Snake medication: weighing and dosing

One of the most important tools in your home veterinary arsenal is an accurate scale. Digital is usually most convenient. I have two, one for weighing smaller snakes and neonates up to 500 grams which is accurate to 0.1 of a gram, and one that goes to 5 kilos and rounds off to the nearest gram. Getting an accurate body weight is important because drug dosages are calculated in milligrams of drug per kilogram of snake.

A drugs's effect is based on the concentration of it in the body tissues. Achieving this requires knowing how much tissue there is to divide the drug among.

There are many places to buy scales, but Midwest has a good one for less than I paid for either of mine.

Some snakes may sit still on the scale like this Atheris squamiger, but for less cooperative specimens you'll want to use a container like this one. The container is tared out or zeroed out first by placing it on the scale, then the snake is put inside for weighing. Don't forget to factor in the lid. All scales have a "tare" button for cancelling the weight currently on the scale and displaying future weights relative to it. Alternatively (if you forget to weight the container before putting the snake in it), you may measure it afterwards and subtract it by hand. For convenience all my weighing buckets have their weight written on them in permanent ink.

Unless you only intend to weigh placid snakes, include a container in the maximum capacity you need when shopping for a scale.

A few words on drug dosages: you need to be able to do enough math to figure out how many cc's of drug need to go into your snake in order for it to get a dose of X many milligrams per kilogram of its weight. Drug products may vary in their potency and may be sold in different concentrations, which means one bottle of Flagyl may have 50 milligrams of drug per cc (milliliter) of liquid and another may have 25 milligrams of drug per cc of liquid. Baytril is usually sold in 22.7mg/ml, but I buy it in larger bottles of 100 mg/ml concentration and make my own dilutions for oral use.

Let's say a snake weighing 500 grams (half a kilogram) needs Baytril. You want to give a loading dose of 7.5 milligrams per kilogram and 5 mg/kg thereafter, given orally every 24 hours. This snake needs 3.25 milligrams of drug for the first dose and 2.5 milligrams thereafter. If every milliliter or cc of your Baytril product contains 22.7 milligrams of drug, what amount of the drug needs to go inside your snake?

Divide the dose you want (3.5 mg) by the concentration in mg/ml (22.7) and you come up with about 0.154 of a cc. That isn't very much liquid, so you probably want to preload a feeding syringe with plain water (up to 1% of your patient's body weight. Draw up the medication in a .3cc tuberculin syringe and inject it into the end of the feeding tube so that the medication is sure to go down first and won't be retained in the syringe.

You may also consider diluting your Baytril with a measured amount of sterile water for use on smaller snakes. It is useful to keep two different concentrations of a drug handy when medicating snakes of different sizes.

Learn more about Fluids and Fluid Therapy in Reptiles at Melissa Kaplan's Herp Care collection.
Read an article on reptile parasites from Melissa Kaplan's Herp Care collection.

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