To determine whether delivery of compounded liquid sildenafil directly to the stomach of dogs with megaesophagus (ME) would affect esophageal clearance, regurgitation frequency, body weight, or quality of life.
10 client-owned otherwise healthy dogs with stable ME.
A randomized crossover study was performed. Dogs received either sildenafil (1 mg/kg, PO, q 12 h) or a placebo for 14 days, followed by a 7-day washout period, then the opposite treatment for 14 days. Esophageal clearance time was assessed by means of videofluoroscopy prior to treatment and on day 1 of each treatment period. Owners maintained logs of regurgitation episodes and quality of life.
Compounded liquid sildenafil moved into the stomach during 21 of 30 (70%) videofluoroscopy sessions. Sildenafil resulted in a significant reduction in the number of regurgitation episodes (median, 3.5 episodes/wk; range, 0 to 14.5 episodes/wk), compared with baseline (median, 6.5 episodes/wk; range, 1.5 to 19.5 episodes/wk) and the placebo (median, 4 episodes/wk; range, 0 to 28 episodes/wk), and a significant increase in body weight (median, 22.05 kg; range, 6 to 26.3 kg), compared with baseline (median, 21.55 kg; range, 5.1 to 26.2 kg) and the placebo (median, 22.9 kg; range, 5.8 to 25.9 kg). There were no differences in esophageal clearance times or quality-of life-scores between sildenafil and placebo.
Although significant differences with placebo administration were identified, clinically relevant improvements were not seen with the use of compounded liquid sildenafil in dogs with ME.
OBJECTIVE To assess the in vitro and in vivo platelet function of healthy dogs during administration of a low-dose aspirin regimen.
ANIMALS 16 dogs.
PROCEDURES Dogs received aspirin (1 mg/kg, PO, q 24 h) for 7 days. Blood and urine samples were collected before (day 1; baseline) and on days 3 and 7 of the low-dose aspirin regimen. Platelet function was evaluated by use of turbidimetric and conventional impedance aggregometry, multiple-electrode impedance aggregometry, a platelet function analyzer (PFA), and determination of urine 11-dehydro-thromboxane B2 concentration. Turbidimetric aggregometry results were compared with the results obtained by the other 4 methods. Fourteen days after cessation of aspirin, platelet-rich plasma was incubated with acetylsalicylic acid and platelet function was assessed by turbidimetric aