Hi,

Debbie
Kitchener, ON, Canada

Cysts are benign (non-cancerous) growths that are common in or under the skin. They consist of a sac or lining of cells that produce secretions. The secretions accumulate within the lining and fill the cyst. Some cysts produce secretions that are very fluid. Others fill with very firm, viscous secretions.

Cysts in or under the skin usually are harmless. They can be unsightly, and they may burst or become infected. However, they rarely lead to life-threatening situations.

Some cysts can be drained with a needle and syringe. If the fluid inside a cyst is very viscous, it may not be possible to perform this procedure. These cysts can be removed (excised) with surgery.

However, in most cases it is not necessary to drain or remove cysts. Since most external cysts are not dangerous, I generally recommend leaving them alone unless they are causing irritation or other problems.

Most cysts appear to be hereditary in nature. They are common in older pets. I doubt that your dog’s diet is playing a role in the syndrome. She most likely has an individual predisposition that causes her to develop cysts.

You mention that the growths on your dog look like cysts, but that you aren’t sure whether your vet has ever had a laboratory analyze the growths to confirm their identity. I recommend that you contact your vet to determine if this has been done.

If a laboratory has confirmed that the growths are cysts, then you don’t have much to worry about. Your dog may produce more of them over time, but they are unlikely to cause harm.

If none of the growths has been tested, then I’d recommend that you have your vet submit a sample to the lab. Laboratory analysis will confirm the diagnosis, and hopefully provide peace of mind.

(A note about the photo: Buster doesn’t have any cysts yet, but if he’s like most dogs some will show up over time.)

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Hello Dr. Barchas,

Angie
London, ON, Canada

Cysts are generally harmless growths that occur in the tissues of animals. They are common in older pets (although they sometimes develop in young pets), and they are encountered most frequently in the skin (although they can occur in other tissues as well).

Cysts are made of cells that involute to form a sac, or empty cavity. In some cases, the cells that make up the cyst secrete fluid into the sac. In others, the cyst incites the immune system to secrete fluid. In either case, the result is essentially the same: a bag of cells with fluid inside of it.

The rate at which fluid enters the cyst depends on a number of factors. Cysts that are irritated, traumatized, inflamed or in areas of high motion may fill faster than other cysts. In many cases, cysts seem to have a mind of their own: after one draining, a cyst may remain empty for months or years. After another, it could be full again the next day.

In many cases it is not necessary to drain cysts. In fact, I only recommend draining if the cyst is causing pain, irritation, or some other sort of trouble. Regardless of whether or not a cyst is drained, it may become irritated or infected. It also may burst or change into a more dangerous type of growth.

Keep a close eye on your pet’s cysts, and have a vet check him out if you notice any major changes. Also, if you have not already done so, have a vet check the new growth above your cat’s eye to ensure that it is, in fact, another cyst and not something more serious.

As long as you confirm that neither growth is dangerous, I see no reason to remove them. They should not interfere with your pet’s longevity or quality of life.

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