Pharmacotherapy in reptiles univ. prof. Zdenek Knotek, DVM, PhD University of Veterinary and Pharmaceutical Sciences Brno Czech Republic

Pharmacokinetism - temperature Reptiles are ectotherm vertebrates. Their metabolism is dependent (influenced with) on external temperature. In nature – reptiles try to keep the body in preferred body temperature (PBT) optimal condition for metabolic pathways. Patients keep their PBT - spending maximum time in special part of the terraria - behavioral thermoregulation.

Pharmacokinetism - temperature Reptiles are ectotherm vertebrates. Preferred optimum temperature zone (POTZ) is condition for PBT. • Keep your patients in POTZ – during treatment, anaesthesia, surgery, recovery period. • Lower (suboptimal) temperatures – prolong the recovery time. • Lower (suboptimal) temperatures – increase the risk of overdose drugs (aminoglycosides).

Special anatomy/physiology of reptiles Quadriped reptiles - renal portal system. Presence/absence – urinary bladder – ventral extension of urodeum. Central organ for final urine production.

Special anatomy/physiology of reptiles • The most of snake species have only the right lung. Do not insert the endotracheal tube into left lung rudiment. • Reptiles have very low respiratory frequence. It is lowest within anaesthesia. • Reptiles can tolerate very low oxygen concentration in peripheral blood (organs, tissues). • Semia-quatic/aquatic reptiles – shunt of blood circulation within the period of submergence.

Special anatomy/physiology of reptiles GIT – in carnivorous reptiles (crocodiles, aquatic terapins, snakes and some lizards) short distance. Transit time for contrast fluids (X-ray), food, drug metabolites is short (days). GIT – in herbivorous reptiles (land tortoises, lizards) long. Transit time for contrast fluids (X-ray), food, drug metabolites is long, very slow passage (weeks).

DIAGNOSIS and TREATMENT §1

Think before treat !

§2

Disease is complex !

§3

Concurrent diseases !

§4

Patient is complex !

§5

Topical and/or systemic treatment !

§6

Follow the recommendations !

§7

Reptiles- crocodiles, chelonians, snakes, lizards

DIAGNOSIS and TREATMENT EMERGENCY ?

Reptiles are generally presented injured or ill. Good history - valuable lead to the problem. In many cases - only an illusion. Prepare your own questionare protocol origin of the reptile housing system feeding regimen temperature, air humidity, water, substrate, UVB any previous treatment? previous reproductive activity?

The success of treating a critical patient relies very heavily on the environment in which the animal must recover. When possible make visually-separated housing for each of the reptile patients. They may experience unnecessary extra stress in a living with visual contact with other reptiles (predators).

Basic equipment to practice with reptiles a gram scale a lightweight plastic transport containers endoscope (2.7 mm or less) X–ray microscope with oil immersion capability quick-staining kit for smears and cytology, centrifuge, haemocytometer biochemistry testing system.

Side effects Aminoglycosides amikacin, gentamycin, kanamycin, netilmycin, tobramycin

+ G- bacterial infections glomerular filtration

-

nephrotoxic (neurotoxic, ototoxic, cardiotox) efects

Side effects Tetracyclin ATBs doxycyclin, chlortetracyclin, oxytetracyclin, tetracyclin

+ G+ i G- infections, low nephrotoxic

-

teratogenic (pregnanc), nauzea, vomitus, hepatotoxicefekt (liver steatosis), bacteriostatic

Side effects Quinolon enrofloxacin, ciprofloxacin + G+ a G- infekcí, suspect teratogenic (pregnancy), negative influence on bones (growth, joints)

Metronidazole + (Clostridia, Entamoeba, Hexamita) - neurotoxic efect of reccommended doses (heavy reptiles)

Ivermectin + (endoparasites, ectoparasites) - toxic for tortoises, turtles

Administartion Per os + GIT Per cloacam

Parenteral SC, IM, IPP, IV, IO

Metabolic (Allometric) scalling BMR (kcal) = K.H0.75 • birds - passerine birds • birds - non-passerine birds • mammals • reptiles

(K = 129) (K = 78) (K = 70) (K = 10)

Antimicrobial Agent Acyclovir

Dosage 80 mg/kg PO q24h x10

agents ATB Comments Tortoises (herpes)

