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Animal Aggressive Australian Shepherd (Also killed another family dog)

My 2 year old Australian Shepherd, Phoebe is animal aggressive. I’ve read several of your posts and I’ve read some awesome answers. However, none that are a perfect fit so here’s my dilemma. Obviously I know she has herding instincts and so this isn’t completely uncommon. She kills birds and snakes and squirrels etc. And that’s fine. Recently she has been killing neighborhood cats, not so okay. Then today, she KILLS another one of our dogs. She was raised with this dog for well over a year! I tried to break up the fight to no avail.

She gets plenty of attention and exercise, so I’m at a loss. Any suggestions for me? She’s usually a well behaved dog. She’s very smart and friendly although she doesn’t like strangers unless she sees we are welcoming of them. I just didn’t know why she would be THAT aggressive especially not being a cross breed. Thank you for your time!

D. H.

Hi D.,

Let me start by saying, take what I have to say with a grain of salt. I’m only going on the basis of the information you’ve shared above and as a result I’m having to extrapolate. It’s not the best medium but it’s all we’ve got. For this sort of issue I’d much rather do a phone consult.

The level of animal aggressive behaviour of a dog like yours can’t be attributed to a single cause. It might be, but that’s rare.

Range of Causes

There are range of possibilities of contributing factors towards this sort of behaviour.

  • Breed
  • Bloodlines
  • Critical socialization
  • Unanticipated faults in genetics
  • Disease
  • Training
  • Handling ability
  • Training methods used
  • Relationship with the handler
  • Day to day environmental influences

The above are a few of the factors that I examine when assessing my aggression cases. Sometimes you can get information in these categories and sometimes it’s not available. If not, it becomes guess work. The value/weight that should be given these guesses is highly dependent on the assessor’s experience.

If I were working with you and your animal aggressive Australian Shepherd, I would be asking quite a few questions before offering a confident opinion as to cause and subsequently treatment. For instance, how does a dog with such a known high prey drive end up with such a high kill rate? That generally indicates that at least part of the problem is tied into your relationship with the dog. The way the dog is handled, and the training approach you’ve used may be a contributing factor as to how things got this far.

Usually a Well Behaved Dog

I’m also leaning towards the relationship/handling as being a potential cause of concern. As a result a place we might start with in our rehabilitation program, based on your describing her as “usually a well behaved dog”. Dog owners that describe a dog that in spite of their best efforts has inarguably become a serial killer, as, “usually a well behaved dog”, are perhaps setting the bar a little low as to what should qualify as a well behaved dog.

I have no doubt that in spite of what this dog has done you still have love for the dog. However, it may be that your love is blinding you a bit to how extraordinary your situation actually is. I’ve found that if this is indeed the case and it’s not honestly addressed it ultimately negatively impacts rehabilitation.

Set Love Aside

Set love aside for a moment and apply this – without distractions – training/respect test which are centered on 3 basic self restraint tasks (stay, recall, loose leash).

1. If you were to make a cup of tea in your own kitchen and told this dog to stay on a mat while you did so would your dog, without treats or your monitoring for the slightest twitch, do so? Or would you be drinking a lot of cold tea?
2. In your own yard, does your dog come when called or does your dog react as if you’ve made a suggestion?
3. Does your dog keep the leash loose regardless of distractions when you say Heel, and walk about the inside of your own home, or yard?

I think a dog that can do these 3 things reliably without serious distractions and without treats is up for consideration as to being on its way to being considered a well behaved dog. However, just barely. If not, something is wrong. You’ve had the dog for some time, it’s already 2 years of age and is of a breed known for their ability to work. It’s possible that your dog sees you as more of a room mate as opposed to the sort of individual it will turn to for guidance. Well trained dogs ultimately learn as part of their training that upon occasion you will not be asking them, but are telling them to do something.

This is important. If you can’t get a dog to exercise it’s suck it up muscles for you when asked to do the simplest of tasks the likelihood that the relationship you have between you is of the sort that will lead to rehabilitation in (whole or in part) and an end to the killing is extremely low in my opinion.

Dog’s Wiring Off?

It’s possible that there’s something wrong with this dog’s wiring as this level of being animal aggressive seems an odd (but not unheard of) characteristic in the breed. I would consider tracking down litter mates from the same or similar litters. See if you can learn if there are dogs from the same bloodlines acting out of context of the norm. Years ago I worked with 3 Australian Shepherd dogs that were over the top territorially aggressive. It turns out they were all from the same litter. Those 3 dogs were all ultimately euthanized and from what I understand so was ultimately the entire litter.

