Ovarian Cysts in Dogs

Ovarian cysts may affect female dogs and are not a life threatening condition. Ovarian cysts rarely turn into malignant tumors, but the cysts should be monitored periodically. If the cysts don’t cause any discomfort and the dog is not used for breeding purposes, the cysts don’t require surgery or any type of treatment.

Causes of Ovarian Cysts

The causes of canine ovarian cysts are not known. Some vets will attribute the formation of ovarian cysts to a recent estrus or to hormonal changes (i.e. an excess of estrogen). However, the condition may also be idiopathic. Unspayed female dogs are more likely to have ovarian cysts.

Types of Ovarian Cysts

There are several types of ovarian cysts in canines including:

  • Follicular cysts
  • Epithelial cysts, that involve tissues
  • Stromal cysts, which involve the connective tissues

Symptoms of Ovarian Cysts

The symptoms of ovarian cysts will depend on the type of cyst found in the dog. If the dog has a follicular cyst, he may display the following symptoms:

  • Swelling of the vulva, due to the high amounts of estrogen in the dog’s body
  • Vulvar discharges that may contain blood and occur outside the regular bleeding in the heat cycle
  • Hair loss

If the dog is affected by an epithelial or stromal cyst, there may be symptoms such as:

  • Irregular heat cycles or lack of heat cycles
  • Extended heat cycles
  • Acne
  • Hair loss
  • Abdominal swelling due to pus or fluid accumulation in the abdominal cavity

Some dogs with ovarian cysts may not present any symptoms.

Diagnosing Dog Ovarian Cysts

A physical exam will be needed and blood tests will be performed. X-rays and ultrasounds will be needed to detect the location and the size of the cysts. The vet will have to rule out ovarian tumors, which often present the same symptoms. The only way to differentiate between a benign growth such as a cyst and a malignant tumor is to have a biopsy. A small sample of tissues will be analyzed under the microscope and the vet will see if the cells are malignant.

Treatment Options for Ovarian Cysts in Dogs

The ovarian cysts are typically benign formations and will not turn into malignant tumors (with rare exceptions). Consequently, the ovarian cysts may not need surgical removal. Surgery will only be recommended if the cysts seem to grow rapidly and may affect other organs in the abdominal cavity. The presence of a cyst may interfere with the dog’s fertility and should be removed if you want to breed the dog. If the cyst is not removed, the dog should be monitored and she should get regular x-rays and ultrasounds to establish if the cysts grow or transform in any way. In many cases, the ovarian cysts disappear without any treatment. In other cases, the vet may recommend hormonal therapy to reestablish the hormonal balance, which can also eliminate the cysts.