How your dog’s size and shape influences her behavior

By Dr. Karen Becker


A study published in 2013 by researchers at the University of Sydney suggests that a dog’s size and the shape of his skull play a significant role in his behavior.1 Using the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) as a data-gathering tool, the research team analyzed information on over 8,300 dogs of 80 different breeds and compared them to the shape of 960 dogs of those breeds.

Their results revealed a strong association between height, bodyweight, skull proportions (width and length), and behavior and concluded that smaller dogs show more aggression than their larger counterparts.

“[In] the most comprehensive study undertaken to date, our research shows that certain physical characteristics in dogs are consistently associated with certain types of behavior,” lead study author Paul McGreevy, Ph.D., of the University of Sydney’s Faculty of Veterinary Science told “Essentially, the shorter the dogs the less controllable their behavior is for their owners.”2

33 of 36 unwanted behaviors were size-related

The researchers found that as the height of the dogs decreased, there was an increase in the incidence of mounting behavior, owner-directed aggression, begging for food and attention-seeking. In contrast, increasing height was associated with trainability. Another finding: When average body weight decreased, excitability and hyperactivity increased. The study revealed that 33 out of 36 undesirable behaviors were associated with a dog’s height, body weight and the shape of her skull. Some of these included:

Begging for food Urine marking
Fear of other dogs Peeing or pooping when left alone
Non-social fear Separation anxiety
Attention-seeking Sensitivity to being touched
Mounting people or objects Aggression toward owner

Additional revelations about dog size and behavioral tendencies

Another interesting insight from the study was that while long-skulled dogs (e.g., Afghans, Salukis and Whippets), excel at hunting and chasing behaviors, they also tend to display certain negative behaviors, including fear of strangers, persistent barking and stealing food.

“Given hunting dogs have not traditionally been companion animals sharing close quarters,” said McGreevy, “this may not be surprising.”

Short-skulled dogs like the Pug and Boxer — breeds that have undergone, and in many cases suffered generations of selective breeding to further “enhance” their pushed-in faces — tend to display more puppy-like behaviors as adults. They also seem to have completely abandoned many of their hunting instincts. Some additional observations from the study:

Unwanted behaviors increase as the size and height of a dog decrease.
Dogs with short muzzles engage in more grooming and compulsive staring.
Smaller breeds, especially terriers, showed more stranger-directed aggression. The researchers wonder if terriers were selected for aggressiveness because their job at one time was to chase and hunt underground prey. It could be that smaller breeds with short legs have inherited aggression.
Smaller dogs engage in more attention-seeking behaviors — which are linked to jealousy and territorialism — during times when their owner is paying attention to someone else.
Larger breeds descended from smaller breeds that were meant as companion dogs may have behaviors that are at odds with their body size.
Lightweight breeds are more apt to be excitable, hyperactive and energetic compared to breeds with heavy bodies.
Coping behaviors in response to stress, such as fly-snapping, are related more to a dog’s weight than height. The shorter and stockier the dog, the greater the tendency to display coping behaviors.
Obsessive tail-chasing isn’t linked to size or breed, nor is coprophagia (poop eating), chewing or pulling on leash.

Owners tend to tolerate and even encourage bad behavior in small dogs

In drawing conclusions from their research, the University of Sydney team considered the fact that dog owners may be more tolerant of undesirable behavior in smaller dogs, which may in turn result in increased behaviors such as excessive barking, nipping, eliminating indoors, begging, separation anxiety and attention-seeking.

The researchers speculate that owners of small dogs may encourage undesirable behaviors and predispose their pets to separation anxiety, puppy-like behaviors, mounting and begging. The tendency to keep small dogs indoors and under-exercised may also be contributing factors.

“Undesirable behaviors such as owner aggression, or mounting, occur more often among small dogs. This suggests that, in small dogs, these behaviors are tolerated more than they would be in larger dogs where such behaviors are more unwelcome and even dangerous. Equally, such behaviors in small dogs may be a result of their being overindulged and over-protected,” McGreevy explained.

Another consideration is that smaller breeds are known to be more reactive, neurologically, to stimuli in their environment than larger dogs, who tend to be more laid back.

“These findings … remind us that domestic dogs are an extremely useful model for exploring the biological forces that produce diverse animal structures and their related behaviors,” says McGreevy. “The interaction of nature and nurture in producing the relationships we have described in this study creates a raft of fascinating questions that further studies will address.”

