Inhaled fluticasone reduces bronchial responsiveness and airway inflammation in cats with mild chronic bronchitis

This study investigated the effect of inhaled fluticasone on lower airway inflammation and bronchial responsiveness (BR) to inhaled carbachol in cats with very mild, chronic bronchitis (n = 5) that were compared with healthy cats serving as controls (n = 6). Chest radiographs, BR tests performed non-invasively by barometric whole body plethysmography (BWBP) and bronchoalveolar lavage (BAL) were performed before and after treatment. BR was quantified by calculating the concentration of carbachol inducing bronchoconstriction (C-Penh300%), defined as a 300% increase of baseline Penh, an index of bronchoconstriction obtained by BWBP. BAL fluid was analyzed cytologically and the oxidant marker 8-iso-PGF2alpha was determined. At test 1, healthy cats and cats with bronchitis were untreated, whereas for test 2 inhalant fluticasone (250 microg once daily) was administrated for 2 consecutive weeks to cats with bronchitis. Control cats remained untreated. Inhaled fluticasone induced a significant increase in C-Penh300% and a significant decrease of BAL fluid total cells, macrophages, neutrophils and 8-iso-PGF2alpha in cats with bronchitis, whilst untreated control cats did not show significant changes over time. This study shows that a 2-week fluticasone treatment significantly reduced lower airway inflammation in very mild bronchitis. BR could be successfully monitored in cats using BWPB and decreased significantly in response to inhaled fluticasone. 8-Iso-PGF2alpha in BAL fluid was responsive to treatment and appeared as a sensitive biomarker of lower airway inflammation in cats.     

Non-invasive assessment of airway responsiveness in healthy and allergen-sensitised cats by use of barometric whole body plethysmography

This study aimed at determining whether airway responsiveness (AR) tests performed by use of barometric whole body plethysmography (BWBP) were repeatable in cats and to what extent AR was affected by the nebulization protocol used, the age of the animals, the inflammatory status of the airways and prior bronchodilator treatment. Repeatability of AR was tested on two occasions in 30 healthy cats. The concentration of carbachol inducing a 300% increase of the enhanced pause (Penh)--an estimator of airflow limitation--was calculated (C-Penh300) and did not differ significantly between the two tests (0.035+/-0.017% compared to 0.034+/-0.016%) and was significantly and positively correlated. The comparison between rapidly and slowly increasing carbachol concentrations was performed in ten healthy cats and showed a significantly lower C-Penh300 (%) when slowly increasing concentrations were used (0.037+/-0.013% compared to 0.039+/-0.015%, P<0.05). A significant age-related increase of C-Penh300 was evidenced by performing AR tests in 15 healthy cats at 12, 18, 24 and 30 months (12 months: 0.026+/-0.008%, 18 months: 0.031+/-0.009%, 24 months: 0.038+/-0.01%, 30 months: 0.043+/-0.014%, P<0.05). C-Penh300 significantly decreased in 12 Ascaris suum-sensitised cats after allergen exposure (0.026+/-0.016% compared to 0.033+/-0.016%, P<0.05) and was negatively correlated with the granulocyte percentage of bronchoalveolar lavage fluid (r=-0.36, P<0.01). Compared with a placebo inhalation, pre-treatment with inhaled salbutamol significantly increased C-Penh300 in four healthy cats (0.093+/-0.021% compared to 0.036+/-0.004%, P<0.05). This study provides evidence that AR determination by use of BWBP is promising as non-invasive indicator of lower airway inflammation or for monitoring response to bronchodilator treatment.     

A pilot study comparing the antispasmodic effects of inhaled salmeterol, salbutamol and ipratropium bromide using different aerosol devices on muscarinic bronchoconstriction in healthy cats

