Hello everyone. I'm a member of The Squirrel Board and am "owned" by an Eastern Grey named Henry. I'm the person who developed Henry's Healthy Blocks. I see there has already been some discussion about these blocks, so I wanted to provide some more info about them. Although they were developed for tree squirrels such as greys and foxers, many flyer owners have expressed interest in the blocks. I am very interested in sharing information here, and finding out what is known about the special dietary needs of flyers, so that a flyer-specific formulation could possibly be developed.
First, some facts about the blocks:
1. Since there is no specific research on the dietary requirements of squirrels, the blocks were formulated according to the nutrient requirements of laboratory rats, their closest relative for which this research exists. (Nutrient Requirements of Laboratory Animals, Fourth Revised Edition, 1995. Chapter 2, “Nutrient Requirements of the Laboratory Rat.” National Research Council. National Academy Press: Washington, DC.) The initial formulation was complete for all essential nutrients--fat, protein (including the full spectrum of amino acids), Vits A, D, E, and the B vitamins, and calcium and phosphorus, as well as containing significant amounts of many other nutrients. The formulation is currently being revised so that it is complete for all 41 nutrients listed in the "Nutrient Requirements."
2. The blocks are nut-based (pecans, walnuts, peanuts), and also contain pure whey protein isolate, eggs, nonfat plain yogurt, baking powder, and salt, along with the vitamin/mineral mix. They contain no corn, grains, starches, soy, preservatives, sweeteners, animal by-products, nitrosamines, or fish meal. Every ingredient is "food grade"; in other words, fit for human consumption. There are no "feed grade" ingredients, which are normally used in all pet foods. The Ca:P ratio is balanced 2:1. They have a glycemic load of close to zero, to avoid overweight and diabetes.
3. The blocks were designed to be fed along with a variety of healthy vegetables, natural foods from outside, and limited treats and fruit.
4. The reason the blocks were developed was because most squirrels won't eat commercial rodent blocks, and squirrel owners constantly struggled to get their squirrels to eat enough calcium, protein, and other nutrients. And MBD was all too common. Dusting things with calcium, vitamin drops in water, etc., were some of the strategies used, but of course one could never be sure how much the squirrel was getting....too much? not enough? I've written a short article describing our efforts on TSB to develop a "Healthy Diet" for pet squirrels. It describes the theory behind the blocks pretty well. I don't see any way of attaching a PDF here, but if anyone would like a copy, I'd be happy to e-mail you one.
After developing the initial formulation, I decided to bring in some expert help. I'm not a nutritionist, and I just didn't feel comfortable otherwise. I decided to start right at the top, and contacted two of the authors of the "Nutrient Requirements." Fortunately one of them, Dr. Calvert, responded and was enormously helpful. I e-mailed him the formulation, including the complete nutrient breakdown in a spreadsheet. We corresponded via e-mail for several weeks and had several long phone conversations. It was wonderful to be able to ask a true expert some of the many questions that had been bugging me for so long. Dr. Calvert contacted several colleagues in the field, including a top person at Mazuri, a leading zoo diet expert, and someone he described as probably the top animal nutritionist in the world. He actually got these people together for a meeting where they discussed the squirrel block formulation, and squirrel diet in general. It seemed to be an interesting little side project for them. But needless to say, we were all thrilled and grateful.
In the end, the squirrel block recipe was "approved" with only one small suggestion--the addition of some wheat bran to the recipe to aid in hind-gut fermentation. (This was later dropped, as the squirrels didn't seem to like the wheat bran, and we felt they got plenty of fiber in the rest of their diet.) Overall, they were very impressed with the formulation, especially the high-quality protein (Now brand 100% pure whey protein isolate), and the low glycemic load.
So that's where the squirrel blocks came from.
Here are a few things I learned while developing the blocks:
The nutrient requirements of rodents are quite high considering their body size. For example, a 1-pound squirrel needs around 357 mgs of calcium per day; a 100-pound human requires around 1,000 mgs per day (slightly higher for people over 50). Once I began analyzing the nutrients in various foods, I was stunned to discover that a squirrel would need to eat 9 entire heads of endive lettuce (very high-calcium veggie) per week to meet his calcium requirement.
I knew squirrels had high calcium requirements, but was surprised at how much high-quality protein they need. Doubtless in the wild they eat a lot of bugs, grubs, bird eggs, and even nestlings and carrion. But most pet squirrels turn their noses up at chicken eggs. A few would eat mealworms, but not enough of them. The lack of protein in the kitchen-based diet we were feeding manifested mainly in fur problems (thin fur, dull fur, missing fur, incomplete shedding and molting) but also contributes to problems with calcium absorption. Protein is even more difficult to supplement than calcium.
Captive or pet squirrels have special problems. They are far less active than wild animals, so they eat less, which means they take in less nutrients. So even if you could go outside and gather the exact same wild foods the wild squirrels were eating every day, a pet squirrel couldn't eat enough of them to meet his nutrient requirements. Or if he did, he would be obese. This is why pet squirrels need a concentrated form of food such as rodent block.
Diabetes. Three squirrels owned by members of TSB were diagnosed with diabetes in one year. None had any symptoms whatsoever; one was a young apparently healthy squirrel who was diagnosed during a routine exam; two were older and were diagnosed when their kidneys failed. It was too late for those two; the other squirrel was immediately placed on a low-glycemic load diet and is doing well so far, 9 months later. We can't be sure of the cause of diabetes in rodents, but Dr. Calvert did warn me about giving our squirrels too much fruit because of the high glycemic load; fructose in rodents apparently leads to fatty liver, obesity, and diabetes. In fact, he recommended feeding no fruit at all.
One last thing: I developed the blocks because I was concerned about my Henry getting proper nutrition, and tired of the daily struggle and worry. I provided the recipe to all (still do) and never dreamed of selling the blocks. But once it turned out that the squirrels were loving them, and we were seeing the results in their fur and overall health, people started asking me to make and sell them. So it is now a small business for me. It's one I feel very good about, since I believe I'm helping provide pet squirrels with better nutrition and preventing MBD.
Sorry for the long post. And please ask all the questions you want.