What is stress?

According to the Oxford Living Dictionary, stress can be defined as a “… state of strain or tension resulting from adverse or demanding circumstances.” While our use of the term typically suggests something undesirable, the causes for stress are not simply negative (adverse), but can also be positive (demanding). For example, we will experience it both if we are about to be attacked, or if we are to embark on an exciting new project.

What are the causes?

Like humans, dogs react to what they feel, see, hear and how they interpret the world around them.

Internal and external stimuli: Stress can be a response to a stimulus either from within the body or from the surrounding environment, and sometimes a combination of the two. It is a natural response that prepares body and mind for a reaction to those influences or as an instinctive alert to something threatening, e.g. danger or pain. Or it can arise from factors which are normally perfectly innocent and rather positive, such as excitement.

External stimuli causes can include (but are not limited to):

• the uncertainty of moving to a new home or other unfamiliar environment
• the presence of a new or unfamiliar dog
• the presence of a new or unfamiliar person
• unknown objects
• loud noises
• any of the above that have caused bad experiences in the past (e.g. manhandling from a person, an aggressive dog of the same size/colour, fireworks etc.)
• presence of a toy or beginning of play
• presence of a known dog or person who brings excitement

Internal stimuli causes can include (but are not limited to):

• physical pain
• unmet needs e.g. lack of mental stimulation, insufficient sleep/rest
• allergies
• neurological disorders
• anxiety and fears
• drives/breed-specific instincts
• disease
• illness

Signs of stress in dogs

Why we need to know them: It is crucial that we are aware of our dogs’ communication methods, and any signs of stress – in other words, how they show when they are uncomfortable. Identifying, respecting, and responding to our dogs’ body language and signals is paramount in identifying what the source(s) may be, lessening or removing the source of stress, and generally understanding our dogs’ likes, dislikes, preferences, and fears. Having complete understanding means that we are also able to avoid potential negative stress, and if appropriate, help gently and positively teach our dogs how to cope with or manage the stress, should it arise in the future. 

What to do if we notice them:

When we recognise signs of stress, we need to address both the immediate stimulus and the dog’s wider circumstances (e.g. their history, or the behaviour of the person or other animal involved in the specific situation). As explained above, the causes might be found internally within the dog, or in the environment. 

Sudden changes in behaviour such as defecating indoors, showing signs of aggression, or physical signs such as skin rashes and excessive panting, etc. may indicate that there is an underlying physical reason that requires further investigation by a veterinary professional.

Like humans, every dog handles stress differently, and some better than others. This capacity is influenced by learned experience and, to a degree, by breed. In addition, ageing has a negative influence on an individual dog’s capacity to cope with stress mainly due to degeneration of nerve tissue. In dogs, in just the same way as it is with people, being incapacitated by arthritis, dementia, or other conditions presents challenges that make everyday activities seem more difficult to cope with, as any further induced stress will come on top of these chronic ailments. 

Mental and physical responses: In situations of stress, both mind and body are involved. This means that a perceived threat will create a mental impulse, which in turn triggers a bodily reaction e.g. panting and raised hackles (the hair between the shoulders and along the back). Alternatively, physical distress (e.g. pain) can cause a mental response that shows itself in changed behaviour e.g. rigid body posture and lip-licking.

What are the signs to look for?

The indicators shown below might not always appear to be associated with stress, but any type of stress (positive or negative) sets in motion a complex set of mechanisms inside the body and the brain.

The list below is not exhaustive. Canine psychology is still a relatively young discipline with much still to be discovered. 

Terminology

When discussing canine behaviour, many signs and symptoms are an instinctual response to the stimuli causing the stress (a.k.a. the stressor). The main instinctual responses are commonly known as the ‘Four Fs’, and Displacement Behaviours:

• Fiddle – these are most commonly seen when the stressor is either another dog, or a person. These signs or behaviours are the dog’s way of communicating that they are uncomfortable and/or don’t want the problem to escalate. 
• Displacement behaviours – similar to fiddle signs, these occur when dogs find themselves in a situation that arouses two possible, conflicting responses, such as fight or flight. It is thought that these actions provide the brain with a time-out, during which it can go back to a calm, basic default position to retreat and reassess the situation seeking the most appropriate response.
• Flight – this response is most often seen when the cause of the stress is environmental. If the dog is able to escape from the stress, they will often flee.
• Freeze – if the dog cannot flee, one option is to stay completely still and hope the stressor will go away on its own.
• Fight – this is usually the last resort, after all other reactions have been attempted. If the dog cannot escape the stress, the last option is to fight it.

The following list outlines several stress signs (both physical and behavioural), however is not exhaustive: 

N.B. Please note that many of the signs below can be indicators of underlying health conditions, alternative causes, and indeed some can be present when the dog is happy and not at all stressed. It is important, therefore, to take into consideration the whole situation, environment, context, and accompanying signals from your dog.

