Police are hunting a woman who kicked a dog in the testicles so hard it had to be castrated - because it was trying to have sex with her pet.
Two-year-old Springer Alfie was set upon when he raced away from owner Keren Northcott, 27, to try to mount a bitch.
Before Keren could pull him away the female dog's owner begun whipping Alfie with a leash and booting him in the groin.
Shocked Keren picked up her battered animal and raced him to a vet but staff said his testicles were so badly damaged Alfie will have to be castrated.
Police are appealing for witnesses to the May 9 attack that took place at a nature reserve in Bodmin, Cornwall.
Keren said she was walking Alfie with her daughter Kelsie when their cherished pet raced towards a white collie-cross bitch and her female owner.
She said: "Alfie was beside me, when her dog came bouncing up to us. Alfie could sense she was on heat and they both ran off together.
"The next thing I knew the woman was trying to separate them. She was yanking his collar really hard, lashing out with her lead and kicking my dog.
"He spent a day in the vets on a drip, and his testicles were so badly injured he will have to be castrated now.
"The woman also injured his windpipe by pulling at his collar, and now he can't bend down to eat and I have to feed him by hand."
Keren said Alfie required three trips to the vet, costing £350, plus the cost of the castration.
Witnesses are urged to contact Bodmin police station.
Keren added: "I do hope the police manage to catch this woman. I also want to appeal to owners to keep their dogs on leads if their bitches are on heat."