Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Fluids and Fluid Therapy in Reptiles

With information on the administration of oral and injectible medications

©2000 Melissa Kaplan

Fluid – water – is one of the main building blocks of all living organisms. Without fluids, our cells cannot function. Without our cells to manufacturer energy and the many chemicals a body needs to function, and to spread those chemicals and nutrients absorbed from food throughout the body, the body dies.

With insufficient fluids in the body, the body’s function is compromised. It cannot sustain all functions necessary for life, and so it starts shutting down operations, closing more and more as the condition worsens, either through the rapid loss of fluid or the failure to obtain sufficient fluids.

The mere act of being alive requires a certain amount of energy (calories) and fluid intake on a daily basis (or aggregate basis, in the case of those species that, as a normal course in healthy members of the species, eat less often than once a day). If, in addition to just sustaining the minimum body functions, the body must also grow, engage in reproduction, experience stress, recover from injury, etc., additional calories and fluids are needed to support the extra demands over and above the basal metabolic requirements (BMR), the bare minimum needed to sustain life.

With reptiles, the fluid requirement issue becomes a bit more complicated as reptile species are found in such a wide range of habitats and live a variety of life-styles. Each species has adapted to its environment over millions of years. If their environment changed very slowly over long periods of time, some members of the population adapted to the changes and survived; those who didn’t died. Eventually, the populations were composed of those individuals whose ancestors best adapted to the changes.

Adapting to life in captivity cannot be compared to the thousands or millions of generations required for a wild organism to adapt to a changing environment. Captivity, even under the best of circumstances, rarely duplicates everything the organism would be subjected to in the wild, including the variables found in water constituents, nutritional and other variables in food animals or plants, amount ultraviolet radiation, microclimates, etc. Many species may appear to adapt quite well and go along for years, portraying the very picture of health and well-being, only to be felled at a relatively early age to organ failure due to something related to the captive environment, or fails to rally after an apparent minor stressor.

Stress itself is a factor in behavior, health, illness, and recovery. Since captive animals, even apparently well-adjusted ones, are living in a condition of chronic stress, routine captive care practices must include mediations to help overcome or compensate for the long term effects of stress.

Huh?

What this all means is that it is important that you provide fluids (including humidity) on a daily basis according to your species’ needs, and that when your reptile is under particular stress you make sure that any extra fluids necessary are administered.

What kinds of stressors can lead to dehydration?

• Being housed in a room cooled by air conditioning.
• Being housed in a room heated by central heating or space heaters.
• Being housed in an enclosure heated to attain and maintain the species required thermal gradients and basking temperatures.
• Temperatures higher than optimum thermal gradient recommended for species.
• Providing water only once a week or only on feeding days.
• Providing water in such as way as to be inaccessible (wrong type of container; standing rather than moving; standing rather than drip or spray, etc.).
• Thermal or chemical burns.
• Systemic antibiotic therapy.
• Diet consisting primarily of dried or pelleted commercial food products or desiccated insects.
• Being in captivity (see Signs of Illness and Stress for other symptoms).

Providing the basic daily fluids may be as simple as installing a bowl or pan of water that your reptile can easily drink from or soak in. For large reptiles, this requires both a suitably large enclosure in which to house the large reptile and its large tub of water and still leave plenty of room for him to move around, thermoregulate, etc. Drip systems, which may be a primitive as a homemade drip bottle or an expensive green house mister, will be needed for species native to humid climates. For other species, an area of substrate will need to be kept damp, or a humidity retreat box provided some or all of the time. These suggestions and more can be found in my article on Microclimates.

A Note On Heating vs. Dehydration...
Someone once wrote to me stating that they were keeping their reptile's room and enclosure cool so as not to dehydrate them. While this person's desire to prevent dehydration is good, the way they were going about it - by depriving the reptile of the temperatures it needed for its body to function properly, was just as ultimately deadly as heating it properly without regard to hydration. Reptiles are complicated animals, with species-specific thermal requirements that must be met for the animal to not only subsist, but thrive. You cannot sacrifice one environmental for the other, but must provide them to ensure overall health and functioning.

