Roundworms are much easier to take care of then coccidiosis. You can always take a stool sample in when it looks funny usually w/o a appointment or office cost. Its about $8-$10 for stool test. I love revolution for fleas & heartworms, I would stick to that & pick up a bottle og nemex2 from your local pet/feedstore. It's $12 & will last you along time verses sentinel tabs every month about $12 each. $$ Just carefully figure the dosage for nemex2
My dogs use to pick up stuff from rabbit & deer poo in the yard all the time. We put up a chainlink fence-problem solved. Well I'm glad to hear it was just pesky ol common roundworms. You can use nemex2 as needed. I used it if I saw worms or diareah & now every few months for prevention. They can get round worms & give them by justtouching noses w/ another pet-thats what my vet told be anyways. Then I wised up & instead of giving the vet $35 a month, I pay $12 every 2 years. Sorry if the coccidiosis thing scared you, it just sounded like it & I wanted you to know about it cause it has become a big problem. take care.