Objective—To determine the relationship between
plasma β-endorphin (EN) concentrations and exercise
intensity and duration in horses.
Animals—8 mares with a mean age of 6 years
(range, 3 to 13 years) and mean body weight of 450 kg.
Procedure—Horses were exercised for 20 minutes
at 60% of maximal oxygen consumption (O2max)
and to fatigue at 95% O2max. Plasma EN concentrations
were determined before exercise, after a 10-
minute warmup period, after 5, 10, 15, and 20 minutes
at 60% O2max or at the point of fatigue (95%
O2max), and at regular intervals after exercise.
Glucose concentrations were determined at the
same times EN concentrations were measured.
Plasma lactate concentration was measured 5 minutes
Results—Maximum EN values were recorded 0 to
45 minutes after horses completed each test.
Significant time and intensity effects on EN concentrations
were detected. Concentrations were significantly
higher following exercise at 95% O2max,
compared with those after 20 minutes of exercise at
60% O2max (605.2 ± 140.6 vs 312.3 ± 53.1 pg/ml).
Plasma EN concentration was not related to lactate
concentration and was significantly but weakly correlated
with glucose concentration for exercise at
both intensities (r = 0.21 and 0.30 for 60 and 95%
Conclusions and Clinical Relevance—A critical
exercise threshold exists for EN concentration in
horses, which is 60% O2max or less and is related
to exercise intensity and duration. Even under conditions
of controlled exercise there may be considerable
differences in EN concentrations between
horses. This makes the value of comparing horses
on the basis of their EN concentration questionable.
(Am J Vet Res 2000;61:969–973)
Objective—To evaluate long-term clinical outcome in dogs with upper airway obstruction treated with laryngeal web resection and mucosal apposition.
Design—Retrospective case series.
Animals—15 client-owned dogs with laryngeal web formation.
Procedures—Medical records of dogs with laryngeal webs treated with a single procedure of web resection with mucosal apposition by use of a ventral laryngotomy were reviewed. Signalment, history, clinical signs, intraoperative complications, postoperative complications, and hospitalization time were recorded. Owners were interviewed 6 months to 6 years after surgery.
Results—Most dogs had a history of oral ventriculocordectomy. Duration of clinical signs ranged from 3 months to 3 years. The most common clinical sign reported was exercise intolerance. Postoperative complications were observed in 4 dogs. Follow-up information was available in 10 dogs, and clinical outcome was classified as excellent in 7 and good in 3.
Conclusions and Clinical Relevance—A single surgical procedure of web resection with mucosal apposition for the treatment of laryngeal web formation in dogs resulted in low morbidity and was associated with a good to excellent outcome.
Objective—To determine whether the active metabolite of leflunomide, A77 1726 (A77), inhibits replication of feline herpesvirus-1 (FHV-1) in cell culture.
Study Population—Crandell Rees feline kidney (CRFK) cell cultures.
Procedures—Cell cultures were inoculated with FHV-1 and treated simultaneously with concentrations of A77 ranging from 0 to 200μM. The antiviral effect of A77 was determined by use of conventional plaque reduction assays. The effect of A77 on viral load was determined via real-time PCR analysis, and transmission electron microscopy was used to evaluate the effect of A77 on viral morphology. To determine whether the antiviral effect was attributable to alterations in CRFK cell viability and number, CRFK cells were treated with various concentrations of A77 and stained with Annexin V and propidium iodide to assess apoptosis and a mitochondrial function assay was used to determine cell viability.
Results—Concentrations of A77 ≥ 20μM were associated with substantial reduction in plaque number and viral load. Concentrations ≥ 100μM were associated with complete suppression of plaque formation. At low concentrations of A77, clusters of intracytoplasmic virus particles that appeared to lack tegument and an external membrane were detected. Treatment of uninfected CRFK cell monolayers with A77 was associated with reduction in mitochondrial function with minimal evidence of apoptosis.
Conclusions and Clinical Relevance—Leflunomide may be an alternative to current calcineurin-based immunosuppressive protocols used in feline organ transplantation because of its antiherpesviral activity.
Objective—To determine clinical outcome of permanent tracheostomy in cats with upper airway obstruction.
Design—Retrospective case series.
Procedures—Medical records were reviewed for information on history, signalment, clinical signs, results of preoperative clinicopathologic testing, cause of upper airway obstruction, surgical procedure, postoperative complications, and outcome.
Results—Causes of upper airway obstruction included neoplasia (squamous cell carcinoma [n = 6] or malignant lymphoma ), inflammatory laryngeal disease (5), laryngeal paralysis (4), trauma (3), and a laryngeal mass of unknown cause (1). Fourteen cats had dyspnea in the immediate postoperative period; dyspnea most often resulted from mucous plugs at the stoma or elsewhere in the respiratory tract. Eleven cats died, including 6 cats that died while hospitalized after surgery and 5 cats that died after discharge; 7 cats were eu-thanatized, most often because of progression of neoplasia; and 2 were still alive at the time of the study. The remaining cat was lost to follow-up after discharge from the hospital. Overall, median survival time for the 20 cats for which information was available was 20.5 days (range, 1 day to 5 years). Cats that underwent permanent tracheostomy because of inflammatory laryngeal disease were 6.61 times as likely to die as cats that underwent permanent tracheostomy for any other reason.
Conclusions and Clinical Relevance—Results indicated that permanent tracheostomy was an uncommon procedure in cats with upper airway obstruction that was associated with high complication and mortality rates.
Objectives—To evaluate use of an ameroid ring constrictor
(ARC) for treatment for single extrahepatic portosystemic
shunts (PSSs) and identify factors associated
with postoperative death, continued portosystemic
shunting, and long-term outcome in dogs.
Animals—168 dogs with a single extrahepatic PSS.
Procedure—Medical records of dogs that had a single
extrahepatic PSS and were treated with an ARC
were reviewed. Signalment, history, clinical signs,
results of preoperative blood analyses and portal
pressure measurements, PSS location, ARC size,
postoperative complications, and postoperative
scintigraphy results were recorded. Owners were
interviewed 6 months to 6 years after surgery.
Results—Postoperative complications developed
in 10% of dogs. Postoperative mortality rate was
7.1%. Predictive factors for postoperative death
included high preoperative WBC count and postoperative
complications. Twenty-one percent of dogs
in which portal scintigraphy was performed 6 to 10
weeks after surgery had continued shunting.
Predictive factors for persistent shunting included
low preoperative plasma albumin concentration,
high portal pressure after complete occlusion, and
high portal pressure difference (postocclusion
minus baseline). Clinical outcome in 108 dogs was
classified as excellent (80%), good (14%), or poor
(6%). Predictive factors for excellent long-term clinical
outcome included high preoperative plasma
albumin concentration, low preoperative leukocytosis,
low portal pressure after complete occlusion,
absence of postoperative seizures, and absence of
Conclusions and Clinical Relevance—Use of an ARC
for treatment for a single extrahepatic PSS resulted in
low morbidity and mortality rates. Certain preoperative
factors were associated with increased risk of postoperative
death, continued portosystemic shunting, and
long-term outcome. (J Am Vet Med Assoc 2005;226: