Thanks for the help everyone, especially Lawrence. Yes, you did make sense.

Shadow did get checked out and his urine and blood work was fine. Ashley is a female kitty a year younger than Shadow and Shadow likes to be her big brother and clean her. It eventually goes to chomping and then she runs away. Ahi is 2 years younger than Shadow and is a boy. Sweet but clueless. I think the problem started when we introduced the boys. Usually, the new cat would run away from Shadow but Ahi stood his ground which threw Shadow off and SHADOW ran away.

We had had another cat, Haupia, who suddenly passed away after we had had him for a year. He and Shadow got along really well. Ahi is actually Haupia's nephew but Ahi doesn't let Shadow groom him, another part of the problem.

Marna Lou, do you have a Bissell Green Machine? That's what we have as well. Along with Spot Shot, Resolve, etc. Our cabinet is full of spot cleaners for those hairballs!