Indeed, old Zylka puts us both to shame, gambolling down to the river when one or other of us can get that far, turning to encourage us to make the effort and hurry along.

As (according to those that know) she is 87 in dog years, she has a decade on the Moth and a decade and a half on me, we’d like to know what her secret is.

In human years she is 15; Dalmatians are old at ten and ancient at 14. Despite having a Vestibular incident two years ago that temporarily took her legs from beneath her, Zylka recovered to the point where only a questioning tilt of the head says she was ever ill at all.

Her eyes are bright, her nose moist and her gums the right shade of pink. Apart from being a few kilos overweight (aren’t we all?) which gives her arthritis, she is in perfect health.

Perhaps it is the kidney diet that keeps her fit. Zylka does not have kidney problems, but Zahli does. This means finding a dog food that has no grains and no red meat added to it, a difficult task, but there is just one on the supermarket shelves.

The only problem is that Zahli doesn’t like it. She will eat whatever I put with it to make it palatable – chicken wings, white fish, milk – but the kibble itself remains largely untouched, unless a little should happen to stick to the chicken. Even then she’s likely to pick it off carefully between her front teeth and spit it to one side.

Unless we’re quick, Zylka will finish her own dinner – also the kidney diet, because it is good for arthritis too – and then go around and eat Zahli’s.

Zahli doesn’t want us to pick up her uneaten dinner – she wants to guard it all night. This involves being sound asleep in her basket one minute, then shooting out the back like a rocket when Zylka so much as twitches.

Zylka has become adept at pretending she was just going out for a drink of water; or she waits until deep sleep finally overtakes Zahli, and  creeps out so quietly, pushing the screen door open gently it doesn’t crash back into place, we don’t even hear her go. What alerts us is the sound of munching from the verandah – Zylka can get out without making the screen door bang, but she hasn’t perfected the art of eating quietly.

The very advent of Zahli into our lives acted as a stimulus. Zylka was twelve when her mother, Coosh, died. She fell into a deep depression, and was barely eating or walking at all. Then along came Zahli, bouncing all over the place, sitting on the best chairs, eating the best food – pure hatred of the newcomer motivated Zylka, who determined that she would evict her from the house.

When this failed she adopted a regimen of several periods a day when she would growl and bark at the interloper, sometimes chasing her around the living room.

Should Zahli have the temerity to play, snuggle up to us or bounce onto the bed, Zylka shows a set of teeth impressive in one half her age and gives vent to barking that can be heard all up the street.

Life became very uncomfortable for a while, but there was no doubt about it – Zylka had the spring back in her step.

Now, she still feels obliged to remind us all that she is the top dog, while Zahli is merely an unfortunate distraction; but she is glad enough of Zahli’s company when the Moth and I are out simultaneously. She will even groom Zahli on occasion, washing her oversized ears with such thoroughness Zahli puts a paw up in protest.

And, on very rare occasions, she will play with her. These are rather uncomfortable games – Zylka advances stiff-legged on Zahli, Zahli watching nervously, unsure whether she is about to be chastised once again. At the last minute Zylka prances to one side and gives Zahli a broadside with her rotund body.

Zahli skips around Zylka, taking care to adopt the submissive position, sometimes rolling on her back with her legs in the air.

Zylka stands over her triumphantly, looking to us for approval.

“See?” she seems to be saying. “See if you can do that when you’re 87, kid!”