Apologies for the appalling length of this! Tabby is an 11-year-old spayed bitch. Rocky is a 5-year-old entire male. Although Tabby is spayed, the vet must have left a bit of ovarian tissue or something behind, because twice a year she becomes mildly interesting to male dogs. This was not a problem until we acquired Rocky, because Tabby is very intolerant of bad behaviour from housemates, and the other males we have owned during her lifetime would never have dared even to sniff her rear end. Rocky, however, became fascinated by Tabby's "mock seasons" - and, for whatever reason, he is the only dog in the world that she cannot tell off, whatever he does. So for the past four years, for about ten days twice a year Rocky has become mildly obsessive about Tabby. He doesn't actually try to mate her, just air-humps beside her, climbs on her back without humping, squeaks at her, and chews her shoulder. She responds by totally ignoring him, while looking distinctly fed up. In between the "mock seasons", he is a great little dog and devoted to my son, but while hooked on Tabby he pays us little attention. This time, things are different. Rocky is much more intense about the whole thing, shows no signs of reducing the behaviour after nearly three weeks, has chewed all the fur off Tabby's shoulder, and is spending very little time with the human family. A few months ago we added a new (male) puppy, Max, to the household, and I think this is the cause of Rocky's obsession. Max and Rocky get on well most of the time - they play chase and tug-of-war and strangle-your-neighbour. However, it's clear that Rocky is jealous when we pay attention to Max - he tends to jump on Max and tries to pin him down (never using teeth), although Max just waves his legs in the air and laughs and goes "Do it again!" I'm assuming that it's jealousy of Max that makes Rocky feel he has to demonstrate that Tabby belongs to him. Max shows no interest in Tabby at all. The situation is stressing Tabby (and us), and I don't believe Rocky is enjoying it either. I don't believe castration would be the answer, as this seems more like a learned habit than sexuality. We've tried various scent-repellent sprays to protect Tabby from the chewing, but none works. We've had Tabby checked by the vet in case Rocky was noticing some health problem. Separating the dogs isn't practicable, as Rocky shrieks and yells, and two human invalids in the house can't cope with the noise. I apologise again for the length of this essay, but - has anyone any helpful suggestions?