Treatment and Screening for Internal Parasites is an Important Part of Preventative Care
Not only does routine intestinal parasite prevention reduce the risk of disease in your pets, it also helps to reduce environmental contamination with the infective stages of the parasite. This reduces the risk of your pet becoming re-infected after treatment as well as transmission to other pets and even humans.
In puppies, deworming should begin at two weeks of age and be repeated every two weeks until they are old enough to begin monthly heartworm prevention. Dogs remain susceptible to intestinal parasites throughout their lives. Many dogs even carry dormant stages of the parasites within their muscles that can shed periodically throughout their lives.
Not all intestinal parasites can be controlled by routine preventatives and no preventative is ever 100% effective. It is important to screen your pet for parasites at least once a year to make sure they are not shedding parasites into the environment that can make themselves, other pets or humans sick.
Compared to adult dogs, puppies are much more likely to carry intestinal parasites due to their early exposure, immature immune systems, and tendency to put things in their mouth. Parasites may also shed intermittently and may not be identified on every single sample. Puppies should have multiple fecal screenings in their first year.