Monday, November 28, 2005

Animal behaviour = Tb transmission opportunity?

We have explained cattle behaviour before on this site (Curious Cows) and described a badger's 'fright & flight' reaction to being startled. (Our contributer had his wellies sprayed when a short sighted badger mistook his boot for a cow-pat)
We hear that New Zealand veterinarians are also interested in methods of transmission of tuberculosis between species, and have done some work using a sedated possum.

While he was groggy and behaving 'atypically' i.e as if he had advanced tuberculosis, the NZ vets put him in 3 different situations and video taped the results. (Sorry, no link. verbal info only)

First with a group of cattle, where he was surrounded, sniffed, licked, nudged and generally thoroughly investigated for a considerable time. Had tb. infection been present in the possum, these actions of curious, maternal cows would certainly have encouraged transmission of Btb, the vets felt.

Then he was introduced to NZ's very own woolly jumpers - sheep. Their reaction was "eeer yes ?" and they continued to graze the grass! No reaction at all. The dopey possum was ignored, which could explain the lower rates of tb found in sheep grazing the same areas with infected wildlife.

But when placed with red deer, the reaction totally amazed the vets. The possum was butted, then thrown in the air and generally mauled. In fact, for his own protection the possum was removed. Contact was made by mouth. The deer grabbed the possum in their teeth, and threw him about.

Given badger group's (Avon Wildlife Trust -'Badgers without Bias') and farmer's experiences already quoted on this site, that when startled or surrounded a badger will 'spit and spray urine', this exercise into the behavioural differences between species of animals exposed to
a bacterial blast from a common wildlife reservoir of Btb is very useful. And anyone who still says "but we don't know how it's transmitted", really needs to get out more.

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