Five signs of aggression
Cloaked daggers: a wagging tail doesn't always mean Sparky is happy. Unlike the long side-to-side friendly wag, wagging at shorter, staccato tempo could well mean that the dog is about to pounce.
Pricked ears: depending on the breed, it is a sign of aggression if his ears are pulled back slightly when they are supposed to be straightforward.
Death glare: a long hard stare from the dog is his way of saying "stay away from me, or else..."
The stalker: if a canine treks you for a distance, intense and silent, with his head drooped and neck level, he sees you as prey and is looking for an opportune time to attack.
Baring of fangs: back off if you see a row of white. Interestingly, a dog corrected for growling could be a larger threat because he will forego that warning signal, and go straight for the chomp.
Five causes of aggression
Resource-guarding: Fido has something he wants to keep from you. Aggression could escalate over time if you continually swoop in to take it away. Hire a trainer to correct this behaviour.
Maternal aggression: hormonal changes or genetic predisposition might cause a new mum to go into a frenzy and launch attacks on strangers invading her space.
Pain-related aggression: an animal that is sick or injured could also exhibit signs of aggression.
Seizures or medically related issues: dogs that are prone to seizures or medical issues could exhibit signs of idiopathic aggression. This refers to aggression that seemingly has no apparent cause. These canines are not in total control of their faculties.
Learned aggression: as soon as an animal learns that aggression leads to a successful outcome, it becomes readily accessed. For example, a stray that is aggressive when it comes to food all his life would probably not turn out this way had he been raised in a stable environment.