- The goal of proper lizard restraint is to control the natural serpentine movement of the lizard while being cautious of the mouth, feet, and tail.
- Be particularly cautious of carnivorous lizards, like monitors and tegus, as they possess powerful jaws and lightning fast reflexes.
- Iguanid lizards tend to protect themselves with their claws and tail.
- Tail autotomy is a defense mechanism that utilizes tail loss to escape predation present in some species like iguanid lizards and geckos.
- To restrain a lizard, place one hand around the neck and pectoral girdle region while the other hand supports the pelvis and tail base.
- To minimize the risk of zoonotic exposure, wear disposable gloves whenever possible and always wash hands thoroughly after handling a lizard.
Lizards should be transported to the veterinary hospital in a secure container, like a commercially available plastic pet carrier. The owner should take measures to prevent heat loss during transport using microwavable bean bags or hot water bottles as long as they are insulated from the reptile (Cannon and Johnson 2014, Eatwell 2013).
Know the natural defense mechanisms for your species of interest and train staff members accordingly. The demeanor of your lizard patient can vary greatly with species, age, and the patient’s health status. Signs of aggression and territoriality in lizards can include head nodding, standing sideways to the perceived threat, swallowing air, standing high off the ground to appear larger in size, and lashing at the threat with the tail (Videos 1-4) (Box 1).
|Box 1. Signs of aggression and territoriality in lizards|
Video 2. This lizard’s posture does not invite contact. The animal displays head nodding, standing sideways to the perceived threat, swallowing air, and the body is held high off the ground. Video credit: Erica Mede, CVT
Videos 3 and 4. Signs of aggression and defense in a chameleon. Video credit: Erica Mede, CVT
Never reach over or across a lizard unless the head is restrained. All lizards can bite, however some species like monitors and tegus are true carnivores, known for their powerful jaws used for crushing and twisting. These long-necked lizards can move very quickly, easily turning around and biting if the head is not properly restrained. If bitten, try not to pull away as this will cause the animal to bite down harder (Bradley 2002).
CLINICAL TIP: Keep a spray bottle filled with isopropyl alcohol near. A few drops sprayed directly on the tongue can be quite effective in getting the animal to release (Mader 2009, Bradley 2002).
Some lizard species, like the green iguana (Iguana iguana), are much more likely to use their sharp claws and tail to defend themselves (Fig 1). Whenever possible, wear a lab coat or long sleeves while handling lizards. A complimentary toe nail trim before beginning the physical exam or any diagnostic procedures is also in the handler’s best interest.
Large lizards also use their tails like a whip and can deliver a nasty blow to the unsuspecting handler. Of course, this aggressive behavior can also increase the risk of tail trauma.
First do no harm
The handler should take measures to protect themselves while doing no harm to the patient.
Never grasp a lizard by the tail. Some species possess tail autotomy, a defense mechanism that utilizes tail loss to escape predation. A vertical fracture plane of fibroconnective tissue and cartilage runs through each caudal vertebra. When the distal tail is grasped, the tail can actually fall off or “drop”, even when very little pressure is applied. This can be very distressing to an owner, and the fact that the tail will regrow as a cartilaginous rod is usually of little consolation (Mader 2009) (Fig 2).
Tail autotomy is present in some species like iguanas and geckos. Tokay geckos (Gecko gecko) are particularly challenging as these lizards often drop their tails when handled or sometimes when a threat is simply perceived (Bradley 2002). Tail autotomy generally does not occur in agamid lizards (like the bearded dragon), monitors, or true chameleons.
CLINICAL TIP: Never grasp any lizard by the distal tail. Restrain the tail at the base or near the pelvis.
Not all lizards possess tough, durable skin. Some lizards, like day geckos (Phelsuma spp.), fish-scale geckos (Geckolepis spp.), and Malagasay geckos have extremely delicate skin that can easily be damaged by capture and restraint (Nugent-Deal 2011). Do not handle these lizards unless absolutely necessary as they can autotomize both tails and skin with minimal physical restraint, causing permanent disfigurement. Instead observe these patients through clear enclosures, such as plastic pet carriers.
