Objective—To identify farm characteristics and management
practices associated with development of
Rhodococcus equi pneumonia in foals.
Design—Prospective case-control study.
Animals—5,230 foals on 138 breeding farms with
Procedure—During 2003, participating veterinarians
provided data from 1 or 2 farms with ≥ 1 foal with
R equi pneumonia and unaffected farms. Data from
affected and unaffected farms were compared by use
of logistic regression analysis.
Results—A number of variables relating to farm size
and desirable management practices were significantly
associated with increased odds of farms being
affected with R equi pneumonia. By use of multivariate
logistic regression, affected farms were determined
significantly more likely to have raised Thoroughbreds,
housed ≥ 15 foals, used concrete floors in foaling stalls,
and tested foals for passive transfer of immunity than
unaffected farms. These results remained significant
even after accounting for exposure of foals to other
breeding farms during the first month of life.
Conclusions and Clinical Relevance—Breeding
farms with large acreage and a large number of mares
and foals have greater odds of being affected by
R equi pneumonia. Clinical relevance of associations
with Thoroughbred breed and concrete flooring in
foaling stalls remains uncertain. Desirable management
factors commonly used on farms were not
effective for controlling or preventing development of
R equi pneumonia. This finding indicates a need to
focus on host factors that influence disease development.
(J Am Vet Med Assoc 2005;226:404–413)
Objective—To evaluate microtiter-plate format ELISAs constructed by use of different diagnostic targets derived from the Ehrlichia ewingii p28 outer membrane protein for detection of E ewingii antibodies in experimentally and naturally infected dogs.
Sample Population—Serum samples from 87 kenneled dogs, 9 dogs experimentally infected with anti-E ewingii, and 180 potentially naturally exposed dogs from Missouri.
Procedures—The capacities of the synthetic peptide and truncated recombinant protein to function as detection reagents in ELISAs were compared by use of PCR assay, western blot analysis, and a full-length recombinant protein ELISA. Diagnostic targets included an E ewingii synthetic peptide (EESP) and 2 recombinant proteins: a full-length E ewingii outer membrane protein (EEp28) and a truncated E ewingii outer membrane protein (EETp28)
Results—A subset of Ehrlichia canis-positive samples cross-reacted in the EEp28 ELISA; none were reactive in the EESP and EETp28 ELISAs. The EESP- and EETp28-based ELISAs detected E ewingii seroconversion at approximately the same time after infection as the EEp28 ELISAs. In afield population, each of the ELISAs identified the same 35 samples as reactive and 27 samples as nonreactive. Anaplasma and E can is peptides used in a commercially available ELISA platform did not detect anti-E ewingii antibodies in experimentally infected dogs.
Conclusions and Clinical Relevance—The EESP and EETp28 ELISAs were suitable for specifically detecting anti-E ewingii antibodies in experimentally and naturally infected dogs. [Am J Vet Res 2010;71:1195-1200)