Tiny terror training tips

If you’re a small dog parent and the above study findings resonate with you, there’s no time like the present to help your little one become a better canine citizen. Training a small dog is really no more difficult than training a large one — you just need to make a few accommodations for size.

  1. Stand small — Towering over a dog is intimidating when the animal hasn’t yet learned human body language and vocal tones. And the smaller the dog, the more overwhelmed she can feel in the presence of a big hulking human.

So, when training your little one, until she’s had some experience reading your signals, be sure to show her welcoming eyes, small movements and a soft voice. Don’t deal with her “head on” immediately. Turn slightly to the side and get down close to her level instead of looming over her.

  1. Use small training treats — Tiny dogs need only tiny training treats. Otherwise, you’ll own a not-so-tiny dog in no time. Anything more than, say, a treat the size of a housefly, is too big. You can buy or make treats to break into very small pieces; you can also use some of his regular food, subtracted from his meals, as treats.
  2. Train on her level — Training a small dog from a standing position can be merciless on your back, and the last thing you want is to be in pain when you’re trying to focus on molding your pet’s behavior. Initially you should sit on the floor not only to save your back, but also to appear less intimidating.

Other ways to do training exercises include sitting on a low stool or chair or moving your dog to a comfortable raised surface such as a table or bed.

  1. Use tiny toys and training tools — Your small dog needs a lightweight collar, harness and leash. Generally speaking, leather and chain collars and leashes aren’t a good idea for little guys. I always recommend harnesses for small dogs to avoid neck injuries. Some very small dogs have incredibly fragile necks. And just as his treats should be an appropriate size, so should your small dog’s toys and other supplies like food and water bowls, crate, etc.
  2. Teach your dog a verbal “lift-off” cue — Small dogs are often startled to be suddenly lifted off the ground by a human. If you put yourself in her place, imagining at any moment you will lose the ground beneath your feet, you can see why this is a stressful event. That’s why it’s good to train your dog with a verbal cue that signals you’re about to pick her up. Just make it a simple one-word signal.

To train her to the cue, put your hands on her, say the word and apply just a bit of pressure without actually lifting her. This gives her time to understand she’s about to be lifted. When you know she’s aware you’re about to pick her up, go ahead and do so. Consistent use of the cue will help her learn to prepare for “lift off.”

  1. Respect his smallness — Little dogs can be difficult to train to lie down – and there’s a good reason for it. Your pet is already small and vulnerable, and he knows it. When he’s lying on the floor, he’s even smaller and more vulnerable. He’s also likely to be more sensitivethan a bigger dog to cold, hard or rough surfaces. So, train your little guy to lie down using a soft, raised surface. He’ll feel less threatened and comfier.
  2. Give your little dog some space — As much as possible, your dog should be allowed to meet new people and dogs on her own terms. Picking up a shy or frightened small dog to force an introduction removes her ability to keep her distance if she needs to. So, leave her on the ground, and respect her wishes. If she seems skittish or unfriendly, don’t force the issue. This may be an area where extra work is needed to properly socialize your pet.
  3. Set big dog standards for your small dog’s behavior — If you wouldn’t allow a 70-pound dog to jump up on you, don’t accept the behavior from your little one. Reward only desirable behavior and ignore behavior you want to extinguish. Little dogs can learn to sit and stay just like the big guys do. The same goes for jumping up into your lap, charging out the door ahead of you or ripping treats from your fingers. Don’t accept rude behavior just because your pet is small.

Lastly, treat your little dog like a dog! He’s not a baby or a dress-up doll. He needs to be socialized, which means having lots of positive experiences with other dogs and people. He needs to be on the ground much of the time so he can learn how to climb stairs, get into and out of your vehicle, and move confidently on all kinds of terrain.



Love These Chews, but They Fracture Teeth Like Dogs Crazy

By Dr. Becker and comments by Diane Weinmanndog-with-bone-2

When it comes to recreational bones and chews for dogs, antlers seem to be a blessing for some dogs, and a curse for others. The upside to antlers is that most dogs seem to love them, they’re long-lasting and they help keep teeth clean.

However, an increasing number of veterinarians are discouraging dog guardians from offering very hard chews, including antlers, due to the potential for broken teeth. In the U.K., veterinarians have seen a steady increase in fractured carnassial teeth. And while broken teeth are common in dogs, fractures in back teeth are not.


The veterinary dentist Dr. Becker works with is fond of saying he has been able to fund an entire wing of his dental clinic thanks to dog owners offering antler bones to aggressive chewers!

