ACVC 2001 - Reptile Formulary

Reptile Formulary

Greg Lewbart M.S., V.M.D., Dipl. ACZM
greg_lewbart@ncsu.edu

I. Introduction

The following formulary is not meant to be a complete listing of all drugs available to treat reptiles nor has the information provided been proven to be safe and effective on all species of reptiles. The doses were compiled from several sources and my personal experience. The information herein is meant only to be a guideline and a quick reference of drugs and dosages for the treatment of reptiles by a licensed veterinarian.

II. Anesthetic/analgesic Agents

1. Alfaxalone-alfadolone acetate (Saffan). This drug is a combination of two steroid compounds that yield excellent results with a good safety margin. Dose is 9 mg/kg IV in snakes and 10-15 mg/kg IV or IM in turtles and lizards. The only problem is that Saffan is not currently available to the private practitioner in the United States (but may be some day). Contraindicated in animals with hepatic insufficiency since it is primarily cleared by the liver. Should not be used in the presence of DMSO since this compound potentiates Saffan.

2. Atipamezole (Antisedan). This is the reversal agent for medetomidine. Use as directed (equal volume with medetomidine).

3. Atropine sulfate. Can be used as an adjunct drug with injectable and inhalant general anesthetics. Reduces salivary and respiratory secretions. Dose is 0.01-0.02 mg/kg IM or IV. Glycopyrrolate may be more effective in reptiles.

4. Butorphanol. Used as an analgesic in many species. Recommended reptile dose is 0.2-0.4 mg/kg SC or IM q. 24 hours following surgery or other painful procedures.

5. Glycopyrrolate (Robinul-V). A newer parasympatholytic drug which is used at a dose of 10 micrograms/kg IM, IV, or SC.

6. Halothane. An acceptable inhalant anesthetic agent in reptiles but it has been largely replaced by isoflurane. More of a myocardial depressant than isoflurane. Induction concentrations of 3-4 % are adequate.

7. Isoflurane. Widely used in reptiles. Tends to have a high margin of safety. Concentrations of 3-5% adequate for induction. Reptiles should be recovered at the same temperature they were subjected to during surgery. Since isoflurane is very lipid soluble, increasing the temperature of the animal may release more isoflurane and result in a very prolonged recovery.

8. Sevoflurane. This new inhalant anesthetic agent, although not widely available and somewhat expensive, appears to provide quicker recovery than isoflurane in sea turtles and snakes.

9. Ketamine hydrochloride (Ketaset). Perhaps the most popular reptile anesthetic agent. A dissociative psychotropic agent, this drug is effective and has a high level of safety in the reptile patient. Snakes and lizards usually require doses of 15-50 mg/kg IM while turtles may require 40-80 mg/kg IM. Lower doses may be used to sedate animals for inhalant anesthesia intubation.

10. Medetomidine hydrochloride (Domitor). This recently approved drug (for dogs) shows some promise for reptile anesthesia. A general dose of 50 ug/kg (that's microgram) IM combined with 2.5-10.0 mg/kg ketamine appears to be quite effective with the benefit of reversibility with atipamezole. Does not appear to work on iguanas.

11. Propofol (Rapinovet). A general dose is 10 mg/kg IV. This drug must be given intravenously. Rapid induction and rapid recovery.

12. Succinylcholine (Sucostrin). This muscle relaxant may be used at a dose of 0.5-1.0 mg/kg IM to relax an animal enough for intubation. Especially helpful with turtles and crocodilians. Is a respiratory depressant so animal's respiratory rate must be monitored closely.

13. Teletamine hydrochloride and Zolazepam (Telazol). A drug that combines the dissociative properties of ketamine with the muscle relaxant qualities of diazepam. Dose is 10-30 mg/kg in reptiles IM. Do not use in animals with impaired renal function and the zolazepam dictates that the drug cannot be used concomitantly with ivermectin.

14. Xylazine (Rompun). Not very popular for use in reptiles because of varying recovery times. A good muscle relaxant with some analgesic properties. Dose of 0.10-1.25 mg/kg IM in reptiles. May be used in combination with ketamine and is reversible with yohimbine hydrochloride.

III. Antibiotics

1. Amikacin sulfate (Amiglyde-V). Can administer a loading dose of 5 mg/kg IM and then 2.5-3.0 mg/kg every 72 hours for 5 treatments total. Potentially nephrotoxic so animals should be well hydrated.

2. Ceftazidime (Fortaz). This human cephalosporin drug has proved to provide good broad spectrum activity in a variety of reptiles with the advantages that its half life is long and it kills Pseudomonas. Dose is 20 mg/kg IM or SC Q 72 hours

3. Chloramphenicol (Chloromycetin). A bacteriostatic drug administered either IM or IV at a dose of 30-50 mg/kg/day for 7 to 14 days. Good activity against many gram negative bacteria but a potential human health hazard.

4. Clindamycin. A drug that is effective against anaerobic organisms when used at a dose of 5.0 mg/kg PO Q 24 hours.

5. Enrofloxacin (Baytril). A quinolone compound that appears to be safe and effective in reptiles. May be used IM, SQ and PO at a dose of 5-10 mg/kg/day for 7-21 days. May be diluted with sterile saline since the concentrated form (2.27%) may be irritating.

