Why is my male horse suddenly chasing and bullying my female pony?

Hello. First, know that this is normal behavior. Mares especially can be aggressive to geldings & even other mares. It can take several days to up to 3 months for everyone to settle down. If possible, the horses should be separated where they can see, smell & possibly touch each other, but can flee if the situation requires it. If you can not place the horses in adjacent paddocks, they should have separate resources far enough apart so that no guarding occurs. 2 water sources & feeding far enough apart ( or confining the mare ) until all grain is consumed & for up to 20 minutes after is necessary. Once the gelding has finished & is grazing quietly, you can release the mare. If any of the horses are wearing shoes, pulling them temporarily may prevent significant injury. If the behavior does not seem to at least be calming down in another week or so, you may need to have your mare evaluated for an ovarian problem or even granulosa cell tumor. These can cause significant hormonal changes in mares resulting in almost stallion type behavior. Have patience, a week is only a short time to try to buddy up two horses. Good luck & thanks for using Petco Pet Education Center, formerly Petcoach.

If your female dog isn't spayed, she could be coming into heat causing this behavior. Female dogs go into heat around every six months, and if you have had her for five months, it would be about time to go into heat again. This behavior will continue every six months unless you get her spayed, which I highly recommend getting done. Best of luck!

It is typical for female pigs to be very grouchy when they are in heat, and because pigs go into every 21 days, this will be a behavior you have to deal with frequently. Penelope will get worse as she gets bigger, and you may see behaviors such as chasing people or other animals in the home, humping inanimate object, excessive rooting, snapping, biting, and charging. There's not much you can do to make Penelope comfortable, as the hormonal behaviors often overtake any training you do with her. The best solution is to have her spayed as soon as possible.

Actually I doubt there is anything wrong with your dog. Your other dog must be a female in heat and Rambo and her were mating. Females in heat will smell very attractive through sexual hormones and will entice a male dog to mate with her. If you do not intend to breed your dogs, then I suggest you have both male and female desexed which will alleviate the problem.

Have him examined by your veterinarian to diagnose illness or injury. Either are common culprits of a sudden behavioral change. Being an intact male may also be playing a role in the behavior. Consider having him neutered. In the meantime, provide additional food/water bowls, beds, toys and litterboxes to prevent food aggression or resource protection. Consider a pheromone product, such as Feliway Spray or plug in diffusers, to decrease any anxiety or aggression in the home.

This is pretty normal. Protecting her from other possible males - doesn't matter if they are human. Doesn't even matter if they are male or female. This could get ugly fast and can turn to severe aggression. If you are not planning on breeding them I suggest you get them spayed/neutered as to not promote any behavioral issues.

Since he is unneutered he may be picking up on her scent even if she is spayed, it's also a way to show dominance over other dogs. If you don't plan to breed him I suggest getting him neutered. This will help the behavior lessen over time and will also prevent some potential health problems as well as reduce the urge to roam and possibly get injured if he escapes looking for a female in heat. You can try getting him obedience training so he will be better behaved and more likely to listen when you try to separate them.