My puppy was lethargic and vomiting last Friday and I rushed to him to the ER. He was tested positive for Parvovirus. My veterinarian gave him Tamiflu and it helped. Tamiflu takes the symptoms of septitis away, if caught in the beginning stages. You should ask your vet about it and tell him to go to
Veterinary Information Network (VIN) - For Veterinarians, By Veterinarians to read more about it.