Iguanas are difficult and expensive animals to own

A few times a year, Nicole Wyre takes a stroll around pet shops in Mong Kok. She's on the lookout for any new animals available to local residents. Last month, she spotted a new lizard in town - a green iguana, also known as the common iguana.

'What we used to see in pet stores were a lot of chameleons, now they are selling iguanas, which I've never seen before in Hong Kong,' says Wyre, an American veterinarian who treats animals and reptiles at the Tai Wai Small Animal and Exotic Hospital.

According to Wyre, many iguana owners may not be aware that small six-inch iguana hatchlings can grow to five- to six-feet long. 'The biggest thing that people need to understand is that iguanas can become huge ... and therefore need large enclosures or even an entire room set aside for them,' she says.

Wyre says the cold-blooded creatures need specific heat and lighting requirements that can be expensive. Owners can expect their lizard to live up to 15 years. However, once the decision has been made to purchase an iguana, Wyre suggests booking an appointment with an exotic veterinarian for a complete body check and nutritional consultation.

Wyre has owned about 15 snakes, bearded dragons and iguanas over the years. For those who want a lizard, the veterinarian recommends getting a bearded dragon, which will stay smaller in size and be less aggressive. 'I have owned many species of reptiles and the iguana is by far the most difficult and expensive pet to own,' she says. Wyre explains iguanas waste no internal energy and are extremely efficient creatures. An iguana's body temperature, digestion, heart rate, blood pressure and immune system are '100 per cent related to the outside temperature'.

A common problem Wyre encounters is owners trying to feed their iguana a high protein diet such as cat or dog food, or eggs, which can lead to developmental and bone issues from not enough calcium in their diet. 'Nutritional deficiencies and excess of protein, for example, are the most common problems seen in young iguanas,' she says.

Iguanas are strict herbivores that should have a diet of leafy vegetables such as bak choi and kale - the greener the leaf, the better. Wyre does not recommend iceberg lettuce as it has little nutritional value. 'Research thoroughly, these animals are from Central and South America, and [owners need to] create a diet and an environment mimicking their natural wild habitat,' she says. 'They require special UVB [ultraviolet] lights which helps them to absorb calcium from their diet, so even if calcium is in the diet, it will not be absorbed without the UVB lights.'

Depending on the iguana's stage of life, Wyre says, different supplements are necessary and can be discussed with a veterinarian. Generally, she advises that iguanas need a high quality calcium supplement, without vitamin D added, given three to four times a week.

Poor diet, poor lighting and environment, and improper humidity can cause problems ranging from bone fractures and soft bones to stunted growth, skin abnormalities and muscle tremors, Wyre says. She finds these lizards fascinating. 'They are more of a pet to watch rather than cuddle, it's a different type of relationship than I have with my bird'.