Fractures and dislocations are a reported complication with improper restraint of lizards, particularly when the patient has “metabolic bone disease” or nutritional secondary hyperparathyroidism.
Before handling any reptile, clearly define roles and gather all supplies that may be needed. To minimize the risk of zoonotic exposure, wear disposable gloves whenever possible and always wash hands thoroughly after handling the reptile.
DON’T SMELL LIKE LIZARD FOOD
Although it is important to wash hands in between all patients, did you just handle a rodent or rabbit? You do not want to smell like food to a carnivorous reptile like a monitor.
Most people prefer to catch lizards by hand as use of gloves often reduces tactile ability and can actually make handling more difficult (Fig 3). A towel or blanket can facilitate capture and restraint of nervous or aggressive lizards (Fig 4). The primary challenge with handling small lizards is to restrain them before they flee from an open container. A small, light-weight towel or a crumpled paper towel can be used to facilitate capture of these tiny individuals using a technique similar to that for catching up a small bird. (Visit the LafeberVet video Passerine Handling and Restraint for additional information).
Lizards vary considerably in size, strength, and temperament and therefore a variety of handling techniques are necessary. Proper restraint focuses on control of the lizard’s natural serpentine movement and generally relies upon placement of one hand around the neck and pectoral girdle region (Bradley 2002). The other hand supports the body near the pelvis, grasping the rear legs up against the tail at or just below the pelvis (Fig 5). Never restrain limbs over the spine because fractures and luxations are a reported complication (Hernandez-Divers 2006). Control the head by firmly grasping just behind the base of the skull with thumb and index finger. Wrap the remaining fingers of that hand around the shoulders to pin the lizard’s forelimbs laterally against the thorax (Fig 6, Fig 7).
To prevent tail whipping, tuck the tail between the hip and the table. Take care not to pin the tail against the table as you restrain the lizard (Bays 2013). When larger specimens are restrained by two individuals, tuck the tail between the hips of the two handlers (Bradley 2002).
Always use firm, gentle pressure when restraining a lizard. As with cats, the more firmly a lizard is restrained, the more likely they are to struggle. Although it is sometimes impossible, try to avoid damaging the dorsal spines during restraint of species like the iguana (Fig 8) (Nugent-Deal 2011).
RESTRICT VISION/VASOVAGAL RESPONSE
Covering the eyes is often the simplest way to facilitate handling of the lizard. Simply placing a towel over the head can aid examination of the limbs and the remainder of the body. A “blinker system”, in which two cotton balls are strapped over the eyes with elastic wrap (e.g. Vetrap, 3M), can also encourage the lizard to sit quietly for a non-invasive procedure, like horizontal beam radiographs. Use of the vasovagal response can be a useful restraint technique for iguanid lizards. Application of gentle pressure to both orbits can put iguanid lizards into a stuporous state for up to 45 minutes or until a painful or noisy stimulus occurs (Hernandez-Divers 2006).
Most chameleons will be much more secure and much less likely to struggle when allowed to perch or grasp onto something, be this a finger or hand, a dowel perch, or even a bunched-up towel (Fig 9).
Before handling any reptile, clearly define roles and gather all supplies that may be needed. Lizards vary considerably in size, strength and temperament and therefore a variety of handling techniques are necessary. These techniques will vary depending on the species, the experience of the handler, and the procedure planned, however the goal of proper lizard restraint is to control the natural serpentine movement of the lizard while being cautious of the mouth, feet, and tail. Standard lizard restraint involves placing one hand around the neck and pectoral girdle region while the other hand supports the pelvis. Be particularly cautious of carnivorous lizards, like monitors and tegus, as they possess powerful jaws and lightning fast reflexes. Iguanid lizards tend to protect themselves with their claws and tail. Tail autotomy is a defense mechanism present in some species, like iguanid lizards and geckos, that utilizes tail loss to escape predation.