This study compared the duration and magnitude of the antispasmodic effects of salmeterol (SLM), salbutamol (SAL), ipratropium bromide (IB) and the combination of SAL and IB (SAL/IB) against carbachol-induced bronchoconstriction in healthy cats, and investigated the gain in efficacy using a two or fourfold increase in drug dosages. The drug regimens used were: (1) SLM 25 microg, SAL 100 microg, IB 20 microg and SAL/IB 100 microg/20 microg for bronchodilators delivered by a metered-dose inhaler (MDI); (2) SAL 3.75 mg and IB 62.5 microg for nebulised (NEB) medications. To monitor the bronchodilator effect, airway responsiveness was assessed at different time points using barometric whole-body plethysmography and calculation of the concentration of inhaled carbachol inducing a 300% increase of baseline Penh (enhanced pause), an estimator of airflow limitation. Maximum C-Penh300 was recorded 15 min after NEB SAL, IB MDI, NEB IB and 1h after SAL MDI and 4h after SLM MDI, respectively. C-Penh300 was significantly different from control values (without treatment) up to 24h for SLM MDI, 8h for IB MDI and 4h for other drugs. In terms of efficacy, SAL/IB MDI showed a synergistic antispasmodic effect at 15 min, 4h and 8h after administration. A fourfold increase of the initial dose of IB MDI and NEB IB significantly increased C-Penh300. Despite a fourfold dose increase, SLM displayed the weakest degree of bronchoprotection compared to other bronchodilators. The study provides evidence that inhaled bronchodilators are efficient at preventing muscarinic-induced bronchospasm in healthy cats and that SAL and IB appear to be short-acting bronchodilators in contrast to SLM.     

Functional, inflammatory and morphological characterisation of a cat model of allergic airway inflammation

The aims of this study were to characterise a model of feline allergic airway inflammation and to test through a longitudinal investigation whether five repeated allergen exposures would lead to signs of airway remodelling that would be detectable in vivo. Eight healthy control cats and eight cats sensitised with Ascaris suum allergens were investigated. Barometric whole body plethysmography (BWBP) was used for the assessment of respiratory variables and airway responsiveness (AR). Bronchoalveolar lavage fluid (BALF) was sampled for cytology and determination of F(2)-isoprostane concentration and matrix metalloproteinase type 9 (MMP-9) activity. Thoracic radiography and bronchoscopy scores were also established. Cats were investigated prior to sensitisation and after inhalation of placebo or allergen challenge 1. BWBP measurements revealed a significant increase of enhanced pause (Penh), an index of bronchoconstriction, and AR in sensitised cats in response to allergen challenge 1. A significant increase in BALF neutrophil and eosinophil %, F(2)-isoprostane concentration and MMP-9 activity, and increased radiography and bronchoscopy scores were recorded. After a recovery period of 6 weeks, all variables except BALF MMP-9 returned to baseline values. Four further allergen challenges induced similar changes to those seen in challenge 1 and no signs of persistent changes suggestive of bronchial remodelling were detectable. The model provides an in vivo approach to functional, inflammatory and morphological changes occurring in response to single and repeated allergen exposure.     

Non-invasive assessment of growth, gender and time of day related changes of respiratory pattern in healthy cats by use of barometric whole body plethysmography

The objective of this study was to establish a reference base for respiratory variables (respiratory rate [R(R)], inspiratory and expiratory time [T(i) and T(e)], peak inspiratory and expiratory pseudoflow [PIF and PEF], tidal volume [V(T)], minute ventilation [V(E)] and enhanced pause [Penh]) of healthy cats by use of barometric whole body plethysmography (BWBP). Eighteen healthy European cats (10 male, 8 female) were studied from the age of 3 to 13 months in order to assess growth- and gender-related changes of BWBP variables. Chest radiographs and bronchoalveolar lavage cytology were performed to confirm pulmonary health status. Diurnal changes were investigated every 2 h over a period of 24 h when the cats were adult. V(T), V(E), PIF and PEF significantly increased during somatic growth and were higher in males than in females, whereas R(R), T(i), T(e), T(e)/T(i) ratio, PEF/PIF ratio and Penh remained unchanged and were not affected by gender. When measured over 24 h, Penh, T(e) and T(i) were significantly increased in the early morning hours (04:00 h), whereas R(R), PIF and PEF were decreased at that time. This study provides reference values of BWBP variables for healthy male and female cats and indicates when circadian changes might be observed.     

