Pain is divided into acute and chronic pain based on duration and intensity. Acute pain is of short duration and much more severe than chronic pain. Chronic pain is long term (more than 3 months) and is usually of medium to moderate intensity. Therefore, it is much more difficult to notice its symptoms than the symptoms of acute pain. An additional difficulty in noticing pain symptoms in dogs is that they hide their ailments for safety reasons. Pain means that the individual is weaker, which can make it prey for another animal. Therefore dogs try at all costs to hide the fact that something is wrong with them. If they present symptoms of pain, it usually means that the pain is so severe that they stop caring about their safety.

Symptoms that your dog is in pain:

- Curled up position

- Stiffened body

- Elevated abdomen

- Arched back

- Smooth forehead

- Ears laid back and pressed against the head

- Visible eye white and dilated pupils

- Tilt of head in case of ear/neck/teeth, sinus pain

- Bow in case of abdominal pain

- lameness or abnormal gait (paw curled)

- Unnatural positions

Signals of stress from the dog

- Turning/lowering head

- Licking

- Blinking

- Yawning

- Avoiding eye contact, looking off into space

- Intense yawning

- Nervous wagging of tail

- Raising front paw

Changes in behaviour

- Frequent looking at the painful area

- Ears turned towards the sore spot

- Licking or biting the sore

- Continuous circling

- Frequent lying down and getting up immediately

SIGNS OF CHRONIC PAIN IN DOGS:

Absence of some behaviours that were previously present, e.g. stopping jumping on the bed, reluctance to climb stairs.
Unusual behaviours that were not previously present, e.g. laying down in warm places, rubbing against objects.
Any lameness or change in gait (stiff, irregular gait).
Lowering of the head below the back line when moving.
Change in behaviour during the night, e.g. frequent changes of position, circling, sighing.
Failure to lift the paw when urinating, or always lifting the same limb.
Always using the same front paw to climb up and down stairs.
Change of behaviour during the day e.g. with pain in the locomotor system, better behaviour in the morning, worse in the evening.
Unwillingness to change position, e.g. sitting, lying down, especially on slippery surfaces.
Adopting unusual positions, e.g. sitting sideways, straightened hind legs when sitting.
Excessively natural behaviour, e.g. increased drinking of water.
Absence or reduction of natural behaviour e.g. reluctance to eat.
Unusual behaviour e.g. swallowing stones, eating inedible things.
Redirected behaviour e.g. copulatory movements on a pillow or another animal.
Decreased reactivity.
Sleep disturbance.

Due to the fear of offending the sore area by another dog or human, the dog may begin to avoid contact with other dogs, touch or treatments. This fear may also lead to aggressive behaviours aimed at discouraging the dog or human from approaching. The following behaviours may also occur:

- Excessive, inappropriate reactions due to irritation

- Increased distancing signals: muzzle crinkling, growling, snapping teeth, banging teeth, banging closed muzzle when attempting to approach the dog

- No aggression sequence - bites without warning

- Aggressive behaviour in a previously benign dog

- Avoidance of contact with dogs

- Avoidance of contact with people

- Silence and withdrawal from social interaction

- Sadness, lack of self-confidence, anxiety

- Failure to play

- Depression