I fostered a dog through heart worm treatment.

I fostered a dog that had heart worms and rescued them from the shelter. We housed and fed the dog and took care of basic needs. The rescue we were helping to find a home for the dog paid for the medications, but we had to pay for food and the vet bills for check-ups. Can I deduct those costs under a charity or what is the appropriate way, if any, to do this?