A veterinarian examines a dog for signs of orchitis

Orchitis (Inflammation of the Testicle) in Dogs

Orchitis is an inflammatory condition of the testes or testicles that can occur in dogs. It may involve one (unilateral) or both (bilateral) testicles and is often associated with epididymitis, which is inflammation of the epididymis, since the two structures are so closely related.

In dogs, orchitis is commonly caused by a bacterial infection where the bacteria enter the testes via the urine, prostatic secretions, blood, mucus membranes or trauma like a puncture wound. Other infectious agents that have been reported to cause orchitis include canine distemper virus, fungal infections (blastomycosis and coccidiomycosis) and tick borne diseases (ehrlichiosis and Rocky Mountain spotted fever).

Trauma to the testicles can also cause an immune mediated orchitis, lymphocytic orchitis, where the body’s own immune system causes the inflammation, and testicular damage.

Orchitis may occur rapidly (acute) or may develop slowly with time (chronic). Intact male breeding dogs or intact male dogs that are allowed to roam free are at increased risk for developing orchitis. Older intact male dogs with a history of chronic prostatic or urinary tract infections are also at risk, as infection can spread into the testicles.

What to Watch For

Symptoms of Orchitis in Dogs may include:

Diagnosis of Orchitis in Dogs

A complete physical examination including the palpation of the testicles and prostate is essential. Additional tests may include:

Treatment of Orchitis in Dogs

Home Care and Prevention

If your dog was neutered, the incision should be checked daily for any sign of swelling or discharge. The scrotal sack may be slightly swollen post-operatively, but the swelling should slowly resolve within a week or two. If skin sutures are used, they should be removed in 7 to 10 days. If your dog begins to lick the area excessively, an Elizabethan collar (a collar designed to prevent licking) may be required.

The best prevention for orchitis is castration at an early age. Animals that are not neutered should have recheck evaluations.

More Information on Orchitis in Dogs

Dogs with orchitis present with different clinical signs depending on whether it is an acute (sudden) or chronic (developing slowly over time) condition. Dogs with acute orchitis are usually very painful and act ill. If the orchitis is caused by a bacterial infection, it can lead to septicemia, which is the spread of bacteria into the blood, and which can be life threatening. Testicular abscesses can also form with severe orchitis. Abscesses can become very large and may even break through the skin of the scrotum.

In dogs the most common cause of acute orchitis is infection caused by the bacteria Brucella canis. Other bacteria that can cause orchitis include Staphylococcus, Streptococcus, Escherichia coli, Proteus and Mycoplasma. Sometimes, the bacterial infection occurs slowly, but it is progressive and leads to a scarring of the testicles and infertility. This chronic orchitis is more difficult to diagnose since many animals feel fine, are not painful and have no clinical signs.

Immune-mediated orchitis is also a chronic condition that may occur after trauma, or infection. It occurs once the barrier between the blood and testicular tissue is disrupted. An immune response to the testicle (specifically the animals sperm cells) then causes inflammation and subsequent tissue damage.

Orchitis may also occur due to urinary tract infections. Infections of the prostate gland (prostatitis) or urinary bladder (cystitis) are common routes of transmission due to their close association with the testes (they are connected via the vas deferens). This can lead to either acute or chronic disease. Other diseases that cause similar symptoms as orchitis include:

More Information on Diagnosing Orchitis in Dogs

The diagnosis of acute orchitis is usually strongly suspected on the basis of a good physical examination. Chronic orchitis is usually more difficult to diagnose and may require further testing.

More Information on Treating Orchitis in Dogs

The two major factors are important in deciding the best treatment for orchitis. One is whether the animal is being used for breeding. Breeding animals present a problem, since the orchitis often leads to infertility. Despite therapy, these animals often have damage to the germinal cells of the testes (the cells producing sperm), fibrosis (scarring) of the testicle, and secondary immune destruction of the testicular tissue. These changes may not lead to infertility initially, but over several months, significant decreases in fertility are commonly seen. Additionally if breeding animals are diagnosed with Brucella canis, they should not be used for breeding again since they may be a potential source of infection to other dogs (and rarely for people), despite treatment. Effected animals should be neutered or euthanized.

The other factor to consider when treating orchitis is whether it is an acute or chronic problem. Acute orchitis needs to be treated more aggressively, since the patient is usually in discomfort and is feeling ill. Animals are often brought to the veterinarian as an emergency due to the severe pain, lethargy, or weakness. Treatment may include intravenous antibiotics and fluids, and a longer hospitalization is often needed. With the chronic disease, animals are usually not ill and are brought to the veterinarian either for infertility or chronic intermittent infections. It is generally difficult to improve fertility in these animals. Specific treatment plans include:

Ongoing Care for Dogs with Orchitis

Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not improve rapidly: