Is he yours? You can very easily help him yourself and it will cost you less than $10.
If you have a Tractor Supply near you, you can purchase a tube of 1.87% ivermectin in the horse worming section. If you go to:
http://www.tractorsupply.com/webapp/...erm=ivermectin
Items 1, 2, 5, 6 and 8 are all exactly the same product and all would work. There are a bunch of companies that make this - all you want is the 1.87% ivermectin with no other meds added to it. They will usually all be called "something or other"mectrin.
If this is something you would like to do I will tell you how to administer it. It is very easy but you need to follow directions. Pick up some pecan halves, too. They will be your carrier. Happily, they make this paste to appeal to horses so it is usually apple flavored, which makes it more appealing to squirrels too.
The other thing you will need to be able to do is deliver a dosed nut to one individual squirrel. You cannot just put a pile of them out - the stuff can be overdosed easily and a single squirrel pigging down several dosed nuts would be in trouble.