Towards a lower prevalence of Oestrus ovis infections in sheep in a temperate climate (south west France)

Abstract

-Oestrus ovis larvae are obligatory parasites of the nasal and sinus cavities of sheep and goats. In the temperate climate of western Europe, fly attacks occur between May and October and the first stage larvae arrest their development within the host between October and February. Oestrosis clinical signs such as nasal discharge and sneezing are well known by sheep breeders in southwest France. According to veterinarian recommendations, most of them treat their animals with long lasting fasciolicides once a year at least, mainly during the fly activity period and at the beginning of the hypobiotic period (when the parasitic population is only constituted of larvae). The consequences of these therapeutic programs were analysed in a local slaughterhouse by larval counts. Both prevalence and intensities of O. ovis infections decreased between 1989-1991 (before the use of systematic treatments) and 1996-1998 (after the spread of these treatments). The use of systematic treatments during the fly activity period and the beginning of the hypobiotic period seems to be very efficient in O. ovis control and could theoretically lead to a possible 'eradication'program as with cattle hypodermosis. Nevertheless the presence of parasites in apparently healthy goats, the possibility for a fly generation to develop before the first treatment in July-August and the succession of several fly generations all around the year in southern Mediterranean and tropical countries will maintain O. ovis infections. Furthermore, there are increased concerns about drug residues on consumer health and environment and this is the basis for the prospect of alternative strategies in O. ovis control. Oestrus ovis / mouton / chèvre / traitement systématique / prévalence

Oestrus ovis larvae in nasal cavity of sheep: a case report

“…1). O. ovis infestation in sheep has been reported from different countries, 33.2-65 % in France (Bergeaud et al 1994;Dorchies et al 2000;Jacquiet and Dorchies 2002;Yilma and Dorchies 1991), 71.1 % in Spain (Alcaide et al 2003), and 55.8-91.0 % in Italy (Caracappa et al 2000). In India 48.3 % prevalence of O. ovis has been reported (Jagannath et al 1989).…”

Epidemiology of Oestrus ovis infestations in sheep in Kars province of north-eastern Turkey

“…By this way, reinfections can be avoided. Ivermectin, doramectin or moxidectin must be used as non-persistent drugs to eradicate the burden when there is no L3 and many hypobiotic L1 Jacquiet and Dorchies 2002;Scala et al 2002;Tabouret et al 2001). Depending on our findings and observations, we advice two strategic treatments per year for O.ovis in the area; the first one is in March, at the beginning of the growing period of the larvae, and the second administration in October, at the end of growing period.…”

“…The prevalence O. ovis infestations in sheep in the world as follows; 33.2-65% in France (Bergeaud et al 1994;Dorchies et al 2000;Jacquiet and Dorchies 2002;Yilma and Dorchies 1991), 71.1% in Spain (Alcaide et al 2003), 55.8-91.0% in Italy (Caracappa et al 2000;Scala et al 2001Scala et al , 2002, 22.6% in Libya (Gabaj et al 1993), 17.2% in Iraq (Jarjees et al 2000), 8.7% in Egypt (Amin et al 1997, 58% in Jordan (Abo-Shehada et al 2000), 5.5% in Saudi Arabia (Alahmed 2000), 21.0% in Ethiopia (Bekele and Mukasa-Mugerva 1994), 10-100% in Morocco (Pandey and Ouhelli 1984), 67.4% in Algeria (Benakhla et al 2004), 6-52% in Zimbabwe (Pandey 1989), and 8.1% in India (Pathak 1992). Oestrosis is commonly seen in sheep and goats in Turkey.…”

Prevalence and intensity of Oestrus ovis in sheep of Shiraz, southern Iran

“…To control and eradicate O. ovis, it would be necessary to use systemic insecticides such as an avermectin (Jafari Shoorijeh and Moazzeni Jola 2001) at the beginning of the hypobiotic period in October or November Dorchies 2002b, Uslu andDik 2006). On the contrary, in countries where O. ovis infections occur all year round, as in tropical countries, strategic treatments seem to be of less value (Jacquiet and Dorchies 2002a). …”