Effect of short-term oral and inhaled corticosteroids on airway inflammation and responsiveness in a feline acute asthma model

The objective of this study was to investigate whether high-dose inhaled fluticasone propionate (FP), alone or in combination with salmeterol (SAL), is as effective as oral prednisolone in reducing airway inflammation and obstruction in cats with experimentally-induced acute asthma. Six cats sensitised to Ascaris suum (AS) were enrolled in a prospective controlled therapeutic trial and underwent four aerosol challenges, at 1-month intervals with AS allergen. The allergen - stimulated animals received four consecutive days treatment with either oral prednisolone at 1mg/kg twice daily, 500 μg of FP inhaled twice daily, or a combination of FP/SAL at 500 μg/50 μg inhaled twice daily, respectively, according to a randomised cross-over design. Treatment-related changes in lung function, airway responsiveness (AR) and bronchoalveolar lavage fluid (BALF) cytology were assessed. Barometric whole-body plethysmography (BWBP) was used for the assessment of respiratory variables and AR. No significant differences in respiratory rate or Penh (an estimate of airflow limitation measured by BWBP) were detected among treatment groups. Allergen-induced airway hyper-responsiveness was significantly inhibited by all three steroid treatments (P<0.05). The mean BALF eosinophil percentage (±SEM) was lower after oral and inhaled corticosteroid treatment and these changes were significant for groups receiving prednisolone and the FP/SAL combination. Findings suggest high-dose FP, particularly in combination with SAL, is effective in ameliorating airway inflammation and hyper-responsiveness in this model of acute feline asthma, and highlight the potential use of these drugs in cats experiencing acute exacerbations of the naturally occurring disease.     

Early biochemical and clinical responses to cobalamin supplementation in cats with signs of gastrointestinal disease and severe hypocobalaminemia

Domestic cats with small intestinal disease may develop cobalamin deficiency because of reduced small intestinal uptake of this vitamin. This study assessed the impact of cobalamin deficiency on biochemical and clinical findings in cats with intestinal disease. Nineteen pet cats, all with severe hypocobalaminemia (< or =100 ng/L) and histories of gastrointestinal signs, were studied. Cats received cobalamin, 250 microg SC once weekly, for 4 weeks. Biochemical indices of cobalamin availability (e.g., serum methylmalonic acid, homocysteine, and cysteine concentrations), serum feline trypsinlike immunoreactivity (fTLI) and serum folate concentrations, and clinical findings were recorded at the start of the study and after 4 weeks of cobalamin therapy. Serum methylmalonic acid (MMA) concentrations (median; range) decreased after cobalamin supplementation (5373.0; 708.5-29,329.0 versus 423.5; 214.0-7219.0 nmol/L, P < .0001). Serum homocysteine concentrations were not significantly altered (mean +/- SD 8.2 +/- 2.9 versus 10.3 +/- 4.5 micromol/L, P = .1198), whereas cysteine concentrations increased significantly (122.3 +/- 38.8 versus 191.5 +/- 29.4 micromol/L, P < .0001). Mean body weight increased significantly after cobalamin therapy (3.8 +/- 1.1 versus 4.1 +/- 1 kg, P < .01), and the average body weight gain was 8.2%. Significant linear relationships were observed between alterations in serum MMA and fTLI concentrations and the percentage body weight change (P < .05 for both, Pearson r2 = 0.26 and 0.245, respectively). Mean serum folate concentration decreased significantly (mean +/- SD 19 +/- 5 microg/L versus 15.4 +/- 6.2 microg/L, P < .001). Reduced vomiting and diarrhea were observed in 7 of 9 and 5 of 13 cats, respectively. These results suggest that cobalamin supplementation in cats with small intestinal disease and severe hypocobalaminemia is associated with normalization of biochemical test results and improvements in clinical findings in most affected cats.     

Flexible bronchoscopy and bronchoalveolar lavage in 68 cats (2001-2006)

BACKGROUND: Bronchoscopy is an important tool for identifying an underlying etiology for respiratory disease in cats. However, the procedure is challenging, because feline airways are small and prone to bronchoconstriction. HYPOTHESIS: Bronchoscopy and bronchoalveolar lavage (BAL) are appropriate and safe diagnostic procedures in the cat. ANIMALS: Sixty-eight cats. METHODS: Flexible bronchoscopy was performed in all cats with the cats under propofol infusion with jet ventilation. The procedures were reviewed for BAL volumes instilled and recovered and for the number and type of complications with the use of 3 flexible endoscopes < 5.0-mm outer diameter. The BAL procedure was compared among scopes by using a one-way analysis of variance. Complication rates were compared by using chi-square analysis. Significance was set at P < .05. RESULTS: Clinical diagnoses included inflammatory airway disease in 46 of 68 cats, pneumonia in 10 of 68, neoplastic disease in 8 of 68, and other conditions in 4 of 68 cats. Mean lavage volumes instilled for the 3 scopes were 2.62-5.05 mL/kg (range, 0.77-9.38 mL/kg). Mean percent fluid recovered for the 3 scopes was 51-73%, (range, 0-140%). BAL cell counts were adequate for cytologic assessment (> 300 cells/microL) in 61 of 64 cats (97%), and in 107 of 120 samples (89%) collected. Complications occurred in 38% of procedures; however, these were mild in 24% of cats; 6% of cats died or were euthanized after the procedure. Complications were not associated with fluid volume instilled or recovered, and could not be related to the underlying disease process. CONCLUSIONS AND CLINICAL IMPORTANCE: Flexible bronchoscopy with BAL was well tolerated in most cats examined.     

