I just got a 9-week old puppy. I am having trouble getting him to eat. Also, the breeder said she treated him with Frontline. However, he still has fleas. What can I give him to eat? He seems very lethargic.

YOu can give him a bath and drown out the fleas. Wet his head first or they will run to the top of his head any type of mild doggy shampoo should work. DO not use a flea wash. Or you can get a finetoothed flea comb and comb him drop the fleas in soapy water and
Drown them. If you bath him make sure to keep him very warm during and after.

Honestly if I were you I would be taking him to the vet for a check up. You need to ask about vaccinations and keeping him safe from being exposed to the parvo virus.

As for the feeding try feeding him the same product the breeder was feeding him or ask the ver for a recommendation. According to what breed he may only need a small amount a few times a day, it may not seem much to you but a lot for a tiny stomach. Also make sure he is drinking plenty of water and having wee's and poo's. He may just need to get used ot his new surrondings.