Objective—To evaluate the efficacy of coumaphos,
an organophosphate (OP) acaricide, at concentrations
up to 2 times higher than the highest concentration
required by the US Eradication Program against all
stages of an OP-resistant strain of Boophilus
microplusin experimentally infested cattle.
Procedure—Four groups of cattle (4 calves/group)
were all infested with Boophilus ticks 3 times before
treatment. Each group was treated with coumaphos
as follows: group 1, at 0.165% active ingredient (AI);
group 2, at 0.299% AI; group 3, at 0.566% AI; and
group 4, not treated. Following treatment, ticks were
collected for 21 days. Ticks collected 1 to 7, 8 to 14,
and 15 to 21 days after treatment were considered
adults, nymphs, and larvae, respectively, at time of
Results—Overall control at 0.165, 0.299, and 0.566%
AI was 52.9, 75.8, and 89.7%, respectively. Control of
adults ranged from 4.3% at 0.165% AI to 73.5% at
0.566% AI. Control of nymphs ranged from 60.6% at
0.165% AI to 97.3% at 0.566% AI. Control of larvae
was > 98% at all coumaphos concentrations.
Conclusions and Clinical Relevance—All coumaphos
concentrations failed to provide acceptable control
for use in the US Eradication Program against OPresistant
ticks. Treatment was least effective against
adults and most effective against larvae. Even at
0.566% AI (2 times higher than required by the US
Eradication Program), ticks were not eradicated, placing
the United States at risk from dispersing cattle
harboring viable ticks to uninfested areas. (Am J Vet Res 2003;64:684–689)
Objective—To develop partial budgets of the economic
costs of 2 test strategies for screening cattle for persistent
infection with bovine viral diarrhea virus (BVDV).
Design—Partial budget analysis.
Animals—938 calves arriving at 2 stocker operations.
Procedure—Calves were tested to determine prevalence
of persistent BVDV infection. Test strategies that
were evaluated included a single-test strategy consisting
of immunohistochemical staining of skin biopsy
specimens from all animals and a 2-test strategy consisting
of polymerase chain reaction (PCR) assaying of
pooled blood samples followed by immunohistochemical
staining of skin biopsy specimens from animals in
pools for which assay results were positive. Breakeven
costs (ie, cost of persistent BVDV infection per
animal necessary to justify whole-herd diagnostic testing)
associated with each test strategy were calculated
as a function of disease prevalence and test cost.
Results—Apparent prevalence of persistent BVDV
infection was 0.32%. Sensitivity and specificity of the
PCR assay for pooled samples were 100% and
89.7%, respectively. Regardless of the prevalence of
persistent BVDV infection, the break-even cost for the
2-test strategy was lower than the break-even cost for
the single-test strategy. However, the economic
advantage was greatest when prevalence was low.
Conclusions and Clinical Relevance—Results suggest
that using a 2-test strategy to screen cattle for persistent
BVDV infection, whereby the first test involves
PCR assaying of pooled samples and the second
involves immunohistochemical testing only of those animals
represented in pooled samples with positive assay
results, will reduce the cost of screening incoming feedlot
cattle, compared with immunohistochemical testing
of all animals. (J Am Vet Med Assoc 2005;226:249–254)
Objective—To estimate prevalence of and identify
risk factors for fecal Salmonella shedding among hospitalized
horses with signs of gastrointestinal tract
Animals—465 hospitalized horses with gastrointestinal
Procedure—Horses were classified as positive or
negative for fecal Salmonella shedding during hospitalization
by means of standard aerobic bacteriologic
methods. The relationship between investigated
exposure factors and fecal Salmonella shedding was
examined by means of logistic regression.
Results—The overall prevalence of fecal Salmonella
shedding was 13%. Salmonella serotype Newport
was the most commonly isolated serotype (12/60
[20%]), followed by Anatum (8/60 [13%]), Java (13%),
and Saint-paul (13%). Foals with gastrointestinal tract
disease were 3.27 times as likely to be shedding
Salmonella organisms as were adult horses with gastrointestinal
tract disease. Adult horses that had been
treated with antimicrobial drugs prior to hospitalization
were 3.09 times as likely to be shedding
Salmonella organisms as were adult horses that had
not been treated with antimicrobial drugs prior to hospitalization.
Adult horses that underwent abdominal
surgery were 2.09 times as likely to be shedding
Salmonella organisms as were adult horses that did
not undergo abdominal surgery.
Conclusions and Clinical Relevance—Results suggest
that a history of exposure to antimicrobial drugs
prior to hospitalization and abdominal surgery during
hospitalization were associated with Salmonella
shedding in adult horses with gastrointestinal tract
disease. Foals with gastrointestinal tract disease
were more likely to shed Salmonella organisms than
were adult horses with gastrointestinal tract disease.
(J Am Vet Med Assoc 2004;225:275–281)
To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only.
351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age.
Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time.
351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%.
Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.