Dog Friendly Tips: Roundworms
If a pregnant dog has intestinal parasites and encysted larvae in her tissues, the pups will be born with microscopically small roundworm larvae in their tissues.
The larvae are transmitted by migrating through the mother's tissues into the growing foetus in the uterus. The nursing puppy can also ingest the larvae through the mother's milk. The larvae get into the intestinal tract and can grow to five inches in length.
The eggs that the adult worms pass in the stool can now re-infest the same puppy or other dogs, if the egg-bearing stool is eaten.
When the worm eggs hatch, larvae are released internally to migrate to the animal's lungs.
Once here, the larvae are coughed up, swallowed again, and finally grow up to adults in the small intestine.
Repeated exposure to egg-bearing stool or contaminated soil can cause exponential numbers of parasites in a dog.
A severe infestation can cause death by intestinal blockage.
Females can produce 200 thousand eggs in a day. Eggs are protected by a hard shell and can exist in the soil for years.
Roundworms can infest adult dogs, too. However, the larvae can encyst in the body tissue of adult dogs and remain dormant for periods of time. They can activate during the last stages of pregnancy to infest the puppies, as above.
Worming the mother has no effect on the encysted larvae in the body tissues and cannot prevent the worms from infecting the new-born. This is because all wormers work only on the adult parasites in the intestinal tract.