Thanks for your reply. All of our cats (with the exception of the kittens we just took in) have been neutered. Critter's vet visit went well yesterday. Outwardly, the vet could find nothing wrong. As a matter of fact, he remarked that Critter appeared to be in great health for his age. He did take some blood, however, and soon we'll have the results from that.

In the interim, we plan to give Critter a very mild sedative every 2-3 days until we have the results. The vet wasn't familiar with Feliway but was familiar with similar products. He is going to get back to us on his recommendation once Critter's tests are in.

Hopefully, we'll soon have our happy family back.