Clinical mite infestations of cattle, that is, when there are obvious signs, are rare in Australia.
In active cases of clinical dermatitis, the common causes of irritation and hair loss, such as lice, should first be ruled out. If mites then remain a possible cause for the dermatitis, a series of skin scrapings will need to be performed with diagnosis by a veterinarian or a skilled laboratory technician.
Mite infestations will most likely be seen in young animals or older animals stressed by malnutrition, disease or overcrowding. Cattle in confinement, such as in beef feedlots or non-grazing dairy operations, are more likely to show signs of infestation.
Lesions are commonly seen on the escutcheon (area below the anus and vulva), base of tail, perineum (area around the anus and vulva), back of the udder and the feet.
Scrapings can be collected by a producer by placing a sheet of paper behind the animal’s back feet and carefully scraping the lesions with a blade downwards to dislodge crusts. The crusts are collected on the paper and transferred to a jar or bag for transport to a laboratory (government and private cattle veterinarians, as well as major worm egg count laboratories, can examine scrapings).
Microscopic examination of the crusts, after caustic digest, will reveal whether mites and/or their eggs are present.
Routine monitoring will not be necessary unless skin conditions are noted. Attention to all other aspects of cattle management to maintain health and productivity of cattle will minimise the potential for mite infections.
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