I buy my medications from my veterinarian, whenever possible. Years ago, my little girl (she's at the Rainbow Bridge now) had dementia, and she needed medication for it. It is the same medication given for Parkinson's disease. There was a national shortage on it, so my vet couldn't get it. I was very happy with Dr. Foster's and Smith, and I was so thrilled to be able to get the medication from them. I was at the vet today with Katie, and there was a sign about being careful about where you get pet medicine. He recommended Dr. Foster's and Smith and Chewy,com.
Heartworm medication is guaranteed by the company if given properly. Taylor (Loves to Dream) is correct in what she said. It is only guaranteed if bought from a veterinarian. Dr. Foster's and Smith have their own guarantee, however. I honestly don't know how you would prove continuous usage.
This is what is posted on their website:
"Heartworm Preventives - In order for this guarantee to be effective, the client or their veterinarian must contact the Doctors Foster and Smith Pet Pharmacy at 1-800-447-3021 prior to beginning any treatment. Proof of a negative heartworm test within the 6 months prior to the pet being started on product purchased from our pharmacy will be required, as well as a positive heartworm antigen test, confirmed by an outside laboratory. We will also require verification of continuous use of the heartworm preventive on a monthly basis, with the last dose being taken within 31 days prior to the diagnosis, as well as proof of annual heartworm testing. We have found the average cost of heartworm treatment to be about $800.00. Doctors Foster and Smith will reimburse the client for diagnostic work-up and treatment, up to and including $1500 per animal.*"
Drs. Foster & Smith Pharmacy guarantees all of the prescription heartworm preventives they sell