Why is my cat so skinny?

Hello everyone, I'm brand new to these forums but I figured I would ask around in case anyone had similar experiences. 

I have 2 sibling cats (boy and girl). I've had them since they were a few weeks old and I've always noticed when feeding that the boy would run by and eat the girl's food as soon as I turned my head (he now goes by "Fatty"). It got to a point where I had to feed them in separate rooms just so he wouldn't eat her food. Fast forward 1.5 years and the boy is a whopping 16 lbs. while the girl is barely 8lbs. Keep in mind the boy is neutered and the girl is not.

She has always been a small cat and definitely the runt of the litter but now I started noticing her bones when she walks and she is very tiny. I recently adopted another stray cat and shes about 5 months old. The stray is actually the same size if not bigger than the original girl.

I currently free feed all the cats. Yes, i know its not the best method but I am not home all the time and my worst fear is that they go hungry. Anyways, I notice she does eat several times a day but only takes a few mouth fulls (2-4 mouth fulls and then runs off). I am debating taking her to the vet because she is so skinny. Her behavior is somewhat normal. I notice she grooms herself quite often and I noticed she used to get these skin bumps so i switched up her food thinking it was a food allergy.

Once a day I call all the cats in for feeding and the other 2 would run upstairs but she never seemed interested. The only time she seems to be interested in food is when I have cheese or sour cream on me. 

Sorry, I know the info kinda jumps around but does anyone have similar issues? Based on what I've been reading it could be anything but my suspicions are.

1. She is stressed from new cat in home (she is barely starting to get along with her without hissing at her now)

2. It is due to allergic reaction to the food.

3. She has a tooth problem and therefore is not eating as much (though i hear he chomp away at the dry food pretty easily)

4. She has developed worms (though I do not see any evidence in her stool).

5. She is just a picky eater and needs special diet

I have attached a few photos. she actually looks normal when she's scrounged up but you can see looks extremely skinny when she's walking.

Any help would be much appreciated

.

She does look skinny. I would have the vet run bloodwork.

Also keep in mind that a cat in heat often goes off feed (even silent heats) and being in heat is pretty stressful on her body. If she checks out health-wise it would be a good idea to spay her. She may put on some weight once she doesn't get all hormone-addled all the time .

Yeah, thank you. Being not spayed was another thought I had, she's always rolling around in heat and stuff.

I know this sounds stupid but a few months ago I watched a video on youtube and someone posted a video of their cat after a botched spay. I think they removed the wrong organ or something but the cat slowly died and it was so horrific and traumatizing that it made me not want to ever spay my cats unless it was 100% necessary. 

I have 3 cats (2 girls 1 boy). Always kept indoor, no access to outside whatsoever and the male is neutered. The last thing I want to do is add to the overpopulation problem. It breaks my heart when I see a stray cat thinking it could easily be one of mine since mine were rescues. 

There are many good reasons to spay your kitty. I agree, it could be contributing to her skinniness but a vet visit is worthwhile to check nothing is going on. Some kitties are just naturally thinner and/or not interested in food. I have a male Maine Coon and he's sitting right around 5.2kg which is the heaviest he's ever been and pretty small for such a big framed cat. He's had all his dental x-rays though, blood works checks out and he does eat but it's not his priority in life, more like a case of not starving to death. He's had times where he has looked much like your girl does. I supplement his food (on my vets advice) with treats of Hills A/D. It's for kitties who have been unwell and is full of nutrients. High calorie foods or kitten foods help to bulk them up a bit too.

It may be also that she has a food intolerance or allergy. Especially if she's overgrooming and has bumps (that can also be stress, running a feliway diffuser might help to calm things down in a multicat house).

Hello, Thank you for the reply Tobilei. That is exactly how I feel she is. Ever since they were young I tried to train them to come to me so I would whistle everytime I feed them. It works like a charm for the other 2 but with her she could care less. Its like she only eats a little bit because she has to but doesn't care for it unless its cheese or some type of raw fish. 

