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Advisor(s)
Abstract(s)
Small ruminant lentivirus (SRLVs) is a group of phylogenetically co-related viruses which are transmitted between caprine and ovine (Cirone et al. 2019). Previously due to different clinical signs developed by each species, caprine ar- thritis-encephalitis virus was associated merely with caprine and Maedi-Visna virus to ovine species. Several seroprevalence studies have shown that SRLVs are present worldwide except in Australia and New Zeland (Lago et al. 2012). In research conducted in 1995, SRLVs seroprevalences were detected in 81.6% of the Portuguese herds and in 34.4% in the animals studied (Fevereiro, 1995). SRLVs cause systemic infection in ovine and caprine species, which may inflict lung, central nervous system, mammary gland and joints (Minguijón et al. 2015). These infections cause chronic, insidious and progressive diseases, seriously affecting animal health and causing economic loss- es (Michiels et al. 2018). Associated respiratory distress and neurological syndromes may evolve to cachexia and death. Joint and mammary chronic infections may lead to disability with different grades of mobility impairment (mostly seen in goats) or decrease milk production leading to lambs and goat kids’ malnutrition (Minguijón et al. 2015). Animals showing these clinical signs are often prematurely slaughtered. Vertical transmission occurs through infected milk and co- lostrum ingested by young animals. Horizontal transmission occurs essentially due to airborne particles, spread through the air inhaled by these animals, being one of the main transmissions routes in intensive production systems. SRLVs transmission can also occur via milking equipment mainly in goats (Leginagoikoa et al. 2006; Villoria et al. 2013; Junk- uszew et al. 2016).
Diagnosis is based on clinical, analytical, and post-mor- tem lesions evaluation. Nevertheless, most animals are asymptomatic and clinical signs may only develop years later after infection (Barquero et al. 2013). Laboratorial methods are essential and may include serological (agar gel immuno- diffusion and ELISA) and molecular techniques (PCR and RT-PCR) (Reina et al. 2009). In the northeast of Portugal, small ruminant production has economic and social importance and animals are produced using mostly traditional methods.
Our main aim is this study is to conduct a research about seroprevalence and risk factors associated with SRLVs infection in sheep and goats in the north-eastern of Portugal.
Description
Keywords
Small ruminant lentivirus (SRLVs) Seroprevalences
Citation
Ferreira, João; Coelho, Ana; Vila, Ana Grau; González, Olga Minguez; Perez, Valentin; Lacasta, Delia; Valentim, Ramiro; Quintas, Helder (2022). Seroprevalence and risk factors associated with small ruminant lentivirus infection in the north-eastern Portugal. In Differential diagnosis in sheep. Zaragoza: Doctor Herriot SL. p. 245-248. ISBN 978-84-09-38757-1