Can older Tegus suddenly decide to hibernate when they never have in the past?

[limelizzard]

Hey everyone,

First of all, thanks to all the great people and info on this site. I don't usually post, but I've lurked around for a couple years and can usually find the answers to any questions pretty easily.

Now, I have a question of my own. I've seen some posts about hibernation, but I'm a little concerned about how to know if my guy is trying to hibernate.

Here's the info:
I have a male, black &white, who is about 3 1/2 years old. He has never hibernated before and I am very familiar with his typical behavior patterns. He has lived outdoors for about a year now. He has a hide outside and his hide has a heat rock in it. However, when it started to get cooler outside last winter, I got worried and kept bringing him inside. (I live in San Diego, so it never actually gets cold.) He typically "asks" to come inside (he bumps his nose on the door to get my attention) every couple days, will do a couple loops of my apartment, play with (or avoid playing with) my cats, sh!t on my carpet >_< and then indicate that he wants to go back outside.
About 2 months ago he started to act more lethargic than usual and started eating less; his poop was also very runny and he seemed to be in pain when going to the bathroom. I took him to the vet ASAP. He had a history of impaction (and a previous surgery about 2 years ago), so they did x-rays and tested his stool for parasites. They found no blockage, no parasites, but they did find an infection and he was put on medication for that. At this point he was still eating enough that I was able to give him his pill in a hard-boiled egg every day (his favorite food).
2 weeks (the length of his medication period) go by and I don't see improvement. We go back to the vet. His stool is tested again. Some leftover infection is still present, but the amount they see has dropped significantly. They find nothing else wrong. We continue the medication a little longer to finish clearing up the infection.
Since then his poop has returned to normal, but his appetite and behavior have not. He still comes inside occasionally. However, he isn't coming out of his hide much and he has only asked to come inside once in the past couple weeks. When I first took him to the vet I thought it was too warm outside for him to be considering hibernating, but now I'm not sure. He has refused food for probably about 3 weeks now. But he has gone to the bathroom as recently as 5 days ago. He is staying in his hide where the heat rock is, but he is rarely coming out to bask (the most recently I saw was over a week ago and it was very brief).

I'm sorry for such a long post, but I figure I should provide as much background as possible. What is boils down to is his behavior is not typical and he has never tried to hibernate before. I don't know if he would suddenly try to hibernate seeing how old he is and has never shown signs of hibernation before.

I appreciate any feedback. Again, sorry for the lengthy post.

[Hokurai]

He's only been living outside for the past year? So he lived inside before? The starting to hibernate may be that he's living outside where the temperature is less controlled and more natural than an indoor enclosure so there is a wider temperature variation. I'd say not to worry but I'm not that experienced.

[tupinambis]

It does indeed sound like your tegu is preparing to hibernate, but if he has an infection I'd be concerned about letting him hibernate. Hibernation is partly due to temperature, but most of the initial behaviour appears to be induced by photoperiod. I'm curious, in your veterinarian examinations, did they look at the plasma calcium levels at all?

[limelizzard]

I'm not 100% certain, but I'm going to say 'No' as they did not do any blood work.

Also, his infection should be cleared up (it was almost gone before the extension of the medication to treat it).

And, yes Hokurai, he did live indoors previously. But eventually he became an escape artist and refused to sleep in his cage, lol.

[tupinambis]

I'd want to make sure the infection is completely cleared up before allowing the tegu to cool down too much. With reptiles, the lower their body temperature, the more it impedes their immune system. If the infection isn't completely cleared up while it goes into hibernation, there's a very good chance it will bloom aggressively and could severely harm your pet.

[Thumper1904]

I live in San Diego (PB) even though the weather never changes much the days are becoming shorter and shorter as mentioned by Tupinambis. So yes he has probably noticed the change, I know I have, and is going into hibernation.

[laurarfl]

Something that pops into my mind is clearance of the medication. Some medications can be hard on reptile kidneys, therefore they need a lot of water while getting treatment. So, is he slowing down because of hibernation, the infection, the medication effects, or a combination? How is he doing now?