Gum disease is extremely common in dogs - with some breeds particularly badly affected. So it's no surprise there are all sorts of products on the market offering to clean your pet's teeth - which might be particularly appealing if you don't fancy grabbing a toothbrush and doing the job yourself. As well as chews of many shapes and sizes, there are additives to water - and even seaweed extract to sprinkle on their food. It's a serious business. We've had loads of emails asking us to look into this one - including from listener Sarah, who wants help on behalf of Heidi, her Miniature Schnauzer. To get them some answers, Greg hears from a pet nutritionist and a vet who's an expert in dental care. Are dog dental chews the best thing since sliced bread? PRESENTER: GREG FOOT PRODUCER: TOM MOSELEY