Friday, November 24, 2006

Tb Spillover - Another Cat

The single thing which our Minister for Animal Health and Welfare, baby Ben Bradshaw did this year, and on which we congratulated him - never failing to give praise when it is due - was to make tuberculosis notifiable in all mammals.

We have already mentioned in our postings and the susceptibility of cats (among many mammals) to bTB. And from a Midlands contributer, comes the sad tale of a ginger tom called errr - 'Ginger'.

Briefly, this puss was a family pet, a neutered male aged three and half, sharing his domicile with another cat, two young children and his owners whose house was on the edge of a development overloking fields. This summer, Ginger began to lose weight and looked ill, so he was taken to the local vet. Initial examinations showed 'a slight wheeziness' (where have we heard that before ?) and antibiotics were prescribed. The cat did not respond and began coughing. Much further investigative work was done on said cat, involving blood tests and X rays finally resulting in his demise a week later on 'welfare' grounds.

Postmortem indicated major lung damage, enlarged lymph nodes, pneumonia and emaciation. Cultures confirmed bTb.

In the immediate local area, no cattle have grazed the fields nearest to the house in which this cat lived for many years. But to the south of the area in 2005 a dead RTA badger tested positive for bTb, and this year, three farms are experiencing what Defra define as 'emerging new cases' in their cattle, involving multiple reactors. As we have said many times, and no doubt will continue to say, it is absolutely no use shooting the messenger - in this case the tested cattle - and leaving the other half (or even threequarters) of the circle, to wander about infecting anything that crosses its miserable path.

The ususal suspects clanked into action within this shocked family's household, with visits from the Communicable diseases section of the local council, TB tests for the children, monitoring of the remaining cat and advice on the symptoms they must look out for in themselves and neighbours and susceptible pets.

The source of this strain (17 spoligotype) of bTb in a domestic, non feral family pet is not linked to infection from either human beings or other local 'pets'. Cattle herds are to be tested within a 3km area. And the badgers, one of which expired locally and tested positive for the same strain of bTb? Sssshhhhhhh ... Defra may not speak its name.


Anonymous said...

Am I right in thinking that you can test for which cattle are infected by TB and thus remove them leaving the healthy ones alone? But when it comes to badgers you cant tell which are infected so in order to clear the desease you would have to kill them all including the healthy ones?

Matthew said...

Yes and no.
Cattle are tested using an international diagnostic tool - the intradermal skin test. And yes, anything which tests positive is slaughtered. As a herd test, the skin test is in the high 90's percentage on both specificity and sensitivety.
The badger group argument is that they are 'not against culling infected badgers', but without postmortem, they are difficult to identify because the Brock live test is very poor on a 'negative' reading.
This ignores PCR diagnostics which do work on sett material and latrines to identify infected material, and it totally ignores the infectivety of bTb within a sett, and within a social group. It ignores transmission from sow to her cubs but mainly it ignores the actions taken by the badgers themselves to exclude a highly infectious, very sick badger.

In our experience, it is these 'dispersers' excluded by their group which cause the real havoc. And we have explained that some farmers are having great success identifying 'off sets' to which these animals slink, and on welfare grounds under the terms of the Badger Protection Act, are dealing with these and only these, leaving the main group alone. More on this in new posting on Ireland.