Feline Asthma: Diagnostic and Treatment Update.

Asthma is an important allergic lower-airway disease in cats affecting approximately 1% to 5% of the pet cat population. New diagnostics are being developed to help better differentiate asthma from other lower-airway diseases and improve monitoring. In addition, new treatments are being developed to help in refractory cases or in those cases in which traditional therapeutics are contraindicated. This article discusses potential pitfalls in the diagnosis of asthma. In addition, current literature investigating new diagnostic tests and therapies for feline asthma is reviewed.

Intravenous adipose-derived mesenchymal stem cell therapy for the treatment of feline asthma: a pilot study.

OBJECTIVES: The aim of this study was to evaluate the feasibility and efficacy of serially administered adipose-derived mesenchymal stem cells (MSCs) in an experimental feline asthma model. METHODS: Allergic asthma was acutely induced with Bermuda grass allergen in six purpose-bred cats. Five intravenous infusions of allogeneic MSCs (n = 4; MSC-treated) or saline (n = 2; placebo-treated) were administered over the first 130 days after asthma induction. Infusions contained 2 × 106, 4 × 106, 4.7 × 106, 1 × 107 and 1 × 107 cryopreserved MSCs/cat. For thoracic imaging additional cats were enrolled as control groups: four untreated, experimentally asthmatic cats (combined with placebo-treated cats), and six healthy, non-asthmatic cats. Outcome measures included airway eosinophilia, pulmonary mechanics, thoracic computed tomography and several immunologic assays. RESULTS: Cats were assessed for 9 months after treatment. At early points, airway eosinophil percentage was not affected by MSC administration (post-treatment average of days 12, 26, 47, 108 and 133 in MSC-treated cats was 41 ± 15% and in placebo-treated cats it was 34 ± 16%). By month 9, eosinophil percentages in all MSC-treated cats decreased to normal reference intervals (MSC-treated 6%; placebo-treated 20%; normal <17%). Diminished airway hyper-responsiveness was noted in all MSC-treated compared with placebo-treated cats at day 133 (dose of methacholine to double baseline airway resistance: MSC-treated median 22.9 mg/ml [range 6.4-64.0]; individual placebo-treated cats 1.1 and 5.0 mg/ml). Lung attenuation (mean ± SEM MSC-treated -865 ± 12 Hounsfield units [HU]; untreated asthmatics -820 ± 11 HU; P = 0.004) and bronchial wall thickening scores (median [interquartile range] MSC-treated 0 [0-1.5]; untreated asthmatic 11.6 [7.3-27.3]; P = 0.010) were significantly reduced in MSC-treated vs untreated asthmatic cats, consistent with decreased airway remodeling at month 9. No clear immunologic mechanisms by which MSCs act were determined. CONCLUSIONS AND RELEVANCE: MSCs may have a delayed effect in reducing airway inflammation, airway hyper-responsiveness and remodeling in experimentally induced asthmatic cats. Results warrant additional investigation of MSC therapy for asthma in cats.

Update on feline asthma.

This article provides an overview of recent advances in the diagnosis and treatment of feline asthma. The authors discuss the potential pitfalls in the diagnosis of feline asthma. In addition, current literature investigating new therapies for the treatment of feline asthma is reviewed.