How do you know if your lizard, or your snake, or your tortoise is stressed?

Muhammed Mahdi Karim photo is here

When animals are under stress, the nervous system responds by releasing adrenaline and other hormones to prepare the body for action. The adrenal glands flood the body with hormones like adrenalin (epinephrine) to prepare the animal for action. Similar hormones are produced in the brain.

For a long time it was thought that cold-blooded animals were “primitive” and therefore did not suffer from stress as much as “higher” animals.Yet reptiles respond in a very similar way to warm-blooded mammals, though their adrenal glands and their hormones are slightly different.

If the snake or lizard or tortoise has to run away, or hide, or do something in response to a threat, then these hormones help them to do it. For instance some lizards shed their tail when chased by predators. But if there is no action available, the hormones just flood the system to no avail. The animal has no relief from emotions like fear. Reptiles in bad conditions of captivity that cannot escape, for instance, will experience the emotion of frustration in countless escape attempts.

This means that they suffer.

And if the stress is chronic, this affects the animal’s welfare. Chronically stressed reptiles (and humans) have a lowered immune system. They are more likely to get various diseases and disorders.

One problem in measuring tis in reptiles is that their response will vary according to their temperature. They cannot produce their own body heat, so when a reptile is cold, its body functions slow down. So the stress hormone levels in a cold reptile will be different from the stress hormone levels in a warm one.

What can we look for? We can look for harmful repetitive behaviours, like the way lizards or tortoises repeatedly push at transparent barriers. We can look for lack of appetite, aggression, and even a change in skin colour in some lizards.  We need to know how a normal reptile behaves, before we can tell how a stressed one behaves.

What can we look for? Diseases and disorders due to stress may involve inability to reproduce, susceptibility to infections, emaciation from lack of appetite or its opposite, obesity.

What can we look for? We can measure the stress hormones or other chemicals in the blood, but taking blood samples, for instance, will cause even more stress. Or we can measure them in the faeces – a better way as it doesn’t hurt the animal.

But….. we don’t still know enough about what is normal for a corn snake, say, or a crocodile, or a boa constrictor, or a Hermann’s tortoise, or a bearded lizard. Each species may differ in the way it responds to stress. We have a lot of research to do.

Read

Silvestre, A. M. (2014) ‘How to Assess Stress in Reptiles, Journal of Exotic Pet Medicine, 23, 240-243.

Too much or too little vitamin D for reptiles? What do we know so far?

Some lizards may use basking not just for heat but for UV light.

By now most reptile keepers realise that too little vitamin D is bad for reptiles. Vitamin D is either absorbed through natural light or through the diet. Although carnivorous reptiles can get vitamin D in their diet: strictly herbivorous reptiles will not get enough just from diet. And it now looks as if relying on diet along, even in carnivores snakes, risks vitamin D inadequacy.
What do low levels of vitamin D do? Vitamin D is important for the growth and development of bones, for the immune system, artery and vein health, and reproduction. So low levels will impact badly on all these functions. We now know for sure that good vitamin D levels are important for the successful reproduction of several captive reptile species.
Vitamin D can be found in supplements that are given to reptiles. But there is a downside to this. It looks as if dietary vitamin D can lead to too high a vitamin D level if supplements are used incorrectly. In reptiles with an overdose of vitamin D, the aorta gets furred up with minerals.  So supplementing vitamin D by diet can be tricky.
Vitamin D levels are also affected by ultra violet light. But there have been no reports yet of vitamin D overdosing because of UV light. Yes, there can be skin damage from "too much" UV light but not vitamin D overdose. There seems to be a mechanism in the skin hat prevents overdose.
So.....
It is safer to use UV lighting or access to natural daylight to give your reptile enough vitamin D. The animal can probably regulate its vitamin D levels to prevent overdose.
Moreover, some (probably not all) carnivorous captive reptiles that get their vitamin D from a diet of mice etc. may well benefit from UV lighting as well. Carnivorous Komodo dragons get more vitamin D from UV light than dietary vitamin supplement. Conversely ball pythons were able to get their vitamin D equally well from either.
What is the take-home message from this? Use of dietary supplements may not be enough and risks overdose if used incorrectly. UVB light on its own will not lead to overdose and is therefore safer. Some reptiles will benefit it even though they get vitamin D from a carnivorous diet.
AND MOST IMPORTANT OF ALL - Keep up with modern developments. This is an area which is still being researched. What was best practice ten years ago is not best practice now. If you think you know it all, you probably don't.

