My dog diagnosed with attention deficit disorder. Should i get him treated or ignore the diagnosis?

my dog always had very poor attention span and was very easily distracted. His concentration levels were extremely low and I encountered some difficulty in training him. It required lots of repetitions several times. Frustrated at the failure of dog to learn basic commands, i hired a dog behaviorist who then said he should see dog psychiatrist. So then I took him to dog psychiatrist who diagnosed him with ADD. Treatment consists of mixing some pills in his food. And behavioral therapy, every week. Expected cost of treatment is about $800 or so. I already paid over $500 for multiple visits to dog behaviorist. I don't feel I can afford anymore. If I just ignore attention deficit of dog, would I be uncaring pet owner?