Anorexia in Snakes
Dr. Nancy Anderson
History. A thorough husbandry history for an anorexic snakes usually includes questions about cage temperature and how it is measured, presence of a temperature gradient, types of heating and light elements, light cycle, presence and type of hide boxes, access to water, selection of prey item (species, live or killed, color, size, temperature if thawed), presence of cage mates, last breeding date, and usual time of feeding. Your veterinarian will also want to know if your snake has ever eaten for you or a previous owner, has ever been attacked by a prey animal, normal time between sheds and stools, any recent changes in these, and the time of the next expected shed.
Hematology. An analysis of red and white blood cells will allow your veterinarian to determine if anemia, blood parasites, or an overwhelming infection is the underlying cause of anorexia.
Serum chemistries. This blood test that evaluates organ function and electrolyte levels can be used to look for underlying kidney or liver disease. In addition, serum chemistries can be used to diagnose mineral or electrolyte imbalances such as hypocalcemia (low blood calcium), hypokalemia (low blood potassium), or hyperkalemia (high blood potassium). In addition to the chemistry values mentioned above, values for glucose (blood sugar), cholesterol, total protein, and bicarbonate (helps to regulate the blood pH) can help your veterinarian give you a prognosis for your snake's recovery.
X-rays or ultrasound. These tests can be used to determine if your snake is not eating due to an obstruction. Many, but not all snakes also regurgitate (throw up) if they have an obstruction.
Cytology. Specialized fecal tests and cultures are important to determine the actual cause of any thickening or infection. A specific cause will allow your veterinarian to select the best treatment plan and also give you an estimation of your snake's chances of getting better.
Tube feedings. If your snake hasn't eaten in a very long time the stomach and intestines atrophy (shrink) to the point where the snake can't digest a whole animal anymore, even if he feels like eating. Depending on the state of atrophy, your veterinarian may start off with a dilute electrolyte and sugar solution similar to solutions used to rehydrate babies. Do NOT use milk formulas for babies or senior citizens. Since snakes cannot digest milk, these will cause diarrhea. Later sugar and electrolyte powders can be added to increase its osmolality (density).
Once this is tolerated, your veterinarian may use combinations of meat baby food, veterinary supplements or ground prey items to feed your snake. Once your snake is producing normal stools with this combination, it is time to offer small prey items. In most cases, if the underlying husbandry and/or disease problems have been corrected, the snake will be ready to eat on his own. Once the snake has formed normal stools, you can start to slowly increase the prey size back up to normal size. On rare occasions your veterinarian may need to force feed the first prey item. This needs to be done by an experienced person to avoid injury to the snake. It is extremely important to contact your veterinarian if your snake starts to regurgitate at anytime during treatment. It is an indication that the reintroduction to solid foods is occurring too quickly or that there is an untreated underlying problem.
Surgery or endoscopy. If your snake has an obstruction due to a foreign body, there is a good chance that your veterinarian will need to either perform surgery or endoscopy to remove the blockage. In some cases where snakes have swallowed lots of small pieces of bedding (such as gravel), oral fluids and lubricants administered along with lubricating enemas can sometimes relieve the impaction. These procedures must be performed very carefully in order to avoid worsening the obstruction, causing aspiration pneumonia or rupturing the gastrointestinal tract.
Drug therapy. If your snake has an obstruction due to compression or a thickening of the intestinal wall, your veterinarian will need to ascertain the specific cause of the swelling. If the cause is diffuse and due to an infectious agent, your veterinarian will likely treat your snake with systemic drugs. If the thickening is localized your veterinarian may need to perform surgery in addition to administering systemic medications.
Home Care In-depth
Unless you only use your heating devices during the day, make sure that they are not giving off visible light. Many people use regular light bulbs to heat cages. When they are left on 24 hours day, they can interfere with the snake's circadian (daily) rhythms. Once the cycle is disturbed, many reptiles stop eating. Use of ceramic or infrared bulbs circumvents this problem. For snakes that use hide boxes or burrow, an under-cage heating pad can provide temperature gradients without excess light.
If your snake's cage is located in a high traffic room, consider getting a cage cover, it can help maintain the normal light cycle and give your snake extra seclusion when its time to rest. If your snake still won't eat, it may be necessary to move it to a quieter location.
The following tricks can be used to stimulate a feeding response in some snakes.
Make sure that you are using fresh prey animals. Even frozen prey will get freezer burn after several months.
Keep all frozen food tightly sealed until just prior to use. Try to prevent frozen food from picking up odors from other items kept in the freezer.
When defrosting frozen prey, place the prey in a sealed plastic bag. This will prevent the surface from changing texture (a desert snake may not like to eat a wet rodent) and picking up flavors that may be in the soak water.
Place the sealed bag in warm water to thaw the food.
Use a thermometer to measure the temperature of the prey item (place in mouth and down esophagus or into rectum). It should match the live animal's typical temperature.
Especially for young snakes, splitting the head open to reveal the brains or the chest to reveal the heart can sometimes stimulate feeding.
It is always best to feed the appropriate prey species to snakes, but should you temporarily run out of feeder snakes, lizards or amphibians you can try the following: Save shed skins from usual prey animals. Stuff small rodents into the shed skins before feeding. Rub the shed skins on feeder rodents. Some people collect the slime from amphibian and fish skin and freeze it in a jar. As needed they thaw a little bit and rub it on the head of alternative prey items.
For cavity feeders (ball pythons), introduce stunned or thawed prey item into hide box. Offer the snake several choices of hide boxes.
Snakes that have been previously attacked by a particular prey item often develop an aversion (fear, distaste) for that same type of prey animal. In these cases switching from mice to young rats or gerbils or hamsters can be helpful (or visa versa). Sometimes just changing the color of fur will be enough to entice the snake to eat.
If you are not familiar with the natural history of your snake and you have been trying to feed it rodents while waiting for your books to come in at the library, try feeding a small lizard.
If your snake has cage mates, try feeding him separately.
Optimal treatment for snakes with anorexia requires a combination of home and professional veterinary care. Follow-up can be critical.
Administer any prescribed medications or food supplements as directed by your veterinarian.
Be certain to alert your veterinarian if you experience any problems while treating your pet. Be especially careful to report regurgitation, decreases in activity or the development of diarrhea.