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  • Author or Editor: Laurent L. Couetil x
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Abstract

Objective—To estimate the association between climate and airborne pollen and fungal factors and chronic obstructive pulmonary disease (COPD) in horses.

Sample Population—Data from 1,444 horses with a diagnosis of COPD.

Procedure—The Veterinary Medical Database was used to identify records of horses admitted to veterinary teaching hospitals in the United States and Canada between 1990 and 1999. Rainfall, mean minimum and maximum temperature, and maximum monthly pollen and fungal spore (mold) counts recorded at the city closest to where the hospital is located were identified for each month data were reported to the Veterinary Medical Database. Associations between climatic and aeroallergen data and monthly prevalence of COPD were estimated by use of crosscorrelation and logistic regression models.

Results—Significant positive correlations were found between prevalence of COPD and rainfall 3 months previously, minimum temperature 1 and 2 months previously, total pollen counts measured 3 months previously, and total mold counts measured during the same month and 1 month previously.

Conclusions and Clinical Relevance—Outdoor aeroallergens and climatic factors may contribute to the occurrence of COPD in horses. (Am J Vet Res 2005;66:818–824)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify risk factors for recurrent airway obstruction (RAO) among horses examined at veterinary teaching hospitals in North America.

Design—Retrospective case-control study.

Animals—1,444 horses with RAO and 1,444 control horses examined for other reasons.

Procedure—The Veterinary Medical Database was searched for records of horses in which RAO was diagnosed. A control group was identified by randomly selecting a horse with a diagnosis other than RAO that matched the institution and year of admission for each of the horses with RAO. Information obtained included hospital, admission year and month, age, sex, breed, and discharge status. The association between risk factors and diagnosis of RAO was estimated with logistic regression models.

Results—The risk of RAO increased significantly with age, with horses ≥ 7 years old being 6 to 7 times as likely to have RAO as were horses ≤ 4 years old. Thoroughbreds were 3 times as likely to have RAO as were ponies. Horses were 1.6 and 1.5 times as likely to be examined because of RAO during winter and spring, respectively, than they were during summer.

Conclusions and Clinical Relevance—Results suggest that RAO was more likely to be diagnosed in females, horses ≥ 4 years old, and Thoroughbreds and that RAO has a seasonal distribution. (J Am Vet Med Assoc 2003;223:1645–1650)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To describe the spectrum of nonspecific airway reactivity in a group of clinically normal foals.

Animals

12 clinically normal mixed-breed foals, 48 to 92 days old, without history of clinical lung disease.

Procedure

Nonspecific airway reactivity was determined by measuring the extent of changes in dynamic compliance during nebulization of incrementally increasing concentrations of histamine aerosol. Degree of airway reactivity was expressed as the dose of histamine that evoked a decrease in dynamic compliance (Cdyn) to 65% of the after saline nebulization value (PC65Cdyn) or increase in pulmonary resistance (RL) to 135% of baseline (PC135RL).

Results

In all foals, it was possible to induce a decrease in Cdyn in dose-dependent manner to ≤ 65% of baseline. Response of foals in terms of RL was more erratic, and, in 1 foal, RL decreased after histamine exposure. Mean ± SD PC65Cdyn was 5.43 ± 1.74 (range, 0.77 to 19.56) mg/ml, and mean PC135RL was 3.34 ± 1.52 (range, −0.749 to 17.35) mg/ml. Body weight was not correlated to baseline Cdyn, RL, PC65Cdyn, or PC135RL.

Conclusions and Clinical Relevance

Clinically normal foals had a wide range of airway reactivity, which may contribute to variation in clinical responses of foals to otherwise similar stimuli, such as infection, inflammation, and challenge exposure with environmental irritants. (Am J Vet Res 1999;60:965-968)

Free access
in American Journal of Veterinary Research

Abstract

Objective—To evaluate the association among clinical signs, results of cytologic evaluation of bronchoalveolar lavage (BAL) fluid, and measures of pulmonary function in horses with inflammatory respiratory disease.

Animals—9 healthy horses, 5 horses with inflammatory airway disease (IAD), and 9 horses with chronic obstructive pulmonary disease (COPD).

Procedure—Clinical examination, lung function tests, and BAL were performed on each horse.

Results—Standard lung mechanics of horses with exacerbated COPD differed significantly from those of healthy horses; however, there were few differences among horses with IAD, horses with COPD during remission, and healthy horses. Most variables for forced expiration (FE) in horses with COPD or IAD differed significantly from those for healthy horses. Results of clinical examination had low to moderate sensitivity and predictive values for a diagnosis of COPD (range, 67 to 80%). Results of FE tests had high sensitivity, specificity, and predictive values for a diagnosis of COPD (79 to 100%), and results of standard lung mechanics tests had low sensitivity and predictive values (22 to 69%). Percentage of neutrophils in BAL fluid was highly sensitive (100%) but moderately specific (64%) for a diagnosis of COPD.

Conclusion and Clinical Relevance—Clinical examination is moderately accurate for establishing a diagnosis of COPD. Forced expiration tests can specifically detect early signs of airway obstruction in horses with COPD and IAD that may otherwise be inapparent. Cytologic evaluation of BAL fluid allows early detection of inflammatory respiratory disease, but it is not specific for COPD. (Am J Vet Res 2001;62: 538–546)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the degree of agreement between 2 analyzers for measurement of total CO2 concentration (ctCO2) in equine plasma.

Animals—6 healthy untrained horses, 6 trained Standardbreds undergoing a simulated race protocol, and 135 trained Standardbreds at a racetrack.

Procedures—Jugular venous blood samples were obtained from all horses. Two analyzers (commonly used analyzer A and less expensive analyzer B) were used to measure plasma ctCO2 in each sample. Validation of both analyzers was conducted in accordance with guidelines established by the Clinical and Laboratory Standards Institute and involved characterization of linearity, total analytic error, and bias estimation.

Results—Total analytic error (instrument SD) was 0.58 mmol/L (coefficient of variation, 1.6%) and 0.49 mmol/L (coefficient of variation, 1.4%) for analyzers A and B, respectively, when measuring an aqueous standard containing 36.0 mmol of CO2/L. A 1 g/L decrease in plasma protein concentration corresponded to an increase in ctCO2 measured with analyzer B of 0.065 mmol/L. A difference plot indicated that analyzer B produced values 2.7% higher than analyzer A for 103 samples from the 6 trained and exercised Standardbreds (mean plasma protein concentration, 67 g/L).

Conclusions and Clinical Relevance—Analyzer B provided adequate precision and linearity for measurement of ctCO2 from 5 to 40 mmol/L and was therefore suitable for measuring ctCO2 in equine plasma, provided allowances are made for changes in plasma protein concentration.

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association