Are Monitor Lizards Poisonous?

Probably you have come across monitor lizards in your field, yard, compound or zoo and wonder if they could be poisonous. You may even have seen them feed on rats, snakes or rodents. But are Monitor Lizards Poisonous?

The direct answer is YES. Monitor lizards (such as Komodo Dragon, Asian Water Monitor, and Tree Crocodile Monitor) can bite and cause poisonous infections since they are venomous.

The venom contains crotamine, which prevents blood clotting leading to a drop in blood pressure and cause death at the long run. On the other hand, Monitor Lizards such as Bengal Monitor and Savana Monitor are believed to be harmless and defenseless. However, these species are few. 

Related: Are Blue Tailed Lizards Poisonous?

Details: Are Monitor Lizards Poisonous?

Monitor lizards are the most poisonous and dangerous species of lizards. They contain venom at the root of their teeth, which they use to paralyze the prey before they swallow. Most Monitor lizards are carnivore and are well known for their tactical hunting skills.

We can therefore say that most Monitor lizards are dangerous carnivores that paralyze prey using their venom before swallowing.

In addition, these reptiles harbor salmonella bacteria that cause infections to both pets and human beings if not treated or disinfected. Meat from Monitor Lizard contains Liver fluke which damages severely the pets’ livers and causes liver inflammation.

1. Komodo dragon (Varanus komodoensis)

This is the largest Lizard ever lived. It grows to a length of 30 meters and 135kg (300 pounds) in weight at adulthood. Komodo Dragon is the most venomous lizard. It can run fast to attack its prey, including human beings.

This reptile bites and injects poisonous venom into you/prey. The venom contains crotamine, which prevents blood clotting and thus leading to death if not urgently attended.

Several reports of human attacks by Komodo Dragon have been reported between 2000 and 2014. This reptile also introduces bacteria from its mouth to the prey accelerating the killing.

2. Malayan, Asian Water Monitor, Two-banded Monitor (Varanus Salvator)

This type of monitor lizard is found in South China Sea, Bengal bay, and Sri Lanka. They are well known carnivores that feed on fish, mollusks, birds, spiders, small mammals, and even other lizards. Asian Water monitor also eats meat from a dead human being.

These monitor bites human beings and injects venom that causes mild effects and infections which may get severe if not attended to. There are rare cases of people who have died out of Malayan monitor’s Venom unlike the case of Komodo Dragon.

People hunt the Asian Water Monitor for their skin and meat, which they use for traditional leather industry and medicine.

3. Tree crocodile, or Crocodile monitor (Varanus Salvadori)

This type of Monitor Lizard loves living in the Islands of New Guinea. They are dangerous and poisonous lizards. Just as the name states, they behave like crocodiles (threatening and hunt alone).

Crocodile monitor are highly aggressive. They are able to bite and kill their prey in minutes. Though people prefer hunting them for their meat and sin, these reptiles are considered a very risky and are mainly capture using traps. 

4. Bengal monitor (Varanus bengalensis)

This is commonly known as the common Indian monitor. It is found in West and southeastern Asia along with Sri Lanka.

This monitor lizard is considered harmless and defenseless by the people of Sri Lanka. It’s highly hunted for meat and fat that is used for various home use.

The skin extract from Bengal monitor is used for making drums by the people of Sri Lanka. This reptile has not been aggressive against people and is considered a nice pet.

5. Nile Monitor or Water Monitor (Varanus niloticus)

Nile Monitor is found in Nile valley of Sub-Saharan Africa. It is well known for hunting in rivers and nearby vegetation.

It is able to kill large animals such as frog, turtle, birds and terrapin for food. Nile monitor rarely hunt human beings. However, when threaten, they can bite and instill a painful injuries.

These reptiles prefer to escape by swimming in the rivers in case of danger.

Related: Do Anole Lizards Bite?

