Caring for Reptiles (especially Iguanas and other Lizards)

HUSBANDRY:

Most clinical problems with reptiles may be traced to improper husbandry, management and/or feeding practices. Comprehensive and accurate booklets are commercially available from Advanced Vivarium Systems; Lakeside, CA 92040; and, Chicago Herpetological Society; 2001 N. Clark St.; Chicago, IL 60614. 

CAGING:

Many reptiles are escape artists and can squeeze through tiny cracks. Cages should be secure, with tightly fitting lids. The sides should be smooth. Wire cages should not be used. Wood cages must be sealed with polyurethane or similar waterproofing agents (allowed to dry for several days plus the cage aired out for several more days) and the joints caulked. Cages, food and water bowls must be cleaned often.   3% Chlorox makes a good cleaning solution. 

Floor-covering material may be newspaper, indoor/outdoor carpet, sterilized bark chips, alfalfa pellets or cyprus mulch. Do NOT use cedar shavings, gravel, crushed corn cob, cat litter, wood shavings or (except in desert species) sand. 

HEAT:

Optimum heating is required for digestion, growth, healing, reproduction and immune system function. Thermal gradients (hotter on one side of the cage than the other) must be provided. Most lizard species, such as iguanas, derive external heat from basking in the sun, not from laying on rocks heated by the sun (therefore, AVOID hot rocks with lizards). 

The best heating scheme is to use a ceramic heating pad UNDER the cage bottom at one end and a reflector lamp. The heating pad should be left on all the time, but the lamp turned off at bed-time.

The ideal temperature gradient is 80 degrees at one end and 98.6 degrees at the other. Sick, injured or stressed lizards need temperatures closer to 93 degrees on the cooler end until they are normal again. 

Temperatures across the gradient need to be measured. An acceptable method is to place a digital thermometer-hygrometer (electronics stores) on the flooring on each end of the cage (or moved from one end to the other once or twice a day). Aquarium thermometers stuck to the side of the cage measure the temperature of the side, not the bottom, and should be avoided. 

Humidity should be kept at 50 - 70%. Bacterial and mold growth can be controlled by adequate ventilation. 

LIGHTING:

Full-spectrum lighting, especially UV, is important for vitamin D synthesis and calcium metabolism. The best sources are, in order, unfiltered sunlight, sun lamps, black lights, and Vita-Lite. Plant lights and black light blue tubes are of no value to reptiles.

Artificial UV lights should be within 18-24 inches of the reptile and not filtered by glass or plastic. They should be used for 20 minutes a day and CAUTION TAKEN TO AVOID HUMAN EXPOSURE OR EYE CONTACT with the UV rays. 

Nothing replaces natural, unfiltered (by glass or plastic) sunlight.

Lizards should never be placed in sunlight in a glass container.

DIET:

All plant material washed, chopped, mixed, and served at room temperature or slightly warmer. 

Hatchlings up to 14 inches in length:

• Feed twice a day or continuous availability 
• Plant matter finely chopped or shredded 
• 85% plant material, 15% animal protein sources 

Juveniles up to 2.5 years or 3 feet in length: 

• Feed once a day
• Plant matter chopped fine to medium or shredded
• 90% plant material, 10% animal protein sources 

Adults over 2.5 years or 3 feet in length: 

• Feed once a day to every other day
• Plant matter coarsely chopped
• 95% plant material, 5% animal protein sources  Ingredients: 
• Calcium rich vegetables: 30-40% of the diet, two or more items per feeding. 
• Turnip greens, mustard greens, beet greens, kale, collards, bok choy, Swiss chard, dandelions, parsley, romaine, escarole, spinach, alfalfa pellets. 
• Other vegetables: 30-40% of the diet, a variety weekly.
• Frozen mixed vegetables, squash, zucchini, sweet potato, bell pepper, broccoli, peas, beans, okra, grated carrot, sprouts. 
• Grain\fiber: optional, up to 20% of the diet. 
• Whole grain breads and natural bran cereals 
• Fruits: no more than 15% of the diet. 
• Figs, papaya, melon, apple, peaches, plums, strawberries, tomatoes, banana (with skin), grapes, kiwi. 
• Animal protein sources: 5% of adult diet, 10% of juvenile diet, 15% of hatchling diet.
• Insects: crickets, mealworms, king mealworms  Meats: cooked chicken, small prekilled mice  Commercial pet diets: soaked premium low fat dog food, primate diets, and trout chow have high levels of vitamin D and should be used with caution.

Iguanas in the wild are mainly herbivores that also eat small quantities of insects. They tend to eat many small meals throughout the day, and their natural eating habits lead toward a diet of mostly fiber and plant protein, with very little fat.

Iguanas that are less than two years old should eat 80 percent plant-based food and 20 percent protein. Adult iguanas (more than two years old) should eat 80 percent plants and 10 percent protein.

When picking plant-based food to make up the majority of the iguana's diet, it's important to choose the different kinds in the right proportions: 80 percent of it should be flowers and vegetables, and 20 percent should be fruits. While iguanas do enjoy the sweeter fruit choices, fruit doesn't have the same mineral and vitamin content as vegetables. To avoid getting your pet hooked on just a few foods, be sure to feed a wide selection of appropriate foods in the right proportions. In these cases, fresh foods are best, with frozen coming in second, and canned coming in last.

Here is a list of a few appropriate vegetables to feed your iguana. You can serve them cooked or raw; just be sure to wash them well:

These flowers are also OK for your pet. Be sure they have not been treated with chemicals or fertilizers:

Appropriate fruit selections include:

Appropriate protein choices include:

*Never feed insects from your yard. Either raise your own specially for your pet or purchase them from a pet store.

Vitamin\mineral supplementation:

Supplementation is advised, because vitamin and mineral deficiencies are common in iguanas.  However, calcium and the fat-soluble vitamins (A,D, E, and K) can  be oversupplemented as well as undersupplemented. To avoid over-supplementation, natural sources from a varied diet is the best choice, with moderate vitamin\mineral use to balance the diet. 

• Vitamins: Vitamin D3 is the form utilized by reptiles, and this is a better source than D2.  
• Minerals: avoid those supplemented with vitamins A and D3. Use powdered calcium carbonate or calcium gluconate, or cuttlebone  shavings. 
• Mix two parts vitamin and one part mineral. 
• Hatchlings and juveniles: one small pinch per feeding 
• Adults: one full pinch per 2 pounds body weight twice a week
• Adult Females: one full pinch per feeding from December until egg laying.
• Groups: 1/8 tsp vitamin/mineral mix per 3 pounds iguana per week. 

We hope that you will find this information helpful in your quest for better pet care. If you have any questions or comments, please call your veterinarian's office, or feel free to e-mail us.

David E. Hammett, DVM
and the Staff of All Creatures Veterinary Clinic, PC