Ckeck out this site
www.petzlife.com for teeth cleaning products. One is for brushing and one is a spray. I don't know if they actually work or not. I did buy the product but my Jack is only one so his teeth are still white. Jack hates to brush and it's a struggle. I only try to brush 2 or 3 times a week and then I can only get the brush in for about 12 strokes on each side. I use the spray on other days hoping it works as well as the web site states. Just thought I'd pass this along as an option.