malignant, immediate removal is required by way of surgery to stop its further spread. 

Here are some of the known and most common types of cancerous lumps or malignant bumps or growths in dogs:

 1. Mast Cell Tumors (MCT)

What are mast cells? Also called allergy cells, these white blood cells are found not only in the skin but in other organs of the body, and play a vital role in the body’s allergic and inflammation responses.

Often found in some specific breeds of dogs like Beagles, Boxers, Boston Terriers, Schnauzers, and Labrador Retrievers, including dogs aging over 8 years, MCTs consist mostly of mast cells, as the name suggests. This is also the most common skin cancer in dogs. It comprises about 25% of all the known tumors in dogs.

As these appear like lumps and bumps, they may look very ordinary to you. But as a responsible owner who thinks only of what is best for your dog, you need to have it checked by the vet the moment you see this on your dog. Once diagnosed with MCT, the vet will have to check also on the extent of the spread.

2. Melanomas

As mentioned in the above portion on melanomas, canine melanomas appear as dark lumps on your dog’s skin. Melanomas can either be benign or malignant and are slow-growing. Thus, there is a need for immediate evaluation by the vet to rule out cancer.

3. Mammary Carcinomas (Breast Cancer)

In case you are not aware of this, dogs have five mammary glands, and these mammary carcinomas are growth in the mammary tissues. These are common in female dogs and rare in male dogs. Among the most common breeds prone to this type of cancer in dogs are German Shepherds, Spaniels, Miniature Poodles, and Toy Poodles.

The chances of getting canine breast cancer are high among female dogs who have not been spayed or even those spayed only after their first heat cycle. 

Not all mammary tumors are cancerous (malignant. Some are also non-cancerous (benign). However, on very rare occasions, when male dogs develop mammary tumors, the chances are 100% malignant.

Looking at dog tumor pictures, you will notice that these mammary tumors vary in consistency, shape, and size. Immediate removal is necessary by way of surgery as these can spread fast to the lymph nodes, other organs, as well as other mammary glands. Chemotherapy is also another option to remove the lumps.

4. Soft Tissue Sarcomas (Fibrosarcomas)

Let us first know what connective tissues are. These tissues are responsible for binding, supporting, connecting, or even separating the various tissues and organs in the body. The connective tissues are made up mostly of fibroblasts. In cases where there is an overgrowth of fibroblasts, this develops into fibrosarcoma.

Also a common tumor especially in large breeds of dogs (middle-aged and older dogs), fibrosarcomas are usually found in the mouth, nasal cavity, body’s trunk (chest and abdominal wall), and extremities (limbs). These can be mistaken as lipomas at times. If you see a dog leg tumor picture showing fibrosarcomas, you will notice the lumps’ semi-firm or firm appearance. 

Usually, this type of tumor in dogs is slow-growing except for those that originate within the leg bone (bone cancer), which grows rapidly. To get an accurate diagnosis, a tissue biopsy is necessary. Once it is fully confirmed, surgical excision should be performed as soon as possible to prevent it from further spreading to the other organs in your dog’s body.

5. Squamous Cell Carcinomas (SCC)

Another tumor linked to excessive exposure to sunlight is squamous cell carcinoma. This develops in the topmost layer of the skin called the squamous layer. Dogs with SCC are usually between 8 to 10 years of age.

You can find these skin cell tumors on hairless or unpigmented areas such as the edge of the nose, lips, vulva, and even the eyelids. This type of skin cancer in dogs can also be present in the ears, paw pads, nail bed, and abdomen.

As to appearance, it is usually a single lesion in one location, but there is this very rare type called Bowenoid carcinoma or Bowen’s disease. Although very rare in dogs, this multicentric squamous cell carcinoma has multiple lesions in varied locations.

These tumors need immediate removal as they are very invasive and can cause disturbing pain and deformities in the organs as it spreads. If left untreated, this can cause your dog’s life.

Seek veterinary help

As a loving owner, you only want the best for your dog, do you? You want to see that apart from giving your dog the proper nourishment to boost their immune system, you also want them to be free from other conditions like a lump, cyst, or bump.

Regular vet check-ups can be of great help in discovering whatever abnormal growth they may have. Whether it is a puppy, an adult, or a senior dog, lumps and bumps can occur at any stage.

Should you find a mysterious bump and are unsure of whether it is a benign or malignant type, schedule a vet check-up right away. One harmless-looking overgrowth or mass can be a source of a major problem later on if you brush it aside. 

Vets are ready to help you and your pet deal with the situation. Aside from biopsy, a microscopic examination of the tissue can help determine which type of cyst or growth your dog has.

There are a lot of ways to treat a cyst or a lump. It could involve surgical removal, and your dog will be given oral medications, or it could involve undergoing radiation therapy to slow the rate of metastasis.

Don’t be afraid to seek expert medical help. Remember that: as with human cancer, early detection can save your dog’s life.

*photo by macniak – depositphotos