Why Does My Reptile Get Sick?

why does my reptile get sick?

reptile care and some common mistakes

Robert Johnson BVSc MANZCVS CertZooMed (RCVS) BA

South Penrith Veterinary Clinic

Penrith NSW 2750

www.reptilevet.com.au

1.  Introduction

The most common cause of disease in captive reptiles is incorrect or poor husbandry. So what is husbandry? In brief it is the practice of caring for, managing and breeding captive animals. A sound knowledge of reptile biology and behaviour is essential for successful reptile keeping. The feeding and habitat requirements of your turtle, lizard or snake must be carefully considered.

Ideally a captive reptile requires:

·  Access to an appropriate temperature gradient– see Table 1

·  Access to suitable hides and retreats, i.e. privacy

·  Suitable humidity

·  Diurnal cycles of light and heat, i.e. try to mimic what happens in the natural habitat

·  Appropriate interaction with members of its own species, e.g. social species need to hang out with their own kind, bearded dragons

·  Appropriate food items, quantity and frequency of feeding

So why do reptiles get sick? In my opinion the commonest causes are incorrect enclosure temperature, poor hygiene, overhandling, inadequate access to UV light, poor diet, incorrect enclosure size (usually too large). Infection will follow but rarely is the primary cause of the disease a virus, bacteria or fungus. So what can you do to stop this from happening? Easy, just follow the 8 H’s of Husbandry.

2.  The 8 H’s of Husbandry

·  Heat (+ light)

·  Hide

·  Humidity

·  Health

·  Hygiene

·  Healthy appetite

·  Habitat

·  Handling

Heat (and light)

Heat

Reptiles are NOT cold-blooded, they are ectothermic vertebrates that regulate their body temperature by behavioural and physiological processes. In other words they rely upon external heat sources and cannot generate their own body heat. Reptiles should be housed at temperatures similar to field conditions, providing temperature variation within the enclosure that allows the animal to thermoregulate. A thermal gradient is achieved by having sufficient room to place heat sources strategically within the enclosure. Two main types of heating are used; radiant (lamps, ceramic globes) and convective (heat mats, tape). It has been shown that large reptiles rely primarily on radiant heat sources for thermoregulation whereas smaller species tend to depend on convective sources. Ground dwelling snakes such as Children’s pythons (Antaresia childreni) prefer sub-floor heating, whereas arboreal or climbing species such as Carpet and Diamond pythons prefer radiant heat. The ambient room temperature should be stable and not place undue stress on the thermal gradient in the vivarium. Mistakes are commonly made when enclosures are kept in rooms subject to temperature extremes. The solution; don’t use the tin shed in the backyard as your snake room, choose the best insulated room in the house instead.

Preferred Body Temperature (PBT)

The preferred body temperature is the temperature at which a reptile’s metabolism works best. The preferred optimal temperature zone (POTZ) is the range that allows the reptile to achieve its PBT. Preferred body temperature (PBT) varies with species. See Table 1 for the PBTs of commonly kept Australian species.

Thermostats

You should know the difference between a thermostat and a thermometer. One regulates the temperature and the other measures it. It is important that you realise that the readings on most thermostats are only a guide. Thermostats must be calibrated for individual enclosures using a thermometer.

Ultraviolet light

Ultraviolet light is essential for the production of vitamin D3 and calcium metabolism. Diurnal species such as Eastern water dragons and Bearded dragons need ultraviolet supplementation when kept indoors (UVB 280-315 nm). Ultraviolet light sources need to be replaced according to manufacturer’s instructions. There is some discussion as to whether the Diamond python (Morelia spilota spilota) requires UVB supplementation in captivity. Take your reptile outdoors if you can by providing a separate “sunning” enclosure. In summer 20-30 minutes in the middle of the day in dappled shade is the UV equivalent of 10 hours under an artificial lamp. If in doubt give your reptile access to UVB anyhow.

