Although herpetoculturists have learned a great deal about the care of reptiles and amphibians, we are still learning. One area - the needs of geriatric herps - remains largely unexplored. Perhaps there is a reason for this. Unlike many mammals, which clearly show the aging process (sometimes beginning rather early in life), aging reptiles and amphibians often show few signs – and even these are subtle – until their death from natural causes is close at hand. There is no graying of scales, and there is often no slowing of actions and reactions. With advanced age, breeding usually decreases. There are fewer eggs or young, and a diminished viability of those that are produced.
What constitutes "old" for a reptile or amphibian varies dramatically by species. There are some small lacertid lizards, for example, that are essentially annual species – hatching, breeding and dying within a year or a year-and-a-half. These could be considered old at 9 months of age.
At the opposite extreme, we have the big, slow-to-mature iguanas and monitors (as well as many smaller species) that may attain longevity of 15 to more than 30 years. These would not be considered old until an age of 10 or 15 years had been attained.
The very popular inland bearded dragon is in the middle, breeding only until it is about 5 years of age, and seldom living longer than 9 years. If well cared for, turtles and tortoises - even the very popular, pet store available, red-eared slider (often sold merely as "baby green turtle") - may live for 45 to 100 years.
Crocodilians are also long-lived. Caiman of various types usually exceed a life span of 15 years, and American alligators may live over 70 years. Boas, pythons, and many of the commonly kept lampropeltine constricting snakes (rat, king, milk and gopher snakes) often exceed an age of 15 years, and occasionally may reach the ripe old age of 30 to 40 years.
Amphibians can be equally long-lived. Although some of the more commonly kept smaller treefrogs and lungless salamanders seldom exceed an age of 10 years. Newts, toads, horned frogs, and some of the larger treefrogs can live for more than 20 years.
Signs of Aging
Aged green iguanas seem more apt to sustain fractures when they drop from their perch or accidentally fall than their younger counterparts. These injuries are not restricted to the limbs, but often involve the spinal vertebrae (backbone) as well. Since iguanas are relatively heavy lizards, these bone-breaks are more common with them then with aged, but comparatively featherweight, species such as basilisks and water dragons.
When death is near, there is a tendency for an aged lizard to bask more, to have sunken eyes, and to appear malnourished (bony), especially above the hips and shoulders.
Old turtles may show somewhat slower reaction times and have sunken eyes; conversely they may show no signs of advanced age at all, eating one day and dying during that night.
Snakes may also appear bonier, especially along the vertebral column when they are aged but, again, this is not always the case.
Crocodilians show few if any signs of aging, and we just don't know what to look for yet with amphibians.
What You Can Do
What you can do depends upon how gracefully your pet ages. It is, however, imperative that you know your reptile and understand its body language. To accommodate an aging arboreal lizard (iguana, basilisk, water dragon, etc., but not a true chameleon), provide it with an elevated basking area of easier access. Replace the sturdy limbs you have routinely provided for climbing and basking with flat, cleated, boards several inches wider than the lizard's body. The lizard will be less likely to accidentally topple from these.
It should go without saying that you should never allow any herp to drop, or even to jump, from your grasp when it is being carried. This is especially so of aged pets. The argument that "he's always done it" will become moot when your pet is severely injured.
Provide your aging semiaquatic turtles with readily accessed flat cleated boards on which they can easily leave the water and flat basking boards that are equally easily reached.
Make your aging herp's life as stress-free as possible. Do not keep elderly males where they can see younger breeding males of the same species. Territoriality (breeding) displays by male lizards are intended to intimidate males within his species. Even when kept in separate terraria across a room, your aging, non-breeding, male will be unnecessarily stressed if he can view ongoing territorial displays by younger males.
Altering dietary needs for aging reptiles and amphibians may become a necessity. Digesting large prey items may become difficult for some elderly snakes, especially if cage temperatures are not ideal and stable. Regurgitation then becomes a very real possibility. Should this happen, be certain that cage temperatures are stabilized and give your snake two small mice (or one small mouse at more frequent intervals) instead of one jumbo breeder, and regurgitation may no longer occur.
Although even at a venerable age most tortoises are fully capable of tearing their vegetation into bite-sized pieces, they tend to eat more, and often more readily, when their food is chopped into smaller than bite-sized pieces (we also do this for hatchling tortoises).
The vitamin and mineral requirements of herps also alters with advancing age. Rapidly growing young herps need a relatively large amount of calcium and vitamin D3 to sustain normal bone growth. Ovulating female herps require an even greater amount of calcium-D3 to provide the materials for the formation of eggshells or for their developing embryos. For both categories we suggest giving calcium-D3 additives 2 or 3 times weekly. This need will drop off radically out of the breeding season or when ovulation no longer occurs. Sufficient calcium-D3 will need to be provided to sustain adequate bone mass (provided as an additive perhaps once a week) but overdoing will accomplish nothing.
The immune systems of aging herps may become somewhat compromised. As if they are aware of this, many heliothermic (sun-basking) species often bask for longer periods and may preferentially choose temperatures a little warmer than normal. It is always best to provide a heliothermic reptile with a rather wide temperature gradient, but this is especially beneficial to elderly reptiles. Of course, all heliotherms should be provided with full-spectrum lighting, be it natural or artificial, in which to bask.
Temperature gradients are also important for non-heliotherms such as certain burrowing snakes and lizards and for all nocturnal species of reptiles and for many nocturnal amphibians. The needed gradient can be easily provided by placing a heat tape or heating pad beneath one end of the tank. Do remember that temperate amphibians prefer temperatures cooler than those needed by most reptiles, so plan and provide accordingly.
How you provide for your aging reptile or amphibian will depend largely on the amount of debilitation (if any) shown by your pet. Some herps continue going full-steam-ahead until the day they die. Others may slow down somewhat and require just a bit of extra attention or slightly altered caging conditions. By learning to "read and interpret" your pets' moods and body language you will be able to provide your reptile or amphibian with the best conditions possible throughout what could and should be a very long life.