Interdog aggression can strike with deadly consequences

Dogs within the same household can become violent with each other. Inthe case study explored this month, one dog is killed by another. The storyof these dogs illustrates the classic interdog aggression scenario and allits misperceptions perfectly.

Readers should know that I did not see these dogs. All of my informationcame from the owner of the dogs after the event. Accordingly, the formatwill be a narrative, not a case report.

The story

The client wrote to me five days after the event because she was thinkingof euthanizing two of her dogs. The client shares a house with a roommateand both have dogs. Prior to the tragedy the household consisted of: a 1.5-year-oldunspayed, female, Pembroke Welsh Corgi belonging to the roommate, a 12-year-oldmale, castrated, hound-terrier mix that weighed about 70 pounds, a 45-pound,7-year-old, female, spayed Staffordshire Bull Terrier, a 10-year-old, female,spayed German Shorthaired Pointer belonging to the roommate, a 45-pound,7-year-old, neutered, male Border Collie/Cocker mix, a 13-year-old, female,spayed Cocker Spaniel, and a 3-year-old female, spayed Siberian Husky.

The first three dogs were the ones involved in the attack in which theCorgi was killed. All of the dogs were in the three-quarter acre yard whenthe attack occurred but none of the other dogs appeared to be involved.In addition to being large, the fenced yard has a series of dog pens, kennels,houses, etc. arranged in a way to ensure that each dog can have space andcan get away from others.

The client realized that there were many dynamics in what she termedthe "pack" behavior, so she provided detailed descriptions ofeach dog.

Closer look

The German Shorthaired Pointer was "spoiled" early in lifeand has developed a problem biting people, but not dogs, within the pasttwo years. She has lived with the client's dogs for two years and seemsto find security in being in the group. She is neither the most forcefulor most deferential dog in the group, but sometimes needs a little extraspace.

The Border Collie mix is totally "submissive" to the hound-terriermix. The Border Collie mix would occasionally get into "obsessive"moods where he would posture over the hound cross and give him "theeye". Otherwise, he appeared to be totally playful and outgoing withthe other dogs and with people. This dog has always been with the clientand the rest of the group since early puppyhood.

After the attack, the client gave the Border Collie mix to a friend becauseshe was afraid for him. Although he was not involved in the attack, shedid not understand what had changed so quickly and did not want to put himat risk. And, as her friends had been saying, seven dogs is a lot and mayhave been too many.

The 13-year-old Cocker Spaniel has always seemed to be on her own planet.At the time of the attack she was almost totally blind and deaf. She hadalso been with the client and group since puppyhood, and until a month beforethe attack no one had ever seemed to notice her.

Savage attack

However, a month before the tragedy, the Corgi savagely attacked theCocker with no provocation that anyone could note. The Corgi drew bloodfrom the Cocker's ears and face before the client physically intervened.The hound mix spent the next four days cleaning the Cocker's ears and babysittingher. The client noted in her letter that she, unfortunately, just thoughtthis was "cute" at the time. She didn't see what the hound mixsaw: that the other dogs needed protection from the Corgi.

The Husky has always been outgoing, but like the Border Collie crosswas always "submissive" in the "pack". She apparentlytried to be everyone's friend. Even the older hound mix would run and playwith her. The Husky seemed to be particularly fond of the Corgi, and theyseemed to be "best buddies."

Three to four months before the attack the Corgi started to be very hardon the Husky: games that seemingly started playfully ended with the Corgihanging from the Husky's throat. The Husky seems confused at first, butafter the Corgi hung from her throat a few more times, the Husky becamepatently scared.

The client also noted that whenever the Husky and the Corgi engaged likethis, all of the other dogs moved and stayed away.

All of the client's dogs are kept in a 6-ft. by 24-ft. kennel with housesand fans during the day if the weather is good. If the weather is poor,they each have their own crates in the house. The client's dogs are separatedfrom the roommate's dogs when they are kenneled. At night they all sleepon their own dog beds in the house. Each dog eats in his or her own crate.

