There is no medical condition associated and we see this quite frequently in our office. It is almost as though there is a strange fascination that they have. It is possible that there may be an inherent sense of preservation to hide all evidence of their being there as a form of self preservation from any potential predator.
Nails are really just a poorly digestable form of protein so it cannot harm them. I can give another example of this in the veterinary office situation: sometimes when cleaning a dogís smelly ear, there is a strange fascination for the dog to actually sniff and lick or even try and eat the cotton balls that have just recently been used to clean their ears in the first place.
Thatís my 2 cents worth.
Martin Slome DVM
Centre Street Animal Hospital
7700 Bathurst Street Units 40-42
Tel. (905) 771-9855