What is small dog syndrome?
Small dog syndrome is the name given to a collection of behaviour displayed by small dogs, behaviours that have the effect of overcoming any deficits caused by being small in stature. Typical behaviours displayed include:

  • Excitable behaviour
  • Jumping up on owners, other people or dogs
  • Growling at people or other dogs
  • Lunging or snapping at perceived threats
  • Avoidance or fear of larger dogs, typically hiding behind or trying to be picked up by owner
  • Reluctance to move off sofas and beds
  • Failure to obey commands

This does not mean that every small dog will display these behaviours, or that each of these behaviours is indicative of small dog syndrome. Collectively, however, these behaviours make life with small dogs difficult for owners and for other people and animals around them but there are ways of improving their behaviour.

Are there differences between large and small dogs?
Dogs come in all shapes and sizes, from the tiny Chihuahua, at under 2.5kgs, to the tall Irish Wolfhound and the heavy (>90kg) Mastiff breeds. Historically humans have bred dogs to be large, to help us hunt and guard, or small, to hunt in more enclosed spaces or simply to keep us company.Small dogs and large dogs grow at different rates with smaller dogs reaching maturity faster than their older counterparts. They also age more slowly meaning that they often have a much longer lifespan. Good news for owners of small dogs.

The metabolisms of small and larger dogs differ too, with smaller dogs having a faster metabolism. This means that smaller dogs may need to be fed more often to ensure they obtain their dietary requirements. Alternatively they can be fed a small dog diet which has all the correct nutrition for their optimum health and may also come into smaller sized pieces of kibble, helping keep their teeth clean.

Do dogs know their own size?
Dogs do like to play with dogs closer to their own size, so it is likely that they have some concept of their own size. Dogs also have the ability to assess the vocalisations and judge the size of other dogs. When listening to recordings of growls, large dogs reacted to the growls of smaller dogs. Smaller dogs were less likely to react to all other dogs. More good news for owners of small dogs, if this means that their dogs are less likely to get involved in combat with other dogs.

How humans affect dog behaviour 
Changing dog behaviour generally involves changing owner behaviour too and, in fact, this syndrome may have more to do with the owner’s behaviour than their dogs! Understanding dog behaviour, and how humans affect it, is the first step in improving small dog syndrome…

There is no doubt that many small dogs get away with behaviours that owners of large dogs would not allow. Jumping up on us, for instance. A large dog would be more likely to knock us over but a small dog can often be encouraged by owners.

Inadvertently, owners often reward the very behaviours we dislike. If your small dog runs to you and begs to be picked up when they encounter a large dog and you oblige, you have reinforced this behaviour and your dog will continue to react this way each time they encounter a large dog.

Small dog owners are less likely to train their dog than owners of larger dogs. Trained dogs are more likely to obey commands, therefore this may be the reason that smaller dogs appear so disobedient. It is because they have never been trained.

What about differences in behaviour?
Increased size and weight may give dogs more strength to reach bench top surfaces, to open doors for disabled owners or to fight other dogs, if necessary. There are, however, also advantages to being small in the canine world… being allowed on their owner’s bed, sitting on laps, being carried around – all can become adored habits of pampered pooches and their owners.A dog, however, is still a dog. Dogs, of all sizes, have the ability to guard property, resources and their owners. All dogs can attempt to steal food or sneak on to the bed while their owners sleep. All dogs are capable of cuddles, playtime and can be trained to extraordinary levels, with patience and committed owners.

Small dogs are renowned for the afore-mentioned behaviours related to ‘small dog syndrome’ but they are also often more fearful than their larger canine compatriots. This fear or anxiety, which is exacerbated by any punishment dealt by the owners, may be expressed as aggressive behaviour when the dog feels threatened. This behaviour gives the impression that small dogs perceive themselves to be bigger than they actually are…

Improving Small Dog Syndrome
Unwanted behaviours in small dogs, such as excitability and poor obedience, are considered to be directly related to owner behaviour. The following owner behaviours may improve their dog’s behaviour:

  • Be more consistent in interactions. Set the rules and boundaries and ensure all family members stick to them.
  • Engage regularly in play sessions with your dog and allow your dog to play with others, especially those of their own size.
  • If they dislike larger dogs, introduce them to ones that you know are friendly and gentle.
  • Do some training with your dog. Ask for commands to be obeyed, for example a ‘Sit’ before feeding them.
  • Avoid any use of punishment. Instead train your dog and motivate them to want to follow your commands.

(1)    Rezac, P., Viziova, P., Dobesova, M. & Pospisilova, D (2011). Factors affecting dog–dog interactions on walks with their owners. Appl. An. Behav. Sc., 134: 170-176.

(2)    Taylor, A.M., Reby, D. & McComb, K. (2010). Size communication in domestic dog, Canis familiaris, growls. Anim. Behav., 79: 205-210.

(3)    Kobelt, A.J., Hemsworth. P.H., Barnett, J.L. & Coleman, G.J. (2003). A survey of dog ownership in suburban Australia—conditions and behaviour problems. Appl. An. Behav. Sc., 82: 137 – 148.

(4)    Khoshnegah, J., Azizzadeh, M. & Gharaie, A.M. (2011). Risk factors for the development of behavior problems in a population of Iranian domestic dogs: Results of a pilot survey. App. Anim. Behav. Sci., 131:123-130.

(5)    Arhani, C., Bubna-Littitz, H., Bartels, A., Futschik, A. & Troxler, J. (2010). Behaviour of smaller and larger dogs: Effects of training methods, inconsistency of owner behaviour and level of engagement in activities with the dog. Appl. Anim. Behav. Sci., 123:131-142.

More evidence of small dog syndrome with Prof Paul McGreevy