Amphibians

Chapter 3 Amphibians



Kevin Wright, Ryan S. DeVoe



TABLE 3-1 Antimicrobial Agents Used in Amphibians.a,b















































































































































































































Agent Dosage Species/Comments
Amikacin 5 mg/kg SC, IM, ICe q24-48h54 Most species; may be used in combination with piperacillin
  5 mg/kg IM q36h21 Bullfrogs/PD
Carbenicillin 100 mg/kg SC, IM q72h6  
  200 mg/kg SC, IM, ICe q24h31  
Ceftazidime 20 mg/kg SC, IM q48-72h53  
Chloramphenicol 50 mg/kg SC, IM, ICe q12-24h31 Caution: even miniscule exposures carries risk of aplastic anemia in susceptible individuals; wear disposable gloves when handling; aplastic anemia-like findings in Bufo regularis exposed to 125 mg/kg PO q24h × 12 wk11
  20 mg/L bath changed daily31  
Ciprofloxacin 10 mg/kg PO q24h54  
  500-750 mg/75 L as 6-8 hr bath q24h54 May be used for large numbers of animals
Doxycycline (Psittavet, Vetafarm) 50 mg/kg IM q7d53 Broad-spectrum antibiotic, part of 4-quadrant therapy; may have antiinflammatory effect; chlamydophilosis
Doxycycline (Vibramycin, Pfizer) 5-10 mg/kg PO q24h50 Chlamydophilosis
  10-50 mg/kg PO q24h35 African clawed frogs/chlamydophilosis
Doxycycline 1% topical gel, compounded Apply topically q8-12h not to exceed 10 mg/kg per day53 Useful for localized lesions; may have antiinflammatory effect
Enrofloxacin (Baytril, Bayer) 5-10 mg/kg PO, SC, IM q24h21,54 Most species/PD (bullfrogs);21 ICe and topical routes also used but without PD54
  500 mg/L as 6-8 hr bath q24h53  
Enrofloxacin and silver sulfadiazine solution (Baytril Otic, Bayer) Apply topically to lesions q12h53 May have some antifungal effect, but does not appear effective on chytrid
Gentamicin 2-4 mg/kg IM q72h × 4 treatments15  
  2.5 mg/kg IM q72h38 Coldwater salamanders (i.e., Necturus)/PD; more frequent dosing may be needed if temperature >4°C (39.2°F)
  3 mg/kg IM q24h at 22.2°C (72°F)39 Leopard frogs/PD; at higher temperatures, serum concentrations will be lower
  Topical to eyes48 All species/ocular infections; dilute to 2 mg/mL
  Intracameral injection once, not to exceed 4 mg/kg53 Panophthalmitis
  1.3 mg/L × 1 hr bath q24h × 7 days15 Bacterial dermatitis; can be toxic
Isoniazid 12.5 mg/L bath35 Mycobacteriosis; therapy may be enhanced with additional medications53
Metronidazole 10 mg/kg PO q24h × 5-10 days30 For chronic diarrhea
  10 mg/kg IV q24h × 2 days54 Anaerobic infections
  12 mg/kg topically q24h × 5-10 days54 For chronic diarrhea
  20 mg/kg PO q48h × 20 days53 Anaerobic infections
  50 mg/kg PO q24h × 3 days54 Anaerobic infections
  60 mg/kg topically q24h × 3 days54 Anaerobic infections
  50 mg/L × 24 hr bath54 Anaerobic infections


Neomycin, polymixin B, bacitracin


(Neosporin, Pfizer)

