Alan Davies stars as Jack the dog, observing Sarah (Claire Goose), her clothes, her little ways, all with the ironic devotion of a really clever pet. Sarah has a boyfriend, Adrian (Darren Boyd), on whom Jack is not at all keen. She also has an annoying mother (Deborah Norton). We can hear Jack's inner thoughts. No one else can. By Graeme Garden, from an original idea by the late Debbie Barham.

This week brought a poignant reminder of this tradition with the broadcast of About a Dog (Radio 4), the realisation of the last project proposed by comedy writer Debbie Barham before her death, at 26, from anorexia last year. She knew all about the different perceptions of men and women where comedy is concerned, mailing her early manuscripts into editors for consideration using her initials rather than her first name so as to bypass likely prejudice.

Barham began sending sketches and jokes into radio at 14, and despite writing to great acclaim for television, retained her love of radio's unique comic possibilities. This short series about a dog's-eye view of the human world, scripted by Graeme Garden, suits the medium perfectly and avoids the anthropomorphic schmaltz that visuals would bring to it. The result is a very affectionate tribute to Barham, and one you immediately sense has been a labour of love. It's also superb, gentle comedy in its own right, with Alan Davies excelling as Jack, the four-legged friend who always sounds at least mildly put out and bewildered by human foolishness.

While he can't understand sexual foreplay ("I just trot up," he says, "give it a quick sniff and murmur, 'stand still a minute'. That usually does the trick"), he has learned that eating his mistress's dinner from the kitchen worktop isn't a popular move. So he licks it instead. "I can never remember if I like olives," he slobbers, sampling her pizza topping. "No, don't like olives. Actually, that pizza looks better for a bit of a lick - what they call a glaze."

About a Dog (6.30pm, Radio 4), starring Alan Davies and Kate Ashfield, was written by Graeme Garden, based on notes left by Debbie Barham, the talented young comedy writer who died last year. Davies is the mutt Jack (I imagine he'd look like Dougal off The Magic Roundabout); Ashfield is his mistress, Sarah. Jack is as happy as a dog with two d***s until Sarah and her boyfriend decide to move in together.