SUCKING AND BITING LICE Linognathus vituli, Haematopinus spp. , Solenopotes spp. Bovicola bovis .
LUNGWORM Dictyocaulus viviparus
DISTRIBUTION: All over NZ. PERFECT CONDITIONS: Winter coats. Animals almost always have a mixed infection of both biting and sucking lice. SIGNS: Can be seen by the naked eye as little black/brown dots around the eyes and neck. Biting lice are very itchy and cattle will rub on fences and other cattle. TREATMENT: Only a pour-on product has good efficacy against both biting and sucking lice. TIPS: The whole life cycle takes place on the cow. Sucking lice suck blood and so oral and injectable products are often able to kill sucking lice as the drugs in the blood are sucked by the louse. The MLs often have persistent activity. No drug kills the eggs (nits). Adult lice lay low numbers of eggs and so will take a long time to build up a large population meaning that one treatment a season is usually enough to control lice. RESISTANCE: None currently reported in cattle in NZ.
DISTRIBUTION: All over NZ. PERFECT CONDITIONS: Warm and wet. Irrigated blocks. SIGNS: Group coughing, faster breathing 3-4 weeks after challenge. Immunity develops quickly but needs regular challenge to maintain. Can be seen the year after a particularly dry summer (low challenge year) or if naïve animals are introduced to infected pasture. TREATMENT: All classes of drench have good efficacy. The MLs have varying levels of persistent activity. TIPS: Larvae hatch from eggs in the cow and so will not show up in faecal egg counts. Disease can be seen before larvae are present in the faeces. Larvae can encyst in the calf over winter. RESISTANCE: No resistance has been reported in NZ.
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