In December, I had a couple of emails from people asking what I recommended as a suitable high-calorie substitute for the Mars bar for a dog. I would like to thank Graham Tweed, a veterinary surgeon, for suggesting what appears to be the perfect answer.

Graham wrote: For more than 50 years, we have produced working dog food for police dogs, agility dogs, sheepdogs, gundogs and, most importantly, working huskies. My main reason for writing is the dilemma of working a gundog in harsh conditions. We make a Pemmikan bar for huskies that will be away pulling sleds for up to six weeks at a time. One bar has about 3,000 calories and is sufficient to feed a husky for 24 hours. It has all the required ingredients for the dogs to work at optimum performance in the toughest conditions. Over the past few years, handlers of agility-, flyball-, sheep-, show- and gundogs, along with greyhounds, have latched on to these bars as a way to give their dog energy at lunchtime, without filling its stomach. The bars are divided into eight squares and one square is enough to boost a dog all afternoon. I have dogs that have worked all season, from grouse and duck to partridge and pheasant. With a cube in the middle of the day, they never suffer from loss of energy.

Graham kindly sent me a sample bar. Named Kronch Pemmikan, it?s made in Denmark and comes wrapped in a reassuringly old-fashioned brown paper bag. It?s when you look at the ingredients that you appreciate why it?s packed with so much energy. It consists of 58.5 per cent crude fat and is made from salmon, fishmeal, barley, maize, brewer?s yeast, sugar beet, garlic and numerous vitamins and minerals. What it doesn?t contain is gluten, soya, intestines or any artificial colourings or flavourings.

The outward appearance is of a slab of chocolate, but the smell is definitely fishy. My spaniels thoroughly approve and I would be surprised if many healthy working dogs could resist it. Pemmikan reaches its full effect after about an hour. Because of this, it?s probably a good idea to split the daily ration into several small portions to keep a constant performance. The manufacturer?s recommendation is that beating and picking-up dogs should be given no more than two squares during the day.

There is one disadvantage, however ? unlike a Mars bar, you might not want to share it with your dog. A bar costs slightly more than £7. For further details, visit www.activepetfeeds.co.uk.

You can email David at STgundog@aol.com