TIFU by giving my cat rice

My cat, Penelope, is 15 years old and like most cats her age, has developed some health problems. I found out she has kidney disease back in September and since then I have kept her on a pretty strict low-protein diet. Since then, she has lost a lot of weight since that it one of the symptoms of kidney disease in cats. Two years ago she was a chonk weighing 16 lbs, now she is only 5 lbs. She is pretty boney now, but acts completely normal and I can tell her new diet has been helping a lot because she rarely pukes whereas before it would be a weekly occurrence.

Although the vet told me it is more important to keep her kidneys healthy then for her to gain weight, every time I pick her up I feel her ribs and I cannot help but feel bad for her. So, I did some research and saw that some people give their cats rice, and rice is actually very helpful for cats with an upset stomach. I figured giving her some in small amounts would give her some extra carbs. Of course, I called the vet before I tried something new and they said they could not see the harm in giving her a little bit of rice every so often.

So, I went to the store and bought a pack of rice and I put some in her wet food dish as a base and mixed it in with some cat food toppers so it appeals to her. I made sure not to put in too much, it was just a thin layer that did not even fill the base of her small wet food dish.

Now for some backstory, the day before my dad told me that Penelope had broken into a bag of almonds he had on the counter. He was in his room at the time so he was not sure as to how many she ate. When I got home from work, I made sure to monitor her and she seemed to be fine and acted her usual self.

Now back to when I first gave her the rice. She absolutely loved it and devoured the entirety of it. There was no issues until about 2am the next morning. She started vomiting and had diarrhea. In the vomiting there was some rice which was expected since that was the last thing she ate. Then she vomited some more and I saw some almond-shaped objects in it as well. I read that almonds sold in stores are not toxic to cats, but it can be hard for them to digest it which may cause some stomach issues.

Once I saw the almonds, I figured what I described above was occurring. When I got up for work, she still seemed kind of out of it, but I did not blame her. I gave her some wet food (no rice) in the morning, she did not seem interested, and then I headed to work. When I got home her wet food was gone which meant she ate it (hooray!). She was acting like normal again so I gave her some rice with meal toppers and she devoured it once again.

It is 5am, I wake up to the sound of her vomiting and sure enough I see rice. I quickly clean it up and go back to sleep. When I actually woke up, I saw more vomit on the floor, I must of slept through it, and my cat was no where to be found. I step into the hallway outside of my door where her litter box is and there is poop everywhere. She tried her best to make it to the litterbox but it looked pretty projectile(I know it sounds disgusting, sorry!). This time, there is clearly rice in her diarrhea.

I was super confused. I thought rice was supposed to not be harmful to cats and is supposed to help them when they have an upset stomach. When I looked up "cat vomiting rice" nothing showed up because people give their cats rice to help with vomiting. I added some more description to it and a page popped up:

"Rice Allergy in Cats"

Sure enough, the symptoms included severe vomiting and diarrhea. Of course my cat is allergic to rice, nothing is that easy.

I found her hiding under my bed. She looked absolutely pitiful. She has not puked since this morning, but she has still had some diarrhea. I was worried because she was not even drinking water, but luckily she started to about a half and hour ago. I pet her and she started to purr. Before she was hiding in a ball, but now she is moving around and seems to be feeling a little better.

The vet I take her to is closed on Sundays, I already have an appointment on Tuesday for her routine bloodwork for her kidney disease, but I am gonna try to see if they can fit me in tomorrow so I can ask the vet some questions.

Regarding her scavenging, I think it is because she is missing something in her diet, so I thought the rice would help. For instance, on multiple occasions she has dragged bags of bread (hamburger and hotdog buns) up the stairs and into my room. She would also rather eat the dog's food rather than her own, which she vomits from that as well. I am definitely going to talk to the vet about what I can do about that.

Now I am questioning if I have been poisoning her her whole life. When she was fat, she would vomit after eating a lot and my mom and I always thought it was because she ate too fast. Now, I am wondering if it is because her cat food contained brown rice(I looked it up). As far as I can tell, cats should react to brown and white rice in the same way so it should not make a difference.

TL;DR: I gave my cat rice to help her gain weight since she has kidney disease and she began to vomit and have diarrhea. Turns out, although uncommon, some cats are allergic to rice.