I guess I will also take some time a find a good vet in my area. The reason I ask on these forums is because my current vet hospital doesn't seem to care too much about my cats. My cat had a raw spot on her paw from overgrooming about a year ago and after a 3 hour wait the vet looked at her for literally 5 SECONDS and gave her a cortisone shot and prescribed antibiotics instead of trying to diagnose the cause. Before going to the vet I looked it up online and people were complaining about the same experience with their local vet. 

Definitely look for a caring vet that likes cats, I had to switch twice to find the perfect one. Cats will come into heat almost constantly if they are not bred. I think it is a horrible experience for her and is wearing her down. Find a good vet who has been through many spays and there is really no reason for not spaying. The situation you describe is a one in a million happening, you would have be struck by lightning  twice to have something like this happen. If she were to get pregnant now, it would be disastrous, the unborn kittens would take what ever strength and life she has left in her. 

She is definitely too skinny. You can bring in a stool sample to check for worms, but I have found most cats are infected and it wouldn't be a bad thing to do. Tape worm segments are the only ones visible to the eye, eggs of others have to be found with a microscope. But I'm wondering if she isn't too skinny to have ANYTHING done at the moment, she looks weak and malnourished. If she was mine, I would buy kitten chow/wet food and build her up. It's a little pricey, but get some KMR or kitten milk replacement, it can be used for helping malnourished cats. Then make sure she is alone and gets to eat without the other cats present, even if you have to keep her in a separate room for a while.Make sure she has a retreat to get to, to get away from the other cats, they may be bullying her when you are not there. You are right to be concerned, you will be blessed for your love for this little girl, now I hope you can get her to eat and to be the beautiful cat she can be. Please keep us posted on how she is doing and what you find out.  

Hello Di and Bob. thank you so much for the reply.

Yeah currently in mysituation spaying will be done if it is necessary. Her wellbeing is my main concern. I do understand it is extremely rare for something like a botched spay to happen but I think I feel safer once I find a vet that I trust. 

I will try to fatten her up but I think its kind of difficult because I think she may be one of those picky eaters. I tried locking her in one of my bedrooms the other day with a can of cat food and she still wouldn't eat it even though she was alone. I opened the door about 30 minutes later and saw her laying next to the full can of food. I will go buy some fish and the kitten milk replacement you recommended to try to get her weight back up.

For the deworming, is it safe for me to use dewormer on her even if I'm not sure she has worms? like a product from amazon?

As far as being bullied I believe there is a small possibility but from what I've been seeing she's always been the dominant one. The boy is a gentle giant and the rescue is extremely submissive whenever she encounters her.

I will keep you guys posted.

In case you guys were interested here are a few pictures of them.  (Stinky is the one we've been discussing)

Batty (Black, 5 months, Female)

Fatty (Grey/White, 2 year old, Male)

Stinky (Black/White, 2 year old, Female)

Some cats are naturally slim but you shouldn't be able to see their hip bones. That's why I think she's TOO skinny. So, yep, bloodwork should show if there's anything wrong inside.

If you want to scare yourself in the other direction, look up some videos about pyometra or mammary cancer .

I second what I said about Stinky needing a vet, just to be sure. We've run the full gamut of tests on Jasper, he's just skinny. He's had times where he's looked like Stinky (bag of bones) but it is interspersed with times where he's just super lean. We spend a lot of time keeping him interested in food. He gets bored of the same thing all the time so he gets 3 different styles of wet food a day and 2 different kinds of dry (hypoallergenic gets left out all the time as that's what his sister is eating and he gets bowls of something else from time to time, I have both Hills I/D and Royal Canin Oral Care for texture/size variety).

I hear you about vets. I ask a LOT of questions because we have so many health issues going on in this house. A lot of vets get annoyed with me (oops) or I feel like they do bare minimum and send you on your way. We currently travel 25 minutes across town (on a good day with little traffic and along the freeway so it's quite a number of kilometres away) to see one we like. Definitely shop around and find one you feel comfortable sending her to for spaying. Ask your friends who have pets or google and check out reviews on facebook pages Keep us updated with how she is!

