Feelings like anxiety evolved to protect dogs from danger. The cortex of the dog’s brain recognizes a threat or a stress and communicates with the rest of the brain through the limbic system, triggering a cascade of chemical changes that affect the entire body. But if these changes last too long, or get triggered too easily by inappropriate stimuli, then emotional disorders may result. The sustained release of stress chemicals can cause long-term damage; and when this happens to older dogs, there is an Alzheimer’s-like deterioration in brain function.

The role of brain chemistry
The eloquent American neurologist Robert Sapolsky wrote, “People with chronic depressions are those whose cortex habitually whispers sad things to the rest of the brain.” In people and in dogs, this whispering takes place in the limbic system of the brain, where mind and body meet. The limbic system is a spider’s web of interconnections in the dog’s brain that orchestrates instincts and emotions through its production of chemical messengers called neurotransmitters. These brain chemicals, such as serotonin, have a great influence on mood, and in humans decreased serotonin levels are linked with depression. Some research in dogs suggests that serotonin is also related to confidence: top dogs have high levels of serotonin, while underdogs may produce less. In humans, levels of mood-altering neurotransmitters can be controlled by drugs and through psychotherapy and counselling. In dogs, techniques such as obedience training, desensitizing, counter conditioning, and exercise all affect neurotransmitter levels, behaviour, and emotions.

Phobias and anxiety
A phobia is an irrational fear of an object or a situation. Dogs develop rational fears – of veterinary clinics, for example – but also irrational fears, of thunder, or men wearing hats or carrying umbrellas. Dogs may also become irrationally anxious when, for example, their owner leaves the room. Phobias and anxiety lead to panic attacks, in which a dog hyperventilates and his muscles become tense. They can also lead to compulsive behaviour, in which a dog ritually performs a certain activity, such as pacing back and forth. An inability to relax or to sleep is an extreme form of canine anxiety. Depression may manifest itself in decreased or, rarely, increased appetite, clinging, or “remote” behaviour, irritability and lethargy.

Excessive Agression or Timidity
Its important to note, that both excessive aggression and excessive timidity are generally not emotional disorders, isntead they are biological, or genetic disorders. A dog that can not help but to attack anything that moves, or a dog so frightened of everything it continually shakes, generally has a genetic problem causing this, and no amount of doggy counselling will avail them. A dog brutalised as a puppy however, may have similar symptoms, and respond well in a loving household.

Diagnosis and treatment
Phobias, anxieties, depression, and grieving have not been considered an integral part of veterinary medicine until recently, and many vets are still uncomfortable in applying these terms to dogs. If you suspect that your dog has psychological problems, seek out a veterinary surgeon with advanced training in behavioural medicine. Dealing with behavioural problems usually involves a combination of drug treatment and therapy. Sedatives such as acepromazine may be used to tranquillize anxious dogs. Anti-anxiety drugs such as diazepam may be prescribed for short-term anxiety, such as that associated with travel. Increasingly, veterinary surgeons are treating canine emotional disorders with a combination of environmental enhancement, desensitizing or counter-conditioning training, and newer mood-altering drugs, such as clomipramine and amitriptyline, which work on neurotransmitters in the brain.

Age-related behaviour problems
The term “canine cognitive dysfunction” (CCD) is often used to describe the deteriorating behaviour patterns associated with old age. The term “senile dementia” is also used in the same context. Dogs exhibit most of the signs of senile dementia that are seen in humans – standing at the wrong place by the door when wanting to go out, for example. Some dogs bark absently; others seemingly forget why they are where they are. Some aspects of aging are irreversible but others can be delayed, or even reversed, with effective use of licensed medication. The drug selegeline, used for delaying the development of advanced symptoms of Parkinson’s disease, is licensed for use in dogs. All older dogs benefit from routine, daily mental stimulation.