By Dr. Laurie Hess, DVM, Diplomate ABVP (Avian Practice)
Chinchillas are rodents that are generally hardy pets. However, they do commonly develop a handful of problems that all chinchilla owners should be familiar with. If chinchilla owners are educated about conditions their pets potentially could develop, they can recognize abnormal signs in their animals and have them treated by a veterinarian as soon as possible to improve the chances of recovery. Common illnesses in chinchillas include:
Chinchillas have open-rooted or continuously growing teeth that grow 2-3 inches per year. In the wild, they eat rough, coarse grasses that help keep these continuously growing teeth worn down. Many pet chinchillas are fed excessive amounts of dry, crumbly pellets, rather than fibrous hay, and as a result, they don’t chew enough and their teeth don’t wear down properly as they grow. In addition, their top and bottom teeth must meet properly to help wear them down as they grow.
A condition called malocclusion occurs when the teeth don’t align properly, so that the teeth surfaces hit each other inside the mouth. Once the teeth grow so long that they hit, there is no room for them to grow longer, and they become impacted in the gums and jaw bone (like wisdom teeth in people). Both the front (incisor) teeth and back (molar) teeth can become impacted — a very painful condition when the chinchilla tries to chew. Overgrown, sharp edges may form along teeth surfaces, leading to cuts on the tongue, cheek, or lips. The roots of overgrown teeth may become infected and abscessed. The chinchilla may have difficulty eating, lose weight, drool, and paw at its mouth. If an owner sees a chinchilla exhibiting any of these signs, the animal should be examined by a veterinarian right away so that treatment may be started.
A chinchilla-savvy vet should perform a thorough oral examination and take x-rays of the animal’s head to assess the teeth roots. If the teeth are overgrown and impacted but not infected, the pet should be started on a softer, easier-to-chew diet (such as shredded veggies and chopped hay), or syringe-fed a liquid diet if it cannot chew at all. It should also be given liquid anti-inflammatory medication.
If x-rays show infected teeth roots, the infected teeth must be surgically extracted under anesthesia. Prognosis for chinchillas with dental disease is better when the animal is treated early on, before they become weak and thin. In general, however, dental problems in chinchillas are recurrent and lifelong.
Chinchillas are common carriers of ringworm — a fungal (not a parasite or worm) skin infection that causes hair loss and crusty, scaly skin, and which is transmissible to people and other pets. Skin on the ears, face, and legs is commonly affected; however, chinchillas have very dense fur and can carry microscopic ringworm spores on their thick haircoat without actually showing any signs. Owners who notice dry, flaky skin or patches of hair loss on their pets should have them examined by a veterinarian immediately. A veterinarian can diagnose ringworm by culturing the affected skin in special fungal culture media or by having a veterinary laboratory run DNA tests on the hair to see whether fungus is present.
Treatment involves thorough clean-up of all areas in which the chinchilla has been in contact to ensure that no infectious hair is left behind that could re-infect the affected animal, other animals, or people. Mildly affected animals can be treated with topical prescription medications applied to the areas of infected skin. More severely affected animals may require long-term treatment with oral prescription medications, as well.
Chinchillas commonly develop two conditions that involve their fur. First, fur chewing in chinchillas is a common behavioral problem in which they chew on their own or their cage mates’ fur so that the haircoat looks patchy. Hair growing back into the chewed regions may be shorter and darker than the original fur.
Chewing occurs most often over the back and tail but can occur anywhere on the body. Theories about why chinchillas do this include stress, hormone imbalances, dietary deficiencies, underlying dental problems, boredom, the presence of other (parasitic or fungal) skin infections, and a genetic predisposition. The most widely accepted explanation is that fur chewing is a displacement behavior in response to environmental stress, such as from an overcrowded cage, the presence of aggressive cage mates or other predatory pets (such as cats and dogs), too frequent handling, or other anxiety-inducing circumstances.