There was only one exception: before the Corgi began to terrorize theHusky, they both shared a giant run most times. After the Corgi began tohang from the Husky's neck, the Corgi was moved into a smaller run nextto the Husky.

The client has always obedience trained her dogs and has had large groupsof dogs before. At one point she had eight Siberians and three other dogs,including two of those discussed.

She has been involved in sled dog events and training, shown in conformationand in obedience training. As part of these activities she met many peoplewith many dogs, and when a friend died, she took in her two old Siberiansa year earlier.

These dogs also live on the property, but not with the other dogs. Theinherited elderly female Siberian does not get along with other female dogs,so the client kept these two dogs on an adjacent piece of land.

This was comprised of a 30-ft. by 18-ft. "habitat" with a 10-ft.by 12-ft. building, pool, etc. While her dogs ignored both of these elderlySiberians, she was not willing to expose her roommate's dogs to them directly.

At about a year of age the Corgi began to run the fence line separatingher from the elderly Siberians and barking non-stop. The client respondedby starting to train the Corgi in some basic obedience, but stopped whenshe became busy at work. As the running and barking continued unabated,the rest of the dogs were becoming unnerved by the constant commotion. So,the client tried a shock-based, bark collar for the Corgi. This approachlasted a week, since the Corgi only seems confused by it and began to directaggression to other dogs.

Torment began

In the month prior to the attack, the client noticed that the Corgi reallybegan to torment the Bull Terrier. Any time the client was not directlypresent, the Corgi went after this dog. As soon as the dogs were let outside,the Corgi bit at the Bull Terrier's heels, feet, face and throat. The BullTerrier snapped at the Corgi once, but usually she redirected her attentionto the Husky, snapping and clicking her teeth, but never making contact.The client noted that while she has allowed her dogs to settle things amongthemselves in the past, she has never allowed them to have a knock-down,drag-out fight.

The client noted that if she had to pick an "alpha" dog fromthe group, before the attack, she would have picked the 12-year-old houndmix. He likes peace, and she described him as a "quiet enforcer."

On the night of the attack the client returned home a little later thanusual. It had been cold, so the dogs had been in their runs. It was toodark to see well when the client let the dogs out of their runs. This concernedthe client because the first 10 minutes when they were out was the timeof biggest upheaval.

Because of her compromised ability to monitor them, the client put theBull Terrier on a leash and let all dogs out in the order she always did.After 10 minutes, everyone had settled down so the client took the BullTerrier off the leash. All the dogs then "piled up" at the backdoor for dinner. The porch light was on, so the client went into the houseto make dinner for all the dogs. After about 20 minutes she went outsideto let the dogs in, but didn't notice anything until they had all zippedinto their crates and the Corgi was missing. The client went into the yardto look for her and found her outside the back door, dead.

A check of the other dogs revealed that the Bull Terrier has some cutsthat looked like teeth slashes inside her nostrils, some smaller cuts onher head, and blood on her collar.

The hound mix was covered in blood - his muzzle, the top of his head,both of his ears - but the blood was not his and there wasn't a mark onhim.

The client called her sister and had both of these dogs taken to a kennel.

The Corgi, when examined, had bite marks on her chin and tongue, andfive to six deep punctures on her throat.

What happened here?

How could something go so wrong in a household that had done so muchin order to meet each dogs' needs?

Quite simply, the Corgi was changing - behaviorally, neurochemicallyand socially - as she reached social maturity (theoretical mean ~ 18-24months; range 12-36 months). The Bull Terrier noticed it, and the Huskynoticed it, and changed their behaviors as a result of it.

The client noticed it too, but not in the way that the dogs did. Simply,the hound mix, the dog the client felt wanted peace, protected the BullTerrier from what was like an offensive attack by the Corgi.

He had shown signs of intervening to stop the Corgi's obnoxious behaviortoward the other dogs before: remember his care of the Cocker?

All the information necessary to understand this tragedy is containedin the client's descriptions. So many of her comments highlight myths andproblems in interpretations about canine behavior that it are worthwhileaddressing next month one-by-one.