Cancer in dogs is the leading cause of death in dogs over ten years of age. In the case of canine testicular neoplasia - popularly known as testicular cancer - the disease mainly affects older, uncastrated male dogs. In addition to advanced age, the presence of undescended testicles (cryptorchidism) is another factor contributing to the formation of tumors in the system.canine genitalia.

A study published by the academic journal BMC Veterinary Research in 2014 found that 27% of the at-risk group ends up developing one or more testicular tumors at some point in their lives. In total, it is estimated that they represent at least 4% to 7% of all tumors found in male dogs. From causes to treatment, through diagnosis and prevention methods, check out the following,all about the subject, with the support of information from veterinary oncologist Caroline Gripp, from Rio de Janeiro.

What are the causes of canine testicular neoplasia?

As with most cancers, the cause of the development of testicular tumors is not so clear. What is known is that there is a specific group of dogs that are more affected by this condition, as explained by veterinarian Caroline Gripp: "testicular cancer is a neoplasm of common occurrence in uncastrated male dogs. It is a disease that usually appears between 8 and 10 years of the animal's life ".

However, male dogs with one or both testicles that have not descended from the abdominal cavity (cryptorchidism) are much more likely to develop a tumor compared to puppies with normal testicles.

Canine neoplasia: types of testicular tumors in dogs

A variety of tumors affect the testicles. The three most common types develop from germ cells (seminomas), which are responsible for sperm production; interstitial or Leydig cells, which produce testosterone; and Sertoli cells, which assist in sperm development. Almost half of dogs with testicular neoplasms have more than one type of testicular neoplasm.testicular tumor.

• Seminomas: Most seminoma tumours are benign and do not tend to spread. However, some can defy the rule and metastasize to other organs in the body.

• Interstitial (Leydig) cell tumours: these testicular tumours are the most common and are usually small and benign. They rarely spread or act aggressively. Dogs affected with this type of tumour have few symptoms.

• Sertoli cell tumors: have the highest potential for malignancy of all types of testicular tumors. They are more common in cryptorchid animals and tend to spread more aggressively than the others.

What are the symptoms in canine testicular neoplasia?

According to Caroline, the guardian himself can notice canine testicular neoplasia by noticing (looking or feeling) changes in one or two of the animal's testicles. "The owner can observe a possible occurrence of the disease through asymmetry between the testicles [one larger than the other], swelling in both, as well as pain when the animal is touched in the place. But the most noticeable sign is actually the swelling in the testicles.testicles", says the professional.

In the case of some estrogen-producing cells, signs of feminization may be evident in dogs affected by the disease. In this case, enlargement of mammary glands and nipples, pendulous foreskin, symmetrical hair loss, thin skin and hyperpigmentation (darkening) of the skin may indicate canine testicular neoplasia.

What to do in case of suspected canine testicular neoplasia? How is the diagnosis made?

If the guardian notices that his pet has swelling, asymmetry and / or discomfort in the testicle area, it is important that he seeks veterinary care as soon as possible. "The guardian should take the dog immediately to the veterinarian for diagnosis. If canine neoplasia is confirmed, the dog must undergo surgery for the en bloc removal of the testicles and also of thescrotum", warns the oncologist.

In addition to the physical examination, such as scrotal palpation and rectal examination (to feel for possible masses), the professional will be able to identify testicular tumors with chest and abdomen radiographs, complete blood count, abdominal and scrotal ultrasounds, and histopathology (biopsy) of the removed testicle.

How is canine testicular neoplasia treated?

"The mainstay of treatment for this type of cancer in dogs is surgical intervention to remove the affected testicle(s) and scrotum. After this surgery, the material is sent to the histopathology laboratory to find out which neoplasm the animal has (type of tumor). In some cases, surgery is curative, while in others it is necessary to institute chemotherapy as well ", explains Caroline.

When chemotherapy in dogs is recommended, the treatment must be carried out rigorously so that the animal achieves complete clinical cure. "Dogs, in general, react very well to chemotherapy and do not usually have the side effects that we see in humans, such as prostration and vomiting, for example. For the dog to get the best results, it is important that the tutor does not miss the appointments.sessions and follow the treatment properly", emphasizes the oncologist.

What is the care of the dog in treatment?

After the removal of the testicles and scrotum, the postoperative period must include some care for the animal to recover well. "Reducing the dog's big jerks at this time is a challenge, but it is extremely necessary. You have to keep an eye on it so that the animal does not touch the stitches or make too much effort ", reinforces Caroline.

Fortunately, surgery is curative for most testicular tumours, as the vet says: "The survival rate of affected animals is high for most tumours, with very high life expectancies. Prevention and early diagnosis help to increase survival, as well as the dog's quality of life."

What are the ways to prevent canine testicular neoplasia?

In addition to frequent visits to the veterinarian for routine checkups, canine testicular neoplasia can be prevented by neutering the animal. "The best way to prevent this type of cancer is with the castration of the dog, preferably by the age of 5," recommends the oncologist. The pros and cons of the dog castration procedure should be discussed with a veterinarian you trust,preferably before canine adolescence.