Lizard in terrarium

When cold weather comes, especially in areas that experience significant climate changes with the seasons, there are some steps reptile owners should take to help ensure their pets stay happy and healthy. With a few minor differences, the concerns for snakes, lizards, turtles and tortoises are the same.

Keep Them Warm

First, all of these coldblooded animals, whose body temperatures adjust to the environment around them, require supplemental heat for proper digestion, immune function and metabolism. This is especially true when temperatures drop.

A reptile who may not need additional heat from an over-the-tank heat bulb or an under-the-tank heating pad during the summer may need these added heat sources during winter. This is especially true for certain reptiles, such as tortoises, which require high temperatures to remain healthy. The best way to determine whether your reptile’s cage temperature is adequate is to use an infrared laser temperature gun to test areas in the tank where your pet hangs out. Different species require different optimal temperatures; with a temperature gun, you can get an accurate idea of what your pet’s tank temperature is and compare it to the recommended temperature range for the species. The best source for recommended temperature ranges for specific species is your veterinarian. If you do not have a temperature gun, at a minimum you should have thermometers that stick on the inside of the tank so that you can monitor the tank for temperature changes.

Any heat source should be plugged into a thermostat that is set to turn the source on and off in order to maintain temperatures within the prescribed range. This helps limit the risk of burning the pet as well as reduces the risk of setting an electrical fire. So-called hot rocks — fake rocks that contain a heating element — should not be used with reptiles. These items cannot adequately heat a tank, and many reptiles lack the necessary sensation in their abdomens to prevent a burn if they sit on them for too long. Reptiles who live in water, such as turtles, must also have their tank water temperatures reassessed when the air temperature drops in winter. If the water temperature drops too low for your pet’s particular species, you need to add additional water heaters.

Let There Be Light

In addition to warmth, nearly all reptiles require ultraviolet (UV) light to produce vitamin D in their skin. This enables them to absorb calcium and phosphorus from their food. Though many reptiles are brought outside into direct sunlight during warm months to fulfill this need, colder weather makes that impossible. Since glass filters out UV rays, placing the tank near a window isn’t adequate either. You should provide direct UV light with a UV bulb designed specifically for reptiles that shines over the cage for 10 to 12 hours each day. Depending upon the manufacturer, the bulb must be changed every 6 to 12 months to ensure proper UV exposure. The onset of cold weather is a perfect time to check that your UV bulb is fresh.

Scaly Skins Need Moisture

With cold weather comes dry air. Most reptiles rely on environmental humidity to stay hydrated and shed their skin. Without adequate humidity, reptiles, including snakes and several species of lizards, can become dehydrated and sick and may retain large sections of skin when they try to shed. If the air in your home gets really dry in cold weather, mist your reptile (or soak him in a shallow bowl of warm water) several times a week. Provide a shallow bathing dish into which he can crawl. Adding sphagnum moss or wet paper towels to the tank may help retain humidity, but be sure to change these moist items daily.

Say No to Hibernation

I often hear reptile owners say that their pets go into hibernation during colder months — that they stop eating and moving around much until warm weather returns. Some people actually put their reptiles in dark, cool closets to promote this activity, thinking that they are helping their pets with a natural behavior. If this happens, however, their metabolism and digestion slow down and their immune systems may not function optimally. In the wild, reptiles hibernate by necessity in response to a lack of food and exposure to cooler temperatures during the winter. In captivity, however, the goal is to keep a constant tank temperature, within the pet’s ideal range, and  make food plentiful all year round. Conditions shouldn’t change with the seasons for a pet reptile, and since hibernating pets may be more disposed to developing infections and metabolic diseases, this more dormant state should be avoided.

Taking Steps for Winter Welfare

Exotic pets like snakes, lizards, turtles and tortoises can be fascinating and truly rewarding to care for. But, in general, when we take reptiles from their natural environments and keep them as pets in somewhat cooler climates, we also have a responsibility to provide them with adequate warmth no matter what the weather is outside. Winterizing for these pets should include a plan for when the power goes out. Such a plan could include having a generator on standby or making arrangements with your veterinarian to board in an emergency. And if you have questions about how to properly care for your exotic pets during the winter, ask your vet. 

Read more articles by Dr. Laurie Hess