Lice are wingless insects and can cause skin disease in cattle, known as pediculosis, most commonly during the housing period. Cattle can be infested with blood-sucking lice such as Haematopinus eurysternus, Linognathus vituli and Solenopotes capillatus and biting lice such as Bovicola bovis*. Blood-sucking lice have thinner, pointed heads enabling them to penetrate the skin and feed off the blood of the host. Biting lice are surface-living and have much wider heads and large jaws, to help them feed on the outer layers of the hair shafts, skin flakes and blood scabs.
It is not uncommon to find a small number of lice on housed cattle and these tend not to have a significant impact on the host animal. However, if larger numbers are present, cattle will spend a lot of time rubbing and licking themselves in an effort to alleviate the irritation. This can lead to hair loss and even weight loss, as priority is given to scratching rather than eating. Where blood-sucking lice are present in high numbers, it is possible that cattle may experience anaemia and weakness, as a result of blood loss. It is difficult to quantify the financial impact of heavy lice infestations. Certainly the hides of affected cattle can be significantly damaged, such that they are of lower quality and therefore value. It is very important to consider whether there is an underlying cause for heavy louse infestations; debilitated animals are far more likely to be affected by pediculosis, with chronic disease or alnutrition the main underlying cause.
As previously stated, lice and their eggs can often be seen on the skin, without the need for magnification. However, microscopic examination of skin scrapings and/or brushings is the only method to determine which species is present.
It is useful to determine which type of louse is present on cattle prior to treatment as this may influence treatment decisions. Whilst injectable treatments are highly effective against sucking lice, they are indicated as an aid in the control of biting lice due to the surface feeding habits of Bovicola bovis*. Pour-On treatments are effective against both biting and sucking lice.
When treating cattle with Pour-On products, it is very important to ensure the correct dose is calculated and that the product is applied correctly. Trying to treat animals that are not correctly restrained will make accurate application very difficult!
Also, it is imperative that every animal in the group is treated, to avoid re-infestation. New animals brought onto the farm need to be treated for the same reason. Dairy cattle can be treated with EPRINEX Multi Pour-On without the worry of having to discard milk after treatment; EPRINEX Multi Pour-On is effective against biting and sucking lice and has a zero milk withhold.
* Formerly known as Damalinia bovis
Mites belong to the same class as spiders and ticks. Infestation by mites is called acariasis and mange is the term used to describe the clinical presentation of mite infestation in cattle.
There are two types of mites, burrowing and non-burrowing.
Burrowing mites feed on blood and lymph, whilst surface feeders live off dead skin cells and secretions and most spend their entire life on the host animal. Transmission primarily occurs by physical contact between infested and uninfested cattle. Cattle mange is most commonly seen in housed cattle during the winter months.
Non-burrowing mites, such as Chorioptes bovis, the most common species of mite to affect cattle, and Psoroptes ovis cause crusting, scaling and thickening of the skin. The severity of these lesions will vary depending on the intensity and duration of infection, and may be exacerabated by ill thrift and underlying disease. Chorioptic mange typically gives rise to lesions around the tail head, legs and lower body. Psoroptic mange, which is rare in the UK, but more common in Ireland, is associated with more severe lesions and itching over the back, shoulders and tail head.
The burrowing mite, Sarcoptes scabei causes sarcoptic mange. Diagnoses are rare in comparison to chorioptic mange. Low numbers of mites cause scaling with little hair loss on the neck, face and tail head areas, but in severe cases the skin becomes thickened and crusted and there is extensive hairloss. Affected cattle experience intense itching.
Persistent scratching, rubbing and licking is not only a potential welfare concern, but can also result in hide damage. Reduced productivity has been documented during mange outbreaks, with milk drop, reduced body condition, and poor growth observed.1,2
The irritation that results from external parasite infestation make cattle more difficult to handle.
Female mites lay eggs, some at a rate of one per day. The eggs hatch to release larvae, which develop on the host to nymphs and then adult mites. It takes approximately three weeks from egg hatch to adult stage.
Chorioptes bovis can survive off the host for up to three weeks and other species can persist for days to weeks. Although the importance of environmental transmission of mites is unknown, it is possible that contaminated bedding, buildings and grooming brushes may contribute to the risk of reinfection.
Unlike lice, mites are not visible to the naked eye and skin scrapes are required to collect mites and examine them under a microscope. Scrapings should sample both the superficial and deep layers of skin to allow detection of surface feeding mites such as Chorioptes and Psoroptes, in addition to Sarcoptes, which resides in the deeper layers of the skin.
Both IVOMEC® Classic Pour-On and IVOMEC Classic Injection and EPRINEX® Multi Pour-On can be used to treat burrowing and non-burrowing mite infestations*. Identification of the mite species will determine the most appropriate treatment.
EPRINEX Multi® was launched in 2017 and is licensed to treat dairying sheep and goats in addition to cattle. It was developed as a line extension of EPRINEX Pour-On, which which was the first dairy and beef eprinomectin wormer with zero- milk withhold launched over 20 years ago.
IVOMEC® Super Injection provides a ‘three-in-one’ solution containing ivermectin and clorsulon in a single injection for the control of gastrointestinal roundworms, liver fluke and external parasites in beef cattle.