Monitor Lizard

Monitors range in size from the dwarf monitor that is a couple inches long to the Nile monitor that is seven feet. In many states you need a permit for the larger monitors that can grow longer than five feet and any snake over six feet long.

Common Characteristics

  • Size: 1 to 20 pounds
  • Lifespan: 6 to 15 years
  • Primarily suited for indoors


Common Reasons for Surrender

The most common reason for surrender is that the monitor lizard got too big. This lizard can get sick with liver problems or heart attacks when their owners feed them too many rodents or don’t keep them warm enough.


The monitor lizards are said to be the most intelligent (and largest) group of lizards.


Some are endangered species and cannot be bought as a pet. Most monitors grow from three to eight feet long and need large living quarters that are at least twice as long as their adult size.


The large monitors eat hard boiled eggs, canned dog and cat food, small rodents, and insects. Depending on their diet, the monitor lizard may need vitamins and nutrients added to their food, especially calcium. Crawl fish help with calcium and should be boiled (not boiled live) to kill any parasites in the fish before feeding to the monitor lizard.


In summertime, you can take them outside on leashes and harnesses and let them walk around and explore. That’s an important issue with tagus and monitors because if the enclosure isn’t big enough and they can’t get out, they need a large enclosure. Get an enclosure as large as a child’s bedroom. That’s only fair.

Possible Health Issues

The monitor is susceptible to parasites, salmonella, and infections. Injuries can happen, especially if two large monitors or tagus are put together. All monitors should be housed separately from one another, as even the females may fight.


Your enclosure needs to be at least twice as long as the maximum size your monitor lizard will grow into. A five-foot monitor lizard will need a pool or a tank at least twice as long and twice as wide as your bathtub. They require warm temperatures of 85 to 90 degrees and need a basking spot of about 120 degrees. If they don’t have that, they can’t digest their food properly and will get liver problems. Research your monitor to determine if she comes from a tropical habitat or a dry desert to regulate humidity for that particular monitor lizard.


Take your monitor to the veterinarian so she can show you how to cut the nails properly. You will cut them much like a bird’s nails, snipping just the tips. Like the tagu and iguana, this lizard sheds in little pieces of scales. They can have difficulty shedding if their room is too dry. Put a thick layer of substrate flooring into their habitat and mist the flooring with a mister spray bottle. Some owners will put their monitor into a warm shower for half an hour.  


The monitor can’t be trained to fetch the paper, but he can figure out your daily routine and where his food is kept.  




They like to explore. It’s fun to hide their food and let them find it instead of putting it right in front of them.  

We want to thank Reptile and Amphibian Rescue, Los Angeles, California, for help with this profile.

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