What is Prostate Cancer in Dogs?
Prostate cancer in dogs is a tumor that develops when the prostate gland cells start growing without control. In general, prostatic tumors are not common in dogs. However, if it develops, it is usually in the form of prostatic adenocarcinoma. Adenocarcinoma is the most common type of prostate cancer.
Canine prostatic adenocarcinoma is aggressive prostate cancer with high metastatic rates. According to PetMD, this type of prostate cancer spreads to other organs and lymph nodes in over 85% of the cases. The tumor spreads to other parts of the urinary tract system (prostatic urethra), lungs, spleen, liver, and bones.
Just like in human men, the incidence of prostate cancer or adenocarcinoma is higher in older dogs (male dogs over 10 years of age). Prostatic carcinoma or adenocarcinoma is more likely to occur in larger breeds.
As lethal prostate cancer, prostatic adenocarcinoma should not be confused with benign prostatic hypertrophy. Namely, just like the human prostate, the dog prostate can become enlarged with age. However, a thorough vet exam is the only way to differentiate between an enlarged prostate and a prostatic tumor. Enlarged prostate is a more common problem than prostate cancer.
Are Dogs with Prostate Cancer in Pain?
No, dogs with prostate cancer are not in pain. Prostate cancer is painless and asymptomatic in the early stages. However, as the condition progresses and forms metastasis to distant body parts, the dog may start feeling pain and discomfort.
The pain may also be caused by the prostatic disease itself. For example, if the prostatic tumor overgrows and compresses the surrounding tissues, it can make the urination and defecation processes painful.
What Causes Prostate Cancer in Dogs?
The exact cause of prostate cancer in dogs is unknown. Cancer, in general, is the result of many triggers and risk factors working together. Here is a short overview of the potential causes of prostatic adenocarcinoma in dogs:
- Genetics. Genetics plays an important role in the development of prostate cancer in dogs. The fact that certain dog breeds are predisposed talks for itself. Dog breeds prone to prostatic cancer are Golden Retriever, Rottweiler, German Shepherd, Doberman Pinscher, Airedale Terrier, German Shorthaired Pointer, Miniature Poodle, Scottish Terrier, Bouvier des Flandres, Shetland Sheepdog, Norwegian Elkhound, and Beagle.
- Environment. As with all cancer types, prolonged or frequent exposure to carcinogen chemicals (tobacco smoke, asbestos, pesticides, volatile organic compounds) increases the risk of tumor development. Some of these chemicals are easily avoided, but exposure to others cannot be controlled.
- Lifestyle. Lack of physical activity and unhealthy nutritional choices lead to weight gain and obesity. Obesity is a known risk factor for certain types of canine cancer. Although there are no research studies linking prostate cancer with increased body weight, poor lifestyle choices are contributing factors.
- Hormonal status. Interestingly, castration is a risk factor for prostate cancer. Namely, compared to intact dogs, fixed males are more likely to develop prostatic adenocarcinoma, prostatic transitional cell carcinoma, and bladder cancer. In contrast, benign prostatic hyperplasia is more common in intact male dogs.
What are the Symptoms of Prostate Cancer in Dogs?
The symptoms of prostate cancer in dogs are related to the urinary tract – significant increase in urination frequency but with small amounts of urine production, urinary incontinence, blood in urine, increased thirst (similar symptoms to urinary tract infections).
However, these symptoms become apparent in dogs with advanced disease. In its early stages, canine prostate cancer is asymptomatic. Also, many symptoms are non-specific, thus disabling early detection of the problem.
Here are some of the clinical signs pet owners can expect in dogs with prostate cancer:
- Ribbon like stool
- Hunched back and unusual tail position
- Straining while defecation or urination
- Lack of appetite and weight loss
- Discharge from the penis
- Extreme lethargy
- Abdominal pain
- Pain in the lumbar spine (lower back).
These clinical signs are not exclusive to prostate cancer in dogs. However, they must be taken seriously. If your dog is showing one or more of these signs and symptoms, call your trusted veterinarian.
Diagnosing Prostate Cancer in Dogs
To diagnose prostate cancer in dogs, vets start with a thorough physical examination. Suspicion for the prostatic tumor is based on the combination of clinical signs and exam results (the vet will feel the enlarged prostate upon rectal palpation).
To confirm the diagnosis, the vet will order additional tests such as urine sample analysis, abdominal radiographs, contrast x-rays of the urinary tract, abdominal ultrasound scans, CT scan, and PSA (prostate-specific antigen) markers. A biopsy is the best way to differentiate between a benign and malignant tumor of the prostate gland in dogs.
With that being said, all older male dogs presenting with similar symptoms to a urinary bacterial infection should be carefully evaluated for prostate cancer.
What can be Done for a Dog with Prostate Cancer?
The treatment for prostate cancer in dogs is complex and depends on several factors. There is no such thing as the best cancer in dogs treatment – it varies among individuals, and sometimes, it can be a mix of different approaches.
Here are some of the treatment options for prostate cancer in dogs.
Surgical Treatment. The surgical treatment of prostate cancer is removing the canine prostate gland (prostatectomy). This is a high-risk procedure, and its effectiveness depends on whether the prostate cancer has spread to other organs. Also, there is the anesthesia risk associated with older dogs.
Radiation Therapy. Targeted radiation therapy can be used alone or combined with surgery. Radiation is recommended for dogs with urinary obstruction due to large and compressing prostate tumors.
Chemotherapy. Another possibility for canine prostate cancer is chemotherapy. The treatment is considered in dogs with metastasis. However, it is not very clear whether chemotherapy is an effective treatment for prostatic cancer.
Non-Steroid Anti-Inflammatory Drugs. Piroxicam and carprofen are helpful in the management of prostate cancer in dogs. They are not a treatment but may help with the symptoms.
Bisphosphonates. Bisphosphonates are a group of medications initially developed for managing osteoporosis in people. These meds are recommended in case of metastatic changes in the lumbar vertebrae and pelvic bone.
What can I do to Prevent Prostate Cancer in Dogs?
Sadly, there is no conclusive answer on how to prevent cancer in dogs. This is because the exact cause of prostate cancer in dogs is poorly understood.
As a pet parent, the best thing you can do is take proper care of your pet – provide a high-quality diet, ensure physical activity, use health-boosting supplements, and practice regular veterinary checkups. Considering the incidence of prostate disease in older dogs, seniors need more than one annual veterinary visit.
How Long Does a Dog Have to Live with Prostate Cancer?
The survival time for dogs with prostate cancer is short and usually equals around 7 months after the diagnosis. As in all cases, the exact prognosis depends on the stage of the prostate tumor, the dog’s overall health, and the treatment type.
The average survival time is much shorter for dogs with prostatic cancer in an advanced stage. In such cases, the owner is advised to consider euthanasia. Euthanasia should also be considered if the dog’s quality of life is severely compromised.