Thanks for all of your help!
Thanks for all of your help regarding Jake! Your information you all shared was very informative and helpful. He is getting a little better it seems; he has more energy. But if he doesn't get truly well within a few days, we'll make an appointment with the vet. An appointment for him would have been made sooner, however, we are trying to see if his sickness will just end as he is showing some improvement.
He might have an allergy as some of you say; the other cats have not obtained his sickness. But then again, they could just have strong immune systems as some of you say, too (thank goodness, I do NOT want them getting sick, as well!) If he doesn't get well soon, we'll go to that vet and see just what is up.
Thank you once again so much. I'll keep in touch.
Catloverforever, with love from her kitties; Nellie, Reggie, Nitschke, and Jake