Parasitic skin disease in cattle can be caused by both lice and mites. Problems develop in winter because thick winter coats provide sheltered, humid conditions that the parasites like. Close contact after housing allows the parasites to spread from animal to animal.
In the UK chewing lice (Bovicola bovis) are the most common and feed on skin scales and scabs. Small numbers don’t cause many problems but when numbers are high affected cattle rub and lick to relieve the itch that they cause. They tend to be found on top of the head and over the neck, shoulders, back, rump and tail head. They are brown, up to 2mm long and can be seen close to the skin when the hair along the back is parted. Eggs are stuck to individual hairs and can also be seen with the naked eye. Ill thriven or sick animals are often infected with large numbers of lice because they do not groom themselves properly. They can also be slow to shed their winter coats which leaves the lice undisturbed. Note that the lice are not the cause of the ill thrift.
Sucking lice (Haematopinus sp., Linognathus sp. and Solenoptes sp.) pierce the skin and feed on blood. They are grey/blue in colour and found particularly around the head, neck and dewlap. Very large numbers could cause anaemia.
Treatment of lice is with pour on/spot on products that contain synthetic pyrethroids. There are many on the market and examples include Dysect, Deltanil and Flypor 4%. Pour on wormers (group 3ML) containing ivermectin, doramectin, moxidectin or eprinomectin will also kill both types of lice. The injectable versions work best against sucking lice. Remember that using a 3ML wormer to treat lice will also expose any worms in the gut to the chemical. Overuse of these products can lead to the worms becoming resistant to them.
Mange mites are very tiny and to make a diagnosis your vet will need to take skin scrapings for examination under a microscope.
- Psoroptic mange – This mite has caused problems in Wales over the last 8 years affecting both beef and dairy herds. The first case in Scotland for 30 years was identified in 2014 following the import of a cow and calf from Ireland. The mite can infect the legs, feet, tail base and the area under the tail. Other areas such as the back and shoulders can also be affected. It causes severe itching and affected animals can lose weight and rub so much that they cause bleeding. Treatment options should be discussed with your vet as they are not straightforward.
- Chorioptic mange – Can infect the legs, feet, tail base and the area under the tail. Usually causes mild signs of itching and rubbing.
- Sarcoptic mange – Uncommon cause of severe itching particularly affecting the neck and tail. The skin can become thickened and hairless.
English and Welsh clients please contact:
SAC Consulting Veterinary Services, Allan Watt Building, Bush Estate, Penicuik, EH26 0QE
Scottish clients please contact
Your local disease surveillance centre