Testicular cancer in dogs is the uncontrolled growth of  cancer cells, resulting in a tumor within a dog's testicles. The early stages of testicular cancer in dogs are asymptomatic and localized before spreading to nearby tissues. A lump is noticeable, and the dog experiences pain as the cancer spreads to the lymph nodes in the groin area. 

Common symptoms of dog testicular cancer include a lump on the dog's testicle, dog swollen testicle, and other signs of testicular cancer in dogs, such as lethargy, weight loss, and changes in appetite. Testicular cancer primarily affects older, unneutered male dogs.

Consult a veterinarian immediately if a dog displays any symptoms. Testicular cancer treatment includes surgical removal of the affected testicle, which is highly effective if the cancer is detected early. Chemotherapy or radiation therapy are other treatment options, depending on the cancer's progression and metastasis. CBD oil for dogs is a complementary treatment option that provides anti-inflammatory properties, pain, and anxiety relief.

Why does my dog have a lump on his testicle?

Your dog has a lump on his testicle for various reasons, such as infections, benign tumors, or cancer. Testicular cancer is a specific cancer type in dogs that primarily affects older, unneutered male dogs and manifests as a noticeable lump or swelling on the testicle, sometimes called dog ball cancer.

 “A malignant testicular interstitial cell tumor with disseminated cutaneous metastases in a dog can cause enlargement of the left testicle and nodules in the skin of the left inguinal region and scrotum,” according to the study by Nascimento, H. et al. titled “Testicular Interstitial Cell Tumor with Disseminated Cutaneous Metastasis in a Dog,” 2019.

How common is Testicular Cancer in Dogs?

Testicular cancer in dogs is relatively common, and 27% of dogs develop tumors in the testicles. “The detection rate of testicular tumors in dogs is 16.8% in male canine tumors and 94.1% in male genital tumors, with cryptorchidism significantly affecting the incidence and type of these tumors,” according to the study by Liao, A., et al.titled “A 12-year retrospective study of canine testicular tumors,” 2009.

Boxers, Weimaraners, and German Shepherds are predisposed to a lump on dog testicle and testicular cancer. Neutering or castration in dogs under 6 months of age significantly reduces the risk of cancer in dogs. 

What are the early stage testicular cancer in dogs?

The early stages of testicular cancer in dogs are listed below. 

• Stage 0 or Carcinoma in Situ: The cancer is asymptomatic, and the abnormal cells are present but have not yet invaded deeper tissues. The cancer remains confined to the lining of the seminiferous tubules within the testicle.
• Stage I or Localized Tumor: A lump on the testicle is palpable, and there is a slight swelling or asymmetry in the testicles, but the cancer is confined to the testicle and has not spread to nearby lymph nodes or other tissues. 
• Stage II: Regional Spread: The cancer begins to spread beyond the testicle to nearby tissues, including the epididymis or the spermatic cord in stage II testicular cancer. The lymph nodes or distant organs remain unaffected, although the dog’s testicle swells more, and pain and discomfort increase. The dog shows systemic signs such as lethargy and decreased activity levels.
• Stage III: Lymph Node Involvement: Cancer cells have spread to regional lymph nodes, typically in the groin area, indicating advanced local spread without distant metastasis. The dog’s lymph nodes are swollen, exhibiting symptoms such as weight loss, appetite changes, and general malaise.

Do Senior Dogs Get Testicular Cancer?

Yes, senior dogs get testicular cancer. The risk of developing testicular cancer increases as dogs age. Testicular cancer is prevalent in unneutered male dogs over 10 years old, making senior dogs particularly susceptible. Senior dogs are at increased risk of various cancers, such as melanoma, bone cancer, and lymphomas, due to prolonged exposure to different environmental factors and the natural aging process of their cells. 

“Mean age at diagnosis of testicular tumors in dogs was 10.7 ± 2.7, with similar values for different tumor types,” according to the study by Manuali, E., Forte, C., Porcellato, I., Brachelente, C., Sforna, M., Pavone, S., Ranciati, S., Morgante, R., Crescio, I., Ru, G., & Mechelli, L. titled “A five-year cohort study on testicular tumors from a population-based canine cancer registry in central Italy (Umbria),” 2020.

How is Testicular Cancer Different from Lymphoma in Dogs?

Testicular cancer is different from lymphoma in dogs because they affect different parts of the body and have distinct symptoms and treatment approaches. “Canine lymphoma is a neoplasm with 7 diagnostic categories: benign hyperplasia, low-grade B-cell, high-grade B- and T-cell, low-grade T-cell, centroblastic large B-cell, and high-grade peripheral T-cell,” according to the study by Valli, V.et al. titled “Canine Lymphomas,” 2013.

Testicular cancer primarily originates in the testicles, leading to symptoms like swelling or lumps in the scrotum, pain, and enlarged lymph nodes. Lethargy, swollen lymph nodes in the groin, weight loss, and decreased appetite are signs of dog lymphoma, which affects the lymphatic system.