6. Gentamicin sulfate (Gentocin). A potent aminoglycocide which takes care of most gram negative organisms. Has a smaller therapeutic window than amikacin and may be more nephrotoxic. Animals must be well hydrated. Dosed the same as amikacin.

7. Trimethoprim sulfadiazine (Tribrissen). A good broad spectrum antibiotic. Dose is 15-25 mg/kg/day IM for 7-14 days.

IV. Parasiticides

1. Dimetridazole (Emtryl). Can be used to treat amoebiasis at a dose of 40 mg/kg/day for 5 days. Safe and effective. Will also kill flagellates.

2. Fenbendazole (Panacur). A good parasiticide for intestinal nematodes. Can be given orally at a dose of 50-100 mg/kg and repeated in 2 weeks.

3. Ivermectin (Equvalan). Contraindicated for use in chelonian species. Turtles given low doses may become paretic in the hind limbs and deaths have been reported. Doses for snakes and lizards range from 200-400 micrograms/kg IM and repeated in 2 weeks. Will kill nematodes and may be effective against ticks and mites. USE CAUTION WITH THIS DRUG, EVEN IN SNAKES AND LIZARDS, SINCE THE KINETICS IN REPTILES HAVE NOT BEEN WELL STUDIED!

4. Levamisole phosphate (Ripercol). Works on the lungworm (Rhabdias) and on intestinal Strongyloides. Dose is 10 mg/kg intraperitoneally (intracoelomically) repeated in 2 weeks. Fenbendazole works well on Strongyloides too.

5. Metronidazole (Flagyl). Used on intestinal flagellates and for amoebiasis at a dose of 100-200 mg/kg PO, repeated in 2 weeks. A dose of 40-50 mg/kg PO should be used in colubrid snakes since there have been some problems with the higher doses in some species. There are reports that Flagyl works as an appetite stimulant in reptiles. This drug is also good for anaerobic bacterial infections. A recent pharmacokinetics report recommends a dose of 20 mg/kg PO Q 48 hours in yellow rat snakes (Kolmstetter et al. 2001).

6. Praziquantel (Droncit). Used to treat cestode and trematode parasites. Dose is 5-8 mg/kg IM or PO repeated in 2 weeks.

7. Sulfadimethoxine (Bactrovet, Albon). Efficacious in the treatment of coccidia. Dose is 90 mg/kg PO on day one and 45 mg/kg PO on 5 successive days. This drug may also be given IM or IV. Adequate hydration must be maintained.

V. Miscellaneous Drugs

1. Arginine vasotocin (AVT). Used to induce oviposition in reptiles. Dosage ranges from 0.01-1.0 ug/kg IV or ICe. Difficult to obtain and can be very unstable once reconstituted. Available through Sigma Chemical 9for research use only).

2. Calcium gluconate. Used as a calcium supplement at a dose of 300 mg/kg given in divided doses over a 24 hour period. Route of administration is IM or ICe. Neocalglucon, an oral calcium supplement (10% solution) can be given at a rate of 1.0 ml per kg of animal once daily as needed.

3. Dexamethasone (Azium). Dose is 0.5-1.25 mg/kg IM as needed.

4. Furosemide (Lasix). Dose is 5 mg/kg as needed.

5. Oxytocin. Used to induce oviposition. Dose ranges from 1-30 IU/kg. A dose of 10 IU/kg appears to be effective in many chelonians. May have to repeat in several hours but there is a risk of oviduct rupture if cloaca is obstructed or eggs cannot pass for another reason.

6. Vitamin A (Aquasol A, Injacom). Used as an injectable vitamin A supplement in reptiles, especially turtles. Use 5000 IU/kg IM as a single treatment.

7. Vitamin B Complex. Used frequently as a general supplement and appetite stimulant. Dose is approximately 0.50 mg/kg IM or SQ as a single treatment. May be repeated in 3 weeks.

VI. Sources of Drug Information

1. Carpenter, J.W., Mashima, T.Y., and D.J. Rupiper. Exotic Animal Formulary, Second Edition. W.B. Saunders Co., 2001.

2. Frye, F.L. Biomedical and Surgical Aspects of Captive Reptile Husbandry (Vols. ! & II). Krieger Publishing Co., Malabar, FL 637 pp., 1991.

3. Jacobson, E.R. and G.V. Kollias. Exotic Animals; Contemporary Issues in Small Animal Practice, vol. 9. Churchill Livingstone, New York, 328 pp., 1988.

4. Mader, D.R. Reptile Medicine and Surgery. Saunders Co., Phila., 512 pp., 1996.

5. Marcus, L.C. Veterinary Biology and Medicine of Captive Amphibians and Reptiles. Lea and Febiger, 239 pp., 1981.

6. Kolmstetter, C.M., Cox, S. and E.C. Ramsay. Pharmacokinetics of metronidazole in the yellow rat snake, Elaphe obsoleta quadrivittata. Journal of Herpetological Medicine and Surgery, 11(2):4-8, 2001.