To read more about this go to:

Watson et al (2014), 'Vitamin D and ultraviolet B radiation considerations for exotic pets,'Journal of Exotic Pet Medicine, 23, 369-379.

 

How iguanas need their vitamin D - from light or a supplement?

There are two ways to get vitamin D - eat it or absorb it through the skin from light. Does it matter which? In the wild green iguanas would regulate their body temperature and their vitamin D by basking in the sun (an ultra violet light source) then going to the shade (without ultra violet light) when too hot. As they are herbivores they cannot get the vitamin from their food.
In 2004 a study suggested that dietary supplements of vitamin D were a good source rather than UV light. The problem with UV light then was that a reliable source of light was then not available.
You will find the details of the study here - http://www.anapsid.org/pdf/jody-hibma-uvb.pdf
In l996, a more complicated study was set up. This time different lighting was used and some of the iguanas showed very high levels of vitamin D, if they were given both a dietary supplement and an UV light. Strangely, though, these high levels didn't seem to poison them - though igs have been known to die of vitamin D overdose. Read the full account here - http://www.anapsid.org?iguana/bernard-d3.html.
So do iguanas need UV light and dietary supplements. They certainly need UV light and when you do put in UV light, you must give the iguana a place in the shade where it can escape the light if it chooses. It will regulate its temperature so the UV light needs to be in the same place as the heat lamp. If it is not the lizard will spend most of its time in the heat lamp area and miss the benefits of UV lighting.
Do they need a vitamin supplement as well? This seems to be doubtful. A lot of the general reptile supplements on the market will do them no good and may do harm. Again, read up on the topic here - http://www.anapsid.org/vitamin.html
It's difficult. It's complicated. And we don't know as much as we should. All this means that a green iguana is a pet for the experienced reptile person, not for a beginner.

Do corn snakes need or want ultra violet light? The vitamin D question.Pete Milligan of Evolution Reptiles

Pete Milligan of Evolution Reptiles, Kidlington

For years it had been thought that corn snakes, a popular and easy reptile pet, don't need special lighting. They just need a heat gradient and a proper diet of defrosted rodents.  The vitamin D which they needed came from their diet (just as cats and other carnivores get their vitamin D from their diet).
Vitamin D is essential for health. It regulates the calcium that is needed to make bones. Studies of vitamin D in humans and birs and mammals are beginning to show that it is essential for good health in other ways, possibly playing a protective part against human breast cancer. All in all it is an important vitamin.
We still don't know for sure how much vitamin D is needed by various reptiles. Do corn snakes need it via ultra violet light? Is their diet giving them enough? Corn snakes, if they are fed the correct diet (not the mince that was recommended as feed for snakes in Ireland in the l960s!), should have enough vitamin D to survive.  But what is enough? Enough to survive? Enough to breed? Enough to flourish?
A group of scientist in Louisiana State University investigated further (see below). Over 4 weeks during which the snakes were not fed, they exposed one group of snakes to UVB radiation, and one group were kept without it. They tested the level of vitamin D in the blood. The levels of radiation were also measured.
The group without UVB radiation showed no change in their vitamin D level: the group with UVB radiation had a higher level of vitamin D. So corn snakes can and will increase their vitamin D level if they are exposed to ultra violet light.There was no significant difference between the two groups in weight at the end of the period.
So now we know for sure that, given UV light, corn snakes will make vitamin D from it, and have a higher level of it in their bodies than a level just obtained from their diet. We can no longer make the assumption that UV lighting is unimportant for corn snakes. "The findings of the present study suggest otherwise," say the scientists. This is the first step towards finding out how important it may be and what levels are needed not just for survival but for good health and happiness (yes, reptiles do feel emotion!).
Pete Milligan of Evoluton Reptiles says: "A snake will benefit from UV - at the moment there isn't enough evidence to say that it is essential."

• The reptile relationship survey has now closed. Thank you everybody who did it.