6. African Savannah Monitor, or White-throated Monitor, Rock Monitor, Savannah Monitor (Varanus exanthematicus)

This Species of Monitor lizard is found in savannah and arid areas of Eastern and southern Africa. It is carnivore in nature and will kill small animals such as baby tortoise and invertebrates for food.

Normally, Savannah monitor loves solitary life. It bites when threated and knocks off its assailants using its long tail. There is no report showing death resulting from Savannah Monitor. This species can be kept as a pet.

Are monitor Lizards Poisonous to Human Beings?

Monitor lizards such as Komodo Dragon, Asian Water Monitor and Tree Crocodile Monitor are termed as human threat since they contain venom. These reptiles do not hunt human beings, however, when provoked or while stressed, they can bite dangerously.

The bite from a Monitor lizard causes poisonous infections. The monitor lizard’s venom contains crotamine, which causes blood not to clot leading to drop in overall blood pressure in victim’s body – this may lead to death if not attended to immediately.

The bite from monitor lizard may be as deep as 0.5 to 2 inches and cause large swelling. The blood Oz continuously from the bite without stopping – you must therefore be quick to act on a bite from Monitor Lizards. The bite may take up to a month to fully heal the scar left during the attack.

In United Kingdom, The Sun Newspaper reported a case of Ronald Huff, 42, who died from venom injected by Monitor Lizard bite in 2002.  In fact, the reptile use to be left to roam in his house freely as a pet. After paralyzing Ronald Huff, the monitor lizard even fed on his hands and stomach organs in this bizarre incidence.

On the contrary, some Monitor Lizards such as Bengal Monitor and Savana Monitor are believed to be harmless and defenseless.

However, these species are few and their behavior may be caused by large weight or hormonal imbalance. Research is still being carried out to establish what can make them aggressive like other species of monitor lizards.

The monitor lizards harbor salmonella bacteria that causes infections to both human beings and pet.  The pet Monitor Lizard should be disinfected often (once per month) to prevent them from dropping these bacteria in your compound.

Are Monitor Lizards Poisonous to your pets (cats & dogs)?

Monitor lizards are poisonous reptiles that will attach your pets on approach. Komodo Dragon and Tree Crocodile Monitors will bite your dogs or cats using their sharp pointed venomous teeth, paralyzing them to death – the teeth of monitor lizards are strong enough to penetrate the skin of your pets unlike other lizard species.

The bite from a monitor lizard may take more than a month for your pet to heal on vet treatment. The Monitor Lizards are always threated by the presence of dogs or cats since these pets tend to feed on them. Monitor lizard uses its paws, crawls and tail when attacking its assailants.

Monitor lizards also house salmonella bacteria (under the skin) that cause severe bacterial infections on your dogs or cats. You must therefore keep off dogs or cats from your pet Monitor lizards. Moreover, disinfect their cage regularly (monthly).

Dogs and large cats tend to hunt monitor lizards for their food. Meat from Monitor lizards contains liver flukes (liver flukes don’t affect the lizards) which when eaten are transferred into your pets’ digestive track. These liver flukes then travel to the liver, gall bladder and finally to the bile duct. They cause severe liver damage and liver inflammation. 

Which Diseases are caused by Monitor Lizards?

Your pet monitor lizards may not be 100% safe for you, your pets or your humans if not well treated. They cause scary skin when held with unprotected hand.

One feels itching sensation, which makes you tend to scratch yourself. The skin of untreated (dirty, scary) Monitor Lizard is believed to excrete a chemical that cause itching and can also be allergic to allergen sensitive people.

The Salmonella Bacteria that is harbored in the skin of Monitor Lizard cause Bacterial infections to both human beings and pets on contact.

These infections is more pronounce in children who tend to play with pet Monitor lizards often. The research shows that Salmonella Bacteria is able to encompass over 2000 types of diseases in both human beings and pets.

The excretes from Monitor lizards need to be handled with care as they cause infectious diseases and can burn your skin. They favor growth of fungi that may lead to fungus infections in your place.

