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Should I Deworm My Pregnant Dog?

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Deworm a Pregnant Dog

As a breeder you may wonder if deworming your pregnant dog is something that is really necessary. It could be you are trying to save money or you are concerned about giving medications to your dog while she is pregnant and wondering if they can harm her puppies. There are actually many good reasons why you should deworm your pregnant dog which is why veterinarians recommend this practice. Following are several reasons why deworming pregnant dogs is important.

A Great Investment


Deworming your pregnant dog is ultimately an investment. When a dog is infested with worms, you are basically not only feeding your dog, but also feeding the worms!

Think about it, those bags of food are, yes, eaten by your dog, but once that food makes it to her digestive tract, it's consumed as well from those pesky parasites, because that's what parasites ultimately do!

Just look at the term "parasite." Dictionaries define parasites as "an organism that has sustained contact with another organism to the detriment of the host organism." In this case, the host is your dog and the parasite is living off of her.

Pregnant dogs who are hosting large populations of parasites are therefore being deprived from nutrients, right when they need them the most, during pregnancy! And all of this happens regardless of how good the food they consume is and how much they are being fed.

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Did you know? Parasites may remain dormant in the dog, but then may reactivate because of the stress of pregnancy. This is known as reactivation or recrudescence, explains Margaret Root Kustritz, a veterinarian specializing in animal reproduction in the book "The Dog Breeder's Guide to Successful Breeding and Health Management."


Passing the Hot Potato

Pregnant dogs should be checked for parasites and dewormed accordingly. Failure to do so, likely results in a litter of parasite stricken puppies. However, even though mother dogs may have tested negative to parasites through a fecal flotation test, her pups can still be infested by worms. How? Roundworm eggs not always show in feces and larvae may hide in cysts, so they can then migrate to her fetuses comfortably residing in their livers or lungs until birth. Afterward, they migrate to the pup's intestinal tracts where they get to mature and produce eggs. Puppies may also be infected when passing through the birth canal or shortly after birth, from nursing on the mother's milk.

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When working for the vet, I used to call clients often to let them know the results of fecal tests. Initially we said that the "sample tested negative for parasites" but then the vets thought that this statement was a bit misleading considering that dogs may still have worms even if their fecal tests were negative. It was therefore later decided that it was best to say "no actual parasites were found in the sample" to prevent misunderstandings.

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A Word About Safety

Is it safe to deworm a pregnant dog? This is an important question. We often know how certain medications are not safe to give to pregnant dogs, so it makes sense to be concerned about giving medications against parasites. Yet, most vets seem to agree that it's safe to deworm a dog during pregnancy. According to veterinarian Dr. Lucy, it is safe to deworm a pregnant dog, as long as certain guidelines are followed as not all dewormers are created equal. She recommends using over the counter fenbendazole (Panacur) a safe dewormer against roundworms, hookworms, whipworms and giardia. This may not stop the puppies from getting worms, but at least It may decrease the amount.

"Panacur® C is safe for use in puppies 6 weeks or older and adult dogs, including pregnant bitches. Do not deworm a dog or puppy that is sick. Consult your veterinarian for diagnosis of the illness."~Merck Animal Health

When to Worm a Pregnant Dog?

Ideally, perspective mother dogs should be de-wormed prior to mating, but many times dogs get pregnant by accident and therefore this was not possible. So if a dog is already pregnant, when should a dewormer be given to a pregnant dog? According to Dr. Kustritz, pregnant dogs should be de-wormed in the last two to three weeks of pregnancy using a safe de-wormer. Panacur (fendenbendazole) is often a common choice. Dog owners should always consult with their vet for more precise guidelines on when to worm a pregnant dog, the proper dosage and which worming products to use, based on the dog's medical history.


The Dog Breeder's Guide to Successful Breeding and Health Management, by Margaret Root Kustritz, Saunders; 1 edition (December 22, 2005)

Photo Credits:

Flickr, Creative Commons, Dennis Hill, fp062407-14, CCBY2.0

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