 Apply topically to wound q24h13 Microsporidian infections; not recommended for bacterial infections, appears to inhibit re-epithelialization53
Nifurpirinol (Furanace, Dainippon) 250 mg/38 L × 1 hr bath q24h15  
Nitrofurazone 10-20 mg/L × 24 hr bath6 Change daily
Oxytetracycline 25 mg/kg SC, IM q24h31 Most species
  50 mg/kg PO q12-24h31 Most species
  50-100 mg/kg IM q48h21 Bullfrogs/PD; especially useful in cases of chlamydophilosis (use up to 30 days)54
  100 mg/L × 1 hr bath54 Most species
  1 g/kg feed × 7 days31 Most useful with axolotls and Xenopus fed compounded pelleted diet53
Piperacillin 100 mg/kg SC, IM q24h54 Anaerobes; may be used in combination with amikacin
Rifampin 25 mg/L × 24 hr bath12 Potentially effective for mycobacteriosis; therapy may be enhanced with additional medications53
Silver sulfadiazine (Silvadine Cream 1%, Marion) Topical q24h12 Antibiotic cream
Sulfadiazine 132 mg/kg PO q24h31  
Sulfamethazine 1 g/L bath to effect31 Change daily
Tetracycline 50 mg/kg PO q12h6  
  150 mg/kg PO q24h × 5-7 days46  
  167 mg/kg (5 mg/30 g) PO q12h × 7 days15  
Trimethoprim/sulfa 3 mg/kg PO, SC, IM q24h6 Unspecified sulfa
Trimethoprim/sulfadiazine 15-20 mg/kg IM q48h23 Chronic diarrhea53
Trimethoprim/sulfamethoxazole 15 mg/kg PO q24h54 Chronic diarrhea
  20 μg/mL and 80 μg/mL in 0.5% or 0.15% salt solution × 24 hr bath24 Bacterial dermatosepticemia; make fresh daily

a Water baths containing antibiotics or topical applications may not provide as consistent distribution as parenteral administration.


b SC can be administered in the dorsal lymph sac of anurans.7



TABLE 3-2 Antifungal Agents Used in Amphibians.











































































































Agent Dosage Species/Comments
Amphotericin B 1 mg/kg ICe q24h54 Internal mycoses
Benzalkonium chloride 0.25 mg/L × 72 hr bath6  
  2 mg/L × 1 hr bath q24h31 Saprolegniasis
  1:4,000,000 bath31 Saprolegniasis; change water 3×/wk
Chloramphenicol 20 mg/kg topically (applied as Chlorsig ointment which also contains paraffin and wool fat)2 Chytridiomycosis; safe for larvae, recent metamorphs, and adults; confirm negative result by real-time PCR;2,53 caution: even miniscule exposure carries risk of aplastic anemia in susceptible individuals; wear disposable gloves when handling; aplastic anemia-like findings in Bufo regularis exposed to 125 mg/kg PO q24h × 12 wk11
  10 mg/L (10 ppm) as continuous bath replaced fresh daily2
  20 ppm as continuous bath replaced fresh daily for up to 30 days29
  30 ppm as continuous bath replaced fresh daily for up to 30 days53
Florfenicol 30 ppm as continuous bath replaced fresh daily for up to 30 days53 Chytridiomycosis; safe for larvae, recent metamorphs, and adults; confirm negative result by realtime PCR53
Fluconazole 60 mg/kg PO q24h54  
Itraconazole 10 mg/kg PO q24h54 Topical route best choice to treat chytridiomycosis; do not use with larvae27
  0.01% in 0.6% salt solution as 5 min bath q24h × 11 days27
Ketoconazole 10 mg/kg PO q24h31  
  10-20 mg/kg PO q24h54  
  Topical cream8 Topical route best choice to treat chytridiomycosis; do not use with larvae53
Malachite green 0.15-0.2 mg/L × 1 hr bath q24h15 Cutaneous mycoses; caution: mutagenic, teratogenic; potentially toxic
Mercurochrome 4 mg/L × 1 hr bath q24h47 Saprolegniasis
Methylene blue 2-4 mg/L bath to effect6 Tadpoles/reduces mortality in newly hatched tadpoles
  4 mg/L × 1 hr bath q24h47 Saprolegniasis
Miconazole 5 mg/kg ICe q24h × 14-28 days52 Systemic mycoses
  Topical cream or solution54 Topical route best choice for chytridiomycosis; solutions containing alcohol may cause irritation; do not use with larvae
Nystatin 1% cream Topical53 Cutaneous mycoses
Potassium permanganate 1:5000 water × 5 min bath q24h4 Cutaneous mycoses
Sodium chlorite (NaOCl2) 20 mg/L as 6-8 hr bath51 Cutaneous mycoses
Temperature elevation 37°C (98.6°F) for 16 hr49 Chytridiomycosis; lower temperatures (down to 30°C [86°F]) may be effective with longer duration53
Tolnaftate (Tinavet cream 1%, Schering) Topical15 Cutaneous mycoses


