Breeding, Internal Parasites and Deworming

Deworming Pregnant Dogs: Dr. Greer’s Canine Deworming Protocol

Deworming pregnant females and breeding dogs is essential to protect the newborn puppies. But not all canine dewormers are considered safe for pregnancy.

Can You Deworm a Pregnant Dog?

When it comes to worming a pregnant dog, Fenbendazole, such as Panacur Canine Dewormer used according to directions, can stop and prevent parasites from moving through the placentas or through the milk and into the pups. So this means instead of waiting for the puppies to get sick with weight loss, loss of appetite, vomiting, diarrhea, and bellyaches, you can pre-emptively treat them by treating the mother while she is pregnant with the litter.

Deworming a pregnant dog preventively is an alternative that allows you to get ahead of intestinal parasites and have healthier puppies from the start. Instead of waiting to treat, for roundworms and hookworms and starting deworming when the puppies are being weaned, treat mom with Fenbendazole for the last three weeks of her pregnancy through day 14 of lactation daily, that is five straight weeks. Give mom 50 mg/kg of Fenbendazole once every 24 hours. In studies, this protocol has been shown to be safe for pregnancy and has been highly effective in preventing intestinal parasites in the new litter.

When using Fenbendazole, make sure to weigh your female to ensure you are giving the correct dose. Use her pre-pregnant weight because her intestinal tract is still the same size that it was before pregnancy. Just because she’s pregnant doesn’t mean her GI tract got bigger. The day that we ultrasound and give that weight and confirm a pregnancy is the weight that I use as my dewormer dosing, not the extra 20 pounds that she puts on during the pregnancy. So for example, if she weighed 80 pounds pre-pregnancy, you give 20 ccs. If she’s 90 or 100 pounds, when she delivers the litter, you still give 20 ccs of dewormer. For questions, call our Pet Care Pros at 800.786.4751.

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When to Deworm Newborn Puppies

Unless the mother was on fenbendazole during her pregnancy and while nursing, I recommend all puppies be dewormed at two, four, six and eight weeks of age. Pyrantal Pamoate is available non-prescription and is a safe dewormer to use. Starting at eight weeks of age, puppies should start on a monthly prescription heartworm preventative. Prescription heartworm medication not only will prevent heartworm disease but will also help manage intestinal parasites such as roundworms, hookworms, whipworms, and in some cases tapeworms.

Deworming Stud Dogs

Ensuring your male dogs are properly dewormed is also important to prevent him from spreading parasites throughout the kennel and to the females and puppies.

The stud dogs can be on pyrantel pamoate, fenbendazole, and most oral heartworm/intestinal deworming medications other than Trifexis, which is not labeled for breeding dogs. Use these at the label doses for the best efficacy.

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If you have more questions on worming pregnant dogs or deworming newborn puppies, call us at 800.786.4751.

Written by: Marty Greer, DVM

Director of Veterinary Services

Marty Greer, Doctor of Veterinary Medicine, has 40+ years’ experience in veterinary medicine, with special interests in canine reproduction and pediatrics. She received her Doctor of Veterinary Medicine from Iowa State University in 1981. She’s served as Revival’s Director of Veterinary Services since 2019. In 2023, Dr. Greer was named the Westminster Kennel Club Veterinarian of the Year.

If you need help, call us at 800.786.4751.