Green iguanas - a particularly problematic species
Green iguanas (Iguana iguana) are complex lizards whose captive requirements drive many iguana keepers running, babbling, and blithering for their own basking spot. One of the problems with keeping green iguanas in captivity is keeping their environment humid enough for them without destroying their captive environment – rotting wood and moldy drywall are hardly conducive to keeping an iguana healthy. Enclosures made of suitable mesh products are great for providing adequate ventilation, but they are almost impossible to keep heated properly without heating the entire room. Thus, green iguanas tend to be rather high maintenance lizards as keepers struggle to provide the humidity needed to fend off early kidney failure while keeping them warm enough to enable proper systemic functioning. Sufficient fluids are particularly critical when the iguana has suffered a thermal burn, is gravid, or is on systemic antibiotics for an infection or fighting a mild infection without antibiotics.

Ways to increase iguana and other wet, rain, and cloud forest species' humidity and fluid intake include:

• For tolerant species, daily baths in water 80-85 F (26-29 C). Not only do long soaks let them breath in humidified air and help them during their frequent sheds, but some water is absorbed through the tissues inside the cloaca, and many iguanas will drink more deeply when their bodies are in water. An added bonus is that many iguanas prefer to poop in the bathtub rather in their enclosure.
• Spraying them several times a day with tap water increases the immediate ambient humidity and is also good for skin getting ready to shed. Using a power-spray bottle (one with a pump mechanism on top to pressurize the bottle, and a simple locking push button to release the spray) makes this easy to do, especially for people with repetitive motion stress conditions.
• Running a good humidifier (cool air mist) 12+ hours a day can increase ambient room humidity. Get one with a reservoir of 2-4 gallons so that you are not have to refill it more than once a day. Vaporizers produce hot steam and, while it is unlikely that the iguana may burn itself on the steam, the unit can get hot and may cause a burn if the iguana lays on it.
• Keeping a pan or tub of water with a large surface area in the enclosure will only marginally increase the ambient humidity, but it does give the iguana a place to soak or stand in a drink...and poop, so be sure to check it frequently so it can be cleaned and disinfected as needed.
• Wet the leafy greens with tap water before serving.
• Offer juicy fruits or wetted leafy greens or edible flowers as treats.
• Install a fogger or misting system made for agricultural or herptile hobbyists.

Fluid Requirements
Generally speaking, the daily fluid intake for reptiles is

Another way to determine fluid requirements is to give 20-25 ml/kg every 1-2 days.^{4, 7}

Certain injectible solutions used for rehydration (and provided by your veterinarian) have specific quantities, determined anecdotally or pharmacokinetically:

Mild hypotonic solutions are used first to provide intracellular diffusion of water. The solute of choice is:

1 part D5W + 1 part Normosol, up to 4% BW q 12-24 h

Fluids can be administered subcutaneously, intracoelomically, intravenously, or intraosseously. Do not administer intracoeloemically if there is a suspected space-occupying lesion, pneumonia, obstipation, egg retention, or preovulatory follicles.

Divided Doses
The daily amount of fluid cannot be administered all at once; instead, it should be divided into 4-5 doses. This prevents overloading the kidneys. Under normal circumstances, healthy animals who are eating and drinking normally and who are living in an environment that meets their humidity needs will succeed in keeping hydrated. The factors described above can lead to dehydration, especially in wounded or starved animals. Green iguanas and others species who evolved in high-humidity environments may experience a chronic low level of dehydration throughout their captive lives that ultimately cause kidney damage and an early death due to kidney failure.

This strain on the kidneys can be worsened if the iguana is put on systemic antibiotics, so all antibiotic therapy should be accompanied by fluid therapy to ensure the iguana is getting sufficient fluids for his normal daily needs as well as additional fluid to compensate for the effect of the drug on his kidneys. If your vet prescribes oral or injectible antibiotics for your iguana, be sure to ask about supplemental fluids (PO, IC or SQ) during the time the iguana is taking the antibiotics.

Routes of Administration
There are various ways that fluids can given to a sick reptile or one requiring additional fluids for a specific reason, such as in conjunction with systemic antibiotic therapy, or to correct moderate to severe dehydration. Reptiles who have been starved to the point of emaciation will require rehydration before nutritional support can be started. The following routes of administration are for these exceptional needs, not for administering basic maintenance fluids on a daily basis to an otherwise healthy reptile.

