My cat has often been sick, maybe once or twice a month. I noticed that last time I gave him worming powder in his food (cannot give him tablets at all), he was sick the next day.
Gave him some more yesterday and he vommed all over the spare bed - whole caboodle had to be washed - then today on our bed 
. In amongst the sick there were blades of grass.
Anyone else had problems with cats being sick after taking worming treatments?