Chill Vibes: Cryosurgery in Exotic Pet Medicine

The tooth will set you free

Ted (or Tedward to his friends) was adopted by his loving family from a home that was not feeding him an appropriate diet. Due to this he had severe periodontal disease (inflammation and damage of the tooth socket and ligaments) as well as stomatitis (irritation of the gingival and mucosa). Ted had several dental procedures to remove the diseased teeth and help make his mouth more comfortable. Several months after his last dental procedure a lump developed on the right side of Ted’s face under his eye. Samples from this mass were very suggestive of a cancerous process.

Hedgehog with facial mass

The growth on Ted’s face was diagnosed as cancerous, the question was what was the best approach to treatment for him? Cryosurgery was chosen as the best option.

Dental disease and malignant transformation

Chronic inflammation and infection in the oral cavity can lead to over proliferation of normal tissue as well as destruction of bony structures and teeth. This overwhelming inflammatory response can make it difficult for the body to appropriately respond to cancerous cells in the region. Cancerous cells start off as normal cells that are dividing routinely. Cells have several built in fail safes that if something goes wrong during division the cell undergoes apoptosis (essentially a self destruct sequence). During a malignant transformation one or more of these fail safes are malfunctioning leading to unchecked division and proliferation of the defective cell. Chronic inflammation can damage the cells leading to more of the malfunctions than normal. It can also make it more difficult for the body’s immune system to detect and eliminate these threats.

Hedgehog with severe dental disease

Prior to the growth’s appearance, we had addressed Ted’s dental disease and extracted his bad teeth. It is likely the chronic disease and stomatitis led the the growth’s development.

A growing problem:

Further investigation of Ted’s tumor was discussed but it was elected to focus on keeping Ted comfortable and happy for as long as possible. Besides his dental disease, Ted also had a different tumor in his abdomen. Symptoms of this tumor were being controlled with steroids and a medication to reduce its growth. Due to the multiple conditions we focused on “palliative care”. This is when we focus on maintaining the patient’s quality of life rather than pursuing treatments that may or may not correct the underlying problem. Ted was happily eating and doing his hedgehog thing on his protocol but gradually the tumor under his eye expanded into his oral cavity and began to put pressure on the eye. Ted was not a good candidate for radiation or surgical removal of the mass. What could we do to slow down the tumor while maintaining Ted’s comfort?

Several teeth needed to be extracted

Ted had several teeth extracted due to the severity of his dental disease.

Cryosurgery:

Cryosurgery is the use of extreme cold (via the liquid state of a gas like nitrogen) to destroy abnormal tissue. This cold can be focused on the unhealthy tissue while sparing nearby healthy cells. This treatment has fewer side effects and a shorter recovery time than radiation and surgery. The main limitation is the depth of the treatment. In human medicine certain probes can be used to target deeper/internal structures. Typically in veterinary medicine cryosurgery is reserved for more superficial issues like papillomas, adenomas, and other defects.

A chilling adventure

It was elected to treat the intraoral portion of Ted’s tumor with our cryosurgery pen. Local anesthetic was applied to his mouth and a long-acting injectable pain medication was administered. Ted was placed under general anesthesia and the tumor was treated with three freeze/thaw cycles. Ted was woken up after the procedure and discharged to the care of his family. Ted was already eating again that evening. Several days later the size of the tumor shrank reducing the pressure on his eye and oral cavity. While Ted’s cancer isn’t cured, it’s been slowed and he is a happy hedgehog!