[The occurrence of Babesia divergens in the Freiburg i. Br. district and piroplasmosis prevention trials in cattle]. / Zum Vorkommen von Babesia divergens im Bezirk Freiburg i. Br. und Versuche zur Piroplasmoseprophylaxe beim Rind.

The occurrence of Babesia divergens in the Freiburg i. Br. district is reported. By interviewing farmers and by serological investigations, three valleys where located in which bovine piroplasmosis occurs since many years. Main objective of this study was to strategically control the vector ticks, Ixodes ricinus with the synthetic pyrethroid flumethrin, in order to prevent clinical piroplasmosis after turnout to pastures in spring, without interfering with protective immunity against Babesia divergens. A total of 200 cattle were used for trials in the period 1990-92. Three pour-on treatments of fortnightly intervals provided best results. Only 4.3% of 163 treated cattle contracted piroplasmosis, in contrast to 19% of 37 untreated cattle. All cattle were sero-negative at the time of turnout. At the end of pasture periods 1990 and 1991 82.4 and 79.6% respectively of treated cattle were sero-positive.

Analytical determination of the distribution of flumethrin on the body surface of cattle following topical pour-on application.

By means of chemical analysis, the distribution behaviour of flumethrin was determined in the hair coat of cattle following topical pour-on application. Flumethrin was applied at 1 mg active ingredient (a.i.) kg-1 body weight along the backline of cattle. It was demonstrated that this compound could be recovered from all hair samples taken on Day 1 following application from dorsal, lateral, ventral and distal body regions in concentrations ranging from 670 to 1 micrograms a.i. g-1 hair, depending on the distance from the site of application. On Days 3, 5 and 10 after treatment, the corresponding concentrations were 125.0-1.5, 23.0-1.0, and 44.0-0.9 micrograms a.i. g-1 hair, respectively. When correlating these values to the body surface of cattle, it is evident that on all sample days and body regions, a concentration of more than 0.01 microgram a.i. cm-2 body surface was present. This amount of active substance is sufficient for effective acaricidal action, as shown by laboratory and field data.

The use of flumethrin 1% pour-on for the control of Amblyomma spp. in various southern African countries.

Efficacy trials with flumethrin 1% pour-on were conducted in 9 different areas in 3 southern and central African countries against Amblyomma hebraeum and A. variegatum on cattle. A dose volume of 10 ml/100 kg body mass applied at bi-weekly intervals provided excellent control of both tick species on their predilection sites, irrespective of locally and seasonally high tick pressure. The trial results demonstrate clearly that this new concept of tick control can be effectively applied in commercial and traditional cattle husbandry situations.