Some types of worms can be treated with over-the-counter medications, while others only respond to prescription medicines. Over-the-counter treatments are best used when your dog needs a routine worming and isn’t showing signs of trouble. Don’t treat a dog that is ill on your own, especially if he is vomiting, has bloody diarrhea or other indications of a serious problem; always take a dog that is visibly sick to a veterinarian immediately, since he may need more than just worm medicine.
Roundworms are the most common type of worms in dogs. Puppies can become infected with roundworms before they’re ever born. If left untreated, roundworms give puppies a potbellied appearance, rough coats and can even cause them to stop growing. It’s possible to treat roundworms with over-the-counter medicines such as pyrantel pamoate. Dogs need several doses spaced about two weeks apart to kill all the worms, because wormers can only kill the worms living in the dog’s intestines and not the eggs or larvae. Repeated doses kill the new worms as they hatch.
Dogs get tapeworms when they swallow one or more infected fleas. Control of fleas in and around your home helps limit your dog’s exposure to tapeworms, but he can still pick them up at the park, or even from a stray cat crossing the yard. Removing tapeworms is best done with praziquantel or epsiprantel, both of which require a prescription from your veterinarian. In most cases a single dose will kill and remove all of your dog’s tapeworms at once.
A heartworm infestation is a serious problem and can be fatal. It always requires treatment by a veterinarian and may even require your dog to be hospitalized while he undergoes treatment. The medication commonly sold for heartworm is actually preventative. This medicine is only available by prescription because dogs must be tested before you give it to them. The normal dosage is once per month, which kills any heartworm larvae in your dog’s bloodstream before they can develop into adult worms. Some heartworm medicines also contain wormers to kill other common canine parasites.
You dog can get hookworms from swallowing soil contaminated with hookworm eggs or close contact with the larvae, since they can migrate through the skin. Hookworms latch onto the intestinal lining to eat. Their feeding robs your dog of blood and may cause him to bleed internally. These worms can kill your dog if left untreated, especially if your dog is young or not in good health. A veterinarian should always treat puppies with bloody diarrhea or other symptoms of hookworms. Older dogs can be successfully treated with pyrantel pamoate or fenbendazole, both of which are available over-the-counter.