I had the same prob with Milo.
He is up to 6 lbs now and has actually filled out!
I feed honest kitchen----thrive and embark.
Also add missing link, and HK's supplements of perfect form & invigor.
I reconstitute with organic, low sodium chix broth and also add shredded asiago and whole wheat couscous ( also cooked with the broth).
He gets this twice a day-- 1/4 cup each time and also gets treats of fresh raw vegs and fruits as well as bits of chix, beef and fish, depending on what I am cooking for our dinner.
He consistantly eats since I switched to HK.
I couldn't be happier!