Serum Thymidine Kinase 1, Canine-C-Reactive Protein, Haptoglobin, and Vitamin D Concentrations in Dogs with Immune-Mediated Hemolytic Anemia, Thrombocytopenia, and Polyarthropathy.

BACKGROUND: Relapses of immune-mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthropathy (IMPA) occur despite normal hematologic and cytologic parameters. Thymidine kinase 1 (TK1), canine C-reactive protein (c-CRP), haptoglobin (HPT), and 25-Hydroxyvitamin-D (25(OH)D) might be adjunct to current monitoring strategies. HYPOTHESIS/OBJECTIVES: Compare serum concentrations of TK1, c-CRP, HPT, and 25(OH)D in dogs with well- and poorly controlled primary IMHA, ITP, or IMPA. ANIMALS: Thirty-eight client-owned dogs. METHODS: Prospective descriptive study. Dogs diagnosed with IMHA, ITP, or IMPA had serum biomarker concentrations measured commercially. Disease control was assessed by hematocrit/PCV and reticulocyte count, platelet count, and synovial fluid cytology for IMHA, ITP, and IMPA, respectively. Statistical analysis performed by Mann-Whitney rank-sum tests and receiver operating characteristic curves. RESULTS: TK1 and c-CRP, but not HPT significantly decreased with well- versus poorly controlled IMHA (P = 0.047, P = 0.028, P = 0.37). C-CRP, but not TK or HPT was significantly lower with well- versus poorly controlled IMPA (P = 0.05, P = 0.28, P = 0.84). Sensitivity and specificity of TK and c-CRP (simultaneously) for detecting dogs with poorly controlled IMHA were 88 and 100%, respectively. Sensitivity and specificity of c-CRP for detecting poorly controlled dogs with IMPA were 13 and 100%, respectively. 92% of dogs were vitamin D insufficient (<100 ng/mL) regardless of disease control. CONCLUSIONS AND CLINICAL IMPORTANCE: Combining TK1 and c-CRP might act markers of disease control in dogs with IMHA. Canine-CRP cannot be recommended as an independent marker of disease control in IMPA. 25(OH)D insufficiency in immune-mediated disorders might benefit from further study to determine if supplementation could improve therapeutic response or reduce disease risk.

Investigation of Neurokinin-1 Receptor Antagonism as a Novel Treatment for Chronic Bronchitis in Dogs.

BACKGROUND: Canine chronic bronchitis (CCB) results in cough lasting ≥2 months and airway inflammation. Adverse effects include risk of secondary infection associated with lifelong corticosteroid administration and prompt investigation into alternative therapies. Neurogenic pathways mediated by tachykinins that bind neurokinin (NK) 1 receptors may induce cough and airway inflammation. Maropitant, a NK-1 receptor antagonist, has been advocated for treatment of CCB based on anecdotal improvement, but without scientific evidence. HYPOTHESIS/OBJECTIVES: Maropitant will blunt clinical signs and airway inflammation associated with CCB. ANIMALS: Client-owned dogs (n = 8) with cough >2 months, thoracic radiographic evidence of airway disease and sterile airway inflammation (>7% non-degenerate neutrophils, >7% eosinophils or both) on bronchoalveolar lavage (BAL) enrolled. METHODS: Maropitant (2 mg/kg) administered q48h for 14 days. Study endpoints included client perception of clinical signs (surveys at baseline and 14 days, and visual analogue scale [VAS] at baseline, 7, and 14 days), and BAL % neutrophils and eosinophils (baseline and 14 days). One-way repeated measures ANOVA (VAS) and Wilcoxon-signed rank-sum tests (BAL cells, cough frequency) used with P < .05 considered significant. RESULTS: Maropitant significantly decreased cough frequency (P < .001) and VAS scores (P = .005). No differences in BAL % neutrophils or % eosinophils noted with treatment (P = .279 and P = .382, respectively). CONCLUSIONS AND CLINICAL IMPORTANCE: Preliminary results suggest that although maropitant may have antitussive properties leading to perceived clinical improvement, its failure to diminish airway inflammation makes it unsuitable for treatment of CCB. Future studies could evaluate maropitant as a cough suppressant for other respiratory disorders in dogs.