I do agree that Kosmo has lost weight, but as you said he is much more active now compared to when little Miss Faith arrived.
Whenever I have seen Kosmo and added chicken breast or stewing beef or even hamburger to his EVO he has always gobbled it up.
I would definetely try adding some to his kibble and some veggies too.
Giving his some cheese for treats is a good idea too, I would also give him a multivitamin.
Darby also looks thin, he is very long.
We have a Vet appointment next Saturday, I will ask if she thinks he is too thin. When Frank took him to be neutered in Dec she said he was perfect and he is heavier now. I also think he looks thinner because his coat has not come in yet either.
Mom to Daniel, Derrick, David
Dudley 3 Years Old
Darby 1 Year Old