Q&A with a Vet: Parasites in Dogs

Are your dogs protected against dangerous parasites? Learn more, in this Q&A with Tony Hawkins, DVM, Valley Vet Supply Technical Service Veterinarian.

What are intestinal parasites in dogs?

“Hookworms in dogs and roundworms in dogs are very common throughout the United States. Dogs are infected most often with these parasites by ingesting larvae from the environment, eating other infected animals or becoming infected as a puppy from their dam. Both hookworms and roundworms live in the small intestine and feed on blood, and hookworms especially are voracious blood suckers.

Both of these parasites have unique life cycles in that the parasite larvae, after they are consumed, will migrate through other tissues in the body -- lungs, liver and muscles -- potentially causing disease in those organs. Adult dogs can certainly become sick from these parasites, but puppies are at high risk for serious disease from severe anemia or respiratory disease due to parasite migration. Another important reason to control these parasites is due to the zoonotic risk they pose to humans. Hookworms and roundworms can infect people and migrate through different areas of the body. The disease is dependent on the location of the larval migration but can vary from itchy, serpentine lesions on the skin to severe abdominal pain, damage to the liver or lungs, retinal damage or neurological disease. The best dewormer for dogs to treat and control these parasites include the active ingredients fenbendazole, milbemycin oxime, moxidectin or pyrantel.

Tapeworms in dogs occur by consuming fleas during self-grooming or by eating other infected animals. Despite the fact that tapeworms in dogs can grow to over 2 feet in length within the small intestine, significant disease in dogs due to tapeworm infection is considered rare. However, infected dogs pass many tapeworm segments, and it can be disturbing to see these wriggly proglottids in the hair of the perianal region. As for tapeworm medicine for dogs, Praziquantel is the best active ingredient and medication to treat and control tapeworms.

Whipworms in dogs are contracted by ingesting eggs from the environment, not by eating other animals. Some infections are asymptomatic, but many infections can be dangerous with bloody diarrhea, anemia, severe dehydration and death. If your dog has been infected in the past, it is likely there are whipworms present in the environment, so there is a high risk for reinfection. Thus, your dog should be given medication to control whipworms at least four times a year but ideally once a month. The medications to treat and control whipworms include the active ingredients febantel, fenbendazole, milbemycin oxime and moxidectin.”

What are heartworms in dogs?

“Heartworms in dogs are at the top of the list of dangerous and deadly parasites that can infect our canine friends. Heart worm occurs all across the United States, posing great risk to those not on heartworm medicine for dogs. Surveys indicate that heartworm infections continue to increase throughout the United States in number and geographic distribution, so infections are becoming common even in historically low prevalence areas.

Heartworms in dogs are transmitted by mosquitoes. Infected pets, stray dogs, and wildlife such as foxes, coyotes and wolves serve as an infection reservoir. Microclimates and variations in weather patterns can support mosquito populations year-round. After a dog is infected with heartworms, it takes six months for these parasites to develop into 12-inch-long worms that live in the heart and lungs for five to seven years.

Heartworms cause severe lung disease, congestive heart failure and damage to other organs in the body -- all of which can be deadly. Even if the heartworms are treated, the damage is permanent and will affect the dog’s health and quality of life for the remainder of your pet’s years. It is important to maintain your dog on heartworm prevention year-round and have your pet tested annually for heartworms. The medications used to prevent heartworm infection include the active ingredients ivermectin, milbemycin oxime, moxidectin and selamectin. There are several trusted dog heartworm meds; you will need to work with your veterinarian because heartworm medication requires a prescription.”

Why is external parasite, flea and tick prevention, so important?

“Fleas and ticks may not be your first thought on the topic of deworming, but these parasites can transmit dangerous diseases to both you and your pets. Ticks transmit serious diseases, such as Rocky Mountain Spotted Fever, Ehrlichia, Lyme disease and Anaplasmosis among others. These illnesses can be difficult to diagnose and dangerous if not treated early; therefore, prevention through tick control is best. Fleas can also transmit several bacterial diseases and tapeworms in addition to causing a severe allergic reaction. Many wild animals carry fleas and serve as a source of infection. When a pet becomes infected with fleas, or an infected, wild animal ventures onto the premises, fleas can rapidly infest the environment.

Year-round administration of flea and tick prevention for dogs is the best way to control fleas and treat, and prevent environmental infestation. There are many options for flea and tick medicine for dogs. Make sure to read the label or consult your veterinarian to pick an appropriate product.”

Seresto collars, Frontline Plus and K9 Advantix II are favorites among customers.

Closing Recommendations

“It is best to maintain every dog on year-round broad spectrum parasite control for heartworms, fleas and ticks, and intestinal parasites. If year-round administration of preventatives cannot be maintained, you should treat your dog four times a year for intestinal parasites. In either case, you should also work with your veterinarian to perform an annual heartworm and tick-borne disease test.

You will notice that many of the medications used for parasites in dogs are the same ones used in horses and cattle. You may be tempted to use livestock dewormers in your dogs, but please don’t do this as these highly concentrated livestock dewormers can cause dangerous overdoses in dogs. It is important to use products labeled for use in dogs and to consult with your local veterinarian for help in choosing the best medications for your area. As they say, an ounce of prevention is worth a pound of cure and will help ensure your dog has many more years to be your helper, protector and friend.”

Keep Dr. Hawkins advice in mind to keep your dogs healthy. Shop ValleyVet.com to offer them the protection they deserve.