What are signs of heartworms in dogs?

i think the stomach rumbles when you put your hand on it.

No. Heartworm comes from mosquito bites; I am not exactly sure how right now but it is not contagious. To prevent your dog from getting heartworm you can go to the vet. They will prescribe some...

if dogs cough do they have heartwarms

In American Sign Language you pat your thigh and then snap. Some people just snap though, but if you just snap you should put your lips in the shape of the "o" in dog.

Dogs most commonly get heartworms when they eat their own feces, or excrement.