Background and Description
Feline aggression is a significant problem reported to behaviorists, second only to inappropriate elimination in its frequency. A wide variety of motivators for feline aggression exist and distinguishing between them is critical to resolution of the problem. One particular subset of feline aggression is sexual aggression, in which a male cat displays inappropriate sexual behaviors which are disruptive to the household, often even after the animal has been neutered.
Sexual aggression can be directed towards an inanimate object (like a blanket or cat bed) or towards another animal in the home. The latter can be particularly distressing to owners given the violent nature of feline sexual activity. The target of this behavior can be another cat, either male or female, or may even be of another species, such as the family dog. Cats displaying sexually aggressive behavior towards another animal will bite and hold the back of the neck of their target as they mount them, which can incite vocalization (screeching, howling) by the victim and frantic attempts to escape, often entailing biting and scratching. This is not always the case, as some owners also report that the target animal remains still and quiet during the event despite their discomfort. This behavior creates discord between two cats in the home, making the target animal fearful of the aggressor and can create a generalized anxiety. In more extreme cases, the two animals may physically harm one another during the struggle. Disrupting this behavior is essential to maintaining a comfortable environment for all the animals in the home.
When directed towards inanimate objects, sexually aggressive cats will often display the same mating behaviors towards objects, most often with blankets, cat beds or soft toys. Furthermore, some cats are reported to display this behavior most frequently in view of family members or guests in the home, which can be embarrassing to owners. Differentiating from other types of aggression
Unlike other types of feline aggression, sexual aggression shows no particular inciting pattern. When occurring between two cats, owners report that the two animals most frequently coexist in relative harmony until a point when, seemingly no trigger, one cat chases and then mounts another.
Cause of male mounting behavior
Sexual behavior shown by males and can occur regardless of whether or not the animal has been neutered, which can be confusing to some owners. In red-blooded males, the behavior is fueled by testosterone. Neutering may quench the fire of maleness – but does not necessarily fully eliminate it. A neutered male is not an “it” – it is a neutered MALE. Masculinization is caused by exposure of the fetal brain to testosterone released by embryonic testes in utero. Male cats are born male and stay that way. Testosterone fans the flames of male sexual behavior but without testosterone (after neutering), male behaviors may still be expressed.
Managing the behavior
In intact male cat not intended for breeding: Given the role that sex hormones play in the expression of sexual behavior, the primary treatment for an uncastrated male with sexual aggression is castration. This may completely eliminate the problem, or diminish it to a manageable frequency.
The curve ball: For cats that have already been neutered, an important consideration is whether some testicular tissue was left behind during the surgery. This sometimes occurs in animals who have an undescended testicle that is not found or removed at the time of castration. Although measuring the testosterone level in the cat’s blood can indicate improper castration, on its own this test is not a fool-proof test as testosterone levels fluctuate widely depending on the season. A hormone challenge test, which can be performed by your veterinarian to check for this problem is far more definitive. GnRH is a releasing hormone produced by the brain which stimulates the release of testosterone from testicular tissue. If your veterinarian gives your cat a dose of synthetic GnRH and takes timed blood samples to measure the testosterone response, a clearer picture emerges. A spike in testosterone levels following the administration of GnRH indicates residual testicular tissue. In that case, surgery is indicated to find and remove the remaining testicle. That procedure usually resolves the problem.
In properly neutered cats: In properly castrated cats, this behavior is simply linked to the development of a strongly masculine brain in the womb and cannot be fixed surgically. For these cats, the most effective deterrent is to apply a male pheromone, androsterone, to the rump of the target animal. The scent of this pheromone informs a sexually aggressive cat that his target is no longer an appropriate one. Anecdotal data suggests that application of this pheromone every other day is sufficient to discourage the behavior. A formulation of the pheromone is used by pig farmers to prevent fighting between males. It can be purchased under the trade name “Hogmate.” A more concentrated and effective form is sold by Sigma Aldrich, but this product must be ordered through a veterinarian. As a testosterone precursor, androsterone and should always be applied with gloves and/or a cloth to avoid skin contact with human skin. Absorption of the compound though the skin can cause hormonal imbalances in people applying the product, just as hormone creams can have unwanted effects in people unless properly applied.