Tony suffers from severe separation anxiety, which means Fayad has had to shift her life to reflect the needs of her dog.
"Luckily my friends (who also have a dog) offered to watch him while I was in Nicaragua," said Fayad. "I kept making sure they really understood what it meant when I said 'Tony can't be alone.'"
Fayad, who lives in Swift Current, Sask., said the man who offered to care for Tony found himself taking the dog to work with him.
"Basically he is never alone," she said. "The only time we leave him is when we get groceries and even then we're constantly checking to make sure we haven't left him too long."
According to Stanley Coren, author of "Do Dogs Dream?" and professor emeritus of psychology at the University of British Columbia, diagnosing anxiety, depression and other mental illnesses in dogs isn't unusual because they share a similar neurochemistry to humans.
He said there has been a lot of research to indicate dogs exhibit symptoms of depression much like a two- to 2 1/2-year-old child would.
"You're dealing with something that's non-verbal, which means symptoms will be mostly behavioural, such as loss of appetite, lethargy and failure to respond to play opportunities that used to make the dog very happy," said Coren.
The identification of depression in dogs began in the early 1980s when Nicholas Dodman, Tufts University's professor section head and program director for the animal behaviour department of clinical sciences, was looking at the symptoms dogs were having.
Because the symptomology in dogs and humans is similar, Dodman started treating the dog with Prozac and the dog showed improvement.
"A whole lot of people considered that confirmation of the fact dogs are having very much the same kind of emotional disorders that human beings have," said Coren.
Eventually Eli Lilly and Company, which first started marketing Prozac, developed a beef-flavoured chewable version of the antidepressant for dogs.
Coren said it is difficult to determine how widespread mental illness is in dogs, but the U.K.'s Sainsbury's Pet Insurance found depression and anxiety are widespread in the British canine and feline population.
Their report showed 623,000 dogs and cats in the United Kingdom had suffered from mental illness in 2008, and more than 900,000 experienced loss of appetite as a result of emotional stress.
As with treating mental illness in humans, Coren said it is important to look at behavioural treatments before popping pills.
While separation anxiety is a common problem in dogs like Fayad's Tony, it is not a disease but a symptom.
"A person would never go to a psychologist and say they are suffering from separation anxiety. The same thing applies to dogs," said Coren. "It is one of those things that is a symptom and is usually caused by the owner."
Behaviour such as making a big deal when leaving and returning home can exacerbate the dog's separation anxiety.
Christine Reynard, who is a certified trainer and owner of Downtown Dogs Metro in Vancouver, has seen how dogs pick up on their owner's cues around going out (such as making lunch and bustling about) and by the time they are actually ready to leave the dog is in a state of panic.
"Separation anxiety is particularly bad for dogs because it is so destructive," said Reynard.
"I've known dogs that have destroyed doors by clawing at them trying to get out. The dogs can actually hurt themselves too. A crated dog will almost pull their teeth out trying to pull the bars of the crate out."
According to Reynard the treatment of mental illnesses in dogs, including depression and anxiety, begins with making sure the needs of your dog are being met, which includes getting enough exercise and stimulation.
"Unfortunately dogs can get left alone for longer than they should and they don't get stimulated enough," she said. "Then you'll see anxious behaviours develop as a result because they don't have anywhere to put that energy."
Both Coren and Reynard agree that, much like humans, lifestyle changes in dogs can contribute to improved mental health. But at times training and obedience work is not enough to fully address the dog's issues and veterinarians can prescribe Prozac and anti-anxiety medications.
Despite Fayad's experience with Tony, which she admits has caused her stress and anguish, she continues to put his needs above her own.
"At the end of the day he is the sweetest dog," said Fayad. "He has really bonded with my daughter and I wouldn't trade that for anything."
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