Raw fed cat needs to gain weight

We feed our eight cats raw food due to having two very allergic cats and one cat that can't tolerate carbs at all. The food they get is ground whole rabbit (with fur but stomach and intestines removed. This is mixed with water, vitamins B complex and E, taurine, and lard to add fat.

One of our older cats got sick in February and lost a lot of weight. She received treatment and is doing much better and eats normally. However she has only gained back a few 10ths of a pound over the last 4 weeks. Our vet is going to confer with the specialist vet we saw a couple of weeks ago and see if they can come up with any ideas.

I wanted to ask the forum how to get her to gain weight while eating raw. She is not one of our allergic cats so maybe we can make her a higher calorie raw food? I would prefer to keep feeding raw, as our cats' overall health has greatly improved on the raw diet.

You might try a different fat other than lard (or add more lard).  Chicken skin comes to mind.  All fats are 120 calories per tablespoon.  You could also mix in egg yolks.  They are 55 calories each, highly digestible and packs with nutrition.

Rabbit is very low in fat/calories and has a fairly high bone content.  You could also try simply adding more boneless meat protein from any fattier animal to reduce the bone content a bit.

Also, are you feeding your cats from a "community plate" or do they get separate dishes?

When I started on raw, I was feeding 3 cats from a common plate.  One cat tended to be over-weight, his littermate brother tended to be under-weight, and the third cat was just right.  (Sort of like a Goldlocks story, but that's neither here nor there.)

In hindsight it occurred to me that the fat brother was picking the fatty pieces out of the food, the skinny brother was picking mostly lean meats, and the one who was "just right" was probably the only one who was truly getting a good balance of ingredients.

You might try feeding your recovering kitty extra food separately (if you're not doing that).