Dog food is a serious expense, especially if you own a fat dog. So pet owners can be excused for looking for any possible deduction come tax time. But even though our pets perform many important services for us -- chasing squirrels off the lawn, eating the leftovers under the baby's high chair -- few of them qualify as professional service animals. If you do have a medical condition that can be helped by a service animal, though, then all pet expenses above 7.5 percent of your adjusted gross income are deductible [source: Saunders].
Under certain conditions, your pet might qualify as a business expense. Let's say you own a farm and your cats perform a critical service as rat and mouse hunters that protect your stored grain. Or you own a junkyard and your dog is the best alarm system money can buy. In both of those cases, you may be able to deduct at least a portion of your pets' "maintenance" costs as a business expense [source: Saunders].
And then there's the case of the California "cat lady" who successfully wrote off her cat food as a charitable expense. No, she wasn't making charitable contributions to the cats. She argued in tax court that she was taking care of the cats for a non-profit organization that found foster homes for feral animals. Even though the IRS denied the deductions, the tax court judge ruled in her favor [source: Saunders].
The next tax deduction is essential for residents of Florida, Texas and Washington state, but a creative option for all taxpayers.