Page 107 - JSOM Summer 2018

An Ongoing Series

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Management of Canine Pyotraumatic Dermatitis (a.k.a., Hot Spot)

Lee Palmer, DVM, MS, DACVECC, CCRP, EMT-T, WEMT, NRP, TP-C

ABSTRACT
Pyotraumatic dermatitis (a.k.a., hot spot) is a rapidly develop- BOX 1 Predisposing Triggers of Pyotraumatic Dermatitis 1,2
ing, superficial, moist, exudative dermatitis commonly induced 1. Allergic skin diseases
by self-inflicted trauma. Although not acutely life threatening, o Atopic dermatitis (atopy)
these lesions are extremely pruritic and distracting and signifi- o Food allergy dermatitis
o Flea infestation (flea allergy dermatitis)
cantly interfere with the canine’s operational effectiveness and 2. External parasites
ability to stay on task. The review discusses a case, including o Lice (Linognathus setosus), ticks, mites (Demodex, Sarcoptes
clinical presentation, diagnosis, treatment, and prognosis. scabiei)
3. Otitis externa
4. Anal sac disease or impaction
Keywords: Operational K9; dog; pyotraumatic dermatitis; 5. Foreign material (splinter, thorn, grass seed) embedded in the
hot spot; acute moist dermatitis skin
6. Contact dermatitis
o Application of topical medications (anti–flea and tick
preventatives)
Introduction o Accidental dermal exposure to irritating liquids or
compounds
Pyotraumatic dermatitis (a.k.a., hot spot) is a rapidly devel- 7. Pain associated with localized trauma (e.g. site of intravenous
oping, superficial, moist, exudative dermatitis commonly catheter placement, injection site reaction, “clipper burn” [skin
induced by self-inflicted trauma. Although not acutely life damage from clipper blades during clipping])
1,2
threatening, these lesions are extremely pruritic and distract- 8. Dermal injury subsequent to excessive rubbing of a collar or
harness that is too tigh
ing to the OpK9. As a result, their presence significantly inter- 9. Painful musculoskeletal disorders (e.g., osteoarthritis)
feres with the canine’s operational effectiveness and ability to 10. Persistently moist or wet (frequent swimming or bathing)
stay on task. In addition, the exudative open wound is a po- 11. Poor hygiene, lack of grooming (unkempt, matted hair coat)
tential source for a severe secondary bacterial skin infection. 12. Warm, humid environments
The inciting cause of the self-inflicted trauma is often an un- its extremities, paws, flank, and underside. Common envi-
derlying pruritic (i.e., severely itchy), painful, or other irri- ronmental and social stressors applicable to an OpK9 include
tating condition that triggers the OpK9 to lick, chew, and/or being deployed to an unfamiliar area; prolonged separation
scratch at the skin in attempts to alleviate the itch or discom- from their handler (separation anxiety); increased social anx-
fort. Left untreated, the compulsive self-inflicted trauma ulcer- iety (e.g., exposure to unfamiliar dogs when housed in a new
ates and erodes the superficial layer of the dermis, creating of kennel system); increased work stressors (e.g., longer work
a markedly inflamed open wound. The intensely pruritic and hours, increased tasks to perform, more difficult search areas,
inflammatory nature of the condition continues to foster the unpredictability in routine); and lack of environmental stim-
viscous cycle of itch, scratch, and self-mutilation. Box 1 lists ulation, particularly in high-drive OpK9s. Any unresolved or
dermatologic and physiologic conditions that may trigger the recurrent anxiety, conflict, or frustration may perpetuate the
itch-scratch cycle and promote the development of pyotrau- self-directed barbering behavior to the point of causing pyo-
matic dermatitis. 1,2 traumatic dermatitis. 3

In some cases, in absence of any known underlying derma- Although many cases of pyotraumatic dermatitis tend to have a
tologic or physiologic condition, the OpK9 may self-mutilate bacterial component, the condition is not the result of a primary
due to a primary self-directed behavioral response. Stress, bacterial skin infection (i.e., pyoderma). Similar to humans,
3
1,2
anxiety, frustration, and / or conflict associated with changes the canine’s skin is covered with commensal bacteria (e.g.,
in an OpK9’s work-related and/or social environment may Staphylococci spp.) that serve an integral part of the skin’s nat-
cause the OpK9 to compulsively lick and chew (barbering) ural protective mechanism for safeguarding against invasion of
Correspondence to 1003 Felton Lane, Auburn, AL 36830; or lpalmer2508@gmail.com.
LTC Palmer is with the Veterinary Corps, US Army Reserves, and is chairman of the K9 Tactical Emergency Casualty Care Working Group.

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