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How to Drain a Cyst on a Dog

How to Drain a Cyst on a Dog

This post contains affiliate links. As an Amazon affiliate I earn from qualifying purchases.

It’s tempting to consider draining a cyst on a dog, especially when they appear ready to pop.

They sometimes look a bit like pimples, although they can get to be the size of a golf ball. The cysts we’re talking about here are epidermal cysts, meaning they occur on or under the skin.

There are several different types of cysts discussed in this post. You’ll learn when to contact a healthcare provider along with common treatment options.

Unfortunately, draining a cyst on your dog without medical intervention can cause pain while leaving your dog’s skin vulnerable to bacterial infection.

Veterinarians should be consulted to examine any new lumps or bumps on your dog. This is especially true for lumps that do not go away on their own (i.e. a bug bite).

This post will give you a better understanding of why you shouldn’t drain a cyst on a dog, why you should get a veterinary evaluation, and what to do if the cyst ruptures by itself.

What is a Benign Cyst?

A cyst is a general term used to describe a fluid-filled lump under the skin. Cysts sometimes look like pimples and appear as a raised bump on the skin.  Typically, they are filled with liquid or solidified materials made up of sebum. Sebum is the oily substance normally secreted by the sebaceous glands.

Sebum plays a role in keeping skin healthy by:

  • preventing dryness
  • lubricating the skin and preventing friction
  • waterproofing the skin and fur
  • keeping heat and water inside the skin
  • regulating the growth of microbes

A benign cyst means that it isn’t cancerous. However, the only way for a veterinarian to make an accurate diagnosis is through a fine needle aspiration. The process involves inserting a hollow needle into the mass for sampling of cells. The tissue is stained and examined under a microscope.

How Cysts Develop in Dogs

Cysts can develop as a result of local injury to the follicles, blockage of skin pores, or – in the case of hairless breeds – result from inactivity of the hair follicles.

They develop from hollowed-out cavities within the body and can appear due to scar tissue, injury inflammation or skin infections. The cause of the cyst isn’t as important as potential treatment.

Cysts, somewhat like calluses and blisters, act as a protective buffer around injured tissue.  In some cases, dogs can develop cysts internally on or around organs.

Examples of different types of cysts include the following:

True Cysts

A true cyst is non-inflammatory and has a membrane that lines the inner surface (secretory lining). They tend to occur in the sweat glands due to blocked ducts.

These cysts are very common in dogs and often appear on the eyelids.

False Cysts

A false cyst does not contain a secretory lining. They are filled with fluid-filled pockets of pus and form as a result of injury or trauma to the skin. Injuries to the skin can cause a disruption of blood flow to the area. Without that blood flow, skin cells will die.

Fluid forms inside the cyst when the dead tissue liquifies. At that point, the body sees the cyst as an invader. The body attempts to protect itself from the cyst by walling itself off from the rest of the bodily tissues.

In many cases, a walled off cyst is not considered a major problem.

Follicular Cysts 

Just as the name implies, follicular cysts develop around dilated hair follicles. A follicular cyst can be considered sebaceous or epidermoid.

If you’ve ever seen blackheads in people, you might notice them on your dog too. Blackheads (known as comedones) are similar to follicular cysts but have wider than normal openings.

Sebaceous Cysts

A sebaceous cyst (also known as a fatty cyst) is a common occurrence in dogs.  They can appear anywhere on the body but are commonly found on the face, neck, upper legs, and abdomen. They occur in the secretory cells of the skin.

The over-production of sebum (oily substance) on a dog will have one of three results:

  1) It will dissolve on its own.

  2) It will rupture naturally.  

3) It will wall itself off. When it walls itself off, it may stay the same size and maintain the same appearance.

Sebaceous cysts are not painful to the dog and can be caused by hormonal changes or diet. In some cases the cysts are considered “idiopathic”, meaning the cause is not known.

Unfortunately, sebaceous cysts are prone to secondary bacterial infection which is why it’s important to properly clean and drain cysts that have opened on their own.

Interdigital cysts occur commonly in older dogs

Dermoid Cysts


Dermoid cysts only happen in utero. They are considered complex congenital cysts and happen before a puppy is born. These are considered rare.

Risk of Bacterial Infection

Popping a cyst on a dog is painful to the dog and could worsen the condition.  In some cases, cysts will open and begin to drain on their own. In that case, it’s important to know how to treat the area.

Continue reading below for more information on how to gently clean an open cyst.

Serious Cysts and Tumors Dog Owners Should Be Aware Of

The only way to tell if it is a benign cyst or cancer is to perform a fine-needle aspirate or tissue biopsy. 

Some telltale signs that it is a benign cyst and nothing more include the fact that it is easy to move. A benign cyst will be soft, painless, and easy to move around.  Cysts are also known as lipomas or tumors, but that doesn’t mean they are cancerous.

Unfortunately, some skin tumors can be cancerous. Again, it’s impossible to make a diagnosis by appearance alone. The following list illustrates the importance of seeking veterinary care to examine any new lumps or bumps.

Malignant Melanoma

Malignant melanomas tend to occur on a dog’s mouth or mucous membranes. They grow quickly and can spread to other organs including the liver and lungs.

Squamous Cell Carcinoma

This type of skin cancer is the result of sun exposure. They tend to spread to the lymph nodes and can aggressively destroy tissue (including bone) around the tumor.

