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Abstract

Objective—To determine the onset, magnitude, and duration of bronchodilation after administration of aerosolized salmeterol xinafoate in horses with recurrent airway obstruction.

Design—Randomized controlled study

Animals—6 horses with recurrent airway obstruction.

Procedure—Horses received aerosolized salmeterol (210 µg) or no treatment, using a crossover design. Salmeterol was administered, using a mask designed for aerosol delivery in horses. Subjective rating of airway obstruction (RAO), maximal change in pleural pressure (ΔPplmax), and pulmonary resistance (RL) were determined at baseline; 5, 15, and 30 minutes; and 1, 2, 4, 6, 8, 10, and 12 hours after administration of salmeterol and in horses that did not receive treatment.

Results—The ΔPpl and RL were improved 15 minutes through 6 hours after administration of salmeterol, compared with values obtained from horses receiving no treatment. The RAO was improved 15 minutes through 2 hours after administration of salmeterol. The maximal response to salmeterol was evident 30 to 60 minutes after administration and was characterized by a 59 ± 19% decrease in ΔPpl and a 56 ± 13% decrease in RL. The ΔPpl and RL were not different from baseline values 8 hours after salmeterol administration.

Conclusions and Clinical Relevance—Duration of action of salmeterol in these horses was approximately 6 hours. Maximal bronchodilation was somewhat delayed (30 to 60 minutes), and the magnitude of response was similar to that of short-acting β2-adrenergic agonists. Salmeterol provides moderately sustained bronchodilation in horses with recurrent airway obstruction and may be an effective drug for long-term control of this condition. (J Am Vet Med Assoc 2001;218:1961–1965).

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate plasma epinephrine and norepinephrine concentrations and serum cortisol concentration in horses with colic and assess the relationship of these variables with clinical signs, routinely measured clinicopathologic variables, and outcome in affected horses.

Design—Prospective observational study.

Animals—35 horses with colic.

Procedure—Blood samples were collected within 30 minutes of arrival at the veterinary hospital from horses referred because of colic. Plasma and serum samples were analyzed for cortisol, epinephrine, norepinephrine, lactate, and electrolyte concentrations and acid-base variables. Heart rate at admission and outcome (survival or nonsurvival) were recorded. Univariate logistic regression was used to calculate crude (unadjusted) odds ratios and 95% confidence intervals.

Results—Of the 35 horses with colic, 26 survived. Higher plasma epinephrine, plasma lactate, and serum cortisol concentrations were significantly associated with increased risk of nonsurvival, but plasma norepinephrine concentration was not associated with outcome. Plasma epinephrine concentration was significantly correlated with heart rate (r = 0.68), plasma lactate concentration (r = 0.87), blood pH (r = –0.83), anion gap (r = 0.74), and base excess (r = –0.81).

Conclusions and Clinical Relevance—The risk of death appears to be greater in colic-affected horses with high circulating concentrations of epinephrine and cortisol. The correlation of epinephrine with other biochemical markers of illness severity and with heart rate indicates that the degree of sympathetic activation in horses with colic can be inferred from routinely measured variables. (J Am Vet Med Assoc 2005;227:276–280)

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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate clinical response, pulmonary function, and adrenal gland response to incremental doses of beclomethasone dipropionate in horses with recurrent airway obstruction.

Design—Crossover trial.

Animals—8 horses with recurrent airway obstruction.

Procedure—Horses randomly assigned to 4 groups were treated twice daily via aerosol administration of placebo or 500, 1,000, or 1,500 µg of beclomethasone dipropionate in a crossover design with a 10-day minimum washout period. Subjective assessment of airway obstruction, serum cortisol concentration, and maximum change in pleural pressure during tidal breathing (ΔPplmax) were determined daily prior to morning drug administration, and ΔPplmax was reevaluated 15 minutes after morning drug administration. Pulmonary resistance and dynamic compliance were determined at baseline and approximately 12 hours after the final treatment.

