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International audience; Small ruminant post-mortem testing programs were initially designed for monitoring the prevalence of prion disease. They are now considered as a potential alternative to genetic selection for eradicating/controlling classical scrapie at population level. If such policy should be implemented, its success would be crucially dependent on the efficiency of the surveillance system used to identify infected flocks. In this study, we first determined the performance of post-mortem classical scrapie detection in eight naturally affected goat herds (total n = 1961 animals) according to the age at culling. These results provided us with necessary parameters to estimate, through a Monte Carlo simulation model, the performance of scrapie detection in a commercial population. According to this model, whatever the number of tests performed, post mortem surveillance will have limited success in identifying infected herds. These data support the contention that scrapie eradication programs relying solely on post mortem testing in goats will probably fail. Considering the epidemiological and pathological similarities of scrapie in sheep and goats, the efficiency of scrapie surveillance in both species is likely to be similar.

The PrP gene polymorphisms at codons 142 (I/M), 154 (R/H), 211 (R/Q), 222 (Q/K) and 240 (S/P) and their association with susceptibility to classical scrapie infection were investigated in five French goat herds displaying a high disease prevalence (>10 %). On the basis of PrPSc detection in the central nervous system and in various lymphoid tissues, 301 of 1343 goats were found to be scrapie infected. The statistical analyses indicated that while P240 mutation had no direct impact on scrapie infection risk, the H154, Q211 and K222 mutations were associated with high resistance to scrapie. The M142 mutated allele was associated with a limited protection level against the disease. These results further reinforce the view that, like in sheep, the control and eradication of classical scrapie through the selection of certain PrP alleles could be envisaged in commercial goat population.

International audience; Endectocides (avermectins/mibemycins) are today one of the most important anthelmintic families for the control in livestock nematodes and their use is increasing in goats because of the high frequency of benzimidazole resistance. Goat has specific pharmacological parameters for endectocides compared to sheep or cattle (absorption and elimination). The behaviour of the drug in the organism, represented by pharmacokinetic parameters, is affected through several ways including the route of administration and drug formulation, and the host animal (nutrition, parasitism, physiological status, amount of fat tissue). For each species, the determination of specific dose rates is needed to insure an optimal activity against nematodes (particularly those inhabiting the small intestine). This scientific knowledge is a prerequisite to a better use of the different anthelmintic families in goats. An important objective in the chemical control of nematodes is to define the best deworming practices that reduce the risk of nematode resistance occurrence through a decrease of selection pressure on nematode populations. The main points of a rational use of anthelmintics include the dose rate, the route of administration, the annual frequency and the period of treatment, the alternative use of families and the selective treatment of high excreting animals.

National audience; As part of a dairy goat‟s disease surveillance network developing in Poitou-Charentes, a group of veterinarians, farms‟ representatives and scientists has designed a form to harmonize epidemiological data collected during the annual health assessment visits done in every farm. A new decree regulating the use of drugs by farmers actually imposes the record of syndromic data. The forms collect by veterinarians and their centralization and analysis by the network central unit is being tested in order to improve and validate this endemic diseases monitoring system

National audience; La fièvre catarrhale ovine (FCO) a émergé brutalement en Europe continentale fin 2006. En 2007 et 2008, l’épizootie due au virus BTV-8 a touché une majeure partie du territoire français tandis que le sérotype 1 était responsable dès fin 2007 des premiers foyers dans le sud-ouest. Cet article synthétise les observations cliniques recueillies dans les troupeaux caprins par les vétérinaires, les techniciens et les éleveurs au cours de l’épizootie 2007-2008 en France et dans quelques pays voisins. Ces informations sont convergentes et indiquent une moindre sensibilité de la chèvre en comparaison des ovins, et des bovins, au moins pour le BTV-8 : faible nombre de foyers, faible nombre d’animaux atteints par foyers, gravité modérée et rareté des complications. Les signes cliniques décrits impliquent principalement l’hyperthermie et son cortège de signes associés (abattement, anorexie, chute de production du lait) ainsi qu’une atteinte de la face et des muqueuses buccales. Dans un certain nombre de cas, les infections chroniques associées (parasitisme, paratuberculose..) ont pu aggraver les signes cliniques et les conséquences de l’infection virale. Les données expérimentales, notamment avec le BTV-8, confirment la différence de sensibilité entre caprins et ovins tout en permettant de retrouver les principaux signes cliniques évoquées ci-dessus et confirment aussi la très bonne réceptivité de la chèvre à de nombreux sérotypes de la FCO (virémies pratiquement comparables aux ovins). Les données obtenues pour le BTV-1, plus éparses, sembleraient indiquer un tableau clinique un peu différent. La survenue éventuelle d’autres sérotypes doit conduire à réévaluer la question de la sensibilité de la chèvre laitière à la FCO.

