Oncology / Cancer Treatment
LUMPS IN DOGS AND CATS
All lumps are abnormal. That is the important message. You should get your veterinarian to check any lump. Sometimes they are a simple cyst or some form of skin disease but sometimes these lumps are cancerous.
Pictured below is a cytology of a benign fatty cell mass called a Lipoma. These fatty lumps are very common in old dogs but should always be checked because they can be mistaken for connective tissue sarcomas or liposarcomas. Always ask your veterinarian to do a fine needle aspirate of any lump for cytology.
SKIN CANCER IN DOGS AND CATS
Canine Mast Cell Tumors
Canine Mast Cell tumors can take many morphological appearances and are often mistaken as "nothing to worry about" when in fact they are very serious indeed and potentially fatal due to metastatic malignant behaviour.
Here is some examples of canine mast cell tumors
At Treendale Pet Medical we will investigate any skin mass by taking a fine needle biopsy or FNA and examining this under the microcope. If we suspect a MCT, we will stage the tumor with blood tests, ultrasound and radiographs as well as checking the local lymph nodes for any evidence of metastasis (spread). Are you worried about your dog's MCT? Read about treating mast cell tumors here
Canine MCT can present in many different forms. You must get all lumps checked by your veterinarian.
Any mass on a scrotum of a dog should be investigated. They are usually sinister. The canine scrotum is a common place to find mast cell tumors, squamous cell carcinomas and melanomas.
BONE CANCER IN THE DOG
Osteosarcoma is one of the most common bone cancers in dogs. It is unfortunately common in the large and giant breeds especially rottweillers, German Shepherds and Great Danes to name a few of the more susceptible breeds. Bone cancers are very painful and respond poorly to analgesia. If your pet has a hard bony swelling and lameness, it should be radiographed. Make sure your vet takes x-rays.
THORACIC NEOPLASIA OF THE DOG AND CAT
Pulmonary mass in a dog with severe breathing difficulty - dyspnoea. One side of the lung field is solid white due to a large pulmonary mass growing in the lung.
Cancer of the Thoracic Wall
Heart Based Tumors
ABDOMINAL NEOPLASIA OF THE CAT AND DOG
Cancer of the Liver
Four different categories of liver cancer occurs in dogs.
- 1. Hepatocellular - carcinoma
- 2. Cholangiocellular (biliary tract) - adenocarcinoma
- 3. Neuroendocrine
- 4. Mesenchymal - haemangiosarcoma
In dogs, primary liver cancer is quite rare. Primary liver cancer in the dog is most commonly hepatic carcinoma. Primary carcinoma comes in three different forms. Massive carcinoma often involves a single liver lobe and has a good prognosis after removal. Some dogs live as long as five years. primary carcinoma of the liver also comes in nodular and diffuse forms that spread through the liver and are not operable. They also respond poorly to chemotherapy. Other kinds of primary liver tumor include haemangiosarcoma which is rare in the primary form but common as a metastatic cancer. Cancer of the liver is more often a metastasis from another place in the body. Cancer of the liver can impact on the biliary system as well causing obstructions to the passage of bile.
Other primary liver cancers in dogs may include Mast Cell Tumor's and Histiocytic sarcomas,
Most liver cancer in dogs is metastatic, ie it has spread from somewhere else. The cancers are either lymphoid or haematogenous.
Cancer of the Stomach
Stomach cancer in dogs is usually quite nasty. Often the cancer is adenocarcinoma which is very aggressive and metastasizes in approximately 80% of cases.
Cancer of the Pancreas
Pancreatic cancer is notoriously difficult to cure. It isn't easy to surgically disect because it is often diffuse throughout the pancreatic lobes and the body needs a functioning pancreas for many vital internal mechanisms. Pancreatic cancer also often metastasizes to the liver.
Pictured above is a liver lobe with metastasis from the pancreas. This is a common sequelae with pancreatic cancer.
Cancer of the Spleen
The spleen tends to be a common place for cancers to spread to and is a common location for cancer to be found in the dog.
Haemangiosarcoma is a common cancer of the spleen.
Can you see the cancerous mass in this ultrasound image of the spleen below?
The mass is enlarged below
Below is an abdominal radiograph (x-ray) of a dog with a mass in the spleen
NEOPLASIA OF THE NECK - CAT AND DOG
Cancer of the larynx is a very challenging condition in animals. Removal of the larynx is not practical for normal life function. Biopsies need to be taken to see whether chemotherapy or radiation therapy may be curative.
The photo above shows an enlarged tonsil in the forground and severe swelling of the larynx due to a cancer called squamous cell carcinoma.
Thyroid cancer can be benign thymoma or malignant thyroid carcinoma. Most thymomas are small and have no clinical signs. Large thyroid masses palpated in dogs are usually thyroid carcinoma. They metastasize about 80% of the time to the lungs or regional lymph nodes. It is therefore important to do sentinel lymph node mapping prior to thyroid cancer removal and to take radiographs of the chest as a part of the staging of the cancer.
Parathyoid cancer is quite rare in dogs. Parathyroid adenoma's secrete large amounts of parathyroid hormone ( PTH )
which tells the body to release calcium from the bones. Excessive PTH
causes elevated levels of blood calcium which can have toxic effects on the intestines, the brain and particularly the kidneys. High levels of calcium in the blood damages the renal tubules leading to renal failure.
ORAL CANCER OF THE DOG AND CAT
Oral cancer is very common in the dog and cat, possibly due to chonic infection of the mouth due to dental disease and the chronic immunoresponse to chronic inflammation, local infection and toxaemia. Healthy teeth and gums are important for our holistic health!
Melanoma is the most common cause of cancer in the mouth of dogs. Squamous cell carcinoma (SCC), fibrosarcoma and osteosarcoma are also common oral cancers in the dog. Mast cell tumors and lymphoma are also sometimes seen in the mouth or gums of dogs. All lumps should be checked by your veterinarian. In cats, squamous cell carcinoma is the most common oral cancer.
Sqaumous Cell Carcinoma SCC
SCC is the second most common type of oral cancer in dogs. Metastasis to local lymph nodes is low in the rostral oral cavity (the front of the jaw) but metastatic rate is high in tongue or tonsillar SCC of the oral cavity.
Rostral SCC dog
Oral fibrosarcoma in the dog is usually histologically low grade but biologically high grade. They sometimes metastasize. They have a predilection for the maxilla and the hard palate so they are a challenging problem because to remove them involves quite extensive surgery to your dog's face. Many dog owners do not find disfigurement of their pet an acceptable solution. Unfortunately, these cancers respond poorly to radiation and chemotherapy.