Topical (5% ointment) q12h Tortoises (herpes) Ampicilin Amikacin

20 mg/kg IM q24h x 7

Tortoises

2.5 mg/kg IM, SC q72h x 7

Nephrotoxic agent

Gentamycin 1.75 - 2.5 mg/kg IM q72 h x7 Nephrotoxic agent Kanamycin

5 - 15 mg/kg q24 - 48 x 5 - 7 Nephrotoxic agent

Antimicrobial agents ATB Agent

Dosage

Comments

Chloramphenicol

20 - 50 mg/kg PO

q24h x 7

Streptomycin

6 - 10 mg/kg IM

q24h x 5 - 7

Tetracycline Tylosine Cindamycin Doxycycline

25 - 50 mg/kg IM, PO

q24h x 6

5 - 10 mg/kg IM

q24h x10 crocodiles

2.5 - 5 mg/kg PO

q12-24h x 7

50(1)+25(3 - 6)mg/kg IM q48 - 72h x 6

Antimicrobial agents ATB Agent Cefotaxime Ceftazidime

Dosage

Comments

20 - 40 mg/kg IM

q24h x 7 - 14

20 mg/kg IM

q72h x 14 - 21

Cephalexin

20 - 40 mg/kg IM

q12h x 7

Cephalothin

20 - 40 mg/kg IM

q48h x 7 chelonians

Cephazolin

20 - 40 mg/kg IM

q24h x 7 - 14

Cephoperazone

125 mg/kg IM

q24h x 7 lizards

Antimicrobial agents ATB Agent Enrofloxacin Ciprofloxacin

Dosage 10(15) mg/kg SC, PO

Comments q24h x 7 - 21

10 mg/kg PO

q48h x 3 - 5

20 - 50 mg/kg PO

q24h x 3 - 5

Trimethoprim / sulfamethoxazole

30(1)+15 mg/kg

q24h x 10 - 14

Sulphadimidine

50 mg/kg PO

q24h x 10

Sulphamerazine

25 mg/kg PO

q24h x 7

Metronidazole

Antifungal agents Agent

Dosage

antimycotics Comments

Amphotericin B

0.5 - 1 mg/kg PO, IPP q24 - 48h x 28

Griseofulvin

20 - 40 mg/kg PO

q72h x 5

topical

ointment

Clotrimazole Fluconazole Itraconazole Ketoconazole

5 mg/kg PO

q24h x 28

24 mg/kg PO

q24h x 28

15 - 30 mg/kg PO

q24h x 28

Antifungal agents Agent

antimycotics

Dosage

Comments

Chlorhexidine

20 ml/gal water bath

Lizards - dermatoph.

Malachite green

0.15 mg/l water x 1 hr

q24h x 14

Miconazole Nystatin Tolnaftate 1% cream

topical 100 000 i.u./kg PO topical

ointment q24h x 10 q12h

Antiparasitic agents Parasites

Amoeba

Flagellata

Agent

Dosage

Metronidazole

20 – 40 (100) mg/kg 3x

Dimetridazole

40 mg/kg q24h x 4

Paromomycin

35 – 60 mg/kg after week

Metronidazole

20 – 40 (100) mg/kg 3x

Dimetridazole

40 mg/kg q24h x 4

Ronidazole

10 mg/kg q24h x 10

Antiparasitic Parasites

Coccidia

Agent

agents Dosage

Toltrazuril

10 mg/kg q72h x 5

Sulfadimethoxine Sulfamethoxydiazine

75 – 90 mg/kg I.day 40 – 45 mg/kg II. – IV. 40 – 60 mg/kg q24h x 4

Sulfadiazine

20 – 50 mg/kg q24h x 3

Cryptosporidium Trimethoprim / sulfa Spiramycin

30 – 60 mg/kg q24h x 7 160 mg/kg q24h x 10

Antiparasitic agents Parasites

Agent Ivermectin

Trematoda Praziquantel

Ivermectin

Cestoda

Dosage 0.2 mg/kg SC  Chelonians 10 – 30 mg/kg q14 days

Praziquantel

0.2 mg/kg SC  Chelonians 10 – 30 mg/kg q14 days

Niclosamid

150 mg/kg q14 days

Antiparasitic agents Parasites

Agent

Dosage

Fenbendazole

10 – 30 mg/kg q 14 days

Pyrantel pamoate

5 mg/kg q 14 days

Nematoda Ivermectin Piperazine

0.2 mg/kg SC  Chelonians 40 – 60 mg/kg q 14 days

Albendazole

50 mg/kg q 14 days

Mebendazole

20 – 100 mg/kg q 14 days

Hormones + steroids Agent

Dosage

Arginine vasotocin

0.5 - 1.0 μg/kg IV,IPP

Oxytocin

1 - 10 i.u./kg IM

Calcitonin

1.5 i.u./kg SC

Dexamethasone

2 - 4 mg/kg IM

q24h x 3

Prednisolone

2 - 5 mg/kg IM, PO

chronic pain

Nandrolone

1 mg/kg IM

Comments q12 - 24h after 2x calcium inj. q8h x 2 - 3

anabolic, PHA

Nutritional Agent Ca - gluconate borogluconate

Ca - gluconate Iodine Iron dextran Lactated Ringer ´s solution

/ mineral / fluid support Dosage 10 - 50mg/kg IM 100mg/kg IPP, SC 2 - 4 mg/kg PO 12 mg/kg IM 10 - 25 ml/kg SC, IPP

Comments hypocalcemia q8h MBD, seizures q24h x 2 - 3w 1 - 2 x w, crocodiles q24h

Nutritional Agent Vitamin A Vitamin B complex

/ mineral / fluid support Dosage

Comments

1000 - 5000 i.u./kg IM

q7-14d x 4

25 mg thiamine/kg PO

q24h x 3-7 days

Vitamin C

10 - 20 mg/kg SC, IM

q24h

Vitamin D3

200 i.u./kg IM, PO

q7days

Vitamin E Vitamin K1

1 i.u./kg IM 25 mg/kg IM

1000 - 5000 i.u./kg IM

hypovitaminosis coagulopaties

Miscellaneous Agent

Dosage

agents Comments

Allopurinol

10 - 20 mg/kg PO

q24h

Sucralfate

500 - 1000 mg/kg PO

q6 - 8h

Cimetidine

4 mg/kg PO, IM

q8 - 12h

Cisapride

0.5 - 2.0 mg/kg PO

Furosemide

5 mg/kg PO, IM

Metoclopramide

0.06 - 5 mg/kg PO

q24h q12 - 24h q24h x 7

Miscellaneous Agent Lactulose Liquid paraffin Dioctyl Na sulfosuccinate Barium sulfate

Dosage 0.5 ml/kg PO 25 (1:1 electr)/kg PO

agents Comments q24h q24h, constipation

1 - 5 mg/kg PO

constipation

5 - 20 ml/kg PO

GIT contrast