Dogs live close to the ground and have a continuing fascination with feces. As this is one of the most common ways for worms to be transmitted, it's usually not a question of whether your dog will contract worms, but when and which kind. While some worming treatments are standard for puppies, it still pays to be attentive to any signs of discomfort in your dog and treat worm infestations promptly, especially since some worms can be transmitted to people through contact with dog stools.
The most common types of worms your dog may have include heartworms, which reside--as their name suggests--in the heart and the lungs of a dog and tapeworms, which are parasites attracted and passed through a dog's digestive system. Roundworms, hookworms and whipworms also typically reside in and are passed through the gastrointestinal system and all produce similar symptoms. It's worth noting that while the name "ringworm" suggests that it should be another worm infestation, ringworm is in fact no worm at all but a fungus that produces round hairless areas on your pet's skin.
Symptoms of heartworms include fatigue, listlessness, reduced eagerness for play, and difficulty breathing. If you suspect your dog has heartworm, take it to the vet immediately. Dogs with other types of worm infestations, including tapeworms and roundworms, may not exhibit any symptoms at all, or they may pass live worms in their stool, vomit worms, show irritation or blockage in their anal glands, or show gastrointestinal symptoms including an inability to digest food, weight loss, flatulence, bloating and loss of appetite.
The vast majority of worms your dog may contract, including tapeworms, hookworms and whipworm are passed through dogs either eating feces or walking through feces and then licking their paws. Roundworm infestations typically develop when the dog ingests roundworm eggs or may result in puppies when the mother was infected during gestation. Tapeworms may also be contracted when dogs eat tapeworm-infested fleas and heartworms may be contracted from mosquitoes.
Early detection is key for treating worm infestations. Be on the lookout for worms passed in your dog's stool--they may look like spaghetti and may or may not be alive and moving--and inspect its rectal area regularly for signs of tapeworm segments, which typically look like grains of white rice and may or may not be moving. Stay alert to other problems and if you're suspicious that your dog may have contracted worms, have a veterinary evaluation immediately.
Many vets recommend regular deworming treatments as a precautionary measure, whether or not your dog shows symptoms of worms. This is especially common in areas where parasites are very common. Keeping your yard and the dog's run free of feces and not letting your dog eat another dog's feces will help reduce the occurrence of worms in your dog. Using anti-flea treatments and installing netting in your dog's run to protect him from mosquitoes will also help to reduce contact with parasites that may in turn transmit worms to your dog.