What are the symptoms of testicular cancer in dogs?

The symptoms of testicular cancer in dogs are listed below.

• Lump on the Testicle: A noticeable mass or lump on one or both testicles is often the first sign of early-stage testicular cancer in dogs.
• Swollen Testicle: A dog with an enlarged or swollen testicle that is firm or painful to touch is a symptom of testicular cancer in dogs. 
• Asymmetrical Testicles: A testicle appearing larger or differently shaped than the other testicle is a symptom of testicular cancer.
• Changes in Skin Color or Texture: The skin covering the testicles changes color or becomes ulcerated, a symptom of testicular cancer in dogs.
• Lethargy: Decreased energy levels and general tiredness are symptoms of testicular cancer in dogs. 
• Weight Loss: Unexplained weight loss is a symptom of testicular cancer in dogs.
• Changes in Appetite: Reduced interest in food or eating less than usual.
• Pain or Discomfort: The dog showing signs of pain, such as licking the area excessively, difficulty sitting, walking, or vocalizing discomfort, is a symptom of testicular cancer.
• Feminization Symptoms: Dogs exhibit feminization symptoms such as enlarged mammary glands when they have testicular cancer due to hormone production by the tumor.

How to know if my dog has testicular cancer?

To know if your dog has testicular cancer, look for lumps or swelling in testicles and note any lethargy or behavior change, including increased lethargy or aggression. Consult a veterinarian for a diagnosis. “Increased testicular volume is the most common clinical manifestation of testicular tumors in dogs,” according to the study by Nascimento, H. et al. titled “Testicular tumors in 190 dogs: clinical, macroscopic and histopathological aspects,” 2020.

The most common signs of dog testicular cancer are firm, enlarged testicles that feel irregular to the touch. Dogs with testicular cancer  exhibit behavioral changes such as increased aggression or lethargy.

Is testicular cancer in dogs painful?

Yes, testicular cancer in dogs is painful, especially as the tumor grows or if it metastasizes to other body parts. Pain caused by testicular cancer includes acute pain from the tumor itself, chronic pain as the disease progresses, and neuropathic pain if nerves are affected. The pain impacts a dog's behavior, causing listlessness, aggressiveness, or withdrawal. It affects their appetite, sleep patterns, and quality of life.

 “The management of chronic testicular pain includes a careful assessment of testicular and extratesticular causes, non-surgical management, and, in some cases, orchiectomy,” according to the study by Kumar, P., Mehta, V., & Nargund, V. titled “Clinical Management of Chronic Testicular Pain,” 2010.

Does the Dog's Low Immunity May Lead to Testicular Cancer?

Yes, a dog's low immunity leads to testicular cancer by weakening the body's ability to fight off abnormal cells. “Dogs with cancer have higher leukocyte counts, higher inflammatory cells, and lower CD4(+)T cells, suggesting a potent suppression of anti-tumor immunity,” according to the study by Itoh, H. et al. titled “Evaluation of immunological status in tumor-bearing dogs,” 2009.

Dogs with low immunity struggle to recognize and eliminate cancerous cells, allowing them to proliferate unchecked, leading to tumors. The dog's immune system response is lower, making it harder for the body to recover after cancer treatments like chemotherapy or surgery.

What does testicular cancer look like in dogs?

Testicular cancer in dogs looks like a noticeable lump or swelling on one or both testicles, accompanied by changes in testicle size or consistency. The lump becomes firm and irregularly shaped. The skin over the lump appears reddened or ulcerated, and in some cases, the tumor reaches a substantial size, causing the testicle to become notably enlarged. The texture of the affected testicle feels harder or more nodular because of the cancerous cells.

 “A large scrotal swelling in a dog is a common symptom of malignant mesothelioma, a rare testicular cancer,” according to the study by Vascellari, M.et al. titled “Malignant Mesothelioma of the Tunica Vaginalis Testis in a Dog: Histological and Immunohistochemical Characterization,” 2011.

How to prevent testicular cancer in dogs?

The ways to prevent testicular cancer in dogs are neutering, avoiding environmental toxins like herbicides and insecticides, examining the dog at home, regular vet visits and a healthy lifestyle. 

• Neutering: The most effective way to prevent testicular cancer in dogs is to neuter them. Neutering removes the testicles, eliminating the risk of testicular cancer. Neuturing dogs before they reach 6 months of age significantly reduces the risk of testicular cancer.
• Regular Veterinary Check-ups: Regular check-ups allow for early detection of testicular abnormalities. Early detection of testicular tumors significantly improves the prognosis if cancer develops.
• Self-Examination: Routinely checking the dog’s testicles for any changes, such as lumps, swelling, or asymmetry, helps prevent testicular cancer. Consult a veterinarian immediately. 
• Healthy Diet and Lifestyle: Maintaining a healthy diet and lifestyle helps support the dog's health and prevent testicular cancer.  A balanced diet and regular exercise contribute to a strong immune system and general well-being.
• Avoiding Exposure to Toxins: Minimizing exposure to environmental toxins and chemicals, such as pesticides and herbicides, helps prevent testicular cancer. 