TABLE 3-3 Antiparasitic Agents Used in Amphibians.a



















































































































































































































































Agent Dosage Species/Comments
Acriflavin 0.025% bath × 5 days31 Protozoa
  500 mg/L × 30 min bath45 Protozoa
Benzalkonium chloride 2 mg/L × 1 hr bath q24h to effect45 Protozoa
Copper sulfate 0.1 mg/L as a continous bath to effect54 Some protozoa; copper may be toxic to some amphibians
  500 mg/L × 2 min bath q24h to effect31  
Distilled water 3 hr bath31 Protozoa
Febantel (in combination with pyrantel palmoate and praziquantel; Drontal Plus, Bayer) 0.01 mL/1 g (10 mL/kg) PO q2-3wk28 Nematodes, cestodes, possibly trematodes
Fenbendazole — Fenbendazole combinations follow
  30-50 mg/kg PO7 Gastrointestinal nematodes
  50 mg/kg PO q24h × 3-5 days, repeat in 14-21 days54 Resistant nematode infections
  50-100 mg/kg PO,30 repeat in 2-3 wk prn Most species/gastrointestinal nematodes
  100 mg/kg PO,42 repeat in 14 days Gastrointestinal nematodes
Fenbendazole (F)/ivermectin (I) (F) 100 mg/kg PO on day 1, then (I) 0.2 mg/kg PO on days 2,1142 Gastrointestinal nematodes
Fenbendazole (F)/metronidazole (M) (F) 100 mg/kg PO, repeat in 10-14 days + (M) 10 mg/kg PO q24h for 5 days42 Concurrent gastrointestinal nematodes and protozoa
Formalin (10%) — Do not use if skin is ulcerated
  1.5 mL/L × 10 min bath q48h to effect8 Protozoans; may be toxic in some species
  0.5% × 10 min bath once31 Monogenic trematodes; may be toxic to some amphibian species
Ivermectin — Caution: may cause flaccid paralysis with overdosage; caffeine or physostigmine may ameliorate effects53
  0.2-0.4 mg/kg PO, SC, repeat q14d prn7 Nematodes, including lungworms; mites
  2 mg/kg topically, repeat in 2-3 wk20 Especially useful for small specimens54 and Rana spp20
  10 mg/L as 60 min bath, repeat q14d prn54 Best route for treating mites
Levamisole — May cause paralysis in some species at suggested dosages;54 caffeine or physostigmine may ameliorate effects53
  10 mg/kg IM,6 ICe,52 topically,54 repeat in 2 wk Nematodes, including lungworms
  12 mg/L bath × 4 days14 African clawed frogs/cutaneous nematodes; use ≥4.2 L of tank water/frog
  100 mg/L × ≥72 hr bath54 Resistant nematodes
  100-300 mg/L × 24 hr bath, repeat in 1-2 wk54 Nematodes, including subcutaneous nematodes in aquatic amphibians; water soluble form is available through aquaculture supply companies
Malachite green — Caution: mutagenic, teratogenic; potentially toxic
  0.15 mg/L × 1 hr bath q24h to effect31 Protozoa
Metronidazole — See fenbendazole for combination
  10 mg/kg PO q24h × 5-10 days42 Protozoa; for unfamiliar or sensitive species
  50 mg/kg PO q24h × 3-5 days54 Confirmed cases of amoebiasis and flagellate overload
  100 mg/kg PO q3d8 Protozoa
  100-150 mg/kg PO, repeat in 2-3 wk or prn31 Protozoa (i.e., Entamoeba, Hexamita, Opalina)
  0.05 mL of 1.008 mg/mL on dorsum q24h × 3 days26 Fire-bellied toads (1.8 g)/protozoa; rinse 1 hr after treatment; results in absorption of 23 mg/kg BW of metronidazole
  50 mg/L × 24 hr bath35 Aquatic amphibians/protozoa
  500 mg/100 g feed × 3-4 treatments6 Ciliates
Moxidectin 200 μg/kg SC q4mo34 Nematodes
Oxfendazole 5 mg/kg PO46 Gastrointestinal nematodes
Oxytetracycline 25 mg/kg SC, IM q24h45 Protozoa
  50 mg/kg PO q12h45 Protozoa
  1 g/kg feed × 7 days45 Protozoa
Paromomycin (Humatin, Parke Davis) 50-75 mg/kg PO q24h52 Gastrointestinal protozoa
Piperazine 50 mg/kg PO, repeat in 2 wk15 Gastrointestinal nematodes
Ponazuril 30 mg/kg PO q12h × 3 days, repeat in 3 wk; often more effective at 30 mg/kg PO q24h × 30 days; may work with less frequent treatments53 Coccidia but not Cryptosporidium; may have some effect on unidentified protozoan cysts
Potassium permanganate 7 mg/L × 5 min bath q24h to effect31 Ectoparasitic protozoa
Praziquantel 8-24 mg/kg PO, SC, ICe, topically,54 repeat q14d Trematodes, cestodes
  10 mg/L × 3 hr bath,54 repeat q7-21d Trematodes, cestodes
Pyrantel pamoate 5 mg/kg PO q14d28 Nematodes
Ronidazole 10 mg/kg PO q24h × 10 days53 Flagellated protozoa, amoebas
Salt (sodium chloride) 4-6 g/L bath31 Ectoparasitic protozoa
  6 g/L × 5-10 min bath q24h × 3-5 days45 Ectoparasitic protozoa
  25 g/L × ≤10 min bath8 Ectoparasitic protozoa
Selamectin (Revolution, Pfizer) 6 mg/kg topically9 Bullfrogs/PD
Sulfadiazine 132 mg/kg PO q24h45 Coccidiosis
Sulfamethazine 1 g/L bath45 Coccidiosis; change daily to effect
Tetracycline 50 mg/kg PO q12h45 Protozoa
Thiabendazole 50-100 mg/kg PO,15 repeat in 2 wk prn Gastrointestinal nematodes
  100 mg/L bath, repeat in 2 wk47 Verminous dermatitis
Trimethoprim/sulfa 3 mg/kg PO, SC, IM q24h45 Coccidiosis; unspecified sulfa

