Prostate enlargement and prostate cancer in dogs

The prostate grows throughout a male dog's life, but it is only when the dog is older that they get symptoms of enlargement. When a dog's prostate enlarges, it presses on the rectum and urinary tract. This can cause pain when urinating and make it difficult for the dog to empty his bowels. 

Symptoms of prostate disease in dogs:

• It takes a long time for your dog to poop, and the faeces is flatter
• A change in your dog's behaviour when he urinates. They may sit like a female when urinating, or pee with a narrow stream or small splash. There could also be blood in your dogs urine.
• Difficulty getting up and lying down due to pain from the abdomen. He may walk also differently, more wide-legged.
• Breeding dogs don't want to mate and can suffer from reduced sperm quality.

Some dogs with prostate diseases don't show any signs at all.

When a dog is neutered before puberty, the prostate gland does not develop due to the lack of testosterone (the male hormone produced by the testicles). This is not a problem for dogs because the prostate's main job is to nourish sperm. When a mature dog is neutered, the prostate will actually shrink. This means that a neutered male is less at risk of prostate enlargement.

Four common reasons for prostate disease:

1. Prostate enlargement

The most common form of prostate disease is a benign enlargement called benign prostatic hyperplasia. The size of the prostate is affected by the male sex hormone testosterone, but enlargement is also a natural process as the dog gets older. Prostate enlargement is seen to varying degrees in almost all male dogs over the age of five.

2. Cysts in the prostate

The cysts are small, fluid-filled bladders in the prostate and are seen during an ultrasound examination of the prostate. Usually they slowly increase in size. For larger cysts, surgery may be required.

3. Infection

Acute prostatitis is when the prostate is affected by a bacterial infection. These infections are often painful and they can be difficult to treat medically. It is important to culture the bacteria causing the infection early so that the right antibiotics can be used together with other complementary treatment.

4. Cancer

Prostate cancer is uncommon in male dogs. If cancer develops, it can spread to other organs such as the liver and lymph nodes, as well as the pelvis or spine. Although prostate cancer is rare in males, it is important to remember that it is a potentially life-threatening disease and can also affect neutered male dogs.

Diagnosis of prostate diseases

To detect problems with the prostate during a clinical examination, your vet can feel it by inserting a finger into the dog's rectal opening. This is called a rectal examination. Your vet can then assess whether it is enlarged and whether it hurts or not.

With the help of ultrasound, the size of the prostate can be measured and any cysts can be seen. A urine sample, or even better a semen sample, is valuable to look for infection or other prostate diseases. 

In male dogs over 6 years of age, by measuring the amount of CPSE (prostate-specific esterase for dogs) in the blood, you can clearly get an answer as to whether the prostate is enlarged  and thus know whether further diagnostics are needed.

Treatment of prostate diseases in dogs

Treatment methods depend on what caused the prostate disease.

• A bacterial infection in the prostate, called prostatitis, often requires targeted antibiotic treatment together with anti-inflammatory and pain-relieving treatment.
• If the disease is not bacterial, it is often treated with anti-inflammatory and pain-relieving medicine, as well as a medicine that reduces the size of the prostate.
• In rare cases, surgical drainage of the prostate cysts is required.
• Cytotoxins/chemotherapy may be an option to treat prostate cancer.

In most cases, the medical treatment is supplemented by surgical or chemical castration. When the testicles are surgically removed, testosterone production ceases, which causes the prostate to shrink. The dog can also be castrated chemically by injecting a chip under the skin and blocking testosterone production for a certain time, the effect is then the same.

Related guides:

• Our guide on how to detect mammary tumours in dogs includes symptoms and signs.
• Some common dog health issues all dog owners should be aware of including ear infections, gum disease and obesity.
• Here are a few typical health issues in older dogs worth keeping an eye out for if you've got an senior dog.

FAQs about prostate problems in dogs