FOR no apparent reason, Biffy seemed to be withdrawing from family life.

Once a lean, fit Springer Spaniel in name and in nature, he had been at the centre of his family for 10 fun-filled years; an ever present in every activity, even when he really wasn’t supposed to be there (think emptying the dishwasher, cooking an evening meal and changing the bed).

But he had been slowing up for a while. Some months ago, he had given up on his favourite ball chasing activity. He would go after the first one that was thrown but return with it reluctantly and then his interest quickly dwindled.

After a lifetime of being first (and noisiest) at the door to greet any family member or guest, he now resolutely refused to leave his basket unless he was seriously cajoled.

Normally, he was Mister Playful, instigating games with anyone he could find, dancing around them and barking to get their attention, but this had stopped too. His days were spent lounging in his bed and his nights were pretty much the same.

With heavy hearts and sore heads, his owners had started the ‘what's his quality of life?’ discussion. It’s a hard one to have when the decline is slow and drawn out. Is there ever a right time?

Then things suddenly got really serious. From nowhere, absolutely out the blue, Biffy, the best ever family pet, bit the owners' grandson.

I had always known them to be a pragmatic pair, so was not surprised when they arrived at the surgery, slightly tearful, but determined that the situation required drastic and determined action.

They wanted Biffy to be put to sleep forthwith. They simply could not take the chance that his aberrant behaviour would be repeated.

Most people react to trauma with a purely emotional response. Sometimes, but not always, you need to stop, compose yourself a little, and wait for some rational thinking to kick in.

What Biffy had done was completely and utterly out of character. He had never shown any aggressive tendency ever. This was not a 'straw that finally broke the camel's back' occurrence.

Careful discussion with the owners and eventually their daughter, revealed that the grandson had run up to Biffy when he was asleep in his basket and smacked him playfully but quite hard on his bottom. He had not, despite his rather dramatic and hysterical response, actually been bitten, although Biffy had most certainly bared his teeth at him.

Meanwhile, poor old Biffy stood benignly in the corner of the consulting room, apparently blissfully unaware of all the raised voices and commotion. And, of course, that's exactly what he was. Completely unaware. Because he was stone deaf.

It explains it all doesn't it? No longer reacting to his owners' shouted recall and joy at his retrieve he had given up on the ball. He no longer heard a vehicle arrive or the front door open.

Unable to hear conversation, he felt ostracised from his family. And then he got the fright. It was time for a rethink. Find out next week.