Over the past few weeks many cattle are likely to have been housed. Coming off grass there is the risk that these animals will bring inside with them a burden of parasites. Winter housing is a key time to treat for both external and internal parasites.
Lice are a common winter problem among cattle and with the tendency for low burdens to be fairly common. They may only be tiny but these little critters can cause intense irritation resulting in hair loss from animals scratching and rubbing themselves. These little parasites have the potential to take a big nip out of cattle performance (if heavy infestations are allowed to take hold), affecting productivity through reduced feed intake, with cattle generally being listless and irritated. Lice cause anaemia which is potentially serious in young calves.
Symptoms and signs to look out for (generally seen in moderate to severe cases);
- Frequent and consistent scratching
- Baldness and hair loss – particularly on the neck, shoulder and rump areas.
- Biting and chewing at hair and skin
Lice burdens and the resulting broken skin from rubbing and scratching can lead to cattle being more susceptible to skin infections. Typically lice burdens are a sign of an underlying condition.
There are two types of lice that affect cattle; Biting and Sucking Lice. Both of which can be seen by the naked eye (particularly along they back when parting the hair of the infected animal).
Bovicola Bovis are more common and lay an egg every two days hatching 7 to 10 days later, becoming adults in about two to three weeks. Populations can build up easily as they live for around 10 weeks. They feed on skin debris, blood and scabs. This species cause the most severe irritation to cattle. Common areas on the animal’s body to find these include particularly the around the poll and forehead and along the neck, back, shoulder and rump areas.
Linognathus Vituli (this species can also transmit tick borne fever and ringworm), Haematopinus Eurysternus and Selenopotes Capillatus are the three main species. They have a live cycle of approx. 1 month with eggs hatching after 10 to 15 days, becoming adults in about two to three weeks. They are usually found around the head and neck of cattle.
Both biting and sucking lice lead to skin irritation causing cattle to rub and scratch themselves causing damage to the hind. This skin irritation also causes further stress which can lead to further health issues such as pneumonia and reduced liveweight gains.
Lice are spread via animal to animal contact which tends to happen faster when cattle are housed for the winter and closer together. Also the thicker winter coat allows the lice to thrive. Clipping the backs of cattle at housing will reduce the likelihood of lice burdens.
Treatment of Lice
With winter housing approaching it would be worthwhile to treat cattle for lice before they become an issue, treating animals in batches as they are housed. To ensure that any treatment is effective you must treat all animals in the group. When treating for external parasites make sure to treat on the same day as they are contagious as if treated on separate days there is the risk they will re infect the treated animals as lice move from animal to animal.
Treatments are available as pour-on or injectable formulations however injectables are more effective against sucking lice whereas a pour-on solution will be effective against both. Care should be taken to ensure that the correct dosage rate is applied as it is a common mistake to under dose or not apply properly.
Any bought in cattle or cattle added to the group should be treated. One treatment is usually effective however with heavy infestations a follow up treatment may be required.
Healthy cattle with self-groom which will reduce the burden of eggs. By maintaining a healthy environment and monitoring cattle for signs of ill health daily when housed the risk of lice should be reduced.
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