Objective—To assess gentamicin concentrations in
serum and bronchial lavage fluid (BLF) of horses during
a 24-hour period after once-daily aerosol administration
of gentamicin (GAER) for 7 days and the pattern
and degree of bronchial tree inflammation associated
with repeated GAER.
Animals—13 healthy adult horses (9 geldings and 4
Procedure—The treatment group comprised 8 horses,
and 5 horses were untreated control animals.
Gentamicin (20 mL of gentamicin [50 mg/mL]) was
administered via aerosol once daily for 7 days.
Samples of serum and BLF were obtained from all
horses before GAER and 0.5, 4, 8, and 24 hours after
the final day of GAER. Gentamicin concentrations were
determined for all samples from treated horses, and
cytologic examinations were performed on all BLF
Results—Peak median BLF gentamicin concentration
detected at 0.5 hours was 2.50 µg/mL. Median serum
gentamicin concentration was < 0.50 µg/mL at all
time points. Significant differences were not
observed in total nucleated cell counts or differential
cell counts in BLF between groups at any time point.
Neutrophil count in BLF for all horses was increased
over baseline at 4 and 24 hours.
Conclusions and Clinical Relevance—We did not
detect evidence of gentamicin accumulation or respiratory
inflammation after once-daily GAER for 7 days.
This protocol appears unlikely to result in local or systemic
toxicosis. Repeated daily GAER to horses
appears to be a safe procedure and may have clinical
use in the treatment of horses with bacterial infections
of the airways. (Am J Vet Res 2004;65:173–178)
Objective—To compare concentrations of gentamicin
in serum and bronchial lavage fluid after IV and
aerosol administration of gentamicin to horses.
Animals—9 healthy adult horses.
Procedure—Gentamicin was administered by
aerosolization (20 ml of gentamicin solution [50
mg/ml]) and IV injection (6.6 mg of gentamicin/kg of
body weight) to each horse, with a minimum of 2
weeks between treatments. Samples of pulmonary
epithelial lining fluid were collected by small volume
(30 ml) bronchial lavage 0.5, 4, 8, and 24 hours after
gentamicin administration. Serum samples were
obtained at the same times. All samples were analyzed
for gentamicin concentration, and cytologic
examinations were performed on aliquots of bronchial
lavage fluid collected at 0.5, 8, and 24 hours.
Results—Gentamicin concentrations in bronchial
lavage fluid were significantly greater 0.5, 4, and 8
hours after aerosol administration, whereas serum
concentrations were significantly less at all times
after aerosol administration, compared with IV administration.
Neutrophil counts in bronchial lavage fluid
increased from 0.5 to 24 hours, regardless of route of
Conclusions and Clinical Relevance—Aerosol
administration of gentamicin to healthy horses resulted
in gentamicin concentrations in bronchial fluid that
were significantly greater than those obtained after IV
administration. A mild inflammatory cell response
was associated with aerosol delivery of gentamicin
and repeated bronchial lavage. Aerosol administration
of gentamicin may have clinical use in the treatment
of bacterial bronchopneumonia in horses. (Am J Vet
Objective—To determine whether conditions representing
activities that are typical in the recreational
use of horses, including transport to and from show
grounds, stall confinement in unfamiliar surroundings,
and light exercise, are associated with increased incidence
of gastric ulcers in horses.
Design—Randomized controlled study.
Animals—20 client-owned horses.
Procedure—Horses had no gastric ulcers as determined
by endoscopic examination on study day –1.
Ten control horses were maintained on-site with no
changes in management variables. Ten horses were
transported via trailer for 4 hours on day 0 to another
site, placed in individual stalls, fed twice daily, and
exercised twice daily for 3 days. On day 4, they were
transported back to the original site via trailer for 4
hours. On day 5, endoscopic examinations were performed
on all horses to assess gastric mucosa status.
Results—Horses that were transported and housed
off-site had a significantly higher incidence of hyperkeratosis
and reddening of the gastric mucosa than
control horses. Two control horses and 7 transported
horses developed gastric ulcers by day 5. Ulcer
scores of transported horses increased significantly
from day –1, whereas ulcer scores in control horses
did not change significantly from day –1.
Conclusions and Clinical Relevance—Activities that
are typical in recreational use of horses were ulcerogenic,
and ulcers in the gastric squamous mucosa can
develop under these conditions within 5 days. ( J Am Vet
Med Assoc 2005;227:775–777)
Objective—To evaluate the efficacy of omeprazole
paste, a commonly used antiulcer drug, on intragastric
pH in clinically normal neonatal foals.
Animals—6 clinically normal foals between 5 and 14
days of age.
Procedure—Intragastric pH was recorded in each
foal by use of a disposable antimony pH electrode
with internal reference. Values for intragastric pH
were recorded every 4 seconds by use of an ambulatory
pH monitor. There were two 24-hour recordings
of intragastric pH for each foal, with 24 hours
between recordings. Foals were not administered
any drugs during the first recording. Foals were
administered omeprazole paste (4 mg/kg, PO) 1
hour after the start of the second recording. Mean
pH was calculated for each hour of each 24-hour
recording session. Hourly mean values were compared
between the first and second 24-hour
Results—Complete data were obtained from 4 of 6
foals during the first 24-hour recording and 6 of 6 foals
during the second 24-hour recording. Foals had significantly
higher mean hourly intragastric pH for hours
2 to 22 following omeprazole administration, compared
with corresponding hourly pH values in foals
during the first recording.
