Testicular Swelling in Cats


PetMD Editorial

Published Jan. 19, 2009

Epididymitis/Orchitis in Cats

Orchitis is inflammation of the testes, while epididymitis is inflammation of the testicular tube where sperm is stored. While the condition can be chronic, acute forms caused by direct trauma to the scrotum are most common. This condition is rare, but not unheard of in cats.

Symptoms and Types

The symptoms of epididymitis and orchitis can be localized in the area of the scrotum. These include:

  • Swollen testicles
  • Licking of the scrotum and scrotal skin irritation (dermatitis)
  • Non-localized symptoms include pain and fever
  • Unwillingness to walk and general lethargy
  • Open wound
  • Refusal to eat
  • In addition, infertility may be diagnosed in animals with this condition


Acute forms of the condition are most often caused by trauma to the scrotum. Epididymitis and orchitis can also be triggered by infectious organisms, as well as by other conditions, including viral causes (i.e., distemper), infections associated with inflammation of the prostate (prostatitis), and inflammation of the bladder (cystitis). Bite wounds on any area of the body can also lead to epididymitis or orchitis.


Your veterinarian will perform a thorough physical exam on your pet, taking into account the background history of symptoms and possible incidents that might have precipitated this condition. Other potential causes of the above mentioned symptoms must be ruled out before your veterinarian can make a definitive diagnosis. The method of differential diagnosis may be used to eliminate the most likely underlying issues that would lead to this reproductive disorder. Some of the conditions include hernia of the scrotum, scrotal dermatitis, twisting of the spermatic cord, sperm-filled mass of inflamed tissue (granuloma), fluid-filled sacks on the spermatic cord (hydrocele), prostatitis, cystitis, and abnormal cell growth (neoplasia).

White blood cell counts may be high in cases of infectious orchitis. If the root cause is prostatitis or cystitis, a urinalysis is likely to reveal blood, pus, or excess proteins. Antibody testing should determine if an infectious organism is at the root of the problem. Ultrasounds of the prostate, testes, and epididymis may also be performed to rule out other causes.

If an open wound is present, it should be checked for bacterial infection. A bacterial culture may also be taken of the prostate, as well as of the fluid in the testes. Semen should also be collected and tested.

Treatment and Care

Treatment depends on whether or not your cat is used for breeding. If it is, and the problem only affects one side (unilateral), partial castration may be an option. However, if the condition affects both sides, or if your cat is not utilized for breeding, full castration is generally performed.

Your cat should be treated with antibiotics for at least three weeks, however, antibiotic treatment alone will not always lead to improvement.

Living and Management

The condition itself, or castration (even if unilateral), can result in permanent infertility. Your cat's semen should be checked for viability again at three months after treatment.


Prompt treatment of wounds, and prevention of infections are the best weapons against epididymitis and orchitis. It is also best to keep your cat in good health, and to uphold a regular visitation schedule with your veterinarian.

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health