Psoroptic mange

What is psoroptic mange in cattle?

 This is a parasitic skin disease caused by Psoroptes sp mites.

How to recognise the disease

Clinical signs are more severe in the autumn and winter. The mites cause a severe dermatitis with scab formation along the back, shoulders and tail head of cattle. There is intense pruritis (itching).

Secondary infection is common leading to bleeding and crusting of the skin. Weight loss can be severe and deaths can occur if skin lesions are extensive.

In the summer, the mites reduce in number and become less active.

All breeds of cattle can be infected. Cases have mainly been in beef cattle but infection has also been confirmed in a dairy herd.   

Buying-in infected cattle is the most likely way of getting the disease. It can also spread by animal contact at market and in livestock lorries. Disease may be difficult to spot in the early stages, or in the summer months when mite numbers are low and clinical signs are minimal.

How to reduce the risk

Initially, look for mites to collect using a hand lens. The mites are up to 0.75mm in length and are present all over the lesion, not just at the edge. They appear dark in colour (in contrast to the mites of sheep scab) due to feeding on the blood exudate.

You can collect a skin scrape by using a scalpel blade held at right angles to the skin. Scab material should also be collected. The material should be transported in a container (e.g. a universal) to the laboratory.

Direct microscopy is normally sufficient for identification as there are usually large numbers of mites. A potassium hydroxide digest may be necessary if there are only a few mites.

The Psoroptes sp. mites are oval with pointed mouthparts. All of the legs project beyond the body. The pedicels (at the end of the first, second and fourth pairs of legs in female and first, second and third pairs of legs in the male) are jointed and end with funnel-shaped suckers.

Geographical location

AHVLA has diagnosed psoroptic mange, caused by Psoroptes sp. mites in cattle in Great Britain. These were the first cases seen since the 1980s and it is probable that the infection had been imported from Europe.  There is no link with Psoroptes ovis (sheep scab) cases.

How to reduce the impact

Farmers should consult their veterinary surgeon as treatment is not straightforward and failure to kill the mites will lead to a prolonged and more serious disease outbreak.

The majority of cases diagnosed to date have failed to respond to macrocyclic lactones (ML) which is the licensed treatment for psoroptic mange.

In most cases successful treatment has been achieved by using a 4% permethrin pour-on product (‘Flypor’, Novartis Animal Health).

This is given at an increased frequency of treatment (three treatments at two weekly intervals) advised by the farmers’ veterinary surgeon, under the cascade. Removal and destruction of the scabs before treatment is also advised.

It is very important to repeat the skin scrapes to check the efficacy of the treatment as clinical signs may improve but live mites may still be present.

The treatment should be given to all animals in the group and any in-contact animals. Movement from infected housing should also be advised. Mites can live off animals and be infective for at least 12 days.

One farm did not respond to either ML or permethrin treatments. In this case the use of Amitraz (‘Taktic’ Schering-Plough Intervet) imported from the Republic of Ireland, under a special licence from the VMD, appears to be the logical treatment to use. Please see the special import certificate application on the VMD website.

It is essential to ensure effective treatment of this disease. Experience from other European countries has shown that it is possible for psoroptic mange to become the most common skin disease in cattle with associated severe production losses and welfare concerns.

Contacting AHVLA

There is no legal requirement for farmers to report this disease to Government veterinary authorities. AHVLA would be interested to hear of any suspected cases of Psoroptic mange. Please contact your local AHVLA Investigation Centre to discuss with a Veterinary Investigation Officer (VIO).

Further information

Page last modified: 15 May 2013