Vaccinations Required for Dogs, Cats and Ferrets 4 Months and Older Rabies vaccination clinics are held monthly through September from 8-10:30 a.m. at the Montgomery County Animal Services and Adoption Center, at 7315 Muncaster Mill Road, in Derwood. The City of Rockville requires all dogs, cats and ferrets older than 4 months to be vaccinated… Read More »Rabies Clinics Begin in April