Dermatological Disorders - Donkey

Introduction

For centuries the donkey has been regarded as a robust and willing servant of man, and most veterinarians accept that, as a species, it suffers rather fewer skin diseases than most other domestic animals. However this may be more in the perception than the actuality because the donkey tends to show few signs of cutaneous discomfort. The concept of a skin disease being a significant factor in the overall health of the animal is not widely appreciated; it is largely viewed as trivial and incidental.

Many of the skin diseases of the donkey (and the horse for that matter) have not been well characterised and so they are often given the names of the ‘similar’ disorders in humans and other animals. This is probably unjustified and may even be grossly misleading when treatments are sought. Extrapolation from other species only works if the conditions have identical pathophysiology and if the various species have identical treatment requirements and tolerances. In the case of the donkey, little is known and much is assumed. Some of the skin disorders that afflict donkeys in tropical climates are very serious both to the donkey itself and to its owners. Zoonotic implications should be considered where fungal skin infections in particular, such as Trichophyton and Microsporum spp. (the causes of dermatophytosis/ringworm) and others such as Cryptococcus spp. and Histoplasma spp. organisms are endemic.

Presenting Syndromes

Categories of Skin Disorders:

1. Genetic and Developmental
2. Immunological
3. Nutritional
4. Allergic
5. Neurological
6. Traumatic
7. Stings and bites
8. Neoplastic
   • sarcoid
   • squamous cell carcinoma
   • fibroma / fibrosarcoma
   • melanoma
9. Iatrogenic / idiopathic
10. Chemical / toxic
11. Infectious
    • Viral
      • Coital exanthema
    • Bacterial
      • Dermatophilosis
      • Staphylococcal / Streptococcal farunculosis or folliculitis
      • Fusobacterial dermatitis
    • Fungal
      • Dermatophytosis
      • Histoplasmosis (epizootic lymphangitis)
      • Cryptococcosis
    • Protozoal
      • Besnoitiosis
      • Trypanosomiasis
    • Parasitic
      • Chorioptic mange / other mite infestations
      • Pediculosis (lice)
      • Habronemiasis
      • Onchocerciasis
      • Ticks

Summary

Skin disease in donkeys is a poorly documented speciality. Donkeys are liable to the full range of infectious and non-infectious diseases but under most natural conditions they remain remarkably free of skin disease.

The robust and uncomplaining character of most donkeys means that many skin diseases are presented late in the course and the number of therapeutic agents that can be used is small, and so there are major problems. For the most part the philosophy should be to limit therapy to the directly effective medications and try to restore the skin to a more natural condition by appropriate management.

Traumatic injuries are a serious complication in many places and secondary infection of these injuries and other inflammatory disorders is common.

References

• Knottenbelt, D. (2008) Skin disorders In Svendsen, E.D., Duncan, J. and Hadrill, D. (2008) The Professional Handbook of the Donkey, 4th edition, Whittet Books, Chapter 8

CLINICAL SECTION - DONKEY