National audience

Une enquête a été conduite dans environ 100 troupeaux caprins répartis dans les principales régions caprines françaises pour estimer la prévalence de l'infection par Mycobacterium avium paratuberculosis (Map). Dans ces troupeaux, tous les animaux de plus de six mois ont fait l'objet d'un test sérologique ELISA vis-à-vis de Map. Les prévalences apparentes et réelles ont été définies et estimées tant au niveau des troupeaux qu'au niveau individuel et intra-troupeau. La prévalence réelle des troupeaux infectés a été estimée à 57% tandis que la prévalence individuelle réelle a été estimée à 5,6% avec IC à 95% = [5,1 - 6,0] dans la population d'étude. La prévalence intra-troupeau réelle est en moyenne de 11,3%, avec un écart-type de 7,7%. Près de 50% des troupeaux infectés ont une prévalence intra-troupeau réelle supérieure à 10%. En dépit de l'absence de résultats pour une région caprine importante (Rhône-Alpes), les résultats de cette enquête montrent que l'infection par Map est largement présente dans toutes les régions et apportent les éléments épidémiologiques descriptifs préliminaires nécessaires à la mise en oeuvre d'un éventuel plan de lutte contre cette maladie., A survey was conducted to estimate the prevalence of Mycobacterium avium paratuberculosis (Map) infection in goat herds in France. All the animals older than 6 months (n= 9420) from 80 goat-herds were tested using an absorbed ELISA. The apparent and true prevalences have been respectively measured and estimated both at herd and individual levels. The within-herd prevalence was also estimated. The true prevalence at herd level was estimated at 57%, while the individual true prevalence was estimated at 5.6% with 95% CI = [5.1 - 6.0] in the study population. The true within-herd prevalence was 11.29 +/-7.66%. Nearly half of the infected herds had a true within-herd prevalence higher than 10%. Despite the lack of data from one important area (Rhône-Alpes), the results of this survey showed that infection by Map is widespread in French goat herds and provide the first epidemiological descriptive data necessary to the implementation for any control program against this disease.

L'intensification récente de la production laitière caprine et l'amélioration des techniques de diagnostic ont conduit à ré-évaluer à la hausse l'impact économique des mycoplasmoses à mycoplasma mycoides subsp. mycoides Large Colony (MmmLC). Cet article propose d'étudier l'épidémiologie de ces infections à l'aide de la technique d'électrophorèse en champ pulsé.

En l'absence de test parfait, la sensibilité (Se) et la spécificité (Sp) d'un test de diagnostic peuvent être estimées par des modèles probabilistes. Afin d'estimer les caractéristiques (Se et Sp) d'un test sérologique (ELISA) et de la culture fécale (FC) pour détecter l'infection par Mycobacterium avium paratuberculosis (Map), deux méthodes ont été mises en œuvre : la méthode du maximum de vraisemblance et l'inférence bayésienne. Des échantillons de sang et de fèces ont été prélevés sur 532 chèvres appartenant à 15 troupeaux. Les résultats des deux modèles sont comparés et discutés. Le modèle bayésien avec « priors » informatifs permet d'obtenir les meilleures estimations. La Se et la Sp de l'ELISA ont été estimées respectivement à 34% et 99%, tandis que les valeurs pour la culture fécale ont été estimées à 53% et 100%., Two latent class models [maximum likelihood (ML) methods and Bayesian inference (BI)] were used to estimate the sensitivity (Se) and the specificity (Sp) of a serum ELISA test and of faecal culture in the detection of infection with Map in French dairy goats. Samples of blood and faeces were collected from 532 goats in 15 herds. Estimates according to ML and BI methods were compared. The more accurate of the 2 tests was found to be the BI (WinBUGS) model with informative priors. The Se and Sp of the ELISA were estimated to be 34% and 99% respectively. For faecal culture, the Se was 53% and the Sp was 100%.

A study was carried out in 15 French goat herds to assess the presence of mycoplasmas in the external ear canal of goats and to estimate the association between the ear isolates (highly pathogenic or non-pathogenic) and the status of the herds with respect to the mycoplasma infections. In each herd, 20 clinically normal goats were investigated once and mycoplasma isolates were identified by MF-dot tests. Influence of herd status on the proportion of animals carrying highly pathogenic species of mycoplasmas was evaluated by calculating the Odds Ratios. The present study gave first of all an estimate of the relative importance of mycoplasma carriage in healthy French dairy goat herds. The species isolated were Mmm LC, Mcc , Ma , Mp (considered as highly pathogenic) and My and Mc (non-pathogenic species). Carriage often involve several strains and/or species in the same ear canal. The highly pathogenic species were significantly more frequent in the herds with prior history of mycoplasma infection. This asymptomatic carrier state makes the sanitary status of a herd ambiguous and represents a risk of subsequent propagation of the etiological agents, during close physical contact or by intervention of vectors (mites).

International audience