Is this a whip worm? (Gross picture)

[Barkerbunch4]

My cat had a weird thing sticking out of her poo. It was tough like plastic. But then I started thinking that maybe she has worms. I gave both cats (I have two) dewormer yesterday and some in their water today. Unfortunately the one cat is throwing it up. Today, I meticulously cleaned their litter box. I cut all the poo in half or smashed it down. I only found one thing. Wouldn’t all their poo have something? Also, I have not seen any eggs around their behind or in the spots they like to lay and their behavior has not changed. I’ve enclosed the picture. What do you think? Thanks!

 

[Ridgeback825]

I'd say plastic or something else they shouldn't have eaten.