What do you do when you have a tortoise that is not feeling well? To date, there have been very few pharmacokinetic studies published in reptiles, and with only limited numbers of antibiotics.
So far, all of the studies have been done on snakes, turtles, and crocodilians. There have been no pharmacokinetic studies done on lizards.
There are a number of factors that must be considered when choosing an antibiotic.
The results of microbiological culture and sensitivity testing, the species being treated, the physical condition of the patient, frequency of administration, cost of the therapy, owner compliance, and a host of other factors are all important.
The veterinary clinician must have a thorough understanding of reptile physiology and biology prior to administering medications.
Since all reptiles are ectotherms, and their metabolism is temperature dependent, they will often react unpredictably to the same drug in different settings.
A good working knowledge of the more common species of reptiles, their life histories, and their peculiarities will help prevent potential disasters during therapy. General considerations Before treatment is initiated the patient should be given a thorough exam including a CBC and serum profile, with a uric acid, to assess hydration status.
Dehydrated or hyperuricemic patients should be properly rehydrated prior to initiating therapy. It is the rare case that cannot wait for one to two days to assure appropriate hydration prior to treatment.
However, if for some reason treatment must be instigated immediately, it would behoove the practitioner to choose a non-nephrotoxic drug. Another important consideration is the ambient temperature of the reptile’s environment.
Pharmacokinetic studies have shown that an increase in ambient temperature tends to increase both the volume of distribution and body clearance of the drug.
A decrease in ambient temperature with a resultant decrease in body clearance could potentially allow a build up in the concentration of the drug to a point where it might reach toxic levels if dosing is not decreased accordingly.
