Need to go to a veterinarian
They do have an animal clinic at affordable prices; otherwise, they can refer you to one of their partner animal hospitals.
You can make an appt with one of their vets and they will check them and give you the medicines needed at a discounted price, less than a regular vet. Explain your situation to them. Believe me, they do want to help and you definitely dont want your dogs to get heartworm. The treatment for heartworm, if they get it, is heartbreaking
I think you have to call a vet for that.
Call them and ask
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