a SC can be administered in the dorsal lymph sac of anurans.7



TABLE 3-4 Chemical Restraint/Anesthetic/Analgesic Agents Used in Amphibians.a















































































































































































































Agent Dosage Species/Commentsb
Alfaxan (Vetafarm) 5-10 mg/kg IM53 May supplement with IM or IV
Atipamezole (Antisedan, Pfizer) Titrate to effect Antagonist for dexmedetomidine22
Benzocaine (Sigma Chemical) — Anesthesia; not sold as fish anesthetic in US; available from chemical supply companies; do not use topical anesthetic products marketed for mammals; prepare stock solution in ethanol (poorly soluble in water); store in dark bottle at room temperature
  50 mg/L bath to effect7 Larvae/dissolve in ethanol first
  200-300 mg/L bath to effect7 Frogs, salamanders/dissolve in ethanol first
  200-500 mg/L bath5 Dissolve in acetone first
Buprenorphine (Buprenex, Reckitt & Colman) 38 mg/kg SC22 Analgesia >4 hr; ED50 in leopard frogs22
Butorphanol 0.2-0.4 mg/kg IM33 Analgesia; efficacy uncertain53
Clove oil (eugenol) 0.3 mL/L (∼310-318 mg/L)18 Anesthesia; deep anesthesia after 15 min bath; caused reversible gastric prolapse in 50% of leopard frogs
  0.45 mL/L (∼473 mg/L)25 Anesthesia; deep anesthesia induced in 80% of tiger salamanders
Codeine 53 mg/kg SC22 Analgesia >4 hr; ED50 in leopard frogs
Dexmedetomidine (Precedex, Abbott) 40-120 mg/kg SC22 Analgesia >4 hr; ED50 in leopard frogs
Diazepam — See ketamine for combination
Fentanyl 0.5 mg/kg SC22 Analgesia >4 hr; ED50 in leopard frogs
Isoflurane — Anesthesia; induction chamber; inhalant of choice
  3-5% induction, 1-2% maintenance33 Terrestrial species
  5%3 Terrestrial species/euthanasia; induction chamber
  Topical application of liquid isoflurane36 Bufo spp (0.015 mL/g BW), African clawed frogs (0.007 mL/g BW)/induce in closed container; once induced, remove excess from animal
  Topical mixture of isoflurane (3 mL), KY jelly (3.5 mL), and water (1.5 mL)36 Bufo spp (0.035 mL/g BW), African clawed frogs (0.025 mL/g BW)/induce in closed container; once induced, remove excess from animal
  0.28 mL/100 mL bath36 Induce in closed container
  Bubbled into water to effect36 Aquatic species
Ketamine — May have long induction and recovery times; does not provide good analgesia so may not be suited for major surgical procedures; other agents preferred; ketamine combination follows; see lidocaine
  50-150 mg/kg SC, IM7 Most species
Ketamine (K)/diazepam (D) (K) 20-40 mg/kg + (D) 0.2-0.4 mg/kg IM33 Variable results
Lidocaine 1-2% Local infiltration16 All/local anesthesia; with or without epinephrine; 2% lidocaine in combination with ketamine has been used for minor surgeries;33 use with caution
Meloxicam (Metacam; Boehringer Ingelheim) 0.4 mg/kg PO, SC, ICe q24h53 Analgesia
