Identify and Manage an itchy horse
Finding the cause to an itch is paramount to finding the right solution, whether it be eradication of the cause or a long term successful management of the diagnosed condition.
Horses confined to paddocks or stables, are often in close proximity to other horses creating a breeding ground for diseases and parasites that affect the skin.
Sarcoptes is perhaps the best known cause of itch and hair loss in the mane and tail of horses. The microscopic female mite when impregnated tunnels into the skin and deposits eggs in the burrow. The larvae hatch in 3 to 10 days, move about on the skin as they mature into adult mites. Adult mites live three to four weeks in the host’s skin.
QLD Itch is an allergic reaction to the saliva of biting midge (biting insects that colonized near a water source and feast at dusk and dawn on nearby stock). Getting an accurate diagnosis from skin scraping or veterinary assessment is the first step to managing this condition correctly.
Science behind the itching reaction
A mast cell is part of the immune system and contains many granules rich in histamine and heparin. Although best known for their role in allergy and anaphylaxis, mast cells play important protective roles as well being intimately involved in wound healing including angiogenesis and defence against pathogens.
Histamine as part of the immune response to foreign pathogens, produced by both basophils and mast cells. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissue.
Heparin has been proposed to defend at such sites against invading bacteria.
To signal the correct response cytokines (small proteins) are released by cells to affect the behaviours of other cells.
The problem with allergic reaction occurs when incorrect signalling occurs at this cytokine level. Loosely put they can signal a Type 1 or Type 2 response to favour either a cellular immune response or an antibody response.B Type2 (Th2 ) over activation against auto antigen will cause Type1 IgE-mediated allergy and hypersensitivity.
Referred to as neck worms the adult Onchocerca Cervicalis worms live in the large nuchal ligament that runs from the poll to the withers. The reproduction process lands the highly irritating microfilaria (larval) around the face, shoulders, chest and abdomen on the horse where biting flies come to feed. The culicoides fly serves as the carrier, reinfecting and spreading the larvae. The adult Onchocerca Cervicalis worms do not usually cause discomfort to the horse and will reside within the neck for around 10 years meanwhile laying thousands of eggs each year.
Often inflammation occurs on the underbelly, ending in self trauma to the skin and chest as the horse rubs intensely to relieve the itch. Another tell tale sign includes a bullseye of hair loss and inflammation on the horse’s forehead. Most horses exhibit dermatitis, crustiness, hair loss, itching, swelling and self trauma, often mistaken for QLD Itch.
Read the full article: QLD Itch The Nude Horse