I wish I had an answer for this, but unfortunately, I'm the same way. There are threads on PT right now that I absolutely refuse to read, for this very reason.
I can't watch any of the t.v. shows that deal with this either. Years ago here in the states, there was a show on one of the cable stations called Emergency Vets. I made the mistake of watching it once, and was appalled by the case they were featuring. It was so horrible, and even years later, memory of what happened to that poor dog, still haunts me. I've never forgotten it. I can't deal with any of the Animal Precinct shows either. I get emotional if I see a dog or cat along the road that has been killed by a car too. I could never work at a shelter or for a vet either. I just don't have what it takes.
I wish I wasn't so sensitive to all of this, but I know of no way to get over it. It's out there, and all I can do, is do my best to avoid situations that upset me, whenever possible.
I will never understand man's inhumanity to any living creature.