The problem i have is many of you seem to want to discount the studies that were done many years ago. Research is research whether it was published in a vet journal or not. It is recorded in the book Luke talks about. When some argue so strongly that it isn't genetic it makes me wonder how many just might breed ones with malo because it is suggested it is just invironmental, which it is not. Even if one starts at a late age I still believe it is genetic and its recessive, barring an accident like a fall or something like that.
I just want to clear this up from my point of view.
Malocclusion is erroneously used as a blanket term to cover all dental problems in the chinchilla world - it is poorly understood in terms of it's development and it's aetiology. Malocclusion is is poorly defined in chinchillas - very rarely do you see differentiation between true malocclusion (where the occlusal surfaces are misaligned or the jaw deformed in some way) and other types of tooth problems (such as dental caries, root elongation, age onset spurs through ?lazy jaw action with no root elongation or deformity, or traumatic injury etc).
We rarely expect a human to reach 50+ without having some form of dental work and yet we seem to expect chins to reach 6+ and not have any dental problems - I find that incongruent tbh. Dogs and cats suffer dental caries and require teeth cleaning, rabbits who do not have enough forage do not wear their teeth properly etc etc ............. there's a whole realm of possibilities that we need to acknowledge. Lauridsen's work showed only 1 chin hit 6+ and then develop malocclusion - he does not define what sort of malocclusion it was and it is not statistically significant in a sample of 2500+ chinchillas - interesting and leaves us with more questions than answers! :duh: Does that mean it is not genetic or have a genetic component? Does it mean it is not environmental or have an environmental component? Not necessarily - it's not proven one way or another and Lauridsen does not distinguish.
The Crossley paper reports that true malocclusion was seen on only a few occasions with chinchillas presenting with tooth problems but he does differentiate between the problems seen - again, interesting and leaves us with lots of questions. He also goes further to examine tooth structure under microscope etc.
I do not think anyone can say with 100% accuracy that malocclusion is either just genetic or just environmental - that is far too simplistic. It is far too under-researched and would take considerable time and enormous numbers of animals to "prove". Having said that I do think there are often multiple causal factors involved and it would be presumptive to think that anyone has a clear answer - even Lauridsen recognises that other factors can be involved and he takes that into account in his paper.
What is undeniable is that malocclusion (and I am using the term in it's broadest sense) is a terribly affliction in chinchillas and any chin showing any signs of malocclusion should be culled from a breeding herd. I think that goes without saying as responsible breeding practice and I do wonder if that's why many people in this thread have not belaboured the point - because for most of us it is a given and does not need reiterating.
As I said previously:
True malocclusion may well be genetic and recessive in origin but, as with the majority of chinchilla issues, it is not clearly demonstrated through robust, valid research. Our "knowledge" is largely gathered through the anecdotal evidence of long term breeders passing down their experiences and "research" (i.e. observational and breeding trends) to others. I would not be too hasty in dismissing some of the very detailed work breeders/ranchers have written in their breeding/herd books - some of which go back decades.
There are certainly other factors which are involved in the development of dental problems in chinchillas - these factors include but are not limited to: trauma and injury, abnormal tooth wear patterns in older age, illness, calcium and other mineral deficiencies (for example, multiple breed backs seen in rescues often results in malocclusion and bone demineralisation or lack of bone density as evidenced on Xray examination etc), and malnutrition.
I do not dismiss Lauridsen's work (I believe it has merit) but in terms of debate and discussion it is not necessarily a robust enough piece of work on which to base an argument (as Luke was trying to do). It does not go into enough depth to allow for critiquing. Nevertheless it is an interesting paper and I would love to see the full work behind it (which is partly what EP and I were asking for) so that I can delve into it further. I'd also like to see the work replicated so we could compare results because I think that would be very interesting.
As in all things chinchillas - we need more good research!! :hair:
