Metabolic Bone Disease
Last Updated on Monday, 13 July 2009 02:43
Metabolic Bone Disease
A good review article is "Metabolic Bone Disease"
by Nonda Surratt, Cedar Hill Wildlife Care:
(Some of Nonda's articles are not specifically for flying squirrels, but tree squirrels in general, and may not be totally correct for flyers)
MBD vs. "Freezing"
(Do not get freezing confused with seizures that can occur with MBD. They could be difficult to tell apart)
Trying to move, but unable
Stays in nest most of the time
Unable to hold a nut without dropping it
Unable to pull his nails free from your clothing
(When flyers begin to suffer from calcium deficiency, they have difficulty pulling their claws off knit fabric. You'll notice they have to jerk their hind legs free from your clothing. Then, they become progressively weak, often in the hind quarters first, then systemically.)
Do not mistake claws that need to be trimmed for MBD.
Vit D toxicity mimics MBD and in truth is just another form of it! Vitamin D is fat soluable and is stored in the body fat. If there is an excess amount of Vitamin D, it causes decalcification or loss of calcium in the body. Decalcification causes the same symptoms and health problems as calcium deficiency or Vitamin D deficiency.
Some of the more subtle signs of MBD are excessive sleeping, not wanting to move around or jump and climb. MBD hurts! The bones (being effected the most), and muscles become weak and the animal is in pain. Swollen joints and improper bone growth (legs splaying in or out) are also sign of MBD's progression. In more drastic cases there are seizures and lack of use of the back legs. Because MBD is the thinning of the bone, a fall that would not normally have any effect can cause a leg or the spine to fracture or break.
Watch how they move and observe their abilities:
Can they hang upside down without discomfort?
Are they using the full extension of their legs and body, (in other words moving *freely*)?
It is important for you to know what *normal* is so that you can identify the possible onset of MBD in the early stages.
"Freezing" in place is a defensive mechanism for small rodents. Cats and other predators rely upon the movement of a small rodent to be able to tell where they are, and grab them. Freezing behavior is instinctive, and will be done even when there is no predator around. Once the flyer is in a sort of "trance," they can often be handled, and turned over, and they just seem like they are little toys, inanimate objects. Sometimes they'll remain in that catatonic state for quite a while.
Flyers and Sunlight
Just about everything in nature depends on light for survival. Animals live in full spectrum light- sunlight. Since flyers are nocturnal, they do not get adequate sunlight.
When animals do not receive enough light, they are unable to manufacture enough vitamin D. Vitamin D (the sunshine vitamin) is fat-soluble and functions to regulate the ratio of calcium and phosphorus. Under normal circumstances the body produces its own vitamin D (needing sunlight to do so), vitamin D is vital to the body's ability to absorb calcium. Researchers have not determined the exact amount of direct sunlight that animals in captivity require daily. However, they have agreed that the minimum amount of sunlight daily is 30 minutes to sustain normal body functions and to thrive.
Glass filters out the majority of ultra violent light. So it is not enough to position a cage close to a window to soak up sunlight.
One of the most common symptom of light deprivation in squirrels is Metabolic Bone Disease (MBD). The bones do not have enough available minerals to grow properly. They simply fail to grow normally. Fractures and failure to heal properly have been found. MBD can get started in as little as 5 days. More subtle signs of MBD are excessive sleeping, not wanting to move around or jump or climb. MBD hurts! The bones and muscles become so weak and the animal is in pain. Swollen joints and improper bone growth are also a sign. Because MBD causes thinning and weaking of the bone, a fall that would not normally have any effect can cause a leg or the spine to fracture or break.
When adding vitamin D to the diet, remember to look for D-3.
(There is no actual evidence that flyers need sunlight to survive. Flyers in rehab have been seen "sunning" themself on occassion. But, are they doing it for the warmth or the Vitamin D? No one knows. Nocturnal animals, including flyers, have evolved to use Vitamin D2 found in plant matter; so Vitamin D3 may or may not be needed and just how much is not known.)
Vitamin D: The Sunshine Vitamin
Vitamin D helps prevent rickets. Either a deficiency or an excess of this vitamin can seriously damage the bones. There are several forms of vitamin D. One form, calciferol, or vitamin D-2, is produced in plants. It is produced from a sterol, a type of chemical compound, when a plant is exposed to ultraviolet light.
Another form, cholecalciferol, or vitamin D-3, occurs in the tissues of animals, including human beings. It has been called the "sunshine vitamin" because it forms in the skin when the body is exposed to sunlight. Fish-liver oils contain much vitamin D-3.
Vitamin D3 is necessary for the utilization of Calcium and Phosphorus, and for the assimilation of Vitamin A. It also has a strong immune enhancing effect. Vitamin D2 does this also.
Vitamin supplements are they really needed
In this day and age when we humans are often taking many different types of vitamin supplements, we do want to stay healthy. We often transfer this to our animals, we want them healthy as well. One slight problem, they are not human. We humans as a collective group often eat on the run, eat not the best foods and it is known that many of us do not get our RDA (daily values) of many important vitamins and minerals. Here is the other problem ... they KNOW how much we humans should have, they know how much most 'common' domestic animals should have, they really don't know how much wilds should have.