Collection of exhaled breath condensate and analysis of hydrogen peroxide as a potential marker of lower airway inflammation in cats

The objective of this study was to describe a standardised and non-invasive method for exhaled breath condensate (EBC) collection in cats and to test whether determination of hydrogen peroxide (H(2)O(2)) in EBC might be used as marker of lower airway inflammation. The technique of barometric whole body plethysmography for cats was combined with a system to condense the effluent air from the plethysmograph, allowing simultaneous EBC collection and respiratory pattern measurement. H(2)O(2) was determined spectrophotometrically. Eighteen experimental cats were used to investigate the impact on EBC volume and EBC H(2)O(2) of plethysmograph ventilation rate, collection duration, sample stability, within-day and day-to-day variability. After determination of a standardised EBC collection procedure, correlation analyses between EBC H(2)O(2) and bronchoalveolar lavage (BAL) cytology of healthy and allergen-challenged Ascaris suum (AS)-sensitised cats were performed. A significant and positive correlation between EBC H(2)O(2) and bronchoalveolar lavage (BAL) neutrophil% was found in healthy cats (P < 0.001, r = 0.55), whereas in AS-sensitised cats, correlation with BAL eosinophil% was significant (P < 0.005, r = 0.61). H(2)O(2) was increased after an allergen challenge in AS-sensitised cats (n = 6, 0.56+/-0.12 versus 1.08+/-0.35 micromol/L, P < 0.05). This study proposes a non-invasive, well tolerated and repeatable method of EBC collection for cats and suggests that EBC H(2)O(2) might be used as non-invasive biomarker for monitoring lower airway inflammation.     

Comparison of barometric whole body plethysmography and its derived parameter enhanced pause (PENH) with conventional respiratory mechanics in healthy Beagle dogs

The purpose of the study was to compare barometric whole body plethysmography (BWBP) and its derived parameter, enhanced pause (PENH), with conventional respiratory mechanics measurements. Resistance (RL), dynamic compliance (Cdyn) and pleural pressure changes were measured in six healthy anaesthetised Beagle dogs using a pneumotachograph and oesophageal balloon technique consecutive to BWBP-derived variables. Upper airway airflow limitation was established (1) by a filter or (2) by insertion of a narrow endotracheal tube. Bronchoconstriction was induced by nebulisation of carbachol at increasing concentrations until PENH exceeded 300% baseline. Upper airway narrowing significantly increased resistance (baseline RL 2.0+/-0.3, RL filter 11.8+/-3.2, RL luminal narrowing 21.1+/-2.3cm H(2)O/L/s; P <0.03), whereas PENH did not change significantly (baseline PENH 0.55+/-0.17, PENH filter 0.49+/-0.10; PENH luminal narrowing 0.50+/-0.18; P >0.05). Carbachol-induced bronchoconstriction caused a significant increase in PENH (baseline PENH 0.43+/-0.14, PENH carbachol 2.62+/-2.14; P <0.02) and resistance (baseline RL 2.1+/-0.3, RL carbachol 28.8+/-13.0 cm H2O/L/s; P <0.01), and a pronounced drop in compliance (baseline Cdyn 163.3+/-73.9, Cdyn carbachol 9.7+/-2.9mL/cmH2O; P <0.02). It was concluded that BWBP detects airflow limitation due to bronchoconstriction but not due to upper airway obstruction in healthy dogs. BWBP represents a valid, although not very sensitive screening tool for respiratory function testing.     

