my vet says that my dog must have a heartworm test before taking heartworm medication otherwise it could kill her if she takes it without the test. is this true and if so why?
If your pet is not on heartworm medication all year round then a heartworm test is recommended prior to starting heartworm preventative. If your pet tests positive for heartworm dz the preventative will not treat the dz. Your pet could die from the dz or an emboli could result from dying microfilaria. I agree with your vet. Good luck, vetcare