Factors associated with the occurrence and level of Isospora suis oocyst excretion in nursing piglets of Greek farrow-to-finish herds

Factors associated with lower odds of oocyst excretion were: use of toltrazuril treatment, all-in all-out management of the farrowing rooms, no cross-fostering or fostering during the first 24 hours after farrowing, plastic flooring in the farrowing pens, farrowing rooms with more than fourteen farrowing pens and employment of more than two caretakers in the farrowing section. Factors associated with lower oocyst excretion level were: use of toltrazuril treatment and caretakers averting from entering into farrowing pens.Apart from prophylactic treatment with toltrazuril, the risk and the level of I. suis oocyst excretion from piglets in their second week of life, was associated with managerial and environmental factors. Changes in these factors, which may enhance prevention of piglet isosporosis – either alternatively or supplementary to medical control – are of increasing importance because of the likely development of resistant parasites under the currently widespread use of anticoccidial compounds.Isospora suis is one of the most prevalent parasites in intensive pig production worldwide [1,2] and can cause significant economic losses due to transient diarrhoea and dehydration in nursing piglets followed by decreased weight gain and poor performance [3,4]. The disease occurs mainly in the second to third week of life and is characterised by high morbidity and low mortality except for cases with secondary bacterial infections [5,6]. Once I. suis has been established in a farm, the infection is probably maintained through transmission from one generation of piglets to the next [7] via contaminated farrowing pens [8,9]. Sows are rarely found to excrete oocysts [9], and may not play a critical role for I. suis infection persistence in an infected herd [2].I. suis is present in all types of farrowing facilities and under all types of management systems [10], regardless of herd size and housing conditions [6,11]. A study carried out in 12 European countries confirmed th