Canine Reproductive Cancer






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Prostrate Cancer Adenocarcinoma



Adenocarcinoma is a malignant tumor originating in the prostate gland tissue. This type of cancer metastasizes rapidly to other organs of body, including the lungs, bones, and lymph nodes. It occurs in intact and neutered dogs. It most often occurs in large breed dog and in dogs from 9 to 10 years of age. Symptoms include difficulty breathing, poor appetite, weight loss, blood in the urine, difficulty passing urine or urine blockage, fever, pain and ribbon-shaped stool.

Treatment includes surgery, which unfortunately because of the location of the tumor is usually unavailable, drug therapy, radiation, chemotherapy. The average lifespan of a dog diagnosed with adenocarcinoma is six weeks to one year.

Tumors of the Testis



Tumors of the Testis (Dogs with retained or undescended testes are prone to tumors of the testes. Dogs over 10 years are prone to tumors of the testes. The following breeds are prone to tumors of the testes: Boxers, Afghan Hound, Weimaraner, Shetland Sheepdog and German Shepherd Dogs.

Symptoms of testicular tumors manifest in several ways: atrophy of the testicle, masses in the abdominal cavity or inguinal space, feminization, bilateral alopecia, darkening of the skin, suspended foreskin, development of abnormally large mammary glands in males, milk flow, , atrophy of the penis, bone marrow underdevelopment, and low red and white cells. Surgery is curative for most testicular tumors. About 10 to 20% of the cases have spread at the time of diagnosis.

1. Sex cord-stromal (gonadostromal) tumors are rare in dogs. It forms in the tissues that support the ovaries or testes. These tumors may release sex hormones. Sex cord-gonadal stromal tumors include granulosa cell, Sertoli cell, and Leydig cell tumors. Also called sex cord tumor and sex cord-stromal tumor.

2. Interstitial (Leydig) cell tumor are rare testicular tumors of the male gonadal interstitium that may be hormonally active and lead to feminizing or virilizing syndromes. These are usually benign, non spreading tumors. It is located in the testes and may cause swelling. It usually affects older dogs. Presents with one or more round masses in a testicle. This condition may lead to underdevelopment of the bone marrow. Treatment: neutering

3. Sertoli (sustentacular) cell tumors are formed from the sustentacular cells of Sertoli, which nurtures the developing sperm cells. Metastasization occurs in 15% of cases. Symptoms include feminization, bone marrow underdevelopment, skin changes, enlarged testicle, shriveled testicle, and an abnormal mass in the abdomen for dogs with undescended testicle. Treatment: castration.

4. Germ cell Seminoma tumors are rare and arise from germinal epithelium and are usually solitary masses. They seldom metastasize. They usually occur in undescended testes and older dogs. It is associated with prostatic enlargement, circumanal gland hyperplasia, and perianal tumors and hernia. Treatment: castration.

5. Germ cell Teratoma tumors are rare, benign but locally invasive neoplasia of dogs characterized by germ-cell tumors containing skin, connective tissue, and sometimes bone. They arise from embryonic notochord. Treatment: Surgical extirpation

6. Germ cell Embryonal carcinoma tumor is a highly malignant germ cell tumor that is a primitive form of carcinoma, probably of primitive embryonal cell origin. Treatment: castration

7. Mesothelioma is is a rare tumor arising from the lining cells of the peritoneal, pleural, and pericardial cavities or the tunica vaginalis of the testis. The tumors are commonly firm and pink. Mesothelioma is most common in older dogs and the average age of onset is 8 years. Fluid released from the tumor places pressure on other organs. Symptoms include coughing, loss of appetite, bloody diarrhea, vomiting, dehydration, lethargy, and excessive fluid retention. Treatment: Draining of the fluid from body cavities, castration, chemotherapy.

8. Mixed Germ Cell-Stromal Tumors are neoplasms characterized by intimately mixed germ cells and sex cord stromal derivatives.

Cancer of the Penis




1. Squamous cell carcinomain is a rare condition manifesting with proliferative lesions of the penis which have a plaque like appearance or raised papillomatous lesions. Metastases are present in over 25% of cases, usually in inguinal lymph nodes.

2. Epithelial hyperplasia manifests as lumps and bumps can appear under or on the skin. A Dog may itch, scratch, bite at the site, have flaky skin, and may have red skin. Treatment: surgery, radiation, chemotherapy, cryosurgery and photodynamic therapy





Mammary tumors



Mammary gland tumors are the most common type of tumor in the unspayed female dog. Tumors usually appear in older females, from 10-11 years. Tumors may be single or two or more and can occur in any breast. However they usually appear in the 4th or 5th breast. The tumors can be firm or soft, well-defined lumps or diffuse swellings. Tumors can be attached to underlying tissues, moveable, skin-covered or ulcerated. They can be different sizes, and they may grow slowly or quite fast. They are hormone dependent. The presence of some cells, with enlarged nuclei and prominent nucleoli, often leads to the over diagnosis of mammary carcinoma. The risk of a dog developing a mammary tumor is 0.5% if spayed before their first heat, 8% after their first heat, and 26% after their second heat. A palpable mass underneath the skin of the abdomen is the most common indication of mammary gland tumors. Other signs are a discharge from a mammary gland, ulceration of the skin over a gland, painful, swollen breasts, loss of appetite, weight loss, and generalized weakness. Over 50% of mammary gland tumors are benign. Mammary gland tumors are extremely rare in male dogs, less than 1%. They can be either benign or malignant. Most canine mammary tumors that are going to cause death do so within 1 year. Treatment: Surgery, chemotherapy, and radiation

Different types of mammary gland tumors

Malignant tumors

Non-infiltrating carcinoma
Complex carcinoma
Simple carcinoma
Tubulopapillary carcinoma
Solid carcinoma
Anaplastic carcinoma

Special types of carcinomas

Spindle cell carcinoma
Squamous cell carcinoma
Mucinous carcinoma
Lipid-rich carcinoma

There are many subtypes of these types of mammary tumors.