Mast Cell Tumors

Mast cell tumors occur in the mast cells of the immune system. They are the most common skin tumors in dogs. Mast cell tumors have a variety of appearances and can easily be mistaken for something else.

Dog Breeds Prone to Cysts

Any dog can develop cysts and tumors. However, there are some breeds that seem to be more prone. These include:

Mexican Hairless

The Mexican Hairless comes in a toy, mini, and standard sized variety. These dogs are elegant but active. They make good watchdogs, but not guard dogs.

Chinese Crested

The Chinese Crested is also a hairless dog. This dog is affectionate, lively, and playful.

Rhodesian Ridgebacks

AKA the African Lion, this dog was designed for hunting and guarding.  

German Shepherds

German shepherds are considered an all-purpose worker. They are large dogs with high intelligence.

Basset Hounds

Sebaceous cysts are common in basset hounds. This dog breed is small and stands at about 14 inches from the shoulder. They have heavy bones and powerful legs. This dog is designed to sniff out small game.

Labrador Retrievers

Labrador retrievers are large but gentle dogs. They are considered the traditional waterdog of Newfoundland and were bred to retrieve hunted ducks and other game.

READ MORE ABOUT SEBACEOUS CYSTS

Draining a cyst at home could cause bacterial infection

Will Your Veterinarian Drain a Cyst on a Dog?

Veterinarians are highly skilled professionals. They are the only people who should attempt to drain a cyst on a dog.

If the cyst is very large (some grow to the size of a golf ball or larger) and is uncomfortable for the dog, the vet may opt to surgically remove it. Small, uncomplicated cysts are typically left alone. 

How to Treat a Ruptured Cyst on a Dog

If your dog’s cyst doesn’t go away, but instead erupts, you’ll need to take care of the wound. It’s important to keep it open and draining freely to get all of the fluid out.  

A warm compress should be applied to the draining cyst for up to 10 minutes, two or three times a day.  At this stage, it’s important to watch for signs of infection.  

Warm Towel or Compress

Gently apply a clean, warm compress to the opened cyst and hold for as long as the dog will allow. Usually ten minutes is long enough but your dog may push you away long before that.

The point is to warm and soften the area to allow free drainage. Make sure it’s not too hot. If it’s too hot for your skin, it’s too hot for the dog’s skin.

Hibiclens Surgical Scrub

This scrub can either be applied to warm towel and used as a compress, or it can be diluted and used to gently wash the area.

Signs of infection could include additional swelling around the cyst, redness, pain, pus, and a foul smell from bacteria/yeast.

The idea is to keep the liquid draining until it is all gone.  Keeping the area moist will prevent a scab from forming.  When a scab forms, the remaining fluid is trapped inside. This can cause a bacterial infection, or can cause the cyst to reoccur.

Be sure to swab the wound with a bacterial cream or wipe several times a day.   

The most difficult part of this is keeping your dog’s mouth away from the wound.  The best suggestion is – of course – the Elizabethan collar. These days, there are a lot of variations that might prove more comfortable for your dog.

The Best Products for Treating a Draining Cyst Include:

Alfie Pet Soft Recovery Collar

Jungle Pet Antifungal and Antibacterial Medicated Wipes for Dogs and Cats

KetoWELL Wipes

Mal-A-Ket Wipes

Open Cyst Drainage

This procedure is especially useful in reducing the pain and pressure of a large cyst.  It must be done in a sterile environment, such as the animal hospital or clinic.

If the veterinarian feels your dog is strong and healthy enough, he/she may decide to go ahead with surgical removal. The first thing will be to put your dog under general anesthesia.  

The surgeon will cut into the skin to expose the cyst.  He/she will then slice an opening to allow the pus (if it’s infected), keratin, or sebum, to drain.  

The surgeon will monitor your dog while he or she is under.  

Once the fluids have completely drained, the surgeon will then cut out the remaining sac of tissue.  Your dog will be sutured and sent home to rest.  

The veterinarian may send you home with antibiotics for your dog.  If so, make sure to give your dog the full prescription as indicated.  

When people stop antibiotics early, bacteria could come back.  The second time this happens, the bacteria are stronger. The more this cycle continues, the greater the risk of developing antibiotic resistance.  

Read More About The Differences Between Cysts and Tumors HERE

Prevent Cysts from Returning

There’s no guaranteed way to ensure your dog will not get any more cysts. However, there are some thing you can do to lessen the risk.

The only sure way to prevent cysts is to avoid injury to your dog. Dogs run and play, they jump and bump.  It’s impossible to keep a dog from encountering minor injuries, especially if you have an active and healthy dog.

Learning everything you can about cysts now will ease future worry should it happen again. Next time around, you’ll have more confidence and knowledge.

Summary

New lumps and bumps must always be seen by a veterinarian for a definitive diagnosis. Cysts and tumors are tricky business that typically require a fine needle aspirate or biopsy. Some veterinarians may recommend a wait-and-see approach if they are confident that what they see is benign.

If your dog’s cyst grows, becomes red, inflamed, bleeds, or appears to be painful to the dog, make an appointment with the veterinarian.

It’s never a good idea to pierce a cyst in an attempt to drain the fluid. This can cause bacterial infection, pain, and recurrence. If the cyst has opened on its own, you can keep the area clean until the doctor can have a look.

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