Thank you for the kind advice. I am currently trying to fatten her up with her favorite fish (KMR being delivered) while looking for a good vet. I am going to try to get her bloodwork done to be on the safe side. Yeah I feel like shes just naturally skinny, shes always been on the smaller side compared to her brother. But its better to get the work done just in case. Thanks again for all the great advice. I will keep you guys posted.

I hope Stinky gets better!
My own kitten had issues and it took her awhile to put on some pounds. We switched her to a grain-free dry cat food called, Fromm. She loves it and I believe she gained maybe 2 pounds since she has been on it. My other cat.

I don't know where you live, but if you have a place called, All About Paws near you, ask for some samples. Place small piles in front of Stinky and let her pick which she looks. Both my cats picked Game Bird.

I have 2 cats - both males and siblings from the same litter.  From the time they were around 3 months old, Connor started getting heavier than Murphy.  They're 8 months old - as of today, actually - and Connor weighs twice as much as Murphy.  Connor is a solid brick of a cat and Murphy is more . . . soft, I guess?  Cats have different body types, just like people.  As long as they're both healthy, I wouldn't worry about it.

I just read through all the other replies.  I agree that it would be a good idea to get her checked out, just in case.  Have they all been wormed since you brought in the new stray?  If not, it's likely that they all 3 have worms and it's affecting her more than the other two.

@Thai Vu

I hope the checkup goes well and nothing is wrong. I am going through the exact same thing with my cat Taz. You are obviously a very caring person whom loves their cats a lot, as do I. I will wish you the best of luck and you can wish me luck and hopefully we can fatten our little friends up a bit. If you are interested my story so far is as follows.

I have two cats at home that are for the most part Maine Coon, I would imagine they are a mix of breeds. I got Taz when he was about 2-3 months old and Zoe was approximately 3 years old when I got her. Zoe has always been a healthy weight where Taz seems under weight. I read that Maine Coon cats are slow developers and do not achieve their full size until they are 3 to 5 years old. My wife and I take Taz in for checkups and shots and my vet says he is healthy. He is very energetic so I figured wait and see. He turned 3 years old in early October and he still seems skinny. I am afraid to try self diagnosing my cats in case I am wrong so I always take them to the vet. I like my vet a lot and trust them with my cats' lives more than I trust myself. My vet looked Taz over, said he is healthy and has even put on a little bit of weight since last visit. We said we are concerned with his weight and the vet said try changing food. I am going to switch food and try what @SebNari96  mentioned.

Welcome to TheCatSite, @Thai Vu  and furmily!  It's always been my and my family's policy to get a new cat checked out at the vet and given the basic innoculation package, and then spayed/neutered as soon as possible.  That's our policy and it's one that most experts would recommend.  I know what you mean about vets -- we used to have a wonderful vet, actually at our last 2 locations, but now we live in an area where money is what matters and a lot of the vets are very avaricious.  We have managed to find a good one, though, and I hope you do, too.  

I believe based on your photos and description that Stinky absolutely needs a vet check-up because she is very thin.  Spaying would be a must, right away, for me, too.  

Thank you for sharing your story and beautiful photos with us -- your cats are lovely, and Batty and Fatty look very nice and healthy.  Hopefully Stinky soon will be as well!  Do keep us posted, won't you?

We currently have a set of siblings at our shelter that are like this. They are five months old. The boy is 8 pounds. The girl is only 4 pounds. Nothing wrong with her according to our vets. She's just small.

Not spaying cats can actually be far more dangerous than having them spayed. Pyometra- a potentially deadly infection, can be caused by going into heat too many times. There is also no guarantee that a cat in heat won't manage to get out and get pregnant. My family lost a cat during a spay surgery once (the vet said there was something wrong with her heart and the anethesia), but we still get each cat spayed since we know that doing so will most likely keep them healthy.