Hi, I've heard of several reactions to Frontline ranging from what you described to even death. The product is a neurotoxin and I feel there are safer options (esp when you have a neurologically compromised pup like I do). Comfortis is great, more "natural" and protects against fleas. You can do a tick collar to protect against ticks. Personally, I've heard of too many horror stories from Frontline. I hope your little guy improves.