Anything your dog chews on that is harder than his teeth can cause a fracture, largely due to the force with which dogs are able to bite down. This typically occurs when a dog moves the chew or bone toward the back of his mouth on one side and chomps down on it like this fellow here:

According to the U.K. DentalVets group, “The teeth damaged have all had the same buccal slab fractures of the upper carnassials (see image). Many have fractured so severely that surgical extraction is the only treatment possible.”1

What Happens When Your Dog Cracks a Tooth

When your dog breaks a tooth, the pulp — which is the sensitive nerve inside — can be exposed. Not only is an exposed nerve extremely painful, it can also lead to a deep infection and root abscess.

Most pets with tooth fractures don’t show obvious signs of pain, but sadly, many suffer silently for weeks, months or even years before the situation progresses to the point where they can’t eat comfortably and lose their appetite. The longer a broken tooth goes untreated, the worse it gets.

Oral bacteria can invade and infect the tooth pulp and cause it to die. Next, the infection often moves from the root tip to the bone, destroying it. In severe cases, the infection moves past the bone into the skin, forming a facial fistula (a whole in the face through which the infection drains).

Fortunately, not all broken teeth are so serious. If only the enamel has been fractured, the tooth can often be smoothed to remove sharp edges.

However, if x-rays indicate the tooth is dead, if pulp is visible or if the tooth has turned from white to pink, purple, grey or black, treatment typically involves either extraction or root canal therapy.

It’s important for every dog parent to understand that a fractured tooth requires prompt veterinary care.

Antlers and Other Hard Chews Result in Lots of Fractured Teeth

I spend a lot of time with dog parents going over detailed recommendations for appropriate recreational bones.

Some of my clients think I’m overplaying the importance of choosing the right type of bone for their dog, but part of the reason I’m so detailed and thorough is to avoid fractures and other chew bone-related catastrophes.

There are some dogs for which no bone or chew is appropriate because they are just too aggressive, or they’ve already broken too many teeth. The veterinary dentist I work with, Dr. Stephen Juriga, sees hundreds of cases of fractured teeth as a result of inappropriate raw bones, and not just from my practice.

He notes that antlers are often a problem, as are Nylabones. Anything you can’t put a dent in with your fingernail has the potential to fracture the crown of your dog’s tooth.

It’s very important to pair the personality, breed, age and tooth condition of the dog with the right type of chew. One size does not fit all when it comes to recreational chews and bones.

The Type of Chew I Recommend for Forceful Chewerschewing-bone

The first thing to ask yourself: “Is my dog an aggressive chewer?” This type of chewer is more interested in eating the bone than leisurely gnawing on it. She wants to consume the chew in its entirety, and the sooner, the better.

Many aggressive chewers fracture their teeth. They acquire multiple slab fractures in their eagerness to break the bone down as quickly as possible. These dogs get hold of a bone and chew like mad, fracturing or wearing down their teeth very quickly.

If this describes your dog, needless to say, she shouldn’t be given hard bones like antlers or marrowbones smaller than the size of her head. I also advise against thin or narrow bones that fit nicely into her mouth, allowing her to apply a strong vertical bite force.

My pack includes pit bulls who are very powerful chewers. They’re not into swallowing their bones, but they’re very passionate chewers. Offering them small, narrow femur rings or antlers would be a really bad idea, because the vertical bite force as they chomped down on an antler could easily break teeth.

What I offer my pitties are big, raw knucklebones. Raw knucklebones are much softer than rock hard antlers and are gentler on the teeth. I also monitor their chewing very closely, because they can whittle a large bone down to the size of a ping-pong ball in about an hour.

Once a bone is that small, it’s too small to be safe, so I watch my dogs closely and when they’ve worked a bone down significantly, I take it away.

Are Antlers Appropriate for Any Dog?

If your dog happens to be a soft chewer who just enjoys holding or gently gnawing on a bone, antlers may be a good choice. You can purchase elk, moose or deer antlers, and they’re very economical because they last forever.

Antlers come in a variety of sizes and can be split, cut or whole, but again, you don’t want to give a small antler to a large dog because of the potential for tooth fracture. Giving small antlers to small dogs and big antlers to big dogs is fine, but first you want to make sure they’re gentle chewers.

An alternative for any chewer is sweet potato chews or liver chews.  They are nutritious for your dog and will not hurt their teeth no matter how hard they chew.  Contact Diane Weinmann to find out where to purchase them.  See