I have a 6 month old black lab mix. The vet yesterday diagnosed him as having whipworms. How serious are these and are they a pain to get rid of? They gave me a 3 day treatment of some kind of powder and we are going to be starting him on Interceptor. Is there any way to prevent him from getting any further cases of these? I do like to take him to the local dog park, which is where I think he got them because I have heard other people talking about their dogs getting worms from there. Is it safe to keep going back there?