A veterinarian can diagnose fur chewing by performing a thorough physical examination and skin tests to eliminate the presence of infections such as ringworm. Proper diet must be assured, too, to rule-out dietary deficiencies. The cause of fur chewing may be difficult to pinpoint; treatment may include elimination of possible stressors by providing a larger cage, handling the pet less often, removing other pets or aggressive cage mates, and ensuring a proper diet. Offering other, more appropriate things to chew on, such as hay and wooden toys, also may help.
The second common fur issue that occurs in chinchillas is fur slip. Fur slip is another name for the release of a large patch of fur in response to being grabbed or handled roughly.
Wild chinchillas have developed this mechanism to escape predators when they are captured. They release big clumps of hair to get out of a predator’s mouth when the predator grabs them. With normal shedding, chinchillas lose small amounts of fur gradually from all over their bodies as hair ages, falls out, and is replaced by new hair growing underneath. This process is gradual, so that obvious bald spots aren’t visible. With fur slip, however, a traumatic event precedes the hair loss, a large amount of hair comes off all at once, and a clean, smooth, bald patch is left behind.
Short, stubbly hairs may grow back in the bald patch within a few weeks after fur slip occurs, but return to a full, thick, normal coat may take up to several months.
Owners can prevent fur slip from happening by never grabbing the animal directly by the fur or skin and by always supporting the pet’s body from underneath the chest, abdomen, and hind end. Also, owners should never allow other naturally predatory pets, such as cats and dogs, near their chinchillas. These other pets may be good-natured and well-intentioned in carrying the chinchilla in their mouths to play with it, but may actually cause fur slip or worse injuries.
Wild chinchillas live in the Andean Mountains where it is cold; they have developed a thick fur coat to keep them warm in a cool climate. But as pets, chinchillas are very susceptible to overheating. They function best at environmental temperatures ranging from 55-70°F and should never be exposed to temperatures above 80°F. They also don’t do well with high humidity.
During the summer, or in warm climates, they should be kept indoors in air conditioned, dry areas, and they should never be exposed to direct sunlight without access to shade.
A chinchilla suffering from heatstroke appears weak and may be collapsed; it will need to be treated by a veterinarian immediately to cool it off with fluids injected beneath the skin, a sponge bath, and direct air flow from a fan.
Chinchillas with heatstroke must be treated as soon as possible or they risk stroke, organ failure, brain injury, and even death.
Gastrointestinal (GI) problems in chinchillas occur secondarily to other systemic illnesses and to other conditions that cause stress or pain. Chinchillas with GI disease may have decreased appetite, lethargy, decreased to no stool production, diarrhea, prolapsed (sticking outside the anus) rectal tissue, and a bloated, gas-filled belly. Several causes of GI disease in chinchillas exist, including sudden diet change, feeding excessive amounts of carbohydrates (typically chinchilla pellets) or vegetables, a reaction to treatment with antibiotics, GI parasite infection, and overgrowth of abnormal intestinal bacteria or yeast. Chinchillas with any of these signs should be seen by a veterinarian as soon as possible.
A veterinarian performing a diagnostic work-up for GI disease in a chinchilla might do a stool examination for parasites, abdominal x-rays, bacterial culture of stool, blood testing, and abdominal ultrasound. Once the veterinarian determines the cause of the chinchilla’s GI signs, in addition to specific treatment of the underlying cause, he or she can provide general supportive care for GI disease, including subcutaneous fluid administration, syringe feeding, pain relief, treatment with antibiotics and/or anti-yeast medications, and gas-relieving agents, as indicated.
Emergency surgery may be warranted in cases where a chinchilla is severely bloated or has ingested a foreign object that is obstructing the passage of food through the intestinal tract, but animals with these conditions are usually extremely debilitated and are poor surgical candidates. Rectal prolapse, often associated with GI parasites and overgrowth of abnormal GI bacteria or yeast, generally requires surgery.
A simple annual veterinary check-up helps keep chinchilla owners up-to-date about preventative medical care. Owners who are educated about common illnesses in their pets generally have healthier, happier, longer-lived animals with a better quality of life.