A cat fight, more technically termed inter-cat aggression, frustrates owners and can cause cats to lose their home. Most inter-cat aggression involves intact same-gender cats, and gets worse during mating season. That's why spaying or neutering before a year old decreases or prevents about 90 percent of inter-cat aggression. But any two cats can decide they hate each other.

After all, you don't automatically love every human you meet.

Why expect cats to be any different?

Kitty Poker Communication

Cats usually work out their social standing with posturing and kitty bluffs, and neither kitty gets hurt. In these situations, cats can usually learn to tolerate and/or avoid each other.

However, the lowest ranking cat (often an older, or ill kitty) can become a target picked on by the other felines. Acting like a victim (slinking around, using submissive body language, hiding) is the equivalent of wearing a "kick me" sign and invites bullies to increase their bluster. Never allow cats to "fight it out" as that rarely settles conflicts but makes matters worse.

Why Cats Fight

Cat-on-cat fights can result from any other kind, such as redirected aggression, play aggression, and fear aggression. Changes to the cat's social group (addition or departure of a member) can prompt an increase in face-offs. Environmental changes such as moving or rearranging cat furniture or feeding/bathroom stations, also can cause the fur to fly. Basically, any change in the routine may leave one or more cats so stressed they take it out on each other.

Cats reach social maturity at two to four years of age when many cats first challenge others for status.

Not enough space predisposes cats to territorial disputes. Cats mark property with cheek rubs, patrolling, and urine marking. Some diabolical felines lure others into their territory and then "discipline" the other cat for trespassing. Feline territorial aggression is notoriously hard to correct, and marking behavior is a hallmark of potential aggression. Outdoor cats are more aggressive on their home turf and the cat closest to home usually wins the dispute.

Cats use verbal and silent communication to elevate their status in the eyes of the other felines. They challenge each other with stares, forward-facing body position, hisses and growls, mounting behavior and nape bites, or blocking access to food, play, or attention. Some dominant cats use "power grooming" behavior-energetically licking the other cat-to make her move away.

10 Tips to Stop Cat-to-Cat Aggression

• Reduce the urge to fight by adding more territorial space so the cats don't have to share climbing, hiding, and perching areas. Create a house of plenty with MORE toys, cat trees, litter boxes and feeding stations than the cats can use all at once.
• Electronic cat doors that can only be opened by the collared victim cat will allow her to access the entire home yet retreat to a safe area the aggressor can't follow. These pet doors open in response to the magnetic "key" inside the collar. Look for "keyed" pet doors at pet products stores or on the Internet, and install in your interior door to keep one cat upstairs, for instance.
• Avoid rewarding poor behavior. Giving food or attention to the aggressive cat may calm the angst but actually pays her to be a bully. Instead, catch Sheba before she gets hissy and redirect her behavior with an interactive toy, such as a flashlight beam, to lure her into play in another direction. That can also help her associate good things with the other cat-rather than with being nasty.
• If the toy doesn't work, interrupt with an aerosol hiss. Then once the cat walks away and is calm, reinforce the desirable response-acting calm-by offering a treat, toy or attention.
• Go back to basics and treat the aggressive cats as though introducing them for the first time. It's best to give the victim cat the choice location of the house, and sequester the bully cat in the isolation room.
• If you see no significant improvement within a week, talk with a veterinary behaviorist to see if drug therapy may be helpful. Drugs may help control the aggressive behavior in the bully cat, while decreasing the "kick me" defensive posturing and vocalizing of the threatened cat. Drugs aren't a cure, but can be a tool that helps training work more effectively.
• Once the signs of aggression, anxiety, and/or hyper-vigilance fade, begin to gradually expose the cats to each other in very controlled situations. Begin with the cats in carriers, or controlled with a harness and leash, at opposite ends of your largest room or longest hallway.
• During each session feed cats tasty foods or engage in play. This helps both cats learn to associate each other with fun, positive rewards.
• Interrupt unacceptable behavior (hisses, growls) with a squirt of compressed air or water gun, and toss small stinky treats to reinforce "good" (calm) behavior. Counter conditioning can take months and require much patience and time.
• Once cats have learned to tolerate each other and are allowed to freely roam, create at least two feeding stations and two bathroom locations but the 1+1 rule is even better (one for each cat, plus one). Locate them so cats won't be trapped or surprised when using either.

Thunder and fury with no blood spilled indicates they have excellent bite inhibition. But few fights resulting in lots of damage indicate that at least one of the cats either has very poor inhibitions, or seriously wants to kill the other cat.

Cats that hate each other and draw blood during fights have an extremely poor prognosis. When all tactics have failed to stop two indoor cats from fighting, then ultimately one cat may need to be placed in a new home or permanently segregated from the other in another part of the house. That's NOT giving up-it's making life better for the cats, and you.