Background: The bluetongue virus serotype 3 (BTV‐3) outbreak in the Netherlands in 2023 caused severe clinical signs in ruminants. The clinical and pathological signs in ruminants and their spread during the outbreak in 2023 are described. Methods: Data from the Dutch monitoring and surveillance system were available to describe clinical signs and pathological findings related to BTV‐3 in sheep, cattle and goats. During the outbreak, 13 farms (five sheep, five cattle and three dairy goats) were closely monitored. Results: In 2023, BTV‐3 infections were confirmed by real‐time polymerase chain reaction in sheep flocks ( n = 1807), cattle herds ( n = 1864), goat herds ( n = 62), alpaca and/or llama herds ( n = 15) and one dog. Sheep exhibited the most severe clinical signs and had the highest mortality. In other animal species, a large variation in both occurrence and severity of clinical signs was observed. Limitation: Only 13 farms were closely monitored. Conclusions: The clinical signs observed in affected animals during the 2023 BTV‐3 outbreak seem to be more severe than those observed during the BTV‐8 outbreak between 2006 and 2008. It seems likely that BTV‐3 will overwinter, similar to BTV‐8. Therefore, the availability of an effective and safe vaccine is crucial to limit the future impact of BTV‐3.

In contemporary society and modern livestock farming, a monitoring and surveillance system for animal health has become indispensable. In addition to obligations arising from European regulations regarding monitoring and surveillance of animal diseases, The Netherlands developed a voluntary system for the monitoring and surveillance of small ruminant health. This system aims for (1) early detection of outbreaks of designated animal diseases, (2) early detection of yet unknown disease conditions, and (3) insight into trends and developments. To meet these objectives, a system is in place based on four main surveillance components, namely a consultancy helpdesk, diagnostic services, multiple networks, and an annual data analysis. This paper describes the current system and its ongoing development and gives an impression of nearly twenty years of performance by providing a general overview of key findings and three elaborated examples of notable disease outbreaks. Results indicate that the current system has added value to the detection of various (re)emerging and new diseases. Nevertheless, animal health monitoring and surveillance require a flexible approach that is able to keep pace with changes and developments within the industry. Therefore, monitoring and surveillance systems should be continuously adapted and improved using new techniques and insights.

Since 1998, WOAH-notifiable bluetongue virus (BTV) serotype 1, 2, 3, 4, 6, 8, 9, 11, and 16 have been reported in Europe. In mid-August, 2006, a BTV-8 outbreak started in Northwestern Europe. The Netherlands was declared BT-free again in February 2012 and annual monitoring demonstrated BT-freedom up to 2023. On September 3 ^rd 2023, clinical manifestations in sheep typical for BT were notified to the Dutch Food and Product Safety Consumer Authority. Laboratory diagnosis confirmed BTV-infection on September 6 and the first notifications of clinical signs in cattle were also reported. Two days later, the virus was identified as serotype 3 by whole genome sequencing. Clinical signs were like these of BTV-8 outbreak and were most serious in sheep. Retrospective analysis revealed no earlier circulation of BTV. It was concluded that the BTV-3 outbreak was detected shortly after introduction, while the virus source and route of introduction remains unknown. Article summary line: During September 2023, a novel serotype 3 Bluetongue virus (BTV) emerged in the Netherlands which affected sheep and cattle.

Monitoring and surveillance systems have an increasingly important role in contemporary society ensuring high levels of animal health and welfare, securing export positions, and protecting public health by ensuring animal health and product safety. In the Netherlands, a voluntary monitoring and surveillance system is in place since 2003 to provide a broad overview of livestock trends in addition to disease-specific surveillance systems, including insight into the occurrence and prevalence of new and emerging non-notifiable diseases and disorders. Being a major surveillance component of this monitoring and surveillance system for small ruminant health in the Netherlands, an annual data analysis on routine census data is performed to retrospectively monitor trends and developments regarding goat health and welfare. This paper aims to describe the process of the data analysis on goat farms in the Netherlands in 2020 and subsequent results are discussed. The data analysis provides key monitoring indicators such as animal and farm density, mortality, animal movements, and numbers and origin of imported small ruminants. Trends were analysed over a five-year, period and associations between herd characteristics and herd health are evaluated. Results showed that in 2020 the Dutch goat population consisted of 670,842 goats, distributed over 14,730 unique herds and increased by 2.3 % compared to 2019. Between 2016 and 2020, although probably underestimated, recorded mortality rates showed a decline on both small-scale and professional farms, with a strongest decrease on farms with herd sizes over more than 200 animals. Seventy-five percent of all professional farms registered animal introductions, in addition to 63 % of small-scale farms, including 2439 imported goats. Performing risks analyses requires demographic knowledge of the goat industry. During and after several disease outbreaks, such as bluetongue and Schmallenberg virus disease, the data analysis proved to function as a valuable tool, however, appeared just as important for recording outbreak-free data. Since its start in 2006, the concept of the data-analysis has continuously been improved, and will in the future be further developed, especially if more complete data sets become available. Subsequently, data analysis will increasingly support monitoring and surveillance of goat health and welfare.

Pithomycotoxicosis, commonly known as facial eczema, is a hepatogenous photosensitisation in grazing ruminants caused by intake of sporidesmin‐containing spores of the saprophytic fungus Pithomyces chartarum . Although this is a significant sheep disease in various countries in the world, it is rarely seen in Europe, and has been reported only once in the Netherlands, but in cattle. In October 2019, both sheep and lambs in a flock of 50 breeding sheep showed clinical signs of photosensitisation, including oedematous facial swelling, reddening of eyelids, ulcerative skin lesions, hyperpigmentation, and in some cases icteric sclerae. The combination of clinical signs, seriously elevated glutamate dehydrogenase, gamma‐glutamyl transferase and total bilirubin, necropsy findings, course of events, time of the year, absence of known toxic plants or mycotoxins, strongly suggest that sporidesmin was the most probable cause of this case of hepatogenous photosensitisation, which makes this the first reported case of pithomycotoxicosis in sheep in the Netherlands.