my 2 fells live together no problem, and are fine with other dogs when im around, wouldnt trust them if i wasnt. when i got my fell dog i was told he was a fighter, in truth there was a long running unresolved feud between him and his litter brother riddick the last fight they had nearly finished the other dog. my fell bitch has to be worked on her own, shes a real jeckel and hyde character when her bloods up, have to give her "alone time" after a dig as she'll start fights otherwise