'DOG food manufacturers are part of the problem,' said MP Chris Mullin last week, as he tabled his Early Day Motion in Parliament in support of our Dirty Dogs Campaign. 'Let's hope they can be part of the solution.'

Many of our readers agree. Dog food is a massive industry, worth around pounds 682m every year. Readers feel that the manufacturers are uniquely placed to help with the vital job of raising public awareness about the problems of dog-fouling. Why can't they put more money into dog hygiene advertising campaigns, we were asked? Would it not be helpful, as a first step, if dog food labels carried a 'clean-up' slogan? Some readers also suggested a small extra tax on dog food, to go directly towards funding dog wardens and by-law enforcement.

Last week we put these points to the dog food makers themselves.

Could they do more to help?

Spillers (makers of Shapes, Bonio, Winalot, Mixed Ovals, Prime, Goodlife, Kennomeat) and Pedigree (Chum, Pal, Cesar, Chappie, Bounce, Biscrok) dominate the dog food market. They are both indignant at the suggestion they are not doing as much as they might. 'We do one hell of a lot,' says Michael Jenkins, Pedigree's external relations manager. The company, which in 1992 spent pounds 6m advertising Pedigree Chum, is coy about the exact amount it sets aside for education - 'a significant six- figure sum - a few hundred thousand'. This money is spent on the Pedigree Petfoods Education Centre, the Good Dog Campaign (which helps local authorities train dog wardens), and distributing half a million leaflets each year. Spillers, whose parent company made a profit of pounds 117m in 1992, produces around 60,000 leaflets every year. But the onus remains on local authorities and individual pet owners to take up what's on offer - 'You can lead a horse to water but you can't force him to drink,' admits Michael Jenkins.

What about a tax on dog food, to fund clean-up measures?

Unfair, said all the dog food manufacturers we spoke to. Dog food is subject to VAT, which is 'already a hefty discriminatory tax against dog owners', according to Michael Jenkins. However, an extra penny or two on a tin of food would raise enough money to increase the number of dog wardens in every local authority in the country. And other products, such as tobacco and alcohol, are taxed directly.

Shouldn't they invest in a high- profile advertising campaign about dog hygiene?

Neither of the large manufacturers would be prepared to commit themselves to a big television campaign. Pedigree and Spillers both say they have contributed to Central Office of Information 'filler' ads; however, these rarely make prime- time showings. Commercial slots are unlikely to be forthcoming. 'It would use a significant amount of our budget,' says Michael Jenkins, adding, 'written material is more cost effective and has a longer life.'

This is debatable. Recent television campaigns on smoking and safe sex, for example, have made a considerable impact. These have been funded by the Department of Health. Perhaps the dog food makers could share the burden of a dog-fouling television campaign with the Department of the Environment? A DoE spokeswoman also said no - the subject is 'too contentious', and the Department is 'not convinced a national campaign would give value for money'.

Couldn't a 'clean-up' slogan be printed on all dog-food packaging?

A large majority of readers would welcome this simple step. 'Quite reasonable,' said a DoE spokesman cautiously. The suggestion was also supported by James Allcock, a vet from the Pet Health Council, which is partly funded by the Pet Food Manufacturers Association. 'It's a good idea. The space on labels is very little, but they could certainly do it. I would suggest 'Teach Your Dog To Do It At Home' or 'Worm Your Dog Regularly'.'

Pedigree did not like the idea. Michael Jenkins believes the company's current labelling, which invites readers to consult their vet or write to Pedigree for information on pet care, is quite adequate.

Spillers, however, was more positive. Following approaches by the Independent on Sunday, they have charged their marketing department with investigating the potential of slogans and logos. 'We will be glad to look into it on all our packs,' said a spokesman. 'A logo like the Tidy Britain symbol could act as a reminder to owners and we would consider that.'

However, he expressed reservations about how many people bother to read written information on cans.

On this question, the experience of other campaigners is encouraging. 'We have noticed a slow but steady improvement in general cleanliness during our campaign,' commented Dee Bingham of Tidy Britain. 'We would certainly say include clean-up instructions. It makes people stop and think.' Warnings on cigarette packets have been law thoughout the EC since 1991 - 'People are very aware of them,' said a Department of Health spokeswoman. 'There are regulations on size, contrasting background and position so they cannot be overlooked.'

SOME of the smaller dog food makers have already made considerable efforts to alleviate the worst effects of dog mess. Hardy Complete Pet Foods has developed a dog food that contains a worming compound effective against Toxocara canis, the parasitical worm that can lead to toxocariasis in humans. 'There are two issues - the yuk factor and the health hazard,' says managing director John Murray. 'Making people clear up after their dogs is very difficult. With a 'complete' dog food, the faeces are smaller, firmer, more user-friendly because the food is very digestible.' The dog food that contains the wormer is the first of its kind. 'It doesn't stop dogs fouling but it does eliminate the danger from the faeces.' John Murray welcomes the Dirty Dogs Campaign, and is prepared to introduce a slogan and logo on to his packaging. 'We will be pleased to work with the Independent on Sunday. We feel very strongly about this issue.'

THE Dirty Dogs Campaign will continue to lobby the dog food companies. We would like to see clean-up slogans on packaging, and greater investment in education and public awareness advertising. We think the Department of the Environment should also make a priority of cleaning up - and provide funds for advertising. If you agree, help us to keep the pressure up - write with your support to the Dirty Dogs Campaign, the Independent on Sunday, 40 City Road, London EC1Y 2DB.