Conclusions and Clinical Relevance—Omeprazole
paste can effectively increase intragastric pH in
clinically normal neonatal foals within 2 hours after
oral administration of the first dose and can be
administered to neonatal foals at the rate of
4 mg/kg, PO, every 24 hours. (Am J Vet Res
Animals—102 horses with normal-appearing gastric mucosa on endoscopic examination that were in light to heavy training.
Procedures—Horses at 4 trial locations were allocated into replicates and sham dosed orally (empty syringe) or treated with a paste formulation of omeprazole (1 mg/kg [0.45 mg/ lb], PO) once daily for 8 days. Training regimens varied among locations and included early training for western performance events; walking, trotting, and cantering in a mechanical exerciser; and race training (2 locations). Prevalences of gastric ulceration at the completion of the 8-day treatment period were compared between groups.
Results—At the end of the 8-day treatment period, the proportion of omeprazole-treated horses free from gastric ulceration (88%) was significantly higher than the proportion of sham-dosed horses free from gastric ulceration (27%).
Conclusions and Clinical Relevance—Results showed that horses in light to heavy training for as short as 8 days were at risk of developing gastric ulcers and that administration of omeprazole paste decreased the incidence of gastric ulcers.
To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and without cardiomyopathy and describe 2 cases of cardiomyopathy with different etiologies.
25 free-ranging southern sea otters (Enhydra lutris nereis) with (n = 14; cases) and without (11; controls) cardiomyopathy and 17 healthy managed southern sea otters from aquariums or rehabilitation centers (controls).
Serum cTnI concentration was measured in live sea otters. Histopathologic and gross necropsy findings were used to classify cardiomyopathy status in free-ranging otters; physical examination and echocardiography were used to assess health status of managed otters. Two otters received extensive medical evaluations under managed care, including diagnostic imaging, serial cTnI concentration measurement, and necropsy.
A significant difference in cTnI concentrations was observed between cases and both control groups, with median values of 0.279 ng/mL for cases and < 0.006 ng/mL for free-ranging and managed controls. A cutoff value of ≥ 0.037 ng/mL yielded respective sensitivity and specificity estimates for detection of cardiomyopathy of 64.3% and 90.9% for free-ranging cases versus free-ranging controls and 64.3% and 94.1% for free-ranging cases versus managed controls.
CONCLUSIONS AND CLINICAL RELEVANCE
Cardiomyopathy is a common cause of sea otter death that has been associated with domoic acid exposure and protozoal infection. Antemortem diagnostic tests are needed to identify cardiac damage. Results suggested that serum cTnI concentration has promise as a biomarker for detection of cardiomyopathy in sea otters. Serial cTnI concentration measurements and diagnostic imaging are recommended to improve heart disease diagnosis in managed care settings.
Objective—To determine the onset of immunity after
IM administration of a single dose of a recombinant
canarypox virus vaccine against West Nile virus
(WNV) in horses in a blind challenge trial.
Animals—20 mixed-breed horses.
Procedure—Horses with no prior exposure to WNV
were randomly assigned to 1 of 2 groups (10 horses/group). In 1 group, a recombinant canarypox
virus vaccine against WNV was administered to
each horse once (day 0). The other 10 control horses
were untreated. On day 26, 9 treated and 10 control
horses were challenged via the bites of mosquitoes
(Aedes albopictus) infected with WNV.
Clinical responses and WNV isolation were monitored
for 14 days after challenge exposure; antibody
responses against WNV after administration of the
vaccine and challenge were also assessed in both
Results—Following challenge via WNV-infected mosquitoes,
1 of 9 treated horses developed viremia. In
contrast, 8 of 10 control horses developed viremia
after challenge exposure to WNV-infected mosquitoes.
All horses seroconverted after WNV challenge;
compared with control horses, antibody responses in
the horses that received the vaccine were detected
Conclusions and Clinical Relevance—In horses, a
single dose of the recombinant canarypox virus-WNV
vaccine appears to provide early protection against
development of viremia after challenge with WNVinfected
mosquitoes, even in the absence of measurable
antibody titers in some horses. This vaccine
may provide veterinarians with an important tool in
controlling WNV infection during a natural outbreak or
under conditions in which a rapid onset of protection
is required. (Am J Vet Res 2004;65:1459–1462)
OBJECTIVE To determine the incidence of and risk factors for clinical feline herpesvirus (FHV) infection in zoo-housed cheetahs and determine whether dam infection was associated with offspring infection.
DESIGN Retrospective cohort study.
ANIMALS 144 cheetah cubs born in 6 zoos from 1988 through 2007.
PROCEDURES Data were extracted from the health records of cheetahs and their dams to identify incident cases of clinical FHV infection and estimate incidence from birth to 18 months of age. Univariate and multivariable Cox proportional hazards models, controlling for correlations among cheetahs with the same dam, were used to identify risk factors for incident FHV infection.
RESULTS Cumulative incidence of FHV infection in cheetah cubs was 35% (50/144). No significant association between dam and offspring infection was identified in any model. Factors identified as significant through multivariable analysis varied by age group. For cheetahs up to 3 months of age, the most important predictor of FHV infection was having a dam that had received a preparturition FHV vaccine regimen that included a modified-live virus vaccine versus a dam that had received no preparturition vaccine. Other risk factors included being from a small litter, being born to a primiparous dam, and male sex.
CONCLUSIONS AND CLINICAL RELEVANCE This study provided the first population-level characterization of the incidence of and risk factors for FHV infection in cheetahs, and findings confirmed the importance of this disease. Recognition that clinical FHV infection in the dam was not a significant predictor of disease in cubs and identification of other significant factors have implications for disease management.