How long can a dog live with testicular cancer without treatment?

A dog can live with testicular cancer for a few months to a year or more without treatment. The lifespan of a dog with untreated testicular cancer depends on the type and stage of the cancer. The prognosis is poorer without treatment. Dogs with untreated testicular cancer have an increased risk of tumor progression and spread to other parts of the body. Weight loss, lethargy, and difficulty breathing become more pronounced as the disease progresses. The cancer metastasizes to distant organs without treatment, leading to a rapid decline in health.

“The majority of dogs with this type of cancer survive, particularly if they undergo an orchiectomy before the cancer spreads. It's usually possible to perform this procedure in time because testicular cancer tends to grow slowly. Dogs that develop severe forms of testicular cancer typically die due to loss of integrity of their bone marrow,” according to the article by Hacker, C. & Duffy, M. titled “Testicular Cancer in Dogs,” 2024.

Is Testicular Cancer in Dogs Treatable?

Yes, testicular cancer in dogs is treatable, especially if detected early. The primary treatment is surgical removal of the affected testicle(s), known as orchiectomy, often curing the cancer if it is localized. “Testicular cancer has a cure rate of >90% with surgery and cisplatin-based chemotherapy,” according to the study by Cheng, L. et al. titled “Testicular cancer,” 2018.

Chemotherapy or radiation therapy is necessary where the cancer has spread. Early detection of testicular cancer is crucial. Regular veterinary checkups are essential to check for signs of testicular cancer in dogs, such as a lump on the testicle, swelling, asymmetry, or changes in the skin texture of the scrotum. 

What is the Treatment for Testicular Cancer in Dogs?

The treatment for testicular cancer in dogs includes surgery, chemotherapy, and radiation therapy. The treatment is tailored to the specific type and stage of the cancer. “Testicular cancer in dogs is treatable with orchiectomy, surgical resection, and cisplatin chemotherapy,” according to the study by Dhaliwal, R. et al. titled “Treatment of aggressive testicular tumors in four dogs,” 1999.

Chemotherapy is administered after the affected testicle(s) are removed to kill any cancer cells that have spread beyond the testicle. Chemotherapy protocols vary based on the type and stage of cancer. Radiation therapy is used to target and shrink tumors that cannot be surgically removed or to treat areas where the cancer has spread locally.  Palliative care focuses on managing symptoms and improving the dog's quality of life in advanced cases where the cancer has spread extensively and is unable to be completely removed.

How long is the Treatment Process for Dogs' Testicular Cancer?

The treatment process for dog testicular cancer ranges from 10 to 14 days of recovery after the affected testicle is removed. Radiation treatment is administered over 3 to 4 weeks. Chemotherapy is given over several weeks or months, depending on the stage and aggressiveness of the cancer.

Chemotherapy sessions are usually administered at regular intervals over a period of several months to target any remaining cancer cells and reduce the risk of recurrence. Radiation therapy sessions, if prescribed, span several weeks to ensure effective tumor shrinkage and control.

 “The treatment process for canine seminomas involves adjuvant carboplatin treatment followed by surveillance or radiotherapy or chemotherapy, with a median follow-up of 47.2 months,” according to the study by Chau, C. et al. titled “Treatment outcome and patterns of relapse following adjuvant carboplatin for stage I testicular seminomatous germ-cell tumour: results from a 17-year UK experience,” 2015.

What dog breeds are prone to testicular cancer?

Dog breeds that are prone to testicular cancer include Boxers, Weimaraners, German Shepherds, Doberman Pinschers and Golden Retrievers. 

Boxers have a higher incidence of testicular cancer, but the exact reason is not fully understood. Experts believe genetic factors increase the risk of testicular cancer. German Shepherds, Dobermans, Golden Retrievers, and Weimaraners have an increased risk of testicular cancer because of genetic predisposition and hormonal influences. 

Can CBD Oil be Used as a Treatment for Testicular Cancer in Dogs?

Yes, CBD oil can be used as a complementary treatment for testicular cancer in dogs. Treatment for testicular cancer in dogs is removal of the affected testicle(s), radiation, and chemotherapy. CBD oil is extremely beneficial as a complementary therapy for testicular cancer in dogs, helping to manage pain and improve quality of life. “CBD effectively reduces canine cancer cell proliferation and induces autophagy and apoptosis, with potential synergistic effects with traditional chemotherapy,” according to the study by Henry, J.et al. titled “The effect of cannabidiol on canine neoplastic cell proliferation and MAP Kinase activation during autophagy and apoptosis,” 2020.

Incorporating CBD oil for dogs as a complementary treatment helps reduce cancer cell proliferation, inflammation, and pain. CBD oil has anti-anxiety properties and helps calm dogs receiving cancer treatment.