ISVEE/718

Prevalence and handling of caseous lymphadenitis in sheep flocks in Peninsula, County,

Nagel-Alne GE (1), Sølverød LS (2,4), Valle PS (2,3), Simon-Nilsen M (5)

(1) Norwegian School of Veterinary Science (2) TINE Norwegian Dairies Advisory Services (3) Molde University College (4) Goat Health Services, TINE (5) Private practitioner, veterinærkontor

Objective

The Goat Health Services started the project "Healthier goats" in 2001. The aim of the project was to sanitize for three contagious diseases caseous lymphadenitis (CLA),caprine arthritis and encephalitis (CAE) and paratuberculosis.

During the sanitation process in Malangen, Troms county, a higher CLA prevalence infection than expected, was found in sheep flocks. The sanitation process was stopped due to lack of knowledge regarding a possible connection between CLA in sheep and goat flocks.

In June 2006, a project was initiated, to gain knowledge about the CLA prevalence in sheep flocks, the risk of infection spread between sheep and goats and re-infection in goats.

Material and Method

Altogether 4224 blood samples from 46 flocks were tested for CLA. The individual sheep were palpated for abscesses and results compared with clinical findings. A herd protocol was filled in to register critical points for spread of CLA such as contact herds and sanitary measures in the shearing process.

Also, a map was sent out to all sheep-and goat farmers in Malangen peninsula in which the farmers were asked to mark their pasture-area.

Results

In 14 flocks all animals tested negative, 20 flocks had prevalence lower than 10 % and 12 flocks had prevalence above 10 %. Out of the same flocks, 14 flocks showed no abscesses, 16 flocks showed abscesses on less than 10 % of the sheep and 6 flocks showed abscesses on more than 10 % of the sheep (4 flocks not investigated).

Comparing individual blood samples and palpation showed that 22 % of the sheep with a positive blood sample also had palpable abscesses on typical spots, and that 25 % of the sheep with abscesses had a positive blood sample.

Preliminary analysis of the pasture map data showed no positive correlation between CLA in sheep and common pasture with goat and sheep. Nor were there any support for spread of infection between flocks related to the sharing process.

Discussion There was a higher prevalence of CLA in the sheep flocks in Malangen than expected based earlier scarce national knowledge regarding CLA. Hence, CLA can not solely be regarded as a goat disease in Norway any more.

There was no significant correlation between a positive palpation finding and a positive blood sample, which in part is related to that several other bacteria can create abscesses.