Tail regrowth in older tegus

[laurarfl]

I have a female tegu that is probably 9yo. She had wet gangrene in her tail after the male bit it and that was about 1 1/2 years ago. The tail had to be broken high, right past the soft muscle, so only about 1/3 of the original tail is left. The end healed nicely and she is doing well. However, no new length has regrown, just a healed rounded end. Is it her age or the high break? She eats well, natural sunshine, calcium supplements plus whole foods. Is she missing anything in her husbandry?

[bubblz]

I've wondered the same things since getting Natsuki. He didn't lose much maybe a few inces off the end but it didn't grow and hasn't tried to grow back since I had him. The scales have actually closed in around the tip and it's just this prickly nub. I don't know if that has anything to do with it, age or what since he is over 4yrs old. But if age had something to do with it you'd think it would be later down the line when they're older.

Although given the circumstances and his condition before and when I got him a number of things could have played into it but,.. it's just something I've been thinking about as well.

[txrepgirl]

That is strange. Because I have seen many photos of the regrown back. It was just all black.

[RamblinRose]

Here is an excellent source for reading on just this subject. I think it will answer a lot of questions you are seeking Laura. She explains it rather well. Just make sure you read the whole page. : )
http://www.anapsid.org/tailloss.html

[txrepgirl]

Thank you Rose for doing your research. Job well done . I don't know why I didn't post the link before .

http://www.thetegu.com/showthread.ph...eaks-and-drops

[laurarfl]

I love her articles! Were you thinking of this part, "If the iguana is big enough to not need the drop-defense anymore, it won't expend the energy to regenerate the tail - instead, all that energy will go into increasing body size."

[Dana C]

That article is fascinating. Gordo lost what I estimate to be 4-6 inches off the end. He has a tiny nub of black, (dead bone?), on the very end but no sighs of regrowth. I think Gordo is over three years old so based upon the article, I am guessing he won't regrow it. He is a tad over 36" currently.

[RamblinRose]

Hi Laura,
Yes, that's what I was thinking.

Dana C,
How long ago was that? Usually the black nub is the regeneration starting point. But with just that much missing on the end, it may be all that it will do. They never grow the entire length back and it will always look somewhat like a nub, never really gain a nice thin "long" pointed end again. However, it is only a small cosmetic effect. A reg. tail still serves it's purpose.

Another thing I find interesting is they never seem to snap them off in the same place twice. Usually it is a bit farther up according to my Vet.

[tupinambis]

While Melissa does give a lot of good information in her articles, she also has a lot of conjecture in it as well. Usually, however, I would have to give her kudos and her conjectures are often harmless.

In this particular case, though, I think her bit on the tail-loss in older animals is a guess at best. I can honestly say in my readings that I don't think I've ever come across an age issue with autotomy, and this may indeed be true. However, I'd caution on the cause. I can think of one far more reasonable, and far more common in all organisms around us. We all lose function as we age. Look at how readily the young heal from injury whereas the elderly do not. As organisms change, so does our physiology in ways many are not familiar with and which are far more profound than many would think. For example, let's look at our nervous system. At birth, evidence suggests that our brains and the functions it is responsible for are predominantly governed by a pacemaker type system. Certain cells are just firing in a monotonous manner, and this rhythm governs things like breathing, heart beats, certain muscular activity, etc. As we age and develop, we appear to replace the pacemaker system with a neuronal network, wherein interconnecting parts are responsible for creating certain aspects of the governing rhythms, but no one cell is responsible for it all. This has the advantage of making these rhythms more adaptable, more maleable to the immediate needs of the organism (think about how our heart and breathing change with exercise...and here's the bit most are unaware of, we actually change these BEFORE we start experiencing the demands of exercise, not in response to them....). A pacemaker system can be manipulated, but not as readily. However, the pacemaker system has its benefits too. You can chill a newborn to near freezing, and at the lower temperature it will appear as if the organism is dead because they cease breathing and cardiac function. Warm them up and they will start breathing on their own and their heart starts beating on its own - because of the pacemaker based system. Do this to an adult, and they are dead without outside intervention, the neuronal network has been disrupted. Regenerative ability in tails may be a function of age, as they age they may lose the cell types (ie. stem cells) in regions necessary to induce regrowth. Furthermore, even in the young, when a tail regenerates, a lot of the tissues aren't the same. They don't regrow the bone, they instead form a cartilagenous rod to provide support.

There's also the specific conditions of laurafl's case here - gangrene. I've seen tails regrow from strictly physical trauma. I've never seen tails regrow when lost through disease. Although the tail was amputated above the disease affected area, we cannot be sure what cellular signals and activity in response to the gangrene were present throughout the tail, and these may indeed impede regeneration even those the tissues in these higher areas were not directly affected by the gangrene.

[laurarfl]

That would make sense. There was a lot of soft tissue damage in the area.