In mammals, fluids are generally given by IV as it is the most direct and efficient way to get the fluids into and circulated throughout the body. Unfortunately, this is tricky at best when it comes to reptiles, as anyone who has ever tried to draw blood from a major blood vein in a reptile knows. Since fluids are most often administered at home by the reptile keeper, most of whom do not have experience hitting a vein intentionally (and repeatedly) in their reptiles, there are other ways that are easier, though it may cause the reptile keeper more stress than it does their reptile.

PO (per os)
Giving fluids or anything else by mouth to reptiles can be difficult, given the vast numbers of sharp teeth, the glottis, and often cranky disposition a sick reptile may have. When dealing with venomous reptiles, matters are rather compounded by the fact that you may get more than a few teeth left behind in a bite wound.

When giving fluids by mouth, you need to watch out for the glottis that sits on the tongue at the back of the mouth in most reptiles; in chameleons and snakes, the glottis will be behind the tongue sheath. When using a French catheter or feeding/dosing tube attached to a syringe, you need to insert it into the mouth, sliding it down one side of the mouth or the other to avoid accidentally threading it into the glottis. While the ideal is to insert the tube all the way down into the stomach, this is not always possible so the catheter or feeding/dosing tube should be inserted as far as need be to prevent the fluid from backing up and flooding into the glottis. When expressing fluids or liquid nutrition (slurries) into a reptile, do it slowly enough so that it flows down towards the stomach, rather than so fast that it backs up into the mouth. If fluid or slurry backs up into a reptiles mouth, stop forcing the fluid or slurry through the tube. Tilt the reptile with its head downward to let the fluid or slurry run out of his mouth and let him catch his breath.

For the most rapid uptake of PO fluids, they should be warmed before being administered.

Intraocoelomic/Intraperitoneal (IC/IP)
Fluids may be injected directly into the body cavity. The advantage of administering fluids in this way is that they are more quickly absorbed and more fluid can be administered at one time than when giving fluids by mouth or subcutaneous injection. The problem with this route of administration is that you need to be shown how to do it, where to place the needle, and watch the slant of the needle. If done incorrectly, you could puncture an organ or the intestine. This is not something to attempt do to on your own without first being shown how and without someone, initially at least, to restrain the reptile for you so that you can concentrate on the injection itself. A mark can be made on most reptiles, using povidone-iodine or even nail polish (formaldehyde and tuolene free), around the injection site to help you remember. Insert the needle between two scales, not through a scale.

Subcutaneous (SubQ, SQ)
Subcutaneous means under the skin. The needle, held at a slant, is inserted between the scales deep enough to get through the skin. The fluid is then expressed slowly out of the syringe. If more fluid than can be injected at one site must be administered, remove the needle and insert in another site. Preferred sites for subcutaneous injections are:

Injections made in the shoulder area need to avoid the neck (cervical) to avoid any damage that could lead to neurological complications.

Intramuscular (IM)
Medications are most often injected Intramuscularly (in the muscle). Locations for IM injections are:

Choosing The Route of Administration
As can be seen, different types of injections have different requirements: loose skin, muscles, cavities. Not all reptiles are designed in the same way, making one type of injection or another difficult or impossible. For example, chameleons have very thin, poorly muscled legs, making it difficult to give medications IM. Chameleons, anoles and day geckos tend to get very highly stressed when handled, especially when handling is combined with the pain of an injection. The injection itself can cause pain and discoloration, and the psychological stress may lead to a worsening of the condition, or at least a delay in recovery. On the other hand, it may be easier to secure a venomous snakes head and administer an injection in the body, than try to insert a pill or oral syringe into its mouth. When it comes to a 15 foot crocodile with a serious attitude, it is easier to hide the medication in a morsel of food and toss it to him.

