A number of cats in Australia have become ill and some have died. Orijen brand cat food is apparently the only thing these cats have in common:
A cat neurologist, Georgina Child, has put down five cats over the past week and treated or consulted with other vets about more than a dozen others suffering from paralysis.
[…]
First symptoms included wobbliness or weakness in the animal’s hind legs, which could then progress to the front limbs. The condition did not appear to be infectious, Dr Child said, nor typical of a nutritional deficiency.
I hope they are able to determine the cause definitively and I’ll post more information as I come across it.