• *Acierno et al., 'Effects of ultraviolet radiation on plasma 25-hydroxyvitamin D3 concentrations in corn snakes (Elaphe guttata),' American Journal of Veterinary Research, 69, 294-297

The third eye - is your pet reptile on a higher plane that you?

The "third eye"on a lizard - Wikipedia

The "third eye" was the seat of the soul, according to Rene Descartes, the French philosopher whose reductionist opinion of animals encouraged vivisection and other cruel animal experiments.
He couldn't have been more wrong. The third eye in reptiles is a functional adaptation which may allow them to "see" predators, like birds of prey, approaching from above. Its ability to function varies from species to species. In some it even has a lens and retina. In most reptiles the parietal eye doesn't have these but may be able "see" light and shade differences. There's a good description here.
The reptile parietal eye, connected to the pineal gland which is similar to the pineal gland deeper in the brain of mammals, responds to light and releases the hormone, melatonin, which regulates circadian rhythms like the sleep wake cycle. It influences the secretion of sex hormones too. And strangely it is the only bit of the middle brain that isn't paired. It's also got a good blood supply from a nearby artery.
In modern new age mysticism the third eye leads to  higher inner consciousness. With your third eye you see or experience stuff that ordinary non-enlightened humans cannot. Could your pet snake or lizard be on a higher plane that you are?

My Reptile Relationships survey is closing at the end of the month.

The third eye - not so much the seat of the soul as a way to regulate circadian rhythms.

The "third eye"on a lizard - Wikipedia

The "third eye" was the seat of the soul, according to Rene Descartes, the French philosopher whose reductionist opinion of animals encouraged vivisection and other cruel animal experiments.
He couldn't have been more wrong. The third eye in reptiles is a functional adaptation which may allow them to "see" predators, like birds of prey, approaching from above. Its ability to function varies from species to species. In some it even has a lens and retina. In most reptiles the parietal eye doesn't have these but may be able "see" light and shade differences. There's a good description here.
The reptile parietal eye, connected to the pineal gland which is similar to the pineal gland deeper in the brain of mammals, responds to light and releases the hormone, melatonin, which regulates circadian rhythms like the sleep wake cycle. It influences the secretion of sex hormones too. And strangely it is the only bit of the middle brain that isn't paired. It's also got a good blood supply from a nearby artery.
In modern new age mysticism the third eye leads to  higher inner consciousness. With your third eye you see or experience stuff that ordinary non-enlightened humans cannot. Could your pet snake or lizard be on a higher plane that you are?

My Reptile Relationships survey is closing at the end of the month.

Is my pet snake too fat? Or too thin?

Because we humans eat every day, it's difficult for us to get our head round the fact that reptiles don't need to. They need less food than we do because they don't have to heat up their bodies - the sun does that for them.
So many pet snakes end up too fat. Sometimes this is because their owners continue feeding them the same amount of food throughout their life. When they are young and growing, they need more than when they get to middle age - just like humans!! So if you feed your mature snake as often as you did when it was young, the result will be a portly animal.
With corn snakes, the fat is likely to accumulate just above the tail - look at the photo on the right and you will see the tail is growing out of a kind of bulge. That's usually a fat snake. If however it is an animal you have just bought, or if that lump occurs suddenly, then you need to take your snake to a vet to make sure it isn't some kind of illness.

The other mistake is not to feed your snake enough. That often occurs because if a reptile is kept at the wrong temperature without enough heat, their whole metabolism slows down. They lose their appetite and just go off their food. Slowly, their colours fade, their spine or ribs start showing and they become weak with starvation. Many of them will be dying before they get to a vet.
So how often should you feed your snake? How much? The detailed answers to this question depend on the snake's species. Get a good online care sheet from Evolution Reptiles here or from the RSPCA. Don't just rely on friends or forums  because the quality of advice will vary.
Finally, how do you decide if your snake is fat or thin or just right. Take a look at the very rough sketch below. It shows a cross section of a snake. The triangular shape on the left is a snake that is too thin - you may be able to see an outline of the spine at the top or even its ribs. The snake in the middle is the right size, a sort of dome-like shape with a flat bottom which is where its muscles pull it along the ground. The snake on the right is round all over - and too fat.