Methoxyflurane 0.5-1 mL in 1 L container (cotton soaked)16 Induction in 2 min; surgical anesthesia maintained for about 30 min; recovery within 7 hr; not recommended because of potential of overdose33
Morphine 38-42 mg/kg SC22 Analgesia >4 hr
Nalorphine 122 mg/kg SC22 Analgesia >4 hr
Naloxone 10 mg/kg SC;22 titrate to effect Antagonist for buprenorphine, butorphanol, codeine, fentanyl, morphine
Naltrexone 1 mg/kg SC;22 titrate to effect Antagonist for buprenorphine, butorphanol, codeine, fentanyl, morphine
Pentobarbital sodium 40-50 mg/kg ICe33 Frogs, toads/seldom used; other agents preferred; can also administer in dorsal lymph sac; anesthesia and recovery are prolonged
  60 mg/kg IV, ICe3 Euthanasia; ICe is preferred route; can also be administered in lymph sacs in anurans
Propofol 10-30 mg/kg ICe41 White’s tree frogs/pilot study; use the lower dosage for sedation or light anesthesia; induction within 30 min; recovery in 24 hr
  35 mg/kg ICe25 Deep anesthesia in 83% of tiger salamanders25
  60-100 mg/kg ICe41 Euthanasia
  100-140 mg/kg topically53 Unpublished data; maroon-eyed tree frogs (Agalychnis litodryas); 15-20 min to max effect at 100 mg/kg dose, 10-15 min to max effect at 140 mg/kg;53 sedation to deep anesthesia; remove and rinse when desired level achieved; recommended only for animals <50 g
Sevoflurane Topical application Rapid recovery unless constant reapplication
  Topical mixture of sevoflurane (5 mL) + water soluble jelly (5 mL)53  
Tiletamine/zolazepam (Telazol, Fort Dodge) 10-20 mg/kg IM33 Results variable between species; rapid recovery; not suitable as single anesthetic agent for anurans19
Tricaine methanesulfonate (MS-222) (Finquel, Argent) — Anesthesia; buffer the acidity by adding sodium bicarbonate to buffer the solution to a pH of 7.0-7.1;10 aerate water to prevent hypoxemia; remove from bath on induction or overdosing can readily occur; following bath, place terrestrial amphibians on moist towel or in very shallow water to recover;6 some species can be induced at much lower concentrations than listed here;52 in some cases, anesthesia can be maintained by dripping a dilute solution of this drug (100-200 mg/L) over the skin or by covering animal with a paper towel moistened with the anesthetic52
  50-200 mg/kg SC, IM, ICe10 Most species/may be irritating administered SC, IM (neutral solution is preferred)10
  100-200 mg/kg ICe37 Leopard frogs
  100-400 mg/kg ICe37 Bullfrogs
  100-200 mg/L bath to effect44 Larvae/induction
  200-500 mg/L bath to effect7 Tadpoles, newts/induction in 15-30 min
  0.5-2 g/L bath to effect7 Frogs, salamanders/induction in 15-30 min
  1 g/L bath to effect10 Most gill-less adult species (unless very large)/induction
  2-3 g/L bath to effect54 Toads/induction in 15-30 min
  10 g/L bath3 Euthanasia; can be administered ICe or in lymph sacs

