Pigeon Fever

Controversial

Feared

Misunderstood

A pain in the behind

Etiology  Corynebacterium psuedotuberculosis  Soil-borne, gram-positive, bacillus, intracellular, facultative anaerobe  Cultures in ~48 hours  2 biotypes Biovar equi  Multiple strains Biovar ovis  Multiple strains

Epidemiology  3 general forms External abscesses 96% Internal abscesses 2% Ulcerative lymphangitis 2%  Cellulitis with multiple draining lesions  Entry via abrasions and/or wounds to the skin or mucous membranes Summer sores (ventral midline dermatitis)  Horses, cattle, humans, sheep, goats

Epidemiology  Transmission Horse to horse contact Insects “Other” vectors Contaminated soil  “Contagious” Not as bad as Strangles Absolute quarantine not required  Survival times Up to 2 months in hay or shavings More than 8 months in the soil

Epidemiology  Yearly fluctuations Herd immunity Environmental factors  Rainfall  Temperature  Hot, dry Not definitively determined at this time  All breeds, all ages are at risk

Risk factors  Appropriate environmental conditions map review  <5 years or age  Horses in contact with others on summer pastures  Horses housed outside or with access to an outside paddock > stabled horses

Pathogenesis  Incubation period 7 to 28 days  Intracellular survival  Toxins reduce disease fighting abilities Similar to that produced by the Brown Recluse spider  Recovery 2 to 4 weeks  Although rare, horses can develop persistent recurrent infections lasting for more than 1 year

External Abscesses  Clinical signs Edema - 100% of the time Lameness or stiffness  100% of the time  location, location Anorexia - general malaise Fever ~25% of the time Weight loss Non-healing wounds

External Abscesses Location…

Internal Abscesses  Clinical signs Consistent with the involved organ or area Changes in lab work  Blood  Abdominal fluid  Thoracic fluid  Urine  Serology  Most commonly found in the liver or lungs

Internal Abscesses

Diagnosis  Index of suspicion  Culture Gold standard  Ultrasonography  Serology Internal abscesses

Ultrasonography

Treatment  Time “You want me to wait?!” Yeah…  lets allow the abscess to “cook” for a bit  Drainage Ultrasound guidance  Determine vascularity, depth, site

Treatment  Antibiotics Variable  Penicillins, Sulfas  Rifampin, Doxycycline  Antiinflammatories Bute, Banamine, Equioxx, Dexamethasone  Hydrotherapy Cold or warm

Survival Rates  <1% mortality rate associated with external abscessation with treatment  30 to 40% mortality rate associated with internal abscessation with treatment 100% without  Ulcerative lymphangitis Similar mortality to internal abscesses

Long-term recovery  In some horses, it can take up to 1 year for them to fully recover from the effects of pigeon fever  Some horses will never fully recover from the effects of pigeon fever They die They are chronically lame They can suffer irreversible damage to vital organs

Any questions?

Up Coming Classes September 30thVeterinary Medicine 101: I want to be a veterinarian October 7thForelimb Lameness 21stHindlimb Lameness November 4thColic and GI Disease 18thRespiratory Disease December 2ndDisease Recognition

Thanks for your time