How Do Lizards Bite?

Monitor Lizards can bite you, when provoked and inject you with venom that kills at long run. Several cases of Komodo dragon and Asian Water Monitor feeding on human being.

The Monitor lizards have sharp pointed teeth that are able to slice through the flesh to a depth of 0.5 to 2 inches. These bites causes continuous bleeding that don’t clot easily and a resultant swelling that may take one month to heal. It is necessary to nurse and treat bites from Monitor lizard immediately in order to save the life of the victim.

During attack, the Monitor Lizards also use their tail power to knock off the prey. They grab prey with their paws, which have crawls are the end for fastening, while eating to prevent them from escaping.

Children, unlike adult, are susceptible to these bites since they love to play with pet monitor lizards a lot. The pet may get agitated by other causes such as reproduction thus biting your kid. In is necessary to keep of your kids from pet monitor lizards as much as possible.

Are the Monitor Lizards Venomous?

Yes. Monitor lizards contain venom at the root of each tooth. The venom contains crotamine chemical, which poisons and paralyzes the prey to death.

Crotamine prevent blood from bite injuries from clotting leading to continuous drop of blood pressure in the body. The Venom also inject chemical that cause immediate swelling and spread infections in the bitten area.

The release of venom from the monitor lizards is faster when it is more stressed or agitated. Since every tooth has venom glad at the root, you much be keen when handling the number of bites so as to administer medicine to each scar appropriately.

The Komodo Dragon Lizard species is said to have very poisonous venom that kill in minutes if unattended.

What are dangers of Overpopulation of Monitor Lizards?

Managing a large population of Monitor Lizards may be tedious and cumbersome to humanity. These Lizards tend to rebel and react negatively over any simple threat. With increased population, food scarcity arises and feeding them becomes challenging.

Hungry Monitor Lizards become carnivores that are more violent with time. They group themselves in crowds that aim at attacking both small and large animals to gain food. These reptiles will become aggressive to a point of attacking human beings (especially children) who try to contain them in their cage or breeding ground.

The colony of Monitor lizards will post threat to other pets and animals within the ecosystem. They rarely interact mutually with other animals – they live a symbiotic life in their lives.

The Monitor Lizard is one of the most fertile species of lizards and reptiles. It can lay up to 30 eggs twice a year, which all hatch a healthy baby monitor lizards. Monitor Lizards give fierce protection to their young ones thus ensuring fully transition to maturing.

Scientific research shows that it has been difficult to control overwhelming population of Monitor lizards due to the dynamics in their breeding pattern. However, to control their natural population increase, you can only do so best by destroying their eggs before they hatch.

Related: What Does a Garden Lizard Eat?

Can Monitor Lizards be Petted?

Yes. You can pet the Monitor lizards. This can be done by using food as bait to lure it. People have petted Monitor Lizards.

However, it is necessary to learn the moods of your Monitor lizards since they may react negatively anytime thus biting and injecting poisonous venom to you, your pets or your humans.

The Monitor Lizard Pet should be kept away from other home pets such as dogs and cats since it can cause bacterial infections or get eaten leading to liver flukes transmission. Your kids should not be allowed to play with your pet monitor lizards alone.


The Monitor Lizards such as Komodo Dragon, Asian Water Monitor, and Tree Crocodile Monitor are poisonous reptiles that bite and inject poisonous venom to their prey, thus paralyzing it to death.

The monitor lizard’s venom contains crotamine chemical which prevents clotting of blood. The blood Oz cause the overall drop of blood pressure in the body. The venom also leaves infections that cause painful swelling on the bitten part.

However, some Monitor Lizards such as Bengal Monitor and Savana Monitor are believed to be harmless and defenseless.

Monitor lizards can also harbor salmonella bacteria, which cause infections to your pets and humans. Proper disinfections and prevention measures should be carried out to maintain healthy life in your place.

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