Track Record

I think is worth bringing up and factoring in your track record regarding keeping other critters that come within the range of this seriously animal aggressive dog, safe. I think you’ll likely agree that frankly it isn’t that great. Especially if things have escalated to the point where another dog in your own household has lost its life. For what it’s worth it’s possible that as far as cause the reason for the the dog’s death is unrelated to the others killings. I’d need to ask a few more questions.

It may be that the socially responsible thing to do is to find a more experienced home to attempt rehabilitation. Alternatively, especially considering this background, it might be best to euthanize this dog. I’m all for saving dogs but not at the expense of risking other lives in order to do so. The theoretical ability to rehabilitate a seriously animal aggressive dog vs the practical application, when there’s this sort of risk, I think requires a risk assessment as part of the decision making process.

Safety Tip

animal aggressive CO2 Fire ExtinguisherWhile you’re mulling over what to do with this seriously animal aggressive character, I take it from the way you worded your email that there are still other dogs in the home.

Go out and buy a rechargeable CO2 fire extinguisher (call your local fire department). Take your purchase out into the yard without the dogs but with anyone else in the household big enough to wield it and take turns putting out a pretend fire so you can get a sense of how everything works.

Hopefully there won’t be a next time but, if another fight breaks out instead of trying to physically intervene yourself (worst injuries result from this type of thing) go for the CO2 fire extinguisher. Use it to spray the dogs down. It breaks up most dog fights. At the very least it usually gives the combatants pause. Long enough for you to more safely get them separated without being bitten.


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11 thoughts on “Animal Aggressive Australian Shepherd (Also killed another family dog)”

  1. Dogs who kill or severely injure humans, cats, or livestock should be euthanized, in my opinion, as a matter of protecting public health and safety, the well-being of other animals, and the public view of dogs as generally non-threatening unless severely provoked.

    If a dog kills a rabbit or rodent or anything else that is a dog’s normal prey, this is not by itself reason for alarm, but if a dog kills a cat, the dog is abnormally dangerous, and a child could be the next victim.

    In historical, evolutionary, and normal household situations, cats are ALWAYS dominant over dogs. Cats are the pure predators; dogs scavenge. Cats kill; dogs take the scraps.

    Whether we’re talking African lions and wild dogs, pumas and wolves or coyotes, or leopards and jackals, dogs are instinctively and intuitively submissive toward cats, if not deranged.

    The stereotype of the dog chasing the cat is based largely on poor observation. If you really pay attention to how that scenario plays out, usually the cat invites the chase, and the dog does a play-bow. The dog stops when the cat turns and hisses, or otherwise indicates that it is time to stop.

    Dogs will chase anything that moves, and in a multi-dog, multi-cat household, there are times when dogs will chase the wrong cats, e.g. timid semi-ferals who have not invited it, but even then, the cats stop it. No dog with a functional brain will continue to chase a creature with four sets of daggers as well as teeth. Cats are dangerous, and dogs respect that.

    If a dog does not respect a cat, the dog is lacking the normal inhibitions and socialization that keep most dogs from being dangerous.

    Attacking livestock is also an abnormal behavior. Dogs have been bred for centuries to hunt and guard livestock, so if they pull down and kill sheep, goats, cattle, pigs, or horses, you have out-of-character behavior. However, it is essential to distinguish between a throat-tearing fatal attack and the “guiding nip” that working dogs use to turn animals they are herding. The guiding nip is directed at the legs, rarely actually breaks the skin, and is just meant to send a message, not to do serious injury.

    Merritt Clifton, editor
    [email protected]
    POB 101, Greenbank, WA 98253

    1. Absolute nonsense it has been seen in the Serengeti/the kruger etc time and again lions stealing hunts form hyenas and wild dogs. Domestic Cats are prey and predator animals. There is no way a cat would be dominant over any dog larger then a small terrier. My dogs (and I have had many different breeds and worked with many different breeds) range from not interested in cats to wanting to hunt them down. My two current dobermans were raised with cats but I do not trust them with strange cats. Both my dobermanns hunt rats and birds, an unfamiliar cat is probably going to be no different to them so to avoid this I do not put them in a position to try that theory out.
      If you do not believe me research lions scavenging from other animals kills, they do this particularly often with hyenas. Nature is opportunistic there are no hard and fast rules. Some research has pointed to lions scavenging kills more often then hyenas.

