Prostate Cancer in Dogs: Symptoms, Diagnosis and Treatment Choices

By Dr Duncan Houston

Blood in the urine or difficulty passing faeces in an older male dog deserves investigation. Prostate cancer is one possible cause, but infection and benign enlargement can produce similar signs.

If cancer is diagnosed, the most useful discussion is about what it is doing now: whether urine can pass, whether your dog is painful and whether disease has spread.

Quick Answer

Canine prostate cancer is uncommon but often aggressive. Diagnosis involves examination, imaging and appropriately planned cell or tissue sampling, followed by assessment for spread. Treatment can include pain relief, selected anti-inflammatory drugs, oncology treatment and procedures to maintain urine flow. Repeated straining with little or no urine is an emergency.

What is prostatic adenocarcinoma?

Adenocarcinoma is a malignant glandular tumour, but not every canine prostate tumour has the same origin. Carcinomas arising from ducts or urothelial tissue can involve the prostate. The pathology result is therefore more useful than treating every enlarged prostate as one identical cancer.

The Merck review of canine prostatic neoplasia explains its invasive behaviour and potential spread to local lymph nodes and bones. Both neutered and entire male dogs can be affected; neutering does not rule out prostate cancer.

What symptoms can it cause?

Signs include repeated attempts to urinate, blood in urine, discomfort passing faeces, weight loss and reduced appetite. Pain or difficulty walking may occur when nearby tissues or bones are involved, but arthritis and spinal disease are alternative explanations.

How is it investigated?

Your vet assesses the abdomen and prostate, often including a rectal examination. Ultrasound helps evaluate the gland, bladder and local lymph nodes. Urine testing can detect an accompanying infection. Blood tests assess general health and the safety of proposed treatment.

Cells or tissue are needed to identify the tumour more specifically. Sampling must be planned carefully, especially when urothelial carcinoma is possible, because some routes can carry tumour-seeding risks. Chest imaging and assessment of suspicious lymph nodes or painful bones help stage the disease.

What else could it be?

Benign prostatic hyperplasia is common in older entire males. Prostatitis, abscesses, cysts, bladder stones and other urinary tract tumours can overlap in presentation. A positive urine culture does not exclude concurrent cancer, and an enlarged prostate on ultrasound is not a complete diagnosis.

Merck’s male reproductive disease overview describes the differences between these conditions. Unlike benign enlargement, most prostate cancers are not resolved by castration.

Which treatments are realistic?

An oncologist may consider a veterinary-prescribed non-steroidal anti-inflammatory drug, chemotherapy or radiation, depending on tumour type, spread and the dog’s condition. These treatments generally aim to slow disease and improve comfort rather than promise a cure.

Procedures such as urinary stenting may help selected dogs with obstruction. Prostate surgery has substantial risks, including persistent incontinence, and is not a routine solution for every patient. Ask what each option is expected to improve and what aftercare it requires.

Anti-inflammatory drugs need particular care in dehydrated dogs or those with kidney or gastrointestinal disease. Do not combine them with another anti-inflammatory or a steroid unless your veterinary team has explicitly planned the transition.

When is this an emergency?

A dog unable to pass urine needs immediate care, even if only small drips are appearing. Severe pain, collapse or sudden inability to walk also warrants emergency assessment. Do not press the abdomen or attempt to empty the bladder yourself.

A practical home plan

1. Watch actual urine flow, not just how often your dog goes outside.
2. Keep a daily record of appetite, toileting, sleep and comfort.
3. Give medicines exactly as prescribed and report vomiting or black faeces.
4. Provide easy access outside, non-slip flooring and comfortable bedding.
5. Agree on rechecks and the signs that should trigger a change in treatment.

Common mistakes

• Assuming constipation is the only reason for straining.
• Believing neutering excludes prostate disease.
• Comparing survival figures from different treatments as if the dogs were equivalent.
• Waiting until a crisis to discuss palliative care.

Prevention and quality of life

There is no established prevention for canine prostate cancer. Early assessment of urinary changes helps avoid untreated pain and obstruction. Choose a few meaningful daily activities to monitor so that comfort remains central to decisions.

Frequently asked questions

Can prostate cancer be cured?

A reliable cure is not available for most affected dogs. Treatment goals should be discussed individually.

Does every enlarged prostate mean cancer?

No. Benign enlargement is common in entire males, but investigation is needed to distinguish causes.

How long can my dog live?

It depends on spread, urine flow, pain and response to treatment. Your dog’s staging results are more useful than a broad internet average.

A good plan protects comfortable toileting and enjoyable daily life while keeping emergency decisions clear.

For help understanding your animal’s care and preparing questions for your veterinarian, visit ASK A VET™. Seek in-person emergency care immediately for urgent signs.