Analgesic - A drug that relieves pain. They are available in three forms: injectable, oral and topical.
Most people would never in a million years consider having surgery without following it up with at least one kind of painkiller. These days, almost no one would subject Fifi to being spayed and not have her treated with painkillers afterward. And yet, an astounding amount of people never even thought about asking their vet for an analgesic after having couple of Iggy's injured toes amputated, or for Igita after she got spayed. Why?
Pain perception in reptiles is still very poorly understood. We're not sure how reptiles process pain, or even how their bodies respond to it. But we do know that they feel pain. Here are some of the signs that your iguana is in pain:
Reluctance to move
Lameness, difficulty moving
Abdminal splinting (stomach tucking)
Agression, protection of painful sites
Depression or anxiety
Refusal of food
Pretty straightforward, right? But what to do about it? Keep reading.
It's fairly widely accepted by herp vets that opioids (drugs related to or derrived from the drug opium, ie codeine, morphine, papverine and heroin.) are a poor choice as analgesics for reptiles. For reasons that are as of yet unknown, reptiles do not respond to these drugs as mammals do. It is possible that some opioids may provide temporary relief but do not induce sedation. Nitrous oxide, otherwise known as laughing gas, provides a most pleasant pre-operative analgesic for humans, and possibly for other mammals. But it won't help Iggy. Why not? Basically, the gas exchnage function in a reptile's lungs is different enough that it is difficult to reach theraputic levels in a reptile without flirting with toxic overdose. Steroidal drugs (ie Cortisone and Prednisidone are steroid-based drugs) are believed to be dangerous to reptiles because they tend to be harder on kidneys.
At this point, non-steroidal anti-inflammatory drugs are the preferred choice for analgesia for reptiles. Here are some of the drugs recommended by Dr. Roger Klingenberg, DVM, practicing herp vet:
Please bear in mind that you can get none of these drugs for your iguana without an examination and prescription by a licensed veterinarian. These drugs are not listed so that a person can treat an injured iguana without going to a vet. This is simply to give the reader an idea of what is used for pain medication and something to refer to. You would be putting your iguana in serious jeopardy by attempting to medicate him or her yourself.
If your iguana is going to have surgery, or you have reason to believe that your iguana is in pain, please discuss the matter of analgesics with your vet. Most vets, even qualified herp vets, do not prescribe analgesia for reptiles as a matter of practice, so it will be up to you to broach the topic. A good vet will be more than willing to do the research if necessary and come up with the proper medication and dosage to make your iguana a much more comfortable lizard.
Reptile Medicine and Surgery by Dr. Douglas Mader, DVM. Heavy reading for the medically minded. See "analgesia" in index.
Pain Perception written for The Vivarium magazine by Dr. Roger Klingenberg, DVM. Magazine Volume 10, Number 4.
Mosby's Medical Encyclopedia published by Signet. Revised edition, 1996.
The VetNetwork Newsletter, non-steroidal analgesia