Staphylococcal tenosynovitis is a world-wide problem
in breed er and broiler chickens and causes economic
loss es due to decreased weight gain , decreased
egg production, and conde mnations of carcasses at
slaughter. 27The route of entry , pathogen esis ofdisease,
and host response to infection are poorly defined.'4.'5.27
The disease is usually chronic and responds poorly to
antimicrobial therap y or immunization. Increased heterophil
counts and marked heterophilic infiltration of
tendons and synovial membranes of th e tibiotarsal
(hock) joint occur in staphylococcal tenosynovitis.
The avian heterophil is analogous to th e human neutr
ophil in its action as a tissue ph agocyte and importance
in host defense against bacterial infections.v"
Defects in neutrophil fun ction have been documented
in human pati ents with recurrent staphylococcal infections.'?
Co nversely, increased in vitro chemotactic
ac tivity ofneutrophils in human pati ents with bacterial
infect ions also has been described."
The chicken has been proposed as an experime ntal
model for ba cteremia, hematogenous arthritis (synovitis),
and osteomyelitis of human beings.v" In our
preliminary investigations using th e avian model, osteomyelitis
with condylar erosions was produced in
additi on to tenosynovitis in birds given 107 staphylococcal
organisms intravenously. The intravenous administration
of 106 organisms produced tenosynovitis.
This dose relationship to clinical dis ease has been documented
by other researchers.s-" Heterophil fun ction
studies in the avian species ha ve been limited and ha ve
not been performed in chickens with staphylococcal
tenosynovitis. The purpose of this study was to determine
whether heterophil fun ction alterations exist in
chic kens with staphylococcal tenosyno viti s. Addition-
41 9
Downloaded from vet.sagepub.com at Ubon-Ratchathanee University on October 29, 2015
420 And reasen et al.
ally, these investigation s can provid e baseline valu es
for avian heterophil function in healthy chickens and
in chicken s with a bacterial inflammatory disease.