Reptile & Amphibian Forums

Hey everyone Just thought I would share some more info. from my classes that may relate to topics discussed here.

When reptiles become dehydrated they usually only lose water. This leaves a higher concentration of electrolytes in the animal, and an overall hypertonic state. This difference from mammals is related to reptile's inability to concentrate urine and to selectively reabsorb water from the bladder/ureter flares, cecum, (or wherever, depending on the species). Reptiles also have a lower osmotic level than mammals. (about 260 vs 275mOsmol). Variation does exist, and generally the more terrestrial, dryer climate animals are on the higher end, and aquatic/semi-aquatic animals are on the lower end. Marine reptiles are the exception and have the highest osmalarity.

What this means is that when replacing fluids they should be hypotonic. You may have heard of "reptile ringers" if in vet med, and this is a diluted fluid to obtain such a result. For the average person, worried about dehydration in there animal, of course take it to the vet. For information however, this knowledge shows that replacing fluids with mammalian pedialyte is somewhat contraindicated, and that regular tap water is the best for oral hydration. This is of less relevence in oral routes, but still nice to know. If truely dehydrated however, oral fluids are not enough, and iv, io, or ico routes are needed.

Hope this proves interesting

Ian Kanda,AHT

That was information I didn't know! I am passing it along.

I'm guessing that a reptile's inability to concentrate its urine is the result of most reptiles already concentrating it in the form of uric acid. I thought that was the advantage of making uric acid over urea was the lesser requirement of expelling water with the nitrogenous waste.
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"I know the human being and fish can coexist peacefully."
Governor George W. Bush, Jr.

"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us."
Calvin and Hobbes (Scientific Progress Goes 'Boink', 1991)

You are correct, reptiles are built to withold water. That is why dryland animals leopard geckos) will have rather hard urates, while tropical forest (iguanas) will have much more liquid expelled. The problem relates to when reptiles are otherwise dehyrated (blood loss, trauma, chronic wasting, ...).