cat vomiting on outside water?

Hello! I have a cat with inflamitory bowel disease who was perscribed prednisone a couple of months ago. She is also taking another anti-nasuea medicine. We upped her dose of prednisone, and she hasn't vomited in about a month. Lately, my cat has wanted to go out on the patio (we live in an apartment, on the second floor). She drank some water from a plate that was outside. The water is rain water (it was raining pretty heavily the night before) and it had a number of leaves in in from the tree near it. She seemed to really enjoy this water, so we put a new bowl out to collect rain, and she has only wanted to drink from this the last two days.

She has drinken this water a couple of times, and I figured rain water wouldn't hurt her. However, we were just on the patio, and she drank some from the plate with leaves on it, and minutes after we came in she threw up for the first time in a month (she was also aiming for her litterbox which is a first for her).

My question is, could the water from outside could have made her vomit? Is one vomiting in a month for a cat with IBD normal? Thanks for reading!

Matt, I would be concerned that the tree (Leaves) might be toxic. I would pull the bowl away from her and give her fresh water in the house. Look at the different types of pet fountains available. Our cats love their fountains, and cats with IBD do benefit from drinking lots of water

Sometimes they just drink (or eat) too much too fast and it comes back up. I've seen it happen with various cats over the years. She might just have had too much of her new and exciting water source, but it's possible there's could be some contaminants in it. Check with the vet, and maybe also about upping the meds on your own too - maybe that's making her more thirsty. Perhaps keep a bowl of regular tap water out there rather than using the rain water?

PS - good kitty for aiming for the cat box!!!

There could be anything at all in the rain water. I would agree with the recommendation to put a bowl of filtered or bottled water (or tap water if you have a well) outdoors.