Answer:
Melarsomine.
Explanation:
The dog heartworm is the parasitic worm that causes dirofilariasis in dogs. This infection can spread from one host to the other host by the mosquito biting.
Melarsomine is the drug used to kill these heartworm. This drug is applicable in case of early infections only. The late infectious stage are resistant to this drug and cause harmful side effects in cats and dogs.
Thus, the answer is melarsomine.
