Lizard Formulary - Disclaimer

Introduction

The following drug dosages are taken from multiple sources and neither their efficacy nor safety can be assured since the information may have been extrapolated from animals other than lizards. There will be interspecific variation.

• Since lizards are poikilothermic, their metabolism is affected by the ambient temperature. The pharmacokinetics of any drug will therefore vary with the temperature. The lizard will need to be kept at the higher end of its POTZ.
• There are no drugs preparations licensed for reptiles. Drugs licensed for use in other species may be administered under the responsibility of the veterinary surgeon who has the lizard 'under his care'.

Antimicrobials

Sample all suspected infections for microscopy, culture and sensitivity. The majority of bacterial infections in lizards are by Gram-negative organisms, particularly Enterobacteriacae. Therapy may be required before the results of bacterial sensitivity tests are known.

• Aminoglycosides and quinolones are effective against most aerobic pathogens and there is little bacterial resistance to them.
• The fluoroquinolone derivative enrofloxacin is bacteriocidal (inhibit microbial DNA gyrase) and is well distributed to tissues. It is active against a wide range of Gram-negative organisms as well Gram-positives and Mycoplama spp. It is not effective against anaerobes.
• Carbenicillin and ceftazidime are good broad-spectrum antibiotics useful against anaerobes as well as most Gram-negative pathogens. If Pseudomonas spp. and anaerobes are present, ceftazidime is the most appropriate choice.

The following has also been advised: amikacin in combination with ampicillin for respiratory infections; chloramphenicol for gastrointestinal infections; an aminoglycoside in combination with a broad spectrum penicillin for general systemic infections.

• All aminoglycosides may affect neuromuscular transmission leading to muscle weakness and cause nephrotoxicity especially in reptiles kept at more than 25°C. They are also more toxic in gravid females.

Any antibiotic therapy, but particularly gentamycin, should be accompanied by fluids to maintain adequate renal function and reduce the possibility of nephrotoxicity.

Amikacin

• Potentially nephrotoxic but no published data
• Administer fluids concurrently
• Frequently used with a penicillin or a cephalosporin
• 2.5 mg/kg IM then 2.5-5 mg q72h
• 50 mg/10ml saline x 30 min nebulisation q12h
• Maintenance temperature if species POTZ unknown is 25°C

Amoxicillin

• Use with an aminoglycoside
• 20 mg/kg SC, IM q24h
• Maintenance temperature if species POTZ unknown is 26°C

Ampicillin

• May be used with an aminoglycoside
• 3-6 mg/kg PO q12-24h
• 3-10 mg/kg IM, SC q12-24h

Carbenicillin

• May be used with an aminoglycoside but at different time of day
• 400 mg/kg IM, SC q24h
• Maintenance temperature if species POTZ unknown is 30°C

Cefoperazone

• Published data in tegus
• 125 mg/kg IM q24h

Cefotaxime

• May be used with an aminoglycoside
• 20-40 mg/kg IM q24h
• 100 mg/10ml saline x 30 min nebulisation q12h

Ceftazidime

• 20 mg/kg IM q72h
• Maintenance temperature if species POTZ unknown is 30°C

Cefuroxime

• 50 mg/kg IM q48h
• Maintenance temperature if species POTZ unknown is 30°C

Cephuroxime

• 50 mg/kg IM q48h

Cephalexin

• 20-40 mg/kg PO q12h

Cephaloridine

• 10 mg/kg IM, SC q12h

Cephalothin

• 20-40 mg/kg IM q12h

Chloramphenicol

• May cause pigmentation changes in chameleons
• 20 mg/kg PO, IM, SC q12h
• 40mg/kg PO, IM, SC q24h

Chlortetracycline

• 200mg/kg PO 24h

Ciprofloxacin

• 11 mg/kg PO q48-72h

Clindamycin

• 2.5-5 mg/kg PO q12h
• 5 mg/kg PO q24h

Dihydrostreptomycin

• Administer fluids concurrently
• 5 mg/kg IM q12-24h

Dimetridazole

• 40 mg/kg PO q24h 5d

Doxycycline

• 5-10 mg/kg PO q24h 10-45d

Enrofloxacin

• 5-10mg/kg q24h PO, IM, SC, ICo
• 1-3 ml of 50 mg/250ml sterile water for nasal flush q12-24h with parenteral antibiotics

Gentamycin

• Do not use in animals over 20kg
• 2.5 mg/kg SC q72h
• 10-200 mg/15ml saline x 30 min nebulisation q12h
• Maintenance temperature if species POTZ unknown is 24°C

Kanamycin

• Administer fluids concurrently
• 10 mg/kg SC, IM, IV q24h
• Maintenance temperature if species POTZ unknown is 24°C