Hide

All captive reptiles need somewhere to hide. Items such as toilet rolls or small cardboard boxes are ideal for hatchling snakes and the smaller terrestrial varieties. When soiled, simply replace them. Porcelain hides and inverted flower pots are also popular. These structures must be waterproof and easy to disinfect. Certain species are more secretive compared with others e.g. Antaresia spp (Children’s pythons).

Large enclosures should be furnished with several hides in a variety of positions in order to aid thermoregulation. Hides can be used as an aid to handling. This is especially relevant to more aggressive or venomous species. The entrance to a favourite shelter may be securely blocked and then used to transport the reptile.

Humidity

Humidity requirements vary with species (40-80%). For example, the environment of a green python (Morelia viridis) needs a much more humid enclosure than an inland bearded dragon (Pogona vitticeps). All snakes need a large water bowl for bathing and drinking. The humidity of a vivarium can be controlled by altering the size of the water bowl. Always place it at the cooler end of the exhibit, except in cases where a rapid increase in humidity is required. In these cases a heat lamp or mat may be placed under the water container to aid evaporation. All enclosures, dry or humid, should be adequately ventilated. Remember, in winter when houses are heated and the air is very dry you will have to pay extra attention to the humidity in your reptile’s enclosure.

Health

The health of a captive reptile is closely linked to the standard of husbandry. Ensure that you recognise the signs of ill health; poor or no appetite, weight loss, slow growth, unusual shedding, unusual behaviour and unusual discharges. Check your snake or lizard regularly for mites. An annual vet check is recommended for all pet reptiles. Owners of large collections should arrange for vet visits. Thorough health checks and faecal examinations can be carried out.

Hygiene

Clean substrate, good disinfection and regular cleaning mean good hygiene. Make sure that water bowls are cleaned regularly, usually 2-3 times a week. Cross contamination from water bowls is a common cause of disease spread in reptile collections.

Substrate

Substrates vary according to species. Newspaper or butcher’s paper is suitable for climbers such as Diamond and Carpet pythons. Ground dwellers such as Children’s pythons and Blue-tongued lizards do best on pelleted newspaper substrate. Hatchling and small pythons should not be fed in containers with pelleted newspaper substrate. Pellets may be accidentally swallowed, causing intestinal obstruction. The feeding area should be a separate container lined with paper. Bearded dragons thrive on fine sand. Gravid females need a suitable substrate for digging and egg-laying. Artificial turf, bark chips and dirt are unsuitable and will often harbour pathogens such as fungi and bacteria.

Water quality

The commonest cause of disease in captive turtles is poor water quality. Water should be tested weekly using a standard aquarium kit, measuring pH, ammonia levels, nitrites and nitrates. Aim for a neutral pH of 7 and no ammonia, nitrites or nitrates. Minor skin ailments will heal if the turtle is removed from the water for a short period. Some keepers feed turtles in a separate tank to avoid contamination of the water with food particles. Others feel that changing tanks places unwanted stress on the animal. Ensure that water changes and not “topping up” is done. Choose an appropriate filter for your turtle’s tank. Finding the right filter and feeding the right amount to your turtle is a fine balance. With time you will work out the right amount of food to offer and any uneaten food can be siphoned off or removed with a net from the aquarium. Hatchling turtles are best placed into an aquarium with a minimal amount of substrate so any uneaten food can easily be detected and removed. The use of a small amount of coral sand will help to elevate the pH levels. Calcium added to the water will aid in the prevention of soft shell. Small internal filters are best for baby turtles, as the turtles grow change to a larger filter.

