A Guide to Bone Cancer in Dogs
Although bone cancer in dogs (tumors) are fairly uncommon they do occur and will either be malignant (cancerous) or benign (not cancerous). The three most common types of bone tumors to affect dogs are Osteosarcomas, Chondrosarcomas and Synovial Cell Sarcomas (all three types are malignant). There are two types of benign bone tumors that affect dogs including Osteochondromas and Osteomas.
A dog suffering from Osteosarcoma will normally develop it around the age of eight years of age (this seems to be the average age of onset). This form of bone cancer in dogs can be found in the front legs, back legs, in the ribs (flat boned) and in the mandible (this is the area around the jaw).
This type of bone cancer in dogs can be seen in males and females however it is more common in certain breeds including large breeds such as Newfoundlands, Saint Bernards, Great Danes and Great Pyrenees. Interestingly smaller toy breeds rarely develop the condition.
Symptoms Of Bone Cancer In Dogs
The symptoms that a dog suffering from a Osteosarcoma may exhibit can include swelling around the bone, lameness and extreme pain when the affected area is touched or manipulated. It is vital that a dog suffering from an Osteosarcoma is diagnosed early (normally through a biopsy, blood tests and an X-ray) as this type can metastasize very quickly to other organs (including the lungs). It is also very important that the chest is also X-rayed as the disease may have already spread from the bones.
Another type of bone cancer in dogs is known as a Chondrosarcoma . This type can affect dogs a little younger (around the age of six years of age) and tends to affect the nasal, pelvic and rib area. The development of the tumor will normally cause the tumor to become hard but will not cause pain when touched or manipulated. Chondrosarcomas have a tendency to spread to other organs, so early diagnosis is very important.
The treatment for Osteosarcomas may involve amputation of the affected limb. However, if the disease has spread to other organs then chemotherapy (alongside amputation) may be the most effective option. Radiation therapy may also be performed if the disease has metastasized.
A dog suffering from an Osteoma is said to be experiencing a benign form of bone cancer (these are tumors that are non-cancerous which are formed from bone and tend to affect the head area and around the skull). This type of benign bone cancer in dogs is very rare which causes a raised area of bone that has a smoother surface covered with tissue. The growth is actually formed from normal bone that has become dense and protrudes from the area it is affecting.
Another type of benign bone cancer in dogs known as Osteochondromas are often seen in younger dogs and focus on areas where cartilage forms prior to calcification. Osteochondromas often develop based on the genetic history of the affected dog (the condition is often inherited). The most common areas for the benign tumors to develop are in the ribs, pelvic area and in the vertebrae.
Osteochondromas are normally diagnosed through an X-ray or bone biopsy. Treatment will normally consist of the growth being removed (this is often performed when the tumor is affecting other body parts such as the nerves or tendons). Surgery is also often performed if the dog is struggling to remain active or is in pain.
Below is a list of a dog’s skeletal system
|Scapula||Metacarpal bones||Coccygeal vertebrae||Ribs|
Interestingly a dog’s musculoskeletal system actually contains many of the same essential components that a human’s contains. The only significant difference is in relation to a dog’s front legs which have to carry 50% of the dog’s entire body weight (of course a human only has two legs).
The main idea behind a dog’s (and human’s) skeletal system is for it to protect the internal organs. Where the bones join each other there is a protective layer called cartilage which helps to stop friction. Alongside the cartilage the bones are held together by ligaments and tendons.
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