Xylitol toxicity

Re: Xylitol toxicity

Chris Geddes — Fri, 23 Jul 2010 08:48:33 GMT

Thanks for your comments Evelyn. I guess trials can always be improved but funding isn't infinite! I for one look forward to reading the study in dogs. We don't pretend Vet Aquadent is a panacea, and would ALWAYS recommend brushing wherever possible, and toothpastes and brushes are the major sellers of the Virbac Dental Hygiene range.. However, we know that some owners cannot or will not brush (ever asked a room full of vets/nurses how many brush? It's depressing!) so we have a range of complementary products such as Vet Aquadent too. These products can also be useful in addition to brushing of course - I use a xylitol mouthwash in addition to brushing and have used chlorhexidine rinses before now, though I can't say I munch any dental chews myself!

Chris

Re: Xylitol toxicity

Evelyn Barbour-Hill — Thu, 22 Jul 2010 20:17:15 GMT

I stand corrected. And in the trial referred to the final concentration of xylitol in the drinking water was 0.005%. I apologise to Mr. Geddes and to Virbac.

However I remain unconvinced about the general usefulness of this drinking water product. The cats (n=30) selected for the trial had no periodontal disease at the start of the trial and had a professional cleaning at the start. Obviously this was essential for the design of the trial.

Overall, plaque and calculus were reduced by just over 50%. However, it is a long way from that to hypothesising that in the long term periodontal disease incidence would be reduced by 50% or any other figure. It might be reduced by nothing at all. To put it simply, if even after a 50% reduction, the remaining 50% was still plaque thick enough and mature enough to cause gingivitis, there would be no effect on gingivitis at all.

It's also a long jump from a trial on cats that started with healthy gingiva to a general population of cats commonly with unhealthy gingiva, that may not receive adequate professional attention, that may have resorptive lesions, and so on.

Re: Xylitol toxicity

Chris Geddes — Thu, 22 Jul 2010 14:11:58 GMT

Dear Holly (and others who may be interested),

Xylitol is used in human chewing gum because it has lower calorie content than sucrose, and also because it has well-documented anti-caries properties as Evelyn mentioned, but also anti-plaque properties (Tanzer JM 1995 Int Dent J 45 (1 Suppl 1): 65-76).

As we know, caries does occur in our patients but is uncommon. Therefore the main reason for the incorporation of xylitol in Vet Aquadent is the effect on limiting plaque and tartar formation. This has been demonstrated in cats (Clark DE 2006 J Vet Dent (23)2:79-82) and I believe a similar study in dogs is about to be published by the same author.

Regarding the concentration – in fact in Michael Clark’s study, the same formulation as Vet Aquadent was used (known as Breathalyzer in Australia at the time), at roughly half the recommended concentration of UK Vet Aquadent – so the evidence indicates that the concentration does have an effect.

Xylitol is thought to have an effect through oral bacteria taking it in and then “starving” them, or through affecting their adhesive properties.

Regarding toxicity, by my calculations a 10kg dog would need to consume 8 litres or 16 large bottles of pure undiluted product before side effects were noted – so I think the risk is pretty slim!

If anyone has any further questions or would like further information please drop them on here, message me, or email me on chris.geddes@virbac.co.uk.

Re: Xylitol toxicity

Evelyn Barbour-Hill — Wed, 21 Jul 2010 17:10:38 GMT

[quote user="Holly Lee"] I'm a little confused as to why veterinary product virbac aquadent contains xylitol - [/quote]

No doubt a Virbac person will be along soon to give us the proper gen, but:

either it's just for flavouring, or it's because xylitol is useful in human dentistry, in chewing gum for instance, to help prevent caries. However caries is not a big problem in cats and dogs (not a problem at all in cats) and in any case I doubt if putting a little bit in what you drink would be any use.

Re: Xylitol toxicity

Alexander Campbell — Wed, 21 Jul 2010 12:30:24 GMT

H i Holly

I've reviewed our files and not only have we had communication from Virbac themselves but there is also some information from the company at the following link which quotes information provided by the company to Your Dog magazine.

http://www.gsdhelp.info/themouth/vetaquadent.html

This indicates a concentration of 5mg/mlin the concentrated version, but when properly diluted the concentration should be 0.1mg/ml. We would only get concerned about doses above 50mg/kg body weight. Hence dogs would need to consume 500ml per kg body weight (!) of the diluted product to achieve this threshold!

I think there is no cause for concern here.

Hope this helps clarify this further!

Alex

Re: Xylitol toxicity

Holly Lee — Wed, 21 Jul 2010 10:55:03 GMT

Thanks very much, appreciate your reply.

Holly

Re: Xylitol toxicity

Alexander Campbell — Wed, 21 Jul 2010 10:18:26 GMT

Hi Holly

We are aware of this product - and as you say the concentration is of a magnitude that is very unlikely to cause toxicity.

Our major concerns are with confectionery (such as sugar free chewing gums etc - unfortunately this includes nicotine replacement therapy chewing gums) and the sugar substitutes for baking.

We have apprised the VMD about the Xylitol issue so presumably this is one of the excipeints they will look out for in veterinary medicines before issuing with appropriate licensing.

The VPIS has an ever expanding list of xylitol containing products and medicines (both human and veterinary) and so if you have any doubt you can always give us a call.
In fact, of all our internal documents we use to formulate our resposnes to veterinary enquiries the xylitol one is the one that has been updated more frequently than any other. (Our documents are all version controlled so we know exactly which one was being used to answer calls at a particular date.).

Wherever we hear of a new product that reportedly contaions it we try and establish from the manufacturers what the actual concentration is.

I hope this reassures you a littel!

Best wishes

Alex

Re: Xylitol toxicity

Holly Lee — Wed, 21 Jul 2010 10:06:36 GMT

Useful press release etc- I'm a little confused as to why veterinary product virbac aquadent contains xylitol - presumably a question of toxic levels but this would worry me a little and stop me from using it in case the directions were not followed to the letter, Anyone any idea of how many times the recommended amount of product would be toxic?

http://www.virbacvet.com/cet/product/cet_aquadent/

Re: Xylitol toxicity

Kate Richardson — Fri, 16 Jul 2010 22:58:59 GMT

Ditto, thanks very much

Re: Xylitol toxicity

Bob Russell — Fri, 16 Jul 2010 15:12:17 GMT

Thank you for the extremely useful post - we will start educating our clients!!!