Thank-you so much for the reply!
I did take my kitty to the vet. She wasn't aware of any negative side effects of Drontal either, but he is 15 years old and somewhat weak and immuno-compromised from progression of the irritable bowel syndrome. I think I just need to be very careful with him...
Can you tell me how long the ataxia lasted in your cat and what you did to treat it? Was it just feeding and sub-q fluids? I treated my cat, who does have digestive issues (IBS) with Drontal earlier this evening and noticed the ataxia, especially in the hind end, about 4-1/2 hours later...I wish...