Yes. Here is what the IRS says in their 2012 Medical and Dental Expenses Publication 502: Guide Dog or Other Service Animal- You can include in medical expenses the costs of buying, training, and maintaining a guide dog or other service animal to assist a visually impaired or hearing-impaired person, or a person with other physical disabilities. This includes any costs, such as food, grooming, and veterinary care, incurred in maintaining the health and vitality of the service animal so that it may perform its duties.

IRS Pub 502 states "You can include in medical expenses the costs of buying, training, and maintaining a guide dog or other service animal to assist a visually impaired or hearing disabled person, or a person with other physical disabilities. In general, this includes any costs, such as food, grooming, and veterinary care, incurred in maintaining the health and vitality of the service animal so that it may perform its duties." Not mentioned, but still qualified, are services for mental disabilities. Caution: This is one that should have extraordinarily good documentation, e.g., doctor's written directive to provide a service animal as mitigation for a medical condition in addition to receipts for maintenance costs.