Hiding oral medication in food is certainly an option, but it should be the least amount of food necessary to mask the medication. Food will interfere with the uptake of the medication, so use this method only if absolutely necessary, and don't top dress the reptile's usual meal with it. A small piece of fruit or leafy green works for herbivores and omnivore. For omnivores and carnivores, insert a pill into the mouth of a prekilled mouse, or inject the fluid medication into the prekilled mouse's abdomen or mouth. Again, the prey should not be meal-sized, just big enough for the predator to grab and swallow. For insect and fish eaters, you will have to use a pill-pusher or syringe with a feeding or dosing tube attached to give oral mediations.

Renal-Portal System
The circulatory system in lizards and snakes is a bit different from those in mammals. Fluids injected caudally (into the lower, or back, half of the body, as from the abdomen down the tail) circulate first through the kidneys then up to the upper part of the body. When medications are injected caudally, they hit the kidneys in a less dilute form than if they are injected cranially (in the upper, or forward, half of the body, as from the ribs to the neck). Since many drugs, including antibiotics (the most common drug administered to reptiles) are already known to be nephrotoxic (harmful to the kidneys), it is important to reduce the impact on the kidneys as much as possible. This can be done in two ways:

• inject drugs cranially
• inject extra fluids (saline, Lactated Ringers), using subcutaneous or intracoelomic injections

When your veterinarian prescribes injections, especially of antibiotics, discuss the need for additional fluids and get from him the type you need and syringe and needles for the injections.

In addition, all reptiles under stress and undergoing any type of drug therapy should be kept well hydrated, by administering oral fluids, ensuring fluids are available for drinking and soaking (if there are no bandaging or casts that must not get wet), and keeping the environment humidified for species native to humid habitats in the wild.

Diluting Antibiotics To Mitigate Tissue Necrosis/Inflammation
Some drugs can cause inflammation or necrosis of the tissue surrounding the injection site. Signs include swelling of skin around site, blood or serous fluid oozing from from the skin between the scales, pus forming at site, discoloration of the skin, etc. This side effect can be mitigated by drawing some saline, saline-dextrose, or lactated ringers up into the syringe. Discuss this first with your vet. Many vets may be unaware of the side effect, especially if their clients have not presented affected animals to them in the past. Two drugs commonly associated with this effect are piperacillin (Piperacil) and enrofloxacin (Baytril).

Definitions

Sources

1. Klingenberg, RJ. 1988. Anorexia in reptiles. Proceedings of the 12^th International Symposium on Captive Propagation and Husbandry. New York-New Jersey Metropolitan Area, pp 621-634.

2. Mader, DM. 1991. Antibiotic therapy. In Frye, FL (ed.) Biomedical and Surgical Aspects of Captive Reptile Husbandry, 2^nd ed., Vol. II. Krieger Publishing, Melbourne FL.

3. Jarchow, J. 1988. Hospital care of the reptile patient. In Jacobson E, Kollias G Jr. (eds.) Exotic Animals. Churchill Livingstone, New York, p. 39.

4. Frye, FL. 1991. Infectious disease. In Frye, FL (ed.) Biomedical and Surgical Aspects of Captive Reptile Husbandry, 2^nd ed., Vol. I. Krieger Publishing, Melbourne FL.

5. Barnard, SM. 1996. Reptile Keeper's Handbook. Krieger Publishing, Melbourne FL.. p. 191

6. Types of fluids for reptiles. Veterinary Emergency Medicine PEARLS, Colorado State University

7. How to administer fluid therapy in reptiles. Veterinary Emergency Medicine PEARLS, Colorado State University

References:

Barnard, Susan M. 1996. Reptile Keeper's Handbook. Krieger Publishing Company, Malabar FL. 252 p.

Klingenberg, Roger J. 1996. Therapeutics. In Mader, Douglas M. (ed.) Reptile Medicine and Surgery, WB Saunders, Philadelphia PA, PP 301-302.

Klingenberg, Roger J. 1994. Basic principles of therapeutics used in reptile medicine. Proceedings Association of Reptilian and Amphibian Veterinarians, Pittsburgh PA, October 22-24, 1994.

Veterinary Emergency Medicine PEARLS, Colorado State University.

Related Articles and Sites

Dehydration in Reptiles - Guidelines for Offering Fluids FAQ, by Tricia Power

Emaciation (Starvation) Protocol