Why Do Dogs Love Some Dogs and Hate Others?

July 9, 2013

By Langley Cornwell

Dogs are amazing creatures. The amount of information they can discern in a short amount of time is really something. I have a friend whose dog, Sally, is like a cartoon character; everything the dog does is exaggerated. Seriously, this dog should have her own reality show! She’s like the Joan Rivers of canines. She knows in an instant if she likes or dislikes another dog, and she lets you – and the other dog – know it.

To give you the entire picture, I’ll start with the dog. Sally is a seven year-old mixed breed from a shelter. My friend has had her since she was 10 months old. The dog lives in a single-dog household with two cats. She gets along wonderfully with the cats, but my friend has been reluctant to adopt another dog because she can never anticipate how Sally will react to other dogs.

When she’s out walking Sally and another dog approaches, Sally can immediately tell if she likes the other dog or not. My friend works hard on breathing calmly and not communicating anything from the other end of the leash. It doesn’t matter what my friend does, though. Sally will make a snap judgment. She’ll bow up with her hackles raised and begin to bark threateningly, or she’ll drag my friend over to the other dog with her head lowered and her tail wagging in a friendly manner.

Her decision is immediate and unwavering. What’s more, Sally can make her assessment from great distances and it seems to have nothing to do with how the other dog is responding to her. In fact, sometimes she’s sized up the other dog before the other dog even notices Sally and my friend approaching.

When I pitched this article idea, Diane at CANIDAE responded by saying that her dog, Breezie, also instantly decides if she likes or hates another dog, and Diane has no idea why. Other friends have shared similar experiences, so I was curious about what the experts would say.

Jean Donaldson is the founder of the San Francisco SPCA Academy for Dog Trainers. Additionally, she’s authored several books on dog training and behavior, including The Culture Clash and Dogs are from Neptune.

In a Modern Dog magazine article, Donaldson confirms that even properly socialized dogs do not and will not like every other dog they meet. She goes on to liken a dog’s behavior to that of a human. She says that outgoing, well socialized humans do not like every other person they meet. There are even some humans who function well in society but only like a few other people.

The difference between dogs and people is that dogs are able to make faster decisions about who they do and don’t like. I’ll go out on a limb here and say they are able to make more accurate decisions, too. Since the canine olfactory sense is so keen, dogs can determine from a great distance if the approaching dog is male or female, neutered or spayed, and maybe even if they had CANIDAE dog food or something else for breakfast.

It’s not just a dog’s ability to take in so much information via the nose; they are also experts on reading body language – canine and human. They can tell immediately if the approaching dog displays welcoming or rude body language. Even though dogs can’t see details or colors as well as humans, they are authorities on picking up on other dogs’ movements and intentions.

Donaldson also suggests that the reasons for some dog’s snap judgments are based on profiling. Not the CSI version of profiling, but rather a reaction to a certain type of dog; as if a certain category of dog bothers your dog and her prejudice causes a pre-emptive reaction.

As an example, Donaldson shares a personal experience with her Border collie. She says her dog was perfectly nice to most dogs and tolerant to practically all dogs but she hated Standard Poodles – all Standard Poodles regardless of height, size, color, haircut, etc.  Donaldson is convinced her dog’s reaction to Standard Poodles is a result of one slightly irritating poodle on one particular occasion.

Is your dog like Sally and Breezie, or does she love everyone?

Top photo by Richard Harrison
Bottom photo by Hunter-Desportes

Read more articles by Langley Cornwell

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The personal opinions and/or use of trade, corporate or brand names, is for information and convenience only. Such use does not constitute an endorsement by CANIDAE® All Natural Pet Foods of any product or service. Opinions are those of the individual authors and not necessarily of CANIDAE® All Natural Pet Foods.

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  1. JANA LONG says:

    i have a male 17 month old border terrier am staff terrier
    poodle mix . He likes about 90 percent of all dogs but sometimes when he greets one either he and the other dog or he will just get nippy and barky growly. it has happened with large and smaller dogs of different breeds. the only common thing is that they are pretty much all male dogs. one of our trainers say that it is just too much energy. my dog is high energy so i kind of have been able to figure out a bit ahead of time. i dont let him greet dogs if there are 2 on a leash, especially if both are male. that creates too much energy which makes my dog react and get a bit aggressive

  2. Connie Breck says:

    My mixed Great Pyrenees and Saint Bernard mix doesn’t like Boxer/Pittbull mixes. He’s only had problems with those dogs. He’s never been aggressive with any other dog but a Boxer mix. He attacked a very nice Boxer/Pitt for NO reason the other day. When he was younger, he’s only 1 year old now, a Boxer/Pitt mix got him down, playing like MALE dogs do, and wouldn’t let him up. He finally rolled him over and let him know he wasn’t happy. But today was the first time he actually went after another dog at the dog park, which we frequent on a daily basis.

  3. janey says:

    I have a rat terrier at age 3 months when taking her to the vet to trim her nails. a man and woman came in with a boxer… Madison act like she was going to eat that poor boxer up. I thought… I do not like this action. well …. when I took her to be spayed in come a person with a boxer she did the very same thing. then around a year old we were out walking with Madison and a couple walking oh- yes! their boxer Madison acted like she would eat that boxer up. then bingo green light went off to this day if she sees a boxer same thing she acts like she will eat it up. any fur kid she loves and she’s been around many up on many but a boxer. now Madison is 10 years old so it won’t change. I just remove her so she doesn’t get upset or upset the owner and their boxer.maybe something happened at the breeder before I got Madison or she herself made up her mind she just doesn’t like any boxer she see’s.no matter what the reason from the time the green light went off and I learned from her actions . I will show her respect as I am her world and will do what I can to keep it calm and going as easy as I can. I am so glad to know that this is normal and not something that she went through that I was not aware of. enjoyed your post.

  4. Breezie has only been like this in the past year or so. I think it is because she has met so many dogs in her lifetime of going to shows and events that she just knows who she likes and doesn't bother with the pretenses any more.

  5. Unknown says:

    Kimchi has a strong love/hate with other dogs. We can never really predict. When walking on leash, we will pull over and let the other dog pass and in most cases Kimchi will try and lunge at the other dog. Off leash he is a little better but we are always weary. We used to spend alot of time at the dog park but he became bored with it if one of his friends was not there. He would always play one on one and chase off other dogs that tried to join in. They say he does great at the Dog spa though. Is he just over protective of us??

  6. Dakota is more like sally. Not only does HE not like most dogs, many of them do not like him either. It truly makes us sad because he is a great dog! He is a Shetland Sheepdog and they tend to be rather skittish and hesitant to begin with.

  7. I've never understood why it is assumed that all dogs should like each other. I can not imagine expecting to like everyone I meet and I always thought dogs the same way. Some of my dogs are tolerant of other dogs when they are by themselves, but all 6 together, forget it! Their pack mentality kicks in when another dog is near. Doesn't matter who it is.

    Great article!