Healthy appetite

Diets vary in Australian reptiles; depending on species, size and state of maturity. Blue-tongued lizards start off life as insect and snail eaters and gradually become more omnivorous (eating vegetables, fruit, insects, animal protein) in their feeding habits. Bearded dragons similarly begin as insectivores and as they mature develop a taste for vegetables and some fruits. All Australian snakes are carnivorous. Python hatchlings will eat small pinkie mice. As they grow food items should be larger (pinkie-fuzzy-weaner mice-adult mice-rats) and feeding intervals further apart. Hatchlings are generally fed every 4-5 days, while an adult python may be fed every 1-2 weeks. Small lizards need to eat daily or at least every second day. Adult lizards are usually fed every 2-3 days. Turtles will normally only eat in water. Some may be trained to accept food out of water. Usually reptiles are fed no more than 20% of their body weight at a time. All mammalian prey items must be pre-frozen (preferably 4 weeks at least) for animal welfare reasons and to limit parasitism. Never feed snakes together in the same vivarium, especially reptile-eating species. Assisted feeding may be necessary at times. Smaller snakes can be fed pinkies with gentle pressure, patience and lubrication. Larger snakes may be tube fed with canine or feline invalid diets such as Hills a/d®. Long crop needles or a variety of sizes of stomach tubes are used. Turtles are more difficult to “assist feed” due to the length of their necks and a tendency to regurgitate. Lizards may be fed food items by hand if necessary. Guitar plectrums or credit cards are useful for opening the mouths of turtles and some lizards.

Habitat

Novice reptile keepers frequently make the mistake of transferring a hatchling or small snake into an enclosure that is too big; often built by a proud Dad whose Mum wouldn’t let him have a snake when he was a child. Snakes should always be housed so that they can stretch to their full body length, however very large enclosures may make it difficult for a small reptile to thermoregulate. Small plastic pet containers are sufficient for hatchling pythons. Sub-floor heating is usually provided by heat-mats or tape. According to some authors the size of the cage may not be as important as how it is furnished. Remember even a tiny hatchling Diamond python still needs somewhere to hide, climb and keep warm.

Handling

Reptiles, especially snakes and small lizards should not be over-handled. Snakes should not be handled for at least 3 days after eating due to the risk of regurgitation. Hands should be washed before touching reptiles to limit the spread of disease and to be rid of any mammalian scent. A snake will strike instinctively if it can smell mammals. Frequently reptiles are brought to my clinic draped around the arm of their owner and not in a container. This can be stressful for the snake and non-reptile owning clients in the waiting room. Such a practice is to be actively discouraged. Remember, when you handle a reptile you are taking it away from its climate-controlled environment. Ensure that snakes are kept warm and secure when being transported. Keep handling to a minimum, even for larger snakes. When handling large pythons ensure that their bodies are well-supported as sudden movements or “slips” can lead to great stress on their spine.

3.  Common conditions associated with poor husbandry

Anorexia

Anorexia is a sign and not a disease. Reasons for anorexia may be physiological (natural cause) or medical. It is imperative that a thorough history is taken paying particular attention to diet and heating of the vivarium. A complete physical examination by your veterinarian will help to tell the difference between an environmental problem and a medical one.

Solution: Check enclosure temperature, food item. In the case of lizards, is the affected animal being bullied and has limited access to feeding areas and basking sites? If you see any signs of disease contact your reptile veterinarian.

Stomatitis (Canker)

Stomatitis is probably the most commonly seen condition in captive pythons. The snakes are usually not eating. In early stages it can present as small pin-point haemorrhages in the gums and salivating. More severe forms of the disease involve swelling of the gums, abscess and exposure of underlying bone. Reptiles will not eat when affected. All orders are affected. The cause is usually poor or inappropriate husbandry, especially lower than normal enclosure temperatures, or in the case of turtles, poor water quality. Severe cases in snakes will need surgery as well as intensive antibiotic treatment.

Solution: Increase enclosure temperature. Check the substrate. See your reptile veterinarian.

Mites

The snake mite, Ophionyssus natricis, has a very short life-cycle. Snakes infested with mites may exhibit dysecdysis (difficulty sloughing skin) and spend long periods soaking in their water bowls. Mite infestation is directly related to poor hygiene and quarantine practices.