Medico Veterinario Zootecnista

Small Ruminant Research 106 (2012) 21–24

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Small Ruminant Research
journal homepage: www.elsevier.com/locate/smallrumres

Eradication of caseous lymphadenitis under extensive management conditions on a Scottish hill farm
Katja Voigt a,∗ , Graham J. Baird b,1 , Fiona Munro a , Fiona Murray a , Franz Brülisauer c,2
a b c

ScottishAgricultural College, Consulting, Veterinary Services (SACCVS) Inverness, Drummond Hill, Stratherrick Road IV2 4JZ, Scotland, UK SACCVS Perth, 5 Bertha Park View, Perth PH1 3FZ, Scotland, UK Scottish Agricultural College, Epidemiology Unit, Drummond Hill, Stratherrick Road, Inverness IV2 4JZ, Scotland, UK

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The application of a test and cull policy tocontrol caseous lymphadenitis (CLA) in a commercial hill flock in Northern Scotland is described. A commercially available ELISA test kit (ELITEST CLA ELISA, Hyphen, France) was employed on blood samples taken at approximately three monthly intervals between November 2007 and August 2009. Following each round of testing all animals identified as seropositive or diagnosed as CLA-positive by bacteriologywere culled. Additional hygiene and management measures aimed at reducing the likelihood of disease transmission were also encouraged in the flock. Initial testing in November 2007 identified a CLA seroprevalence of 10% (n = 1010). Following the described test-and-cull protocol and a controlled reduction in flock size the seroprevalence was reduced to 0.4% (n = 538) by August 2009. The flock is stillmonitored by regular palpation of external lymph nodes and bacteriologial examination of any purulent discharge. No external CLA lesions were diagnosed in the flock by clinical examination from July 2008 to date, however in May 2009 sub-clinical CLA was confirmed by post mortem examination in one ewe which had tested positive serologically. The role and potential benefits of serological testing as atool in CLA eradication are discussed. © 2012 Published by Elsevier B.V.

Article history: Available online 7 May 2012 Keywords: Caseous lymphadenitis Eradication Serological testing Sheep

1. Introduction Whilst caseous lymphadenitis (CLA) is widespread in the majority of sheep-rearing countries worldwide (Baird, 2007), it has been absent from the United Kingdom (UK) until 1989, when the firstcases were confirmed in two

This paper is part of the special section entitled: Animal health challenges for Scandinavian and northern European countries, Guest Edited by N.D. Sargison. ∗ Corresponding author. Current address: Clinic for Ruminants, Sonnenstr. 16, D-85764 Oberschleissheim, Germany. Tel.: +49 89 2180 78865; fax: +49 89 2180 78851. E-mail address: katja.voigt@lmu.de (K. Voigt). 1Current address: Pfizer Animal Health, Walton Oaks, Dorking Road, Walton on the Hill, Surrey, KT20 7NS, UK. 2 Current address: SACCVS Inverness, Drummond Hill, Stratherrick Road IV2 4JZ, Scotland, UK. 0921-4488/$ – see front matter © 2012 Published by Elsevier B.V. http://dx.doi.org/10.1016/j.smallrumres.2012.04.014

dairy goats in England (Lloyd et al., 1990). Subsequently further cases wereconfirmed in goats and sheep in England (Robins, 1991) with the first case of CLA in Scotland being reported in 1996 (Anon., 1996). Cases of ovine CLA have subsequently also been reported in Northern Ireland (Malone et al., 2006). In the UK, CLA has often been perceived as a disease of terminal sire breeds and was thought to be particularly prevalent in rams (Baird et al., 2004). In recent years there hashowever been growing evidence of spread into the hill and upland flocks, which form the base of the stratified British sheep industry (Anon., 2004, 2007). Discharging lesions and aerosols are recognised ways of transmitting the disease, with skin lesions, yarding or housing, shearing and dipping being established risk factors (Baird and Fontaine, 2007). Corynebacterium (C.) pseudotuberculosis...