non-diabetic cat loosing too much weight on low carb diet?

First, I love this site! Our kitty was diagnosed a few months ago with diabetes and I stumbled into your site and never left. Any question I have had so far I have been able to find an answer to here. We have 2 cats, Bubba J and Soxie and fed them dry Purina Cat Chow all their life (I didn't know how bad it was). A year or so ago, Bubba started having troubles with crystals in his urine. We switched to Science Diet Urinary (dry food still) and he seemed to be doing much better! But then Soxie was diagnosed with diabetes about 6 months ago. Long story short, we switched from dry to all wet.. I chose Fancy Feast Pates as the low carb food, as we are not extremely wealthy LOL. And things seemed to be going just fine. I was home testing and did curves with the help of your chart. My vets were impressed at how we had taken Soxie's sugars from 575 down to 150 with a simple food switch. We started out on WAY TOO MUCH insulin, but have since gotten down to 2 units at the most, 1/2 unit at the least and numbers have been great! Super right?! And it was also great that Bubba's crystal problem was still under control. All wet food was working out for everyone!

Bubba was always a chunkie monkey. We called him Hubba Bubba, Chubby Bubby, not super overweight but thick. He is bigger framed, small part main coon with the tuffed ears and all that jazz. Also very cuddly and snuggly. And Soxie was a petite smaller sized kitty and definitely not a lap cat. She can be friendly and want some petting, but only on her terms and her time. Well, Bubba started loosing a bit of weight, going from free fed dry food to 2-3 meals a day all wet, which I figured was ok enough. And few weeks ago, we noticed that Soxie (the diabetic) was loosing small patches of hair by her ears, above her eyebrows... and upon closer inspection we noticed that all of her whisker follicles were raised and almost bloody looking. And the hairless areas were also full of bumps. And then noticed that under her chin was also bumped. We don't often get too close to her as she does her own thing and isn't snuggly much at all. It seemed to get worse by the next morning. Now even more hair was gone and skin was pinkish red. There were opened bloody bumps (like she had licked or scratched) and so off to the vet we went. They didn't know what to think. They hadn't seen anything like it before. They gave me antibiotics and thought maybe it was bacterial infection of some kind.. if it didn't improve I was to go back. Well, it just got worse. Meanwhile I am researching and researching... maybe this is a food allergy. Maybe for a month or so, Soxie's favorite FF was beef. So we had been feeding a lot of the beef pate. And maybe it was a food allergy! I read some cats have trouble with FF. Maybe it could be beef. Maybe chicken. Who knows. I took Soxie back and she had gotten worse. More of her little whisker follicles were raised and bloody. She was loosing more hair on her temples and up into her ears.. Her skin was still pink and she was hiding in the basement, only coming out for food. I never saw if she was scratching/licking/fussing at it. But she wasn't better. So back to the vet we went. They were shocked that things had worsened. I asked if it could be a food allergy. They said possibly. Could this be something from the diabetes.. blood sugars? They didn't know. They said they had never seen anything like it. Gave me a stronger antibiotic along with prednizone and said that if she didn't improve, our next trip would be to a specialist down at Iowa State (superb vet school) .... with a BIG price tag! And again, we are not wealthy! So I told them I was going to switch foods again and see if that helped. I went with Nature's Variety Limited Ingredient Rabbit. And got some limited ingredient Duck from Merrick, I think. I didn't know which would go over. Both do. And Soxie seems to be getting better. We are adjusting insulin for the steroids too... But in all of this mayhem, Bubba J was all of a sudden almost "too skinny". I hadn't noticed, we were so focused on Soxie. Bubba was feeling skinny!! He was not drinking any more than normal. Someone in the house had thrown up some clear liquid a few times, but we thought it could just be the food switch. Took him to the vet. Had blood work done and his kidneys are fine. Heart & lungs sound fine. Strictly indoors so not much chance of worms (but dewormed anyway) So maybe I am just not feeding him enough?!?? Maybe I am starving him? Maybe he needs more food than Soxie... I don't know. We have never done a strictly wet food diet before. The vet wants me to maybe give him some dry food again. But I know it isn't good for him & his urinary issues. And getting him dry food without Soxie seeing/having some would be a challenge. But we need to do something. He needs to put some weight back on. And truth be told, we are not going to be able to afford giving both cats an abundance of this limited ingredient food. It is expensive and we can barely afford what we are feeding them now. So what would be a good "fattening" food to sneak into Bubby's diet. Something that will put some meat on his bones. Does this "healthy food" cause kitties to loose weight? Too much weight? Soxie isn't loosing weight anymore... in fact, she seems to have bulked up a bit. But why is Bubba loosing weight. Maybe some muscle mass. I forgot to ask the vets about hyperthyroid... can they tell that from blood work done for Kidneys? I don't know! I am just worried about my skinny Chunkie Monkey. I want to fatten him up! But I don't want to mess Soxie up either. Suggestions would be greatly appreciated. Thanks for reading! And thanks for all the wonderful knowledge on this site! You guys are amazing!!

 

There are others that are more experienced here than me, so I will just give the basics that I can give.
Is Bubba getting more food a day than Soxie? He should be getting 1oz/lb of lean body weight of the friskies. By your description, he is significantly bigger than Soxie. How much a day are you giving? Catinfo.org has some math to do to figure out how much to give for weight loss and maintenance, but the basics are feed more if too skinny, feed less if too fat. Also, iirc, the limited ingredients have no carbs- he could need just a little.
You could sneak in some of the gravy friskies as they are higher carbs. Also, the natural balance reduced calorie has high protein, and reasonable priced compared to the limited ingredient at least.
For feeding them separate- if Soxie is unable to jump high, Bubba could be fed on a counter or dresser that she can't reach.

Edit: for feeding separately, I've had people suggest getting feeders that go by proximity to microchips or collars... which is great if your cats are chipped or will wear a collar. They are also expensive! I am using the feed high method for my two singapuras until Rhubarb is able to jump again.

 

A senior blood panel should include thyroid tests, but you'll have to ask if that's what they did.

Both my civvies lost weight when we switched to all canned (but they needed to lose it!)

Kitten foods have more calories per ounce than cat food and the Fancy Feasts are also low carb but we want to be careful not to irritate whatever was going on with Soxie

There are a couple of low carb dry foods but they're expensive (and we still don't really recommend dry for any cat but these are definitely an option) They're Dr. Elsey's Clean Protein (available at Chewy.com) and Young Again Zero (available on their website only). They are pricey but they're also "nutrient dense" so cats don't need to eat much.

 

I use the microchip feeders that majandra mentiomed and I can truly say they have been a lifesaver. My cats have different dietary requirements and have totally different eating habits. This has allowed my once overweight kitty to drop weight and lets me know when my diabetic kitty may be starting to have a pancreatitis flare (not finishing his food). They are very expensive, and I put off buying them for a year before finally going for it, but I have had good luck with them personally so I thought I’d share. This is the brand we have: https://www.surepetcare.com/en-us/pet-feeder/microchip-pet-feeder If you have any questions just ask! All the best

 

I have looked at Dr Pearson's table and that is really not true. Most cat food meets the requirements for all life stages (Adult Maintenance, and Growth/Reproduction)
https://www.onlynaturalpet.com/holi.../253/pet-food-life-stages-do-they-matter.aspx