Results—An immediate treatment effect was not identified. Within 24 hours, ΔPplmax and airway obstruction were lower in horses receiving beclomethasone. Onset and magnitude of response was similar among the 3 beclomethasone dose regimens. Pulmonary resistance was improved only after administration of all 3 doses of beclomethasone, whereas dynamic compliance was improved after administration of 1,000 µg and 1,500 µg of beclomethasone. Reduction in serum cortisol concentration occurred with all 3 beclomethasone dose regimens; however, the magnitude of adrenal gland suppression was greater in horses receiving 1,000 or 1,500 µg of beclomethasone.

Conclusions and Clinical Relevance—Low-dose (500 µg) beclomethasone administration caused similar improvement in pulmonary function, compared with high-dose beclomethasone (1,000 and 1,500 µg), with the exception of dynamic compliance, and caused less suppression of endogenous cortisol production. (J Am Vet Med Assoc 2000;217:359–364)

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in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

Abstract

Case Description—A 7-year-old Quarter Horse gelding used for unsanctioned racing was examined because of fever and anorexia.

Clinical Findings—Physical examination revealed fever, tachycardia, and tachypnea. Results of a CBC indicated anemia and mild thrombocytopenia. Results of microscopic examination of a blood smear indicated piroplasms in erythrocytes, consistent with Babesia spp. Regulatory authorities were contacted, and results of serologic testing at the National Veterinary Services Laboratories confirmed acute Babesia equi infection.

Treatment and Outcome—Equids on the home premises of the index horse were placed under quarantine. Those equids were tested for piroplasmosis, and 6 of 63 horses had positive results for B equi. Another horse that had previously been housed on the index premises also had positive results for B equi. Competent tick vectors for piroplasmosis organisms were not identified. All 8 horses with piroplasmosis were Quarter Horses that participated in unsanctioned racing and were trained by the same person. Two of the horses were illegally removed from the index premises; these 2 horses and the other horse with piroplasmosis that was previously housed on the index premises could not be found. The other 5 horses with piroplasmosis were euthanized. Investigators concluded that transmission of B equi among horses was most likely iatrogenic.

Clinical Relevance—The United States has been considered piroplasmosis free. However, veterinarians should consider piroplasmosis in horses with signalments and clinical signs similar to those of the index horse of this report. Regulatory authorities should be contacted regarding horses in which piroplasmosis is suspected.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration is useful in discriminating between cardiac and noncardiac (ie, primary respiratory tract disease) causes of respiratory signs (ie, coughing, stertor, stridor, excessive panting, increased respiratory effort, tachypnea, or overt respiratory distress) in dogs.

Design—Multicenter cross-sectional study.

Animals—115 dogs with respiratory signs.

Procedures—Dogs with respiratory signs were solicited for study. Physical examination, thoracic radiography, and echocardiography were used to determine whether respiratory signs were the result of cardiac (ie, congestive heart failure) or noncardiac (ie, primary respiratory tract disease) causes. Serum samples for NT-proBNP assay were obtained at time of admission for each dog. Receiver-operating characteristic curves were constructed to determine the ability of serum NT-proBNP concentration to discriminate between cardiac and noncardiac causes of respiratory signs.

Results—Serum NT-proBNP concentration was significantly higher in dogs with cardiac versus noncardiac causes of respiratory signs. In dogs with primary respiratory tract disease, serum NT-proBNP concentration was significantly higher in those with concurrent pulmonary hypertension than in those without. A serum NT-proBNP cutoff concentration > 1,158 pmol/L discriminated between dogs with congestive heart failure and dogs with primary respiratory tract disease with a sensitivity of 85.5% and a specificity of 81.3%.

Conclusions and Clinical Relevance—Measuring serum NT-proBNP concentration in dogs with respiratory signs helps to differentiate between congestive heart failure and primary respiratory tract disease as an underlying cause.

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in Journal of the American Veterinary Medical Association