My vet said to put 2 drops in each ear twice a day for 2 weeks, but I need help holding my cat Sammy and only get that help once a day. I was only able to use the drops for 1 week when on his return visit the vet said to continue for 2 more weeks. I'm reading that this should only be used for no more than one week. Is this safe to use for this long? Thank you.