Efficacy of inhaled budesonide for the treatment of severe equine asthma.

BACKGROUND: Corticosteroids are the most potent drugs for the control of severe equine asthma, but adverse effects limit their chronic systemic administration. Inhaled medications allow for drug delivery directly into the airways, reducing the harmful effects of these drugs. OBJECTIVES: To evaluate the efficacy of inhaled budesonide specifically formulated for the equine use and administered by a novel inhalation device in horses with severe asthma. STUDY DESIGN: Experimental studies in horses with naturally occurring asthma with cross-over, randomised, blinded experimental designs. METHODS: In Study 1, budesonide (1800 µg twice daily) administered using a novel Respimat® based inhaler was compared to i.v. dexamethasone (0.04 mg/kg). In Study 2, 3 doses of budesonide (450, 900, and 1800 µg) were compared to oral dexamethasone (0.066 mg/kg). Lung function, bronchoalveolar fluid cytology (Study 1), CBC, serum chemistry, and serum cortisol and adrenocorticotropic hormone (ACTH) values were evaluated. RESULTS: In Study 1, there was a marked and significant improvement in the lung function of all horses treated with budesonide and dexamethasone. Neutrophil percentages in bronchoalveolar fluid decreased in all horses treated with dexamethasone and in four of six horses treated with budesonide. Serum cortisol and blood ACTH concentrations decreased with both treatments. In Study 2, there was a significant improvement in the lung function with all dosages of budesonide, and the effects of higher dosages were comparable to those of dexamethasone. Dexamethasone and budesonide at the two higher dosages induced a significant decrease of cortisol concentrations. MAIN LIMITATIONS: The Respimat® based inhaler is not currently commercially available. CONCLUSIONS: Administration of budesonide with the Respimat® based inhaler provided dose-dependent relief of airway obstruction in horses with severe asthma, but also a suppression of serum cortisol.

Isolation of equine bone marrow-derived mesenchymal stem cells: a comparison between three protocols.

REASON FOR PERFORMING THE STUDY: There is a need to assess and standardise equine bone marrow (BM) mesenchymal stem cell (MSC) isolation protocols in order to permit valid comparisons between therapeutic trials at different sites. OBJECTIVE: To compare 3 protocols of equine BM MSC isolation: adherence to a plastic culture dish (Classic) and 2 gradient density separation protocols (Percoll and Ficoll). MATERIALS AND METHODS: BM aspirates were harvested from the sternum of 6 mares and MSCs isolated by all 3 protocols. The cell viability after isolation, MSC yield, number of MSCs attained after 14 days of culture and the functional characteristics (self-renewal (CFU) and multilineage differentiation capacity) were determined for all 3 protocols. RESULTS: The mean +/- s.d. MSC yield from the Percoll protocol was significantly higher (6.8 +/- 3.8%) than the Classic protocol (1.3 +/- 0.7%). The numbers of MSCs recovered after 14 days culture per 10 ml BM sample were 24.0 +/- 12.1, 14.6 +/- 9.5 and 4.1 +/- 2.5 x 10(6) for the Percoll, Ficoll and Classic protocols, respectively, significantly higher for the Percoll compared with the Classic protocol. Importantly, no significant difference in cell viability or in osteogenic or chondrogenic differentiation was identified between the protocols. At Passage 0, cells retrieved with the Ficoll protocol had lower self-renewal capacity when compared with the Classic protocol but there was no significant difference between protocols at Passage 1. There were no significant differences between the 3 protocols for the global frequencies of CFUs at Passage 0 or 1. CONCLUSIONS AND CLINICAL RELEVANCE: These data suggest that the Percoll gradient density separation protocol was the best in terms of MSC yield and self-renewal potential of the MSCs retrieved and that MSCs retrieved with the Ficoll protocol had the lowest self-renewal but only at passage 0. Then, the 3 protocols were equivalent. However, the Percoll protocol should be considered for equine MSC isolation to minimise culture time.

Comparison of radiography and ultrasonography for the diagnosis of osteochondritis dissecans in the equine femoropatellar joint.

REASONS FOR PERFORMING STUDY: Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FPjoint. OBJECTIVES: To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. METHODS: The medical records of all horses diagnosed with FP OCD between 1995 and 2006 were assessed. Inclusion criteria included availability of both radiographic and ultrasonographic images. Lesion characteristics were evaluated in each trochlear ridge and trochlear groove. For assessment of the accuracy (sensitivity and specificity) of both imaging techniques in the diagnosis of OCD, only cases with an arthroscopic or necropsy examination were studied. RESULTS: Twenty-one horses were included. OCD lesions were diagnosed by radiography (30/32 joints) and ultrasound (32/32 joints). The lateral trochlear ridge (LTR, 91%) and the medial trochlear ridge (MTR, 17%) were involved on radiography. The localisation on ultrasound examination was similar (97% LTR, 25% MTR). All but one lesion seen on radiography were also detected with ultrasound; 2 LTR and 3 MTR lesions, not seen on radiography were diagnosed by ultrasound and confirmed at arthroscopy or necropsy. The specificity was 100% regardless of the site and imaging procedure except for the distal third of the MTR (94% for ultrasound). The sensitivity varied, depending on lesion site. CONCLUSION: Ultrasonography is a valuable diagnostic tool to diagnose OCD lesions in the FP joint and more sensitive than radiography for lesions affecting the MTR of the distal femur. CLINICAL RELEVANCE: Ultrasound should be considered as a useful adjunct to radiography for diagnosing equine FP OCD, especially in cases of high clinical suspicion but equivocal radiographic findings. Images can be generated immediately when digital radiography is not available, permitting an immediate on-site diagnosis.