Experimental hyperkalaemia in rabbits: effects of salbutamol and norepinephrine treatments on blood biochemistry and electrocardiography

The effects of salbutamol and norepinephrine on the electrocardiogram (ECG), serum potassium level and enzyme activities were studied in rabbits with hyperkalaemia; norepinephrine and salbutamol may be therapeutically useful. For induction of hyperkalaemia, 300 mM KCl solution was used and then isotonic saline solution containing 6 microg salbutamol and 3.9 microg norepinephrine per ml were administered. Norepinephrine and salbutamol decreased the serum potassium from 7.36 +/- 0.26 and 7.21 +/- 0.31 mmol/L to 5.62 +/- 0.27 and 4.35 +/- 0.33 mmol/L, respectively, and caused the ECG changes (flatness of P wave, widening of QRS complex and bradycardia) to return to the control conditions (time 0). Norepinephrine, but not salbutamol, decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) to the control levels. These results suggest that monitoring of the enzyme activities might be useful as it yields indexes suitable for evaluating the therapeutic approach with norepinephrine in hyperkalaemia.     

Spontaneous feline hypertension: clinical and echocardiographic abnormalities,and survival rate

Systemic hypertension was diagnosed in 58 of 188 untreated cats referred for evaluation of suspected hypertension-associated ocular, neurologic. cardiorespiratory, and urinary disease, or diseases frequently associated with hypertension (hyperthyroidism and chronic renal failure). Hypertensive cats were significantly older than normotensive subjects (13.0 +/- 3.5 years versus 9.6 +/- 5.0 years; P < .01), and had a greater prevalence of retinal lesions (48 versus 3%; P < .001), gallop rhythm (16 versus 0%; P < .001), and polyuria-polydipsia (53 versus 29%: P < .01). Blood pressure was significantly higher (P < .001) in cats with retinopathies (262 +/- 34 mm Hg) than in other hypertensive animals (221 +/- 34 mm Hg). Hypertensive cats had a thicker interventricular septum (5.8 +/- 1.7 versus 3.7 +/- 0.64 mm; P < .001) and left ventricular free wall (6.2 +/- 1.6 versus 4.1 +/- 0.51 mm; P < .001) and a reduced diastolic left ventricular internal diameter (13.5 +/- 3.2 versus 15.8 +/- 0.72 mm; P < .001) than control cats. Left ventricular geometry was abnormal in 33 of 39 hypertensive subjects. No significant difference was found in age or blood pressure at the initial visit between cats that died or survived over a 9-month period after initial diagnosis of hypertension. Mean survival times were not significantly different between hypertensive cats with normal and abnormal left ventricular patterns. Further prospective studies are needed to clearly identify the factors involved in survival time in hypertensive cats.     

Pulmonary disposition of erythromycin, azithromycin, and clarithromycin in foals

The objectives of the present study were to determine and compare the pulmonary disposition of azithromycin, clarithromycin, and erythromycin in foals. A single dose (10 mg/kg) of azithromycin, clarithromycin, or erythromycin was administered intragastrically to six healthy 1- to 3-month-old foals using an orthogonal design. Activity of the drugs was measured in serum, pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells by use of a microbiologic assay. Peak drug activity in PELF was significantly higher in foals treated with clarithromycin (48.96+/-13.26 microg/mL) than in foals treated with azithromycin (10.00+/-7.46 microg/mL). Quantifiable erythromycin activity in PELF was only found in two of six foals. Peak drug activity in BAL cells was not significantly different between azithromycin (49.92+/-26.94 microg/mL) and clarithromycin (74.20+/-45.80 microg/mL) but activity for both drugs was significantly higher than that of erythromycin (1.02+/-1.11 microg/mL). Terminal half-life of azithromycin in serum (25.7+/-15.4 h), PELF (34.8+/-30.9 h), and BAL cells (54.4+/-17.5 h) was significantly longer than that of both clarithromycin and erythromycin. Peak azithromycin and clarithromycin activity was significantly higher in BAL cells, followed by PELF, and serum. In contrast, peak erythromycin activity in BAL cells was not significantly different from that of serum.     

Effects of age and dietary beta-carotene on immunological variables in dogs

beta-Carotene is a naturally occurring carotenoid reported to have health-promoting effects in several species. Advancing age is known to have a negative impact on various immune variables in several species. This study was conducted in order to assess the effect of age on immune response in dogs and to determine whether beta-carotene is able to reverse this age-associated decline. To test this hypothesis, young and old dogs (n = 36) were fed either a control diet or experimental diets containing supplemental beta-carotene for 2-month periods. Age significantly (P < .05) lowered CD4+ T cell populations (47.2% versus 33.7%; young-control versus old-control, respectively) and beta-carotene restored percent distributions in old dogs to nonsignificance versus younger controls (41.0%). T cell proliferation was lower in old dogs (30,254 +/- 2,248 versus 14,811 +/- 2,497 cCPM; young-control versus old-control, respectively; P < .05), and beta-carotene supplementation significantly improved responses in this age group (21,329 +/- 2,275 cCPM). Although B cell proliferation was depressed with age (17,967 +/- 1,384 versus 7,535 +/- 1,469 cCPM; young-control versus old-control, respectively; P < .05), beta-carotene supplementation improved B cell proliferation in young dogs (23,500 +/- 1,339 cCPM). Old dogs displayed lower delayed-type hypersensitivity test (DTH) responses versus younger controls to both phytohemagglutinin-P (PHA; 11.1 +/- 0.95 versus 7.57 +/- 1.15 mm; young-control versus old-control, respectively; P < .05) and sheep red blood cell (RBC; 9.12 +/- 0.62 versus 8.08 +/- 0.75 mm; young-control versus old-control, respectively; P < .10). beta-Carotene improved these responses, mostly within the first 24-48 hours after injection. In summary, older dogs have lower immunological responses compared with younger controls. beta-Carotene supplementation significantly restored immune responses in older dogs when compared with their age-matched controls and younger counterparts.     

Postoperative pain control in cats: clinical trials with medetomidine and butorphanol

OBJECTIVE: To evaluate the analgesic effects of medetomidine (MED) and butorphanol (BTO) in cats after ovariohysterectomy. STUDY DESIGN: A placebo-controlled, blinded monocenter clinical study. ANIMALS: Healthy adult female client-owned cats. METHODS: Sixty-four cats weighing 3.15 +/- 0.6 kg, presented to the University of Helsinki's Small Animal Teaching Hospital for routine elective ovariohysterectomy, received MED at 15 microg/kg (n = 18), BTO at 0.1 mg/kg (n = 23), or saline (PL) (n = 23) intramuscularly immediately after ovariohysterectomy. Level of pain perception, degree of restlessness, and extent of sedation were scored subjectively before and at 30, 60, 90, and 120 minutes after test-drug administration. RESULTS: BTO provided the best pain relief, followed by MED. Saline provided the least pain relief. Both MED and BTO effectively and identically prevented postoperative restlessness. MED and BTO produced an identical degree of sedation that was better than the PL. CONCLUSIONS: Both MED (at 15 microg/kg) and BTO (at 0.1 mg/kg) prevent postoperative pain in cats after ovariohysterectomy. Clinical Relevance-MED and BTO are useful for preventing postoperative pain in cats.     

Evaluation of respiratory function by barometric whole-body plethysmography in healthy dogs

The objective of the present study was to assess the validity of barometric whole-body plethysmography (BWBP), to establish reference values, and to standardise a bronchoprovocative test to investigate airway responsiveness using BWBP in healthy dogs. BWBP measurements were obtained from six healthy beagle dogs using different protocols: (1) during three consecutive periods (3.5min each) in two morning and two evening sessions; (2) before and after administration of two protocols of sedation; (3) before and after nebulisation of saline and increasing concentrations of carbachol and histamine both in conscious dogs and in dogs under both protocols of sedation. Enhanced pause (PENH) was used as index of bronchoconstriction. Basal BWBP measurements were also obtained in 22 healthy dogs of different breeds, age and weight. No significant influence of either time spent in the chamber or daytime was found for most respiratory variables but a significant dog effect was detected for most variables. A significant body weight effect was found on tidal volume and peak flow values (P<0.05). Response to carbachol was not reproducible and always associated with side effects. Nebulisation of histamine induced a significant increase in respiratory rate, peak expiratory flow, peak expiratory flow/peak inspiratory flow ratio and PENH (P<0.05). The response was reproduced in each dog at different concentrations of histamine. Sedation with acepromazine+buprenorphine had little influence on basal measurements and did not change the results of histamine challenge. It was concluded that BWBP is a safe, non invasive and reliable technique of investigation of lung function in dogs which provides new opportunities to characterise respiratory status, to evaluate airway hyperresponsiveness and to assess therapeutic interventions.     

Evaluation of pulmonary function variables by using plethysmography in cats with respiratory disease associated to Dirofilaria immitis

Heartworm Associated Respiratory Disease (HARD) is a pulmonary syndrome that results from the vascular and parenchymal inflammatory response associated with the arrival and death of Dirofilaria immitis in the distal pulmonary arteries. Barometric whole-body plethysmography (BWBP) is a non-invasive pulmonary function test (PFT) that allows a dynamic study of breathing patterns and is useful to study airway disease and the response to different treatments. The aim of this prospective non-blinded study was to compare respiratory function variables between healthy cats and HARD cats (seropositive to D. immitis) by use of BWBP. Twenty-five healthy cats and six HARD cats were put into the plethysmograph chamber and different respiratory variables were measured. The results were analyzed and compared between the two groups of animals. There were significant differences for bronchoconstriction index variables Pause (P-value<0.001) and enhanced pause (P-value<0.001), minute volume (P-value<0.05) and tidal volume (P-value<0.05) between healthy and HARD cats. There were no significant differences in respiratory rate and inspiratory and expiratory times between both groups of animals. The results obtained in our study support that HARD cats show significant differences in pulmonary function variables obtained by BWBP due to an acute inflammatory response at bronchial, vascular and parenchymal level. This PFT could be a useful method to facilitate the diagnosis of pathological states of bronchoconstriction in HARD cats.     

Effect of atropine-dobutamine stress test on left ventricular echocardiographic parameters in untrained warmblood horses

The aim of this study was to investigate the effect of combined atropine low-dose dobutamine stress test on left ventricular parameters in adult warmblood horses, to establish a potential protocol for pharmacological stress echocardiography. Seven healthy untrained warmblood horses aged 9 to 22 years were used. Heart rate (HR) and left ventricular B- and M-mode dimensions were recorded at baseline and during stress testing with 35 microg/kg atropine IV followed by incremental dobutamine infusion of 2 to 6 microg/kg/min. HR increased significantly (P < .05) during the pharmacological challenge, and a maximal HR of 156.6 +/- 12.5 bpm was reached at maximal dobutamine infusion rate. Systolic and diastolic interventricular septum thickness, systolic and diastolic left ventricular free wall thickness, and fractional shortening increased significantly and reached a maximum at the highest infusion rate (mean +/- SD: 4.51 +/- 0.27 versus 5.65 +/- 0.31 cm, 2.89 +/- 0.19 versus 3.78 +/- 0.10 cm, 3.72 +/- 0.34 versus 4.77 +/- 0.18 cm, 2.44 +/- 0.28 versus 3.11 +/- 0.34 cm, 34.98 +/- 3.82 versus 50.56 +/- 3.42%, respectively). Systolic and diastolic left ventricular internal diameter decreased significantly during dobutamine infusion. Left ventricular external and internal area were significantly lower at a dobutamine infusion rate of 2 microg/kg/min but no further decrease was observed during the subsequent steps. Systolic and diastolic myocardial area was significantly lower after the administration of dobutamine but not significantly different during dobutamine infusion, when compared to baseline values. This pharmacological stress test induced significant changes in left ventricular echocardiographic parameters in adult warmblood horses. Additional research should evaluate the value of this stress test in horses suffering from cardiac disease.     

Serum alhpa 1-acid glycoprotein concentrations in healthy and tumor-bearing cats

The purpose of this study was to evaluate alpha 1-acid glycoprotein (AGP) concentrations in tumor-bearing and healthy cats. The hypothesis of the present study was that AGP concentrations would be significantly increased in tumor-bearing cats. Serum from 51 healthy and 97 tumor-bearing, client-owned cats was harvested at the time of presentation and stored at -80 degrees C until assayed. Cats with measurable, histologically confirmed malignancies, and healthy cats of similar ages were included. Serum was assayed for AGP concentration by using a radial immunodiffusion method. AGP concentrations were significantly (P = .0051) higher in tumor-bearing (763 +/- 595 microg/mL; mean +/- SD) when compared to healthy cats (501 +/- 377 microg/mL; mean +/- SD). Of the tumor-bearing cats, 35 had carcinomas, 33 had sarcomas, and 26 had discrete, round cell tumors. AGP concentrations were 645 +/- 62 microg/mL, 660 +/- 540 microg/mL, and 967 +/- 860 microg/mL, respectively, and there were no significant differences among the groups.