Last month I talked about dental disease and had this comment on that post.
Have you heard of this product: http://www.virbacvet.com/Products/DentalHealth/RinsesandFoams/C.E.T.AQUADENTDRINKINGWATERADDITIVE.aspx
It contains xylitol, which I've read from several reputable sources as very dangerous for pets.. But I also know it's a good dental disease preventative.. Huh?
Being a bit surprised by this, I decided to look into it. For those who aren't aware, xylitol is an artificial sweetener used mainly in sugar-free gum. It has the potential of being very toxic to dogs and can lead to sudden hypoglycemia and seizures. I first posted about it back in 2009. Knowing the toxicity potential but not being aware of its use in dental products, I contacted Virbac (the manufacturer of C.E.T. pet dental products) and asked about this. I want to thank Alyson Bentz, a veterinary technician in their technical services department, for providing me with several articles and some great information.
Back in 2006 two veterinarians associated with the ASPCA Poison Control Center produced a paper, Risk Assessment of Xylitol in Dogs and Cats. According to the data, the lowest acute oral exposure that resulted in acute hypoglycemia is 150-200 mg/kg. Liver toxicity happened at >1600 mg/kg. Keep in mind that there isn't good data on cats, and these numbers are based on studies in dogs.
A product like the C.E.T. Water Additive contains 5 mg/ml of xylitol, or total of about 4g total per bottle. The solution is supposed to be mixed at 10ml (2 tsp) per quart of water, giving a final concentration of 0.05 mg/ml. A 2 pound (0.91kg) dog will consume about 123ml of water per day, which would result in ingestion of xylitol equivalent to about 6.8 mg/kg per day. The larger the dog, the lower the concentration (a 100lb/45kg dog would drink about 2.3L daily, for a concentration of 2.5 mg/kg per day. The estimated amounts in cats are similar. So with this data, it should be quickly obvious that even at the highest concentrations (remember, these are daily accumulated totals) we are factors of ten below the lowest toxicity level.
Okay, so let's say the pet drinks the concentrate straight (maybe it spills). To reach hypoglycemia toxicity levels a 5lb/2.3kg pet would need to drink a minimum of 68ml. A 55lb/25kg dog would have to drink 3/4 of a liter! So even though the toxicity risk is obviously greater with the concentrate, there still needs to be a relatively large amount drunk to be a problem.
Why even risk it? Xylitol has been shown to have anti-bacterial properties on oral bacteria as well as prevents calculus formation. The data seems to suggest that low doses of xylitol are beneficial for oral health without any significant risk.
So there you go! Thanks to Sheena for pointing this out and giving me the inspiration to look into this!