This site is optimised for modern web browsers, and does not fully support your browser version, we suggest the use of one of the following browsers: Chrome, Firefox, Microsoft Edge, some sections of the website may not work correctly such as web forms
6 November 2016
Late summer/autumn is the time of year we start to see cases of harvest mites, which are actually the larval stage of the adult mite, Trombicula autumnalis.
The adult mites live on plants, but the larvae (which have 6-legs compared to the adults’ 8-legs) live on mammals (including cats, dogs and humans) and birds, feeding on fluid from the skin. The larvae are present on plants, are most active during the day when it is warm and dry, and will attach themselves to any warm-blooded animal that brushes past the plant. They feed by injecting enzymes into the skin which breaks down the tissue; the liquid that is formed is then sucked up by the larvae. Once they have fed for 2-3 days they will drop off to complete the life cycle from larvae to nymph to adult.
The irritation caused by the harvest mites feeding on the skin can cause the skin to become itchy, and in some cases dermatitis (inflammation of the skin) can develop, which can make the skin appear red and have small spots/scabs present. If the patient scratches the skin a lot, the skin can become traumatised and occasionally may become secondarily infected with bacteria, leading to a skin infection. The mites tend to feed on areas of the body where the skin is thin and there is little hair, such as the base of the ears (including the little pocket of skin at the base of the ear flap, Henry’s Pocket), around the chin and mouth, under the front legs, on the underside of the belly and in between the toes.
The harvest mite is generally orange in colour and big enough to be just about visible to the naked eye. Harvest mite infestation can often be diagnosed by observation of the mite on the skin, then by taking a skin scrape to confirm under a microscope.
Harvest mites can be treated with certain flea treatments (please discuss with a vet as to which products are suitable), and occasionally if the skin is damaged or infected, antibiotics and medications to reduce itchiness may be required. In severe cases patients may need to wear an Elizabethan collar to stop them causing excessive trauma to the affected areas.
If you are concerned that your pet may have harvest mites, please contact your vet to discuss.
See also our: