Lice
Lice are mainly a problem of housed cattle. Spread by direct contact, the four most common species can be divided into two categories:
Sucking lice
- 3 species common in the UK
- Pierce skin and suck blood
- Cause anaemia in large numbers
- Found around the head and neck of cattle
Biting lice
- 1 species (Bovicola bovis) found worldwide
- 2mm long, large brown round head
- Feeds on skin debris, blood and scabs
- Biting causes severe irritation
- Found on the neck, shoulders, back and rump
Symptoms
Lice cause irritation of the skin that leads to:
- Itching
- Hair loss
- Hide damage
- Anaemia (sucking lice)
Economic effects
- Lice blemish the hides of cattle, downgrading the value of the leather.
- Lice can reduce productivity – the degree of which is however hard to assess as they are often seen in animals in poorer condition.
Timing
Transmitted by close contact lice are a problem of housed cattle in the winter months.
Diagnosis
- Lice can be confirmed by finding evidence of their lifecycle stages – eggs, nymphs or adults.
- Eggs are found on hairs next to bald, rubbed areas.
- Nymphs (small adults) and adult lice can be spotted using a magnifying glass.
Treatment
Lice are able to survive off the host for a few days and tend to be a group problem, therefore treatment should be applied in Autumn / early Winter to all in contact cattle to control lice throughout the housing period.
Treatment options
- Synthetic pyrethoid Pour-ons
- Flypor® Pour-on (4% permethrin) is effective against both sucking and biting lice with a single dose normally sufficient to control all lice.
- Other alternatives are deltamethrin or alphacypermethrin based products.
- 3 ML Pour-ons
- Depidex® Pour on (ivermectin) treats and controls both sucking and biting lice.
- Other alternatives are doramectin, eprinomectin and moxidectin
- 3 ML Injections
Points to consider:
- Not all insecticides treat biting and sucking lice (e.g. ML injections are more effective against sucking than biting lice).
- Consider asking a Vet to diagnose whether you have sucking or biting lice.
- A second treatment may be needed 3-4 weeks later, monitor the cattle and retreat if required in consultation with your Vet.
- Never under-dose, it can increase the chance of resistant lice developing.
- Treat all cattle on the farm at the same time.
- Keep treated and untreated animals apart to avoid cross contamination.
- Animals should ideally be treated when they are not stressed or in poor condition.
