The world's smallest wolf revealed her true nature when first she saw a piece of raw chicken. It was like seeing the great white shark when its lips roll back ready to bite...

Sadly, the question of where she should deposit that which she no longer needs has challenged us rather than her - we are reduced to shouting 'no' rather weakly after the event. Indeed the event consists of something so small that at times we don't see it at all and nasty skating accidents result.

The dog books tell us we must spot her at the time, then say 'no' in hurt tones. Since she loves us, the hint of a furrowed brow will make her abandon her illegal activity and strive ever harder to please.

Every time she sinks her little wolf teeth into my hand I say 'no' with a wounded and pained expression, but she now interprets this as human affection and wees ever more.

Yesterday we had a success, but it did involve the combined shouting, in forbidding tones, of three people, one of whom picked her up in mid-wee and dumped her on newspaper. She obliged, then rushed to thank me for my praise by sinking her teeth into my thenar eminence. Sadly, I was so grateful that she had desecrated The Sunday Times rather than the washing pile that I offered further praise.

There are parallels with our attempts to persuade our patients to change. Mrs Vast expects us to help, but we offer smiley faces and non-threatening encounters with weighing scales touched by our knowledge of the pending patient satisfaction questionnaires: 'Mrs Vast, your BMI is nearly 60, which is very impressive, the biggest I've seen.'

Thanks to Lulu, I am considering a different approach, one that has us lurking in groups outside the pie shop with a megaphone and a head of lettuce.

When they appear with a pie, a group of nurses and doctors will rush forth from our alley crying 'STOP!' while wielding a cattle prod, and a hoist with which to drop them into the salad.

I'll let you know how it goes.

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