Skip to content
Search Library
thumbnail

Insect bites are an annoying fact of life for horses and other animals that live outdoors. Some horses, however, are exquisitely reactive to insect bites, especially those of the biting midge Culicoides variipennis.

Horses with insect bite hypersensitivity, or IBH, have a severe allergic reaction to proteins in the insect’s saliva. Protecting horses with insect sprays and fly sheets can be labor-intensive and expensive, and is usually not very effective in preventing the intensely itchy bites. Antihistamines and steroid creams offer some relief but are also of little long-term help. Immunotherapy, which can desensitize a horse with repeated injections of the allergenic proteins, is effective but somewhat impractical because about 10,000 midges are needed to obtain enough of the saliva proteins to treat just one horse.

A research group including a number of scientists from the cell biology and immunology group at Wageningen University in The Netherlands has developed a way to clone the proteins rather than collecting them from Culicoides midges.

The researchers identified seven allergenic proteins in a similar midge from the same genus and tested them in horses, finding that they produced the same type of skin irritation. The team determined how the midge’s genes produced the proteins and then programmed laboratory Escherichia coli bacteria to produce them.

These cloned proteins have already been used to develop the first reliable diagnostic test for the disease. With this method, the scientists hope to manufacture a reliably large supply of the proteins so that desensitizing protocols can be developed for treatment of horses affected by IBH.

X

Subscribe to Equinews and get the latest equine nutrition and health news delivered to your inbox. Sign up for free now!