LAST week, I told you about Gus, an apparently amiable, gentle giant of a dog who suddenly and without warning killed a host’s cat when he was attending a house party with his owner.

I made the point that despite the thoughts of his owner, who considers him to be her best friend, he remains a dog, with doggy thoughts, canine instincts and none of the social skills that humans learn through normal society.

But that doesn’t mean that I underestimate dogs. Oh no.

Remember Gus, but meet Glen.

I love Glen. Glen is an amiable but near geriatric West Highland White Terrier who belongs to a client I have known for so long that she seems more like family than a customer.

He is the third generation that I have looked after and his two predecessors, who were together for most of their lives, were similar in nature. All were happy, hardy and reliable, just the way pets should be, and all proved that, if you treat them right, they behave right.

Sure, given the breed involved, they suffered minor issues with itchy skin here, a sore ear there and the occasional upset tummy, but generally life was good and the companionship they provided was priceless. But then things changed.

Glen, normally so laid back and unfazed (even by the appearance of a new, rather naughty Westie puppy), suddenly became an agitated wee dog.

Sitting still became a difficult thing for him to do. He was restless, unsettled and discontented.

From nowhere, symptoms of separation anxiety appeared, so that he barked relentlessly and paced whenever his owner left the house. At night, he slept poorly, always looking to his owner for her reassurance. He did not seem like a happy dog at all.

Fearing he might have the start of Canine Cognitive Disease (a disorder much like Alzheimer’s in humans), Glen was put onto mediation in an attempt to improve the stressful situation. But it didn’t work. Then things got worse.

After a routine mammogram, his owner was diagnosed with breast cancer and the inevitable series of hospital appointments meant she was in and out the house more often.

Glen’s symptoms were exacerbated and the wee guy seemed miserable all the time. Given the circumstances, it was especially difficult for his owner.

Eventually, after biopsies and MRI scans, her oncology consultant arranged a date for surgery during which he would attempt to excise her cancer.

She fretted about how Glen would react to her absence and worried more about him than her own recovery.

But the day dawned, she recovered well and her surgeon advised her he would contact her in a week or so with the pathology results that would determine whether she would need further surgery or the chemotherapy she dreaded.

But as soon as she got home she knew she was going to be okay. Remarkably, Glen was immediately back to his usual calm self.

A week later, her consultant confirmed what she already believed. Her cancer was completely gone. And with it went Glen’s agitation. However do they know?