title: Effects of obesity on lung function and airway reactivity in healthy dogs.
abstract: The present study investigated the effects of bodyweight (BW) gain on respiratory function and airway responsiveness in healthy Beagles using barometric whole body plethysmography (BWBP). Six adult dogs were examined before and after a fattening diet. The high-energy diet induced a mean increase in BW of 41±6%. BWBP basal parameters were recorded prior to airway reactivity testing (using increasing concentrations of histamine nebulisations). An airway responsiveness index (H-Penh300) was calculated as the histamine concentration necessary to reach 300% of basal enhanced pause (Penh, bronchoconstriction index). The same dogs underwent a doxapram hydrochloride (Dxp) stimulation testing 2 weeks later. Basal measurements showed that obese dogs had tidal volume per kg (TV/BW) that was significantly decreased whilst respiratory rate (RR) increased significantly. H-Penh300 decreased significantly in obese Beagles, indicating increased bronchoreactivity. Dxp administration induced a significant increase in TV/BW, minute volume per kg (MV/BW), peak inspiratory and expiratory flows per kg (PIF/BW and PEF/BW) in both normal and obese dogs although the TV/BW increase was significantly less marked in the obese group. In conclusion, obesity induced changes in basal respiratory parameters, increased bronchoreactivity and a blunted response to Dxp-induced respiratory stimulation. This combination of basal respiratory parameters, bronchoreactivity testing and pharmacological stimulation testing using non-invasive BWBP can help characterize pulmonary function and airway responsiveness in obese dogs.
authors.affiliation: Department for Clinical Sciences, Faculty of Veterinary Medicine, University of Liège, 20 boulevard de Colonster, 4000 Liège, Belgium. jmanens@ulg.ac.be
authors.forename: J
authors.initials: J
authors.lastname: Manens
authors.forename: M
authors.initials: M
authors.lastname: Bolognin
authors.forename: F
authors.initials: F
authors.lastname: Bernaerts
authors.forename: M
authors.initials: M
authors.lastname: Diez
authors.forename: N
authors.initials: N
authors.lastname: Kirschvink
authors.forename: C
authors.initials: C
authors.lastname: Clercx
mesh_terms: D000818:Animals; D001985:Bronchial Provocation Tests / Q000662:veterinary; D016084:Bronchoconstriction; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs; D004315:Doxapram / Q000008:administration & dosage*; D007275:Injections, Intravenous / Q000662:veterinary; D008168:Lung / Q000503:physiopathology*; D008297:Male; D009765:Obesity / Q000503:physiopathology / Q000662:veterinary*; D010993:Plethysmography, Whole Body / Q000662:veterinary; D015656:Respiratory Mechanics; D019141:Respiratory System Agents / Q000008:administration & dosage*; D013990:Tidal Volume
chemical_list: D019141:Respiratory System Agents; D004315:Doxapram