Tumors of the Ovary




Ovarian tumors are rare in dogs. These tumors are categorized based on their cell origin. They are epithelial tumors, germ cell tumors and sex cord stromal cell tumors. They most often arise between 4 to 15 years of age. They are asymptomatic unless they grow very large. If they grow large they may produce an accumulation of carcinogenic fluid in the abdomen, excessive fluid between the layers of the pleura outside the lungs, or hormonal dysfunction. When there is an increase of estrogen and progesterone the vulvar will enlarge, a red discharge will appear from the vulva, females will not go out of estrus, loss of body hair, and there will be a low red blood cells count. Treatment: complete ovariohysterectomy and chemotherapy.

Epithelial Cell Tumors
Epithelial cell tumors account for 50% of all canine ovarian tumors. These type of tumors arise from the epithelial cells, which form the covering of most internal and external surfaces of the body and its organs. These types of tumors are subdivided into papillary adenomas, papillary adenocarcinomas, cystadenomas and undifferentiated carcinomas.

Papillary adenomas and adenocarcinomas form symmetrical halves on either side of a unique plane. These two types of cancer are distinguished based on parameters like size, measure of the infiltration status of a cell population, proliferation into the soft tissue of the blood vessels of ovary and into the lining of the abdominal cavity. Papillary adenocarcinoma is also distinguished by a malignant accumulation of fluid in the peritoneal cavity. It can metastasize to the lymph nodes that lie in front of the lumbar vertebral bodies near the aorta, omentum, which stores fat and a stress hormone called cortisol, liver and lungs.

Cystadenomas develops from the structure, which forms the primary sex cords in females. They consist of multiple thin walled cysts.

Carcinoma is usually a malignant tumor that originates in the glandular cells lining the surfaces of the body. It is called ´undifferentiatedĦ when the tumour cells have no similarity to normal glandular cells. It is ?undifferentiated˙ when one cannot determine what type of embryonic cell the cancer originated from. This type of cancer is aggressive.

Germ Cell Tumors
Germ cell tumors comprise 6 to 12% of all canine ovarian cancers. These are subdivided into dysgerminomas, teratomas and teratocarcinomas.

Dysgerminomas originate from undifferentiated germ cells. From 10 to 30% metastasize. It metastases to abdominal lymph nodes, liver, kidney, omentum, pancreas and adrenal glands.

Teratomas arise from differentiated germ cells. These tumors have a 32% potential to metastasize. Both teratomas and teratocarcinomas may metastasize to abdominal sites, lungs, anterior mediastinum on the left side, and bone.

Teratocarcinomas arise differentiated and undifferentiated germ cells. Teratocarcinomas have a 32% potential to metastasize.

Sex cord stromal tumors
Sex cord stromal tumors have been divided into granulosa cell tumors, and sertoli-leydig cell tumors.

Granulosa cell tumors are firm, lobulated, with multiple cysts and grow very large. These account for 50% of cancerous tumors. They metastasize to sublumbar lymph nodes, liver, pancreas, lungs, and have the potential to spread throughout the body.

Sertoli-Leydig cell tumors occur bilaterally.






Tumors of the uterine tube are rare in dogs.

Mesenchymal tumors

Lipoma is a rare oviductal tumor that is located in the ovarian bursa of dogs. The lipomatous mass has the characteristics of mature adipose tissue.


Adenocarcinoma has been reported in dogs, as an epithelial tumor with implantations in the abdominal cavity.




Uterine and cervical tumors in dogs account for 0.3 to 0.4 % of all canine tumors and are extremely rare. These tumors usually affect middle-aged to older female dogs that have not been spayed. These tumors arise from the uterine smooth muscle and epithelial tissues. There are usually no outward signs of these tumors but occasionally abdominal distension, lack of appetite, constipation, vomiting, weight loss, lethargy, frequent thirst and a urge to urinate frequently may present.

Canine Transmissible Venereal Tumor




Canine transmissible venereal tumors are histiocytic tumors of the external genitalia, transmitted during mating, sniffing, licking or biting an infected dog. It is one of four known transmissible cancers. The tumor cells are themselves what is transmitted to the dog and the tumors which develop are unrelated to the dog host genetically. The tumors may be repressed by the dog's immune system. The tumors have a less than 5% chance to metastasize, but this usually occurs in puppies or dogs with weak immune systems. The Penis and the foreskin is effected in male dogs while females exhibit the tumors in the area of the vulva. Treatment: Surgery is ineffective as the tumors grow back. Chemotherapy works well on this type of tumor.

*This tumor can be transmitted to the nasal area of the dog.





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