Lincomycin

• Potentially nephrotoxic
• Administer fluids concurrently
• 6 mg/kg q12-24h

Metronidazole

• May be administered concurrently with amikacin
• Low dose may stimulate depressed immune system
• 12.5-40 mg/kg q24h > 7d
• 100-275 mg/kg PO as a single dose

Oxytetracycline

• May produce local reaction at injection site
• 6-10 mg/kg IM, IV q24h

Penicillin, benzathine , benzathine

• May be administered concurrently with amikacin
• 10,000 units/kg IM q48-96h

Penicillin G

• Infrequently used
• 10,000-20,000 units/kg IM, SC, IV, ICo q8-12h

Piperacillin

• Administer fluids concurrently
• May be used with an aminoglycoside
• 50-100 mg/kg IM q24h
• 100-200 mg/kg IM q24-48h in chameleons
• 100 mg/10ml saline x 30 min nebulisation q12h

Streptomycin

• Potentially nephrotoxic
• Administer fluids concurrently
• Avoid with renal/hepatic dysfunction
• 10 mg/kg IM q12-24h

Sulphadiazine

• Administer fluids concurrently
• Do not use with renal impaired animals
• 25 mg/kg PO q24h

Sulphadimethoxine

• Potentially nephrotoxic
• Administer fluids concurrently
• 90 mg/kg IM then 45 mg/kg q24h

Tetracycline

• May disturb the normal intestinal microflora
• 10 mg/kg PO q24h

Ticarcillin

• Administer fluids concurrently
• 50-100 mg/kg IM q24h

Tobramycin

• Potentially nephrotoxic
• Administer fluids concurrently
• Potentiated by â-lactams
• 2 mg/kg IM q24h
• 2.5 mg/kg IM q12h in chameleons

Trimethoprim/sulphadiazine

• Administer fluids concurrently
• 15 mg/kg IM q24

Trimethoprim/sulphamethoxaline

• Administer fluids concurrently
• 10-30 mg/kg PO q24h

Tylosin

• Reported useful for mycoplasma respiratory infections
• 5 mg/kg IM q24 10-60d

Antifungals

Fungal infections are not uncommon in reptiles and can be the primary disease agent or secondary in already compromised individuals. Antifungal drugs may be useful but treatment regimens have not been established adequately.

Amphotericin- B Potentially nephrotoxic Can be used with ketaconazole Administer slowly 0.5 mg/kg IV q48-72h 5 mg/150ml saline x 1h nebulisation q12h 7d

Fluconazole 5 mg/kg PO q24h

Griseofulvin Limited success 20-40 mg/kg PO q72h 5 Rxs

Itraconazole Has been used in spiny lizards (Sceloporus spp.) at 23.5 mg/kg

Ketaconazole Potentially hepatotoxic 15-30 mg/kg PO q24h 2-4w

Nystatin 100,000 IU/kg PO q24h 2-4 w

Antiparasitic

Parasitic infections are common in lizards especially wild caught specimens.

Environmental treatment is important.

Albendazole Antinematode 50 mg/kg PO as a single dose

Emetine Antiamoeba, antitrematode 0.5 mg/kg IM, SC q24h 10d

Fenbendazole Antinematode 100 mg/kg PO as a single dose

Ivermectin Antinematode, antiascarid May cause skin discoloration at injection site in chameleons Not for use in chelonia -0.2 mg/kg IM, SC, PO Repeat as appropriate

Levamisole Antinematode including lungworms Avoid concurrent use with chloramphenicol Avoid in debilitated animals Low dose may stimulate depressed immune system Can be used IM but less effective 10 mg/kg SC, ICo, repeat in 2 weeks 200 mg/kg PO as a single dose

Metronidazole antiprotozoal 100 mg/kg PO q3d 2-3w 125-250 mg/kg PO, repeat in 2 weeks 40 mg/kg PO, repeat in 2 weeks for trichomonad ocular lesions in geckos 200 mg/kg PO, repeat in 2 weeks for trichomonad SC lesions in geckos

Nitrofurazone Anticoccidia Seldom used 25.5 mg/kg PO

Oxfendazole Antinematode 68 mg/kg PO as a single dose

Paronomycin Antiamoeba 35-100 mg/kg PO q24h up to 4w

Praziquantel Anticestode, antitrematode 3.5-7.5 mg/kg SC 100 mg/kg PO

Pyrantel palmoate Antinematode 5mg/kg PO, repeat in 2w

Sulphadiazine, sulphamerazine Anticoccidia Administer fluids concurrently Do not use with renal impaired animals 25 mg/kg PO q24h 3w 50 mg/kg q24h 3d, then 3d off, then 3d on 75 mg/kg PO then 45 mg/kg q24h 5d

