Reptiles, like other animals with dividing cells, can and do develop cancer. The uncontrolled cell growth that defines cancer is a risk inherent to all multicellular life, and reptiles are no exception. While once considered rare, cancer is now being diagnosed more frequently in reptiles, partly due to longer lifespans in captivity and better diagnostic tools available to veterinarians.
Types of Cancer Found in Reptiles
Skin cancers are relatively common and include squamous cell carcinoma and melanoma. Squamous cell carcinoma often appears as sores or hardened plaques on the skin or in the oral cavity, particularly in lizards. Melanoma, a cancer of the pigment-producing cells, can also develop, similar to how it appears in mammals.
Internal tumors also occur and can be more challenging to identify. Fibrosarcomas, which are tumors arising from connective tissues, can develop internally or as firm lumps under the skin. Cancers of the blood and lymphatic system, such as lymphoma and leukemia, are also seen. For example, lymphoma is one of the more frequently reported cancers in lizards.
Potential Causes and Risk Factors
The development of cancer in reptiles is often linked to a combination of environmental, viral, and genetic factors. Improper environmental conditions are a risk factor, especially for skin cancers. Overexposure or incorrect wavelengths of ultraviolet (UV) light can damage skin cells and lead to mutations, increasing the likelihood of squamous cell carcinoma.
Certain viruses are known to cause tumors in reptiles. Some retroviruses, for instance, have been associated with malignant tumors in species like corn snakes and California king snakes.
Genetics and age also play a part in a reptile’s cancer risk. Just as in many other animals, the risk of developing cancer increases as a reptile gets older. A predisposition for certain cancers may also be inherited, making some individuals or family lines more susceptible than others.
Recognizing the Signs in a Pet Reptile
One of the most apparent signs of potential cancer is the appearance of new lumps, bumps, or swellings anywhere on the body. Sores on the skin that fail to heal over time can also be an indicator of a surface-level tumor. Changes in a reptile’s physical condition or behavior can also signal an internal issue.
- Unexplained weight loss
- A persistent lack of appetite or difficulty eating
- Swelling in a limb or the jaw
- Lethargy or weakness
- Spending an unusual amount of time hiding
Veterinary Diagnosis and Treatment
When a reptile shows potential signs of cancer, a veterinarian specializing in exotic animals will perform a thorough evaluation to reach a diagnosis. The process begins with a physical examination to assess the animal’s overall health and inspect any visible abnormalities. To investigate further, the vet may use imaging techniques like X-rays or ultrasounds to look for internal masses and determine their size and location.
For a definitive diagnosis, a tissue sample is required. This can be obtained through a fine-needle aspiration, where a small number of cells are drawn from a lump with a needle, or a biopsy, where a small piece of the tumor is surgically removed for analysis. This histopathology allows a pathologist to determine if the cells are cancerous and, if so, what type of cancer it is.
The most common treatment for solid tumors in reptiles is surgical removal. If a tumor is completely excised before it spreads, surgery can be curative. Other treatments, such as chemotherapy and radiation, are used less frequently in reptiles compared to mammals but are viable options in certain cases.