Iguanas - Owning

General Information

The common green iguana is a large arboreal (lives in trees and bushes) lizard form Central and South America. They are herbivores (plant eaters). They have a long tail (used as an effective whip to defend itself) and a row of spines running down their back. The iguana is a popular pet lizard, although their popularity is on the decline in recent years with the availability of other smaller, easier to keep, species of lizards. Mature males (2 years and older) are easily distinguished from females as they have a significantly larger head and jowls, thicker neck, more developed dorsal spinal crest and larger and more pronounced femoral pores on the inner aspects of the thighs. These pores are openings of glands that are used in marking behaviors. Under proper conditions, adult males can reach 15 - 20 lbs (7 - 9 kg) and big ones can grow to 6 feet (1.8 m) in length. The average length is 3 - 5 feet (1 - 1.5 m). Therefore, proper provisions must be made for a larger enclosure as the pet grows.

"Iguanas are NOT suitable pets for young children or young teenagers."

Sexual maturity is reached by 2 years of age. Females can produce and lay eggs without a male, although the eggs will be infertile and will not hatch. With proper care, your iguana can live 10-15 years although 25 years has been reported. When young, they are bright green in color; their color gradually fades to a brown, dull orange or grayish green as they reach adulthood. Iguanas are usually fairly docile and harmless, but can cause severe scratches with their long claws. If not socialized well or wild caught, some individuals (especially sexually mature males) may be very aggressive and territorial and if they are provoked, have a nasty, painful, damaging bite. Iguanas are NOT suitable pets for young children or young teenagers. They do not make appropriate "family" pets. They are better suited for the skilled, knowledgeable reptile enthusiast.

How do iguanas differ from other pets?

  • Iguanas do not have diaphragms; they use muscles located between their ribs (intercostal muscles) for breathing.
  • Iguanas have a three-chambered heart; dogs, cats, and people have four chambers in their hearts.
  • Iguana's tails will break off if roughly handled. They do slowly grow back again, but with a duller color.
  • Iguanas have a renal portal blood system, where blood from the hind limbs is filtered by the kidneys before reaching the general circulation. This means toxins from the rear limbs (as could occur from wounds on the legs), as well as drugs injected into the rear legs, would probably be filtered before entering the general circulation.
  • Iguanas excrete uric acid (the white portion of their excretions) as their main waste product of protein metabolism (dogs, cats, and people excrete urea). This allows them to adapt to desert environments where water supply might be restricted.
  • Males have two reproductive organs called hemipenes.
  • Iguanas have a cloaca, which receives secretions from the urinary, gastrointestinal, and reproductive systems. The external opening of the cloaca is the vent, located on the ventral or under surface between the back legs.
  • The skin is covered with scales and is usually shed in patches as the iguana grows, unlike snakes where the skin is usually shed in one piece.
  • Unlike many reptiles, iguanas have a urinary bladder.
  • Iguanas explore their environment by flicking out the tongue and licking or tongue-testing with a light touch of the tongue. This is like "sniffing" and is a sensory function

How do I select an iguana?

Most owners buy iguanas locally from a breeder or pet store. Young, captive-raised animals make the best pets. Older imported animals are harder to tame, may harbor internal parasites, and often suffer from the stress of forced captivity. Avoid sick-looking animals.

"Avoid lizards that appear skinny, have loose skin or sunken eyes, and appear inactive or lethargic."

Start out right with a healthy pet. Avoid lizards that appear skinny, have loose skin or sunken eyes, and appear inactive or lethargic. A young healthy iguana is usually bright green, aware, active, and alert as often evidenced iguanas-owning-1by the front legs pushing the chest and head upright and high. The girth of the tail by the back legs should be round, plump and full, not sunken and bony. The vent or cloaca should be clean and free of wetness or stool stuck to it. If you can GENTLY open the mouth (tapping lightly on the snout with a finger often works), you should see a small amount of clear saliva and a bright pink tongue and oral cavity. Mucus that is cloudy or "cottage cheese" in appearance is a sign of mouth rot, as is redness or pinpoint hemorrhages (small spots of bruising) on the mucous membranes. Always inquire about the guarantee, in case the iguana is found to be unhealthy.

My iguana looks healthy. Does he need to see the veterinarian?

Within 48 hours of your purchase, your iguana should be examined by a veterinarian familiar with reptiles. The physical examination includes measuring the animal's weight, as well as checking for any abnormalities.

"Consider all iguanas (even those bred in captivity) to have pinworms"

The animal is examined for signs of dehydration and malnutrition. A fecal test is done to check for internal parasites. Many veterinarians consider all iguanas (even those bred in captivity) to have pinworms, so your iguana may be routinely dewormed for these parasites (these species of pinworms are not transmissible to people). The oral cavity is examined for signs of infectious stomatitis (mouth rot). No vaccines are required for iguanas. Your doctor may recommend blood tests, bacterial cultures, or radiographs (X-rays) to check for other diseases. Like all pets, iguanas should be examined and have their feces tested for parasites annually.

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