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Why is my cat still feeling sick days after vaccines and bloodwork?

Updated on September 23rd, 2025

Pet's info: Cat | Mixed Breed | Female | spayed | 10 years and 4 months old | 7.6 lbs

My cat had 3 shots on Monday. Tuesday, she felt miserable. Wednesday she felt better, but went for bloodwork. Thurs and part of Fri, she was doing ok. But late yesterday, she has been feeling awful. Will sip on water. Has eaten some bites, but thrown them up. It is so odd that she hasn't been completely back to herself since Monday. Do you think she's still suffering from the side effects of the shots and/or blood draw?

1 Answer

Most Helpful Answer

Answered By Megan, DVM, CVA

Veterinarian

Published on December 9th, 2017

Poor Izzie! It is doubtful that she is still having the side effects of the vaccines this far from when they were given. I am concerned that something else is going on and that this is a huge coincidence. I would talk to your vet to see what type of bloodwork they ran and if it would show why she may be acting this way. Since she got a little better but now feeling awful, I would consider having your vet do another exam. They will be able to run additional blood work, do a urinalysis or even do X-rays if needed. Also, they will be able to assess her hydration to ensure she isn’t dehydrated. There are so many different things that can cause lethargy, decreased appetite, and vomiting, but your vet will be able to narrow down the possibilities and get her started on some meds to help her feel better. I hope this helps!

1Pet Parents found this answer helpful

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