How Do Dogs Get Worms From Each Other?

In Utero

There are several ways for dogs to get worms from each other. Hookworms, so-called because they feed by hooking onto the walls of the dog's intestines, and roundworms, which use three big lips surrounding their mouths to feed on partially digested food in the dogs' intestines, are passed from dog to dog in utero. The mother passes the worm eggs to her puppies through the umbilical cord.

Ingesting Feces

Another way dogs become infected is by eating another dog's feces, which are laced with worm eggs. The types of worms that are transmitted via this method are roundworms, hookworms and whipworms.

Via Insects

Lastly, dogs pass on worm eggs via insects. Heartworm is passed from dog to dog via a mosquito. Mosquitoes become infected with heartworm by biting an infected dog. It then passes on the heartworm eggs to the next dog it bites. Similarly, tapeworms are passed through fleas. Tapeworms are passed when a flea with tapeworm eggs jumps from an infected dog to another dog and the subsequent dog eats the flea.