Some things they do know, calcium/phosphorus, optimal is 2:1, they also know that this is not on a daily basis but balanced over time. In other words over the course of weeks depending on the foods eaten the over all Ca/p will come in at 2:1 or 1:1. They know that animals (mammals) need D3 to properly synthesize calcium, do they need it everyday, probably not but 5-10 minutes of UVB does the job. Window glass filters out UVA/UVB light and sunlight coming through it does nothing to help prevent MBD. Reptiles are a completely different ball game.
How mammals deal with sun overload, they don't know. They do know that in the wild they (the mammals) do a right fine job of getting the amount of sun they need when they need it. They also know that certain food items will block calcium absorption, as well as excessive amounts of certain minerals such as manganese.
Most if not all of the good commercial foods for animals on the market today had a pretty standard about of the vitamins, minerals, etc., to keep an animal healthy Certain vitamins like D are fat soluble and can build up, become toxic and cause death. The interesting this is Vit D toxicity mimics MBD and in truth is just another form of it!
So again keeping things simple is the way to go. Good UVB lights, not all all-spectrum bulbs have usable UVB, by a cage will allow the animal got get the extra boost if they need it and naturally. If one just has to give a supplement once a week, MAYBE twice is plenty and the amount should be infinitesimal.
Some things we do know ... while vitamin D2 is not as good as D3, nocturnal animals have adapted to D2. D2 is found in plants etc. Flyers while nocturnal have been seen outside the nest on sunny days 'sunning.' Often normal behavior patterns (holing up when it is cold outside, doesn't make one bit of difference when they are in our homes, they know) and a change in activity levels and time of activity (winter) many times spooks us into thinking there is a health issue when it is just natural instinctive behavior.
With vitamins, more of a good thing may not be better. Too much D3 can cause calcium reabsorption which is the opposite effect as what it is given for. If you are feeding a good varied diet and the squirrels are eating it, a vitamin supplement isn't as important.
Greens like kale, broccoli, and romaine lettuce have calcium and D2 in them. Vitamin D2 is what nocturnal animals have adapted to making use of since they are not in the sunlight much to get D3.
No one knows what the vitamin needs for flyers might actually be. They do not need much in the way of vitamin supplements. Keep the amounts very small or to only give them once or twice per week.
Vitamin D Toxicity
Vitamin D toxicity also causes MBD and the symptoms are exactly the same as not enough. The rub is it is not known exactly what wilds do with, or, how they synthesize D3 when they are exposed 'naturally' to too much UVB/UVA. They don't know how much wildlife needs period, which is why when using UVB light the animal must have a way of getting out of the light if they want to. We do know that 10-20 minutes day of natural sun will do the job adequately for captive animals.
The normal photo period for diurnal animals is how ever long the sun is up. It is also known the nocturnal animals have morphed to being able to use D2. Flying squirrels in the wild have been observed to come out and 'sun' themselves on occasion, possible utilization of both D3 and D2. We have observed that here in the rehab flyers, once in outside caging.
Vitamin D should only be supplemented with extreme caution, too much causes bone reabsorption, calcification of soft tissues, including the urinary, circulatory, and respiratory systems. It is not unusual for people to think the animal is not getting enough when the truth is they are getting too much.
Free ranging wildlife do not store D3 in the body since it is converted from sun to became D3. Supplemented D3 is fat soluble so it is stored. MBD is MBD no matter how you slice it, be it not enough or too much D2 or D3.
The best reptile light going right now (independently tested for usable UVB) is the ZooMed Reptilite 5.0. Now remember these are for reptiles that need tons of UVB. These can be used with mammals but I would limit exposure time. I personally use Ott Lights, they are not as high rated for UVB but Grumps eats well, his monkey chow has D3 in it, and the lights are on all day on each end of his cage. He can sun himself or not. Remember 5-10 minutes a day is really all that a mammal needs of 'good' UVB. IF they are getting that from natural sun OR high rated lamps, you do NOT want to also be supplementing with D3.
So not all lights are equal and since UVB can be harmful to humans in excess (skin cancer), many lights have UVB shields. Or they say they are UVB rated and really have so little useable UVB as to be worthless.
So we are back again to foods the animals eat, do they already have D3 in them? If so, then the lighting is a nice bonus, or if there isn't D3 in what the animal is eating the lighting can take care of all their need for it and you can chuck the supplement, highly advisable. The more natural these things can be provided the less likely you are going to inadvertently cause problems.
Calcium ... to supplement or not and the best ways and type of calcium to use. The biggy is how much elemental calcium is actually in the calcium supplement. Calcium carbonate by far as the most elemental calcium (40%) and calcium carbonate is the one used by animals in the wild, egg shells, bones, deer antlers etc. Other products such as the popular Neo-calglucon (calcium glubionate) is only 6.5% elemental calcium. Obviously the best way to provide calcium, besides a good diet it to provide natural calcium sources as mentioned above, cuttlebone is also good.