Aggression (increased)	An overall increase in aggressive behaviour may indicate underlying health concerns such as pain, disease, arthritis etc. Consult your veterinarian and a professional
Air snapping	Fight – a precursor to a bite. Respect and adapt to this message; failure to take notice of your dog’s communication will likely result in more ‘effective’ aggressive behaviour in the future
Appetite (reduced or no appetite)	Instinctively, when stressed, the dog may eat less or not at all; this is to prevent weighing the body down further if the dog needs to flee. Additionally, this allows the body to prioritise blood flow to muscles and organs required for the flight or fight response, rather than supply the gastrointestinal system
Baring teeth	Fight, usually accompanied by vocalisation and raised hackles.   Some dogs show their teeth in a ‘grin’- this is NOT a smile and is often a Displacement behaviour
Biting	Fight, not to be confused with mouthing. Mouthing is most common with puppies, but some dogs may do this as an outlet for built-up excitement or nervousness. If persistent or severe, consult a professional. Caution: never punish a bite – a dog will only bite if they feel there is no other option. Any punishment will worsen the situation and can easily lead to future behavioural problems and aggression. If necessary, consult a professional
Body posture (stiff)	Freeze
Breathing rate (decreased/holding breath)	Freeze
Breathing rate (increased/panting)	When stressed, your dog’s heart rate often rises and blood flow increases, resulting in excess heat which must be dissipated, this results in panting. Panting can also occur with excitement, after exercise, or when hot. Take the context into consideration. Unusual or out-of-context panting may indicate underlying stress. Caution: If breathing rate becomes in any way abnormal, particularly on very hot days, and is combined with factors such as drowsiness and lethargy, this may indicate a serious underlying medical issue. Consult your veterinarian. Remember, ‘Dogs Die in Hot Cars’
Circling	Displacement behaviour: Slow (similar to humans pacing), which indicates negative stress   Fiddle: Frantic spinning which indicates excitement
Cowering/crouching	Displacement behaviour: Cowering the length of the body to the floor is your dog’s way of making themselves seem smaller and less intimidating.    Fight: Crouching, however, can be preparation for a pounce or attack
Diarrhoea	May indicate stress (both negative and excitement); take context into consideration. May also indicate underlying health issues, if persistent or severe, contact your veterinarian
Drinking (increased)	Dogs may drink as an attempt to alleviate discomfort or pain, or as a means of replenishing expended reserves. If persistent, consult your veterinarian
Escape (or attempts to escape situation)	Flight
Eyes (averted)	Often accompanied by lowered head; signals a desire to avoid confrontation and/or conflict. Direct eye contact between dogs is an aggressive behaviour.
Eyes (‘whale eye’)	Showing a portion of white of the eye indicates uneasiness and is a Displacement behaviour
Fur/hair (loss)	Hair loss can be caused by stress itself, but can also be a symptom of other stress-induced concerns e.g. obsessive licking   Consult your veterinarian, as this may be a result of other medical conditions e.g. parasites, hormonal defects, allergies etc.
Hackles (raised)	Can indicate both mild stress e.g. noticing an unknown person; or aggression e.g. accompanied with bared teeth and growling
Licking and biting (obsessively; own body)	Light grooming can be a Displacement behaviour   Obsessive, or relentless and otherwise uncaused licking and biting of the body can indicate both external stress, and is one way of coping; but also internal stress, and is a sign that your dog may be in pain or discomfort. Consult your veterinarian
Licking and biting (obsessively; objects)	Casual and infrequent chewing of objects is common amongst puppies. Excessive licking and biting of objects may indicate stress, as chewing is self-soothing for dogs.
Rolling on to back	Predominantly a Displacement behaviour/Fiddle sign, however some dogs learn to do this to ask for positive attention and fuss from humans.  Take context into consideration- if you do not know the dog well, assume the dog is stressed
Scratching (own body)	Displacement behaviour/Fiddle
Sneezing	Displacement behaviour/Fiddle
Sores (body)	May be caused by excessive self-grooming; see Licking and biting (obsessively; body). May indicate underlying health condition; consult your veterinarian
Skin (rash)	See Skin (reddened), may indicate underlying health condition such as allergies; consult your veterinarian
Skin (reddened)	With the increase in blood flow often seen with stress, your dog’s skin may appear flushed or reddened.  Look out for sudden itchiness, hair loss, crusts etc. – these can have many causes including parasites and internal problems. Consult your veterinarian
Tail (between legs)	Can indicate nervousness, discomfort, pain, and stress. Look for context and accompanying signs
Tail (raised)	Alert, inquisitive, assessing the situation
Tail (straight and rigid)	Alert or as part of Freeze response
Tail (wagging; fast)	Tense, rapid wagging at the end of the tail, with a rigid base indicates stress
Tail (wagging; slow)	May indicate stress, uncertainty, and is also a Fiddle sign
Toileting (decreased/no)	May indicate intense stress or underlying medical condition; consult your veterinarian
Toileting (indoors)	Most often associated with separation anxiety (and if so, usually accompanied by vocalisation and destructive behaviour)   If your dog toilets where they shouldn’t (and don’t normally), other causes must be considered and may require veterinary attention; e.g.: change in diet, change in feeding times, medical reasons (infection, parasites, ageing etc.)
Urination (submissive)	Most common in puppies, although can occur at any age.  Entire (unneutered) males may do this voluntarily when another unfamiliar dog enters their personal space.    Caution: other causes must be considered, including bladder infection, kidney problems, ageing. If in doubt, contact your veterinarian
Vocalisation (growl, bark, grumble)	May occur during animated play, and barking as part of separation anxiety or to get your attention- take context into consideration Fight, used as a caution   Caution: never punish a growl- a dog will only growl when they feel there is no other option. Any punishment will make the situation worse and can easily lead to future behavioural problems and aggression. If necessary, consult a professional
Vocalisation (whine, whimper)	Most common with puppies, may be due to separation anxiety, or a physical need such as hunger or needing to go outside to toilet
Vocalisation (yelp)	Indicates pain, if this continues, consult your veterinarian
Weight (loss)	See Appetite (reduced/no), may also indicate underlying medical condition, consult your veterinarian
Withdrawing	Displacement behaviour/Flight
Yawning	Displacement behaviour/Fiddle