Testicular Cancer in Dogs
When it comes to the health of intact male dogs, testicular tumors are a serious health concern. These tumors, which are often malignant can grow in one or both testicles. This means that there is a high risk of the cancer spreading to the surrounding tissues and other parts of the body.
Causes of Testicular Cancer in Dogs
The precise cause of testicular cancer is unknown. However, most testicular tumors are seen in older, unneutered male dogs. Other risk factors for these tumors include:
- Undescended testicles (cryptorchidism)
- Conditions that cause hormonal imbalances
- Breed type
Breeds that face an increased risk of developing testicular tumors include boxers, German shepherds, collies, Shetland sheepdogs and Weimaraners.
How Common is Testicular Cancer in Dogs?
It is estimated that about 27% of intact male dogs will develop testicular tumors in their lifetime. In dogs with undescended testicles, prevalence is significantly higher. One large study of cryptorchid dogs (dogs with undescended testicles) reported that 5.7% had developed testicular tumors.
Symptoms of Testicular Cancer in Male Dogs
Catching early signs of testicular cancer in dogs can result in excellent treatment outcomes, however, many dogs show no obvious signs of testicular cancer.
Although symptoms may be very subtle, it's a good idea to watch your male dog for any of the following:
- Enlarged testicles
- A firm or irregular mass
- Enlarged mammary glands
- Hair loss
- Discomfort and repeated licking around the scrotum
- Uncharacteristic irritability
- Decreased appetite or weight loss
- Anemia
- Lethargy
Three Types of Testicular Tumors in Dogs
The three most common types of testicular tumors are:
- Seminomas: these develop from the cells that make sperm (germ cells)
- Interstitial tumors: these develop from the cells that produce testosterone (Leydig cells)
- Sertoli cell tumors: these develop from the cells that help in the development of sperm (Sertoli cells)
Other types of tumors may develop from other cells within the testicles, but these other types are rare.
All male dogs over the age of seven face an increased risk of developing testicular tumors. However, cryptorchid dogs (dogs with testicles that have not descended) have a much higher risk of developing testicular tumors, particularly Sertoli cell tumors and seminomas.
Diagnosing Testicular Cancer in Dogs
If your vet suspects that your dog has a testicular tumor, they will perform a thorough physical examination focusing on the testicles and surrounding areas. Your vet may recommend ultrasound imaging to assess the internal structures of the testicles and to look for abnormalities.
Because many dogs do not show early signs of testicular cancer, if your dog has undescended testicles, your vet may perform an ultrasound as a proactive measure, even if symptoms are not present.
Blood tests may also be done to look for markers of testicular cancer, and to provide insights into your dog's overall health.
In some cases, the veterinarian may take a sample of the area through a biopsy or fine needle aspiration. This will allow for an in-depth examination of the tissue to identify the type of tumor.
Treatment of Testicular Tumors in Dogs
Castration is the treatment most often recommended for dogs with testicular tumors. Although the most common testicular cancers have a low risk of spreading, removing the testicles further reduces the risk.
In cases where the cancer has spread, (or originated in another part of the body), chemotherapy or radiation may be recommended.
Prognosis for Dogs with Testicular Cancer
Your dog's prognosis largely depends upon the type of tumor they have developed and whether the cancer has spread to other parts of the body. Most testicular tumors in dogs are benign (noncancerous) and the prognosis is good following surgery. If the tumor is malignant (cancerous), the prognosis may still be good if the tumor is caught early, before spreading, and surgery is performed right away. If the cancer has already spread, the prognosis will depend upon various factors and more aggressive treatments may be required.
Preventing Your Dog from Developing Testicular Tumors
Neutering your dog at a young age is the easiest way to prevent testicular tumors from developing. This common surgery also offers other benefits, such as curbing undesirable behaviors (ie: dog aggression, roaming and humping) and helping to reduce the number of homeless dogs in your area.
Taking your dog in for regular checkups can help to ensure that any symptoms are spotted right away and addressed immediately. Early detection of abnormalities gives your dog an excellent chance at a good treatment outcome.
Be especially mindful of your dog's testicular health if your pup is an intact male. Monitor your dog for any signs of testicular tumors or other illnesses. The sooner developing conditions are diagnosed the easier they tend to be to treat. Early diagnosis and treatment not only give your dog their best shot at a full recovery, they could also save you money in the long run.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.