I'm getting pissed of for you mate, if a farmer threatened to kill my cat like he did yours id go nuts. Had my cat for 9-10 years, in my eyes its a blood relative now

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I say we get a SSDi RL raid planned, and raid your friend the farmer, take all his chickens, and Graffiti his Barn with SSDi tags.
Really hope you find your cat mate, i can't make any other suggestions than the guys have already done, other than going to your old digs and yelling your cats name, (although I'm presuming you have already done that).
Good luck mate
Monty