The Clues: Okay, these were fairly obvious: the cat (Magenta) was scratching her neck a lot. Almost continuously in fact. This caused the second clue: a huge raw patch of skin, which developed into an open wound. Because she was constantly itchy, she unfortunately spattered blood everywhere around the house (fun to clean off, let me tell you!) thus creating the “crime scene” effect.
(Incidentally, if you are cleaning your walls and floor of blood, this can be done with warm water, vinegar and a splash of tea tree. Use your microfibre cloth on the walls and furniture, and the usual mop on the floor. Soft furnishings I scrubbed with the same solution and the microfibre cloth too, using the scourer section of a sponge on the difficult bits) There was a slightly less obvious clue in the scabs that had formed around Magenta’s neck (they were tiny, but many).
Eliminations: I knew this wasn’t a flea allergy, because I treat all my animals for fleas and worms. Personally I use Advocate. I don’t really like the idea of medicating my animals for no reason, but when you think about intestinal worms, heartworm and fleas, the Advocate really is the better option. With cats, make sure you apply it to the back of their head, as they can easily reach the back of their neck and lick the stuff off, which is really not good for their health.
Actions: This particular incident went from “itchy cat” to “blood everywhere” in a very short space of time – just about a week, in fact. So as soon as I noticed that Magenta was bleeding, and why, she was taken to the vet.