Puppies and dogs can become infested with parasitic worms in various ways. They may eat dirt containing worm eggs, eat infected wildlife or swallow infected fleas. Puppies can even get certain types of worms from their mother before they are born. You may notice some symptoms that indicate the presence of worms, but you may also need to take your dog to the veterinarian to confirm your suspicions.
Some types of worms show virtually no symptoms, but roundworms often give puppies a distinctive pot-bellied look. They also impair growth. Although roundworm eggs hatch in the puppy's intestines, their larva are carried up to the lungs through the bloodstream. The Canis Major Dog Owner's Guide says they will crawl up into the windpipe. The puppy will swallow them, which often causes it to cough and gag. For other types of worms, the main symptoms are weight loss and a failure to thrive.
Some types of worms are only visible under a microscope, but others may be seen by the naked eye. Roundworms may be seen in the faeces or vomit of infected puppies and are wormlike in appearance. Tapeworms look like tiny white grains of rice and may be present in the faeces or be stuck around a dog's or puppy's anal area. Hookworms and whipworms are identified by the presence of eggs in the faeces. A veterinarian typically examines a sample under a microscope. The Canis Major Dog Owner's Guide says that whipworm infestations are usually light, so it may take several examinations to make the diagnosis. If an infestation does become heavy, the worms may be visible in the faeces.
Certain types of worms only infect puppies, while others can attack dogs of any age. According to the Canis Major Dog Owner's Guide, roundworms are usually found in puppies, while tapeworms and whipworms can affect both puppies and adult dogs. Hookworms can also affect dogs of any age, but they are not usually harmful in older dogs.