a SC can be administered in dorsal lymph sac in anurans.7


b ED50, effective dose for 50% of the population.



TABLE 3-5 Hormones Used in Amphibians.a







































Agent Dosage Species/Comments
Gonadotropin-releasing hormone (GnRH) 10 μg SC to female followed by additional 20 μg after 18 hr; 5 μg SC to male43 Tomato frogs (Dyscophus guineti)/ovulation and spermiation
  0.1 mg/kg SC, IM, repeat prn31 Induction of ovulation in those non-responsive to PMSG or hCG; administer to females 8-12 hr before males
Human chorionic gonadotropin (hCG) 50-1007 to 30031 U SC, IM For mating or release of sperm in males; follow with GnRH in 8-24 hr
  250-400 U SC, IM7 African clawed frogs, axolotls/induction of ovulation; may be used with PMSG and/or progesterone
Luteinizing hormone–releasing hormone 10 μg in 0.05 mL of 40% DMSO applied to ventral drink patch32 Bufo americanus and B. valliceps/induced spermiation in 70% of males
  5 μg ICe per animal40 Salamanders (Desmognathus ochrophaeus)/induced oviposition in 94%
Pregnant mare serum gonadotropin (PMSG) 50-200 U SC, IM7 African clawed frogs, axolotls/induction of ovulation; administer 600 U hCG SC, IM 72 hr later31
Progesterone 1-5 mg SC, IM7 African clawed frogs, axolotls/use in addition to PMSG or hCG for induction of ovulation

a SC can be administered into the dorsal lymph sac of anurans.7



TABLE 3-6 Miscellaneous Agents Used in Amphibians.a





































Agent Dosage Species/Comments
Amphibian Ringer’s solution (ARS) 6.6 g NaCl, 0.15 g KCl, 0.15 g CaCl2, and 0.2 g NaHCO3 in 1 L water8,54 For treating hydrocoelom and subcutaneous edema; place animal in shallow ARS bath until stabilized (image24 hr or more); replace with fresh solution daily; may need to wean animal off ARS by placing it in gradually more dilute solutions;54 hypertonic solution created by using 800-950 mL water instead of 1 L and may be more effective for some cases of hydrocoelom;54 up to 10 g of glucose may be added per L, but then solution must be made fresh daily53
Atropine 0.1 mg SC, IM prn54 Organophosphate toxicosis
Caffeine Use caffeinated tea bag; steep (soak) until solution is “weak tea”; place amphibian in shallow bath, replace q6h53 Stimulant; may help reverse ivermectin or levamisole toxicosis, or excessively deep anesthesia53
Calcium glubionate 1 mL/kg PO q24h54 Nutritional secondary hyperparathyroidism
Calcium gluconate 100-200 mg/kg SC54 Hypocalcemic tetany
  2.3% continuous bath (with 2-3 IU/mL vitamin D3)54 Nutritional secondary hyperparathyroidism
Critical care diets    


• Carnivore Critical Care (Oxbow)

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Aug 21, 2016 | Posted by in EXOTIC, WILD, ZOO | Comments Off on Amphibians

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