here - Australian College of Veterinary Scientists

50
Management of the Atopic Horse
ACVSC Proceedings Dermatology Chapter Science Week 2005
Janet Littlewood
Once a diagnosis of atopic dermatitis has been made in any companion animal, the
various therapeutic options available need to be considered and discussed with the
client. As with any hypersensitivity condition, allergen avoidance is the ideal solution,
but this may not be achievable, depending on the trigger factors implicated. Other
therapeutic approaches include hyposensitisation (immunotherapy), other
immunomodulatory approaches and symptomatic ant-inflammatory and anti-pruritic
treatments.
Allergen avoidance:
For horses with clinical disease related to indoor allergens, maintaining the horse at
pasture all the year round is the ideal solution. However, for horses with pollen
allergies and insect bite hypersensitivity, keeping the horse stabled for the majority of
the time is more appropriate. Treatment of horses with insect bite hypersensitivity
will be covered in a later presentation and will not be addressed further in this
presentation. Those patients with both indoor and outdoor allergens implicated in
their disease process are the most challenging in terms of allergen avoidance.
Nonetheless, it is possible with management modification to reduce allergen
exposure in the indoor environment, which, in the author's experience, can be very
effective in controlling the disease in many patients.
Management measures that are recommended include housing the horse in a stable
with its own air space, but with good ventilation, not underneath or next to a
hay/grain loft or store, removal of birds nests, removal of all loose bedding,
vacuuming and pressure cleaning of the stable interior on a regular basis. Rubber
matting is the ideal flooring, with no loose bedding at all, since even “low allergen”,
dust-free beddings may provide a suitable micro-environment for dust and storage
mite species. This flooring is well tolerated by even the largest horses, although
owners tend to anthropomorphise about the comfort of their horse!
Feeding of low allergen foods may also be helpful – such as vacuum-packed wilted
grass products, or blow-dried (dust-free) ley-grown hay, and cubed rather than loose
grain concentrate foods.
For horses with reactions to dust mite species that show lesions on the skin under
rugs, presumably due to mites living in the rugs/horse duvets, the author has had