Thiabendazole Antinematode 50-100 mg/kg PO, repeat in 2w

Anaesthesia associated drugs

Acetylpromazine Pre-anaesthetic 0.05-0.5 mg/kg

Alphadolone/alphaxalone Saffan 3 mg/ml alphadolone and 9 mg/ml alphaxalone giving a 12mg/ml solution Induction and maintenance of general anaesthesia 6-9 mg/kg IV 9-15 mg/kg IM Incremental doses according to the animal's response

Atropine Pre-anaesthetic Use with bradycardia 0.01-0.1 mg/kg IM,SC

Buprenorphine Analgesic 0.005-0.02 mg/kg IM q24-48h

Butorphanol Analgesic No established dose

Diazepam No established dose

Doxapram Respiratory stimulant 5 mg/kg IV

Halothane Gaseous anaesthetic 3-4% induction 1.5-3% maintenance

Isoflurane Inhalational anaesthetic of choice Less hepatotoxic than other inhalants Rapid induction and recovery in lizards Up to 6% induction 2-3% maintenance

Ketamine Muscle relaxation and analgesia may be marginal Prolonged recovery with higher doses Larger reptiles require lower dose Painful at injection site Questionable safety in debilitated animals Avoid use with renal impairment Lizards require lower dose than other reptiles 10-30 mg/kg IM as a sedative, facilitates intubation Useful in large lizards (11.6 mg/kg) in combination with midazolam (0.34-0.35 mg/kg)

Lignocaine Local anaesthetic

Midazolam May be useful in some species 2 mg/kg

Pentobarbitone Euthanasia 60 mg/kg IV, ICo

Propofol Injectable anaesthetic of choice Rapid induction and rapid recovery 10 mg/kg IV Additional doses of 10% of the original may be administered for maintenance

Tiletamine/ zolazepam Not generally used but useful in larger lizards 5.5 mg/kg in a 55kg komodo dragon (Varanus komodoensis) led to easy handling within 30 minutes but heavy sedation the day after the anaesthetic 10-40 mg/kg IM- 8-20 minute induction, 2-10 hour recovery in smaller individuals

Xylazine Infrequently used 0.1-1.25 mg/kg IV, IM

Hormones

Arginine vasotocin Use in dystocia Administer after calcium More effective than oxytocin 0.01-1.0 mg/kg IV, ICo

Calcitonin May be useful in MBD Administer after calcium supplementation Do not use if hypocalcaemic Administer fluids concurrently 50 IU IM and repeat in 2w

Dexamethasone Septic/traumatic shock 0.6-1.25 mg/kg IV,IM

Oxytocin Dystocias Administer after calcium supplementation 2-5 Iu/kg IM

Prednisolone Septic/traumatic shock 5-10mg/kg IV, IM

Nutritional support

Calcium borogluconate

• MBD
• Hypocalcaemia
• Hypocalcaemic dystocia
• 10-50 mg/kg IM, SC, ICo

Calcium carbonate

• PO

Calcium glubionte

• MBD
• Hypocalcaemia
• Hypocalcaemic dystocia
• 10-50 mg/kg PO

Calcium gluconate

• MBD
• Hypocalcaemia
• Hypocalcaemic dystocia
• 100-200 mg/kg IM, SC, ICo

Calcium lactate / calcium glycerophosphate

• MBD
• Hypocalcaemia
• Hypocalcaemic dystocia
• 1-25 mg/kg IM, SC

Vitamin A

• Hypovitaminosis A
• Overdose will cause epidermal sloughing
• 1,000-2,000 IU/kg IM, SC q7d 2-6w

Vitamin B complex

• Hypovitaminosis B
• Appetite stimulant
• 5-10mg/kg IM,SC

Vitamin B12

• Appetite stimulant
• 0.05 mg/kg IM,SC

Vitamin C

• Supportive treatment for bacterial infections
• Ulcerative stomatitis
• 10-20 mg/kg IM,Sc q24h
• 100-250 mg/kg PO q24h

Vitamin D3

• MBD
• Hypocalcaemia
• Herbivores sensitive to excess
• Give PO preferably
• 100 IU/kg IM, repeat in 1w
• 200 IU/kg IM, repeat in 4w
• 200 IU/kg PO q7d

Vitamin E

• Hypovitaminosis E
• 50-100 mg IM

Vitamin K1

• Hypovitaminosis K
• May aid formation of clotting factors
• 0.25-0.50 mg/kg IM

Miscellaneous agents

Allopurinol

• Decreases production of uric acid
• Dose not established

Aminophylline

• Bronchodilator
• 2-4 mg/kg IM

Atropine

• OP toxicity
• 0.1-0.2 mg/kg IM

Cimetidine

• Gastric and duodenal ulcerations
• Oesophageal and gastric reflux
• 4 mg/kg PO, IM q8-12h

Flunixin meglumine

• Non-steroidal anti-inflammatory
• 0.1-0.5 mg/kg IM, SC q12-24h 1-2d

Furosemide

• Diuretic
• 5 mg/kg PO, IM, IV q12-24h