Cattle infested with heavy lice infestations experience up to 10 per cent production losses due to reduced feeding time and damaged hides.
Louse populations are highest in cattle kept indoors during the winter months and those in poor body condition rather than the reverse situation where lice cause debility.
Five species of louse infest cattle: the biting or chewing louse. Spread occurs by direct contact with increases in population size during housing and cooler weather. The life cycle, egg, three nymph stages, and adult is three weeks and spent entirely on the host.
Heavy infestations cause irritation leading to rubbing against feed barriers etc. resulting in hair loss most often over the neck and shoulders and disrupted feeding patterns.
Careful inspection of the skin using a magnifying glass will identify adult louse populations and eggs adherent to hairs. Further examination under a microscope at x100 will differentiate the particular lice species present.
Treatment uses a pour-on synthetic pyrethroid preparation such as deltamethrin. Injectable group 3-ML anthelmintics (ivermectin, doramectin and eprinomectin) will remove all sucking lice and >98 per cent of biting lice, and all lice when used as pour-on preparations. All cattle in direct contact must be treated.
Disease is caused by infestation with Sarcoptes scabiei (bovis) but is rare in the UK.
Infestation causes severe rubbing (pruritus) with serum exudation and gross thickening of the skin particularly over the neck. The intense pruritus can lead to disruption of feeding patterns, and weight loss progressing to debility in neglected cattle.
Skin scrapings collected by a veterinary surgeon with microscopic demonstration of mites.
Potential treatments include a pour-on synthetic pyrethroid or organophosphate preparation, and injectable or pour-on group 3-ML anthelmintic.
Biosecurity measures should prevent the introduction of infested cattle.
Psoroptic mange is caused by infestation with Psoroptes ovis but is rare in cattle in the UK.
Clinical signs include serum exudation and thickening of the skin particularly over the neck and dorsal midline. Diagnosis is based upon microscopic demonstration of mites in skin scrapings.
Potential treatments include a pour-on synthetic pyrethroid or organophosphate preparation, and injectable or pour-on group 3-ML anthelmintics but the response is poor.
Chorioptic mange, caused by infestation with Chorioptes bovis, is commonly seen in adult cattle in the UK towards the end of the winter housing period.
Infestation with C. bovis causes serum exudation and thickening of the skin characteristically at the base of the tail. Infestation may spread to the udder, scrotum and limbs.
Skin scrapings with microscopic demonstration of mites.
Treatment for chorioptic mange is rarely undertaken and lesions resolve spontaneously when cattle are turned out to pasture in the spring.
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