  2. Christine Scolaro

    Help Please. My young Aussie has been raised with two cats. She is pretty rough with them Altho one doesn’t mind. The other is close to terrified of our Aussie. The dog seems to bully the timid cat. But our Aussie and other cat are fond of each other overall even grooming each other.
    Problem is when we lift our cats the Aussie gets crazy biting at their tails and dangling legs. Of course we now hold the cats close and protect their bodies from drooping while we transport them. But after putting the cats down our Aussie wildly jumps on them and “attacks” (without puncturing). And she barks incessantly and chases us when we hold that cats in the air.
    Can you tell me why our Aussie has this extreme impulse particularly when we pick our cats up???
    Thank you sooo much.

  3. We adopted a two year old old Aussie. He was a gem for a month to 6 wks then he started attacking our other dog, growling at my children for hugging me and responded in a puffed up snap at my husband for a collar grab at the door.
    He also started stalking humans.

    We have since rehomed to a home without other pets and kids and knowledge of the situation. it was unsafe for the children and other dog and the balance of a unpredictable dog with our life wouldn’t work but this is the first time I’ve experienced this.

    We have always done rescues but I might feel otherwise now.

    1. Marci Lawrence

      We took a 3 yo Aussie rescue in Jan. He disemboweled one of my Chihuahuas while we were gone last night. I just found this site… trying to make the right decision for him. I’m broken hearted…

      1. Hi Marci, I’m sorry this has happened to you. I’ve found, at least in the region I live, that many rescues operate more like rescue mills rather than rescues that properly screen the dogs they encounter and, or prepare and support the human beings opening their homes. Many times I’ve found they were fully aware of problems and sold the dog without disclosing those problems.

        This may help you make a decision regarding the Aussie you rescued. It’s an article I wrote to help people review the steps available when they have a seriously aggressive dog. SEVEN OPTIONS AVAILABLE TO DOG OWNERS WITH DOGS WITH VERY SERIOUS BEHAVIOR PROBLEMS (AGGRESSION)

        – John “Ask The Dog Guy” Wade – Embracing Science and Common Sense

        Visit For A Free Weekly Newsletter
        & FREE Brain Drain Activity Guide For Your Dog

        PS Don’t forget if you find that the many free resources I provide companion dog owners via Ask The Dog Guy website ( and elsewhere (YouTube, newsletter, etc.) inform, save you time and, or money, why not buy me a coffee? Click the link to Buy Me A Few Coffees

        PPS You can also become a Patron and support spreading the word about science and common sense in companion dog training by clicking on the membership link instead. Click the link to Become An Ask The Dog Guy Patron (Various levels of sponsorship have benefits for you as well.)

      2. K Golab

        Recently my male 65 lb Aussie attacked and kill my little yorkie It was a very vocal and yippie dog so my trainer said some dogs who show no other aggression can have their prey drive triggered from another dog just yelping and will attack it.I do not leave my other little dogs alone with my Aussie anymore and crate him at night for sleeping and he likes that and it keeps my other animals safe.I also bought a special muzzle that he wears most of the time while around my other small animals for their safety and he can still drink and pant just fine he just can’t bite so I feel 1000% better and he gets to stay with our family cause the rescues I called to see if they would take him on and they said no that he would not be adoptable now that he has killed.So this solution works for us just wanted to share as it may help others from having this happen and apparently it can happen at anytime I wish I had known this as I would have done things very differently.

        1. I’m sorry you’ve had to navigate these waters. For anyone else with a dangerously aggressive dog here’s an article I wrote for my Ask The Dog Guy readers on what your options are. Seven Options Worth Considering For Dog Owners with Dogs With Very Serious Behavior Problems

          – John “Ask The Dog Guy” Wade – Embracing Science and Common Sense

          Visit For A Free Weekly Newsletter
          & FREE Brain Drain Activity Guide For Your Dog

          PS Don’t forget if you find that the many free resources I provide companion dog owners via Ask The Dog Guy website ( and elsewhere (YouTube, newsletter, etc.) inform, save you time and, or money, why not buy me a coffee? Click the link to Buy Me A Few Coffees

          PPS You can also become a Patron and support spreading the word about science and common sense in companion dog training by clicking on the membership link instead. Click the link to Become An Ask The Dog Guy Patron (Various levels of sponsorship have benefits for you as well.)

  4. Just wanted to add- it’s not fine for a dog to kill birds or other wildlife. Songbird populations are in decline due to predation by pet dogs and cats.

    1. If this is true, it’s the first I’ve heard of it. The predation of our songbird and other animal population has been attributed to domestic cats, not dogs. Research exists to support feline influence. Zero mention of the domesticated dog in any of the literature I’ve come across.

      The Moral Cost of Cats – Smithsonian


      John ‘Ask The Dog Guy’ Wade
      Embracing Science and Common Sense

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