Often one of the first things I hear is "I have put all that stuff in and the squirrel hasn't touched it," this is to be expected. The squirrel is not going to gnaw on the bone, antler, etc., everyday they don't in the wild either. It is on an as needed basis. Sometimes it does become necessary to make sure they are getting calcium on a regular schedule, shaving off a but of cuttlebone or adding a pinch of powdered calcium carbonate to a nut half or apple piece a couple time a week does the trick. This is usually not necessary and I personally have only had to do that on a couple occasions. If the squirrel is showing symptoms of MBD then they will need calcium everyday, HOWEVER, the main diet, which was most likely the cause of the MBD in the first place, has to be corrected. Adding calcium is not the end all to end all. Can a squirrel get too much calcium? Sure when we are the ones controlling it. The old 'gee' if this much is good more will be better is not how it works.
The whole gist of the matter is, start out with a good diet, provide natural calcium sources they can access when they feel the need, and you will be a happy human with a healthy happy squirrel. This isn't rocket science and the good old adage keep it simple is always the way to go.))
(Neither Dennis nor Beverly are veterarians, but have years of experience with flyers.These methods are recommended from their experiences . It can be easy to overdose with vitamins by direct dosing unless you are VERY knowledgable about what you are doing. Direct dosing of pure Vit D should be attempted only under the direct supervision of a veternarian.)
Dennis Quinter Method
(Dennis is a rehabber/hobby breeder with over 30 years experience: http://www.voy.com/55490/)
There are three main causes for Metabolic Bone Disease. Lack of calcium, lack of Vitamin D, and too much Vitamin D. Too much Vitamin D can cause calcium reabsorption. Also, a high phosphorous diet may interfere with calcium absorption. If you think it is lack of calcium, take the calcium block and scrape it to get some powder to put on some food. Small amounts are enough, flyers are very small.
In size comparison to humans, it would take about 1/800th of a calcium tablet made for humans to supply plenty for a flyer. If you think it is a lack of Vitamin D, you can boost that with a supplement for a short time to get things straightened out.
As a regular part of the diet, you might include some Dannon yogurt which is high in calcium. Dark green veggies like broccoli, is a good source for calcium. Flyers being nocturnal have evolved to use Vitamin D2 from plant material instead of Vitamin D3 from
the sun. So fresh greens are a source for calcium
(IF the problem the flyer is having is related to calcium deficiency or lack of Vitamin D3, this should help the situation. It may take at least a week to see any improvement.)
1. Buy a calcium block or powdered Pet-cal and some LM vitamins
that are made for small mammals.
2. Take a knife and scrape the calcium block to get about 1/16
teaspoon of powder. Mix that in some peanut butter or some
applesauce that you know the flyer will eat.
3. Repeat this 3 times in a week.
4. Add the vitamins to fresh water three times a week. (Use the
vitamin dosage as listed on the bottle for hamsters and gerbils).
5. Put a calcium block in the cage.
6. After a week of this, give the flyer Dannon yogurt twice a week
and add the vitamins to the fresh water twice a week.
7. Try to get the flyer to eat broccoli and other dark green veggies
several times per week.
Beverly Lawrence-Sutton Method
(Beverly: http://www.voy.com/81231/ has had only one flyer herself with MBD symptoms, but she does know of two other flyers with MDB symptoms which responded well to her treatment protocal, recovering fully.)
I've used Curt Howard's recommended dirct dose treatment with success. If a flyer shows what appear to be MBD symptoms, but that flyer has been getting a supplement of a daily multivitamin all along, I would not do a direct dosing. I only suggest using such when dealing with a flyer that was NOT getting a daily multivitamin supplement.
Dose the flyer with a liquid multi vitamin that has a generous amount of Vitamin D3 in its formula. I used L&M Animal Farms Daily Liquid Vitamins.
Use a small dropper, hold the flyer in one hand, and place 3 drops of the liquid vitamins directly on the flyer's lips (I put it right where the cleft in the upper lip meets the lower lip), so that the flyer pretty much has to suck the droplet in. Do this 3 times a day, 6a.m., 2 p.m. and 10 p.m., for 10 days.
Keep the flyer in a quiet place, bedded in a nest box with 100% cotton balls, and have water (enhanced with the normal dose off vitamins, which is one drop of vitamins per ounce of water), easily available to the flyer, and a dish of favourite foods handy, too.
I found that by the 5th day, I was seeing some improvement in my flyer, and by the 7th day, he seemed pretty much better. By the 8th day, it was actually hard to catch him, to finish the final two days, and he was feeling well enough to give me a good hard bite! It was the happiest bite I ever got! :~}
Two others that I know who had a flyer with symptoms of a calcium deficiency used this method with success, too. Of course, just 3 people reporting success does not mean this method is always successful, but it did seem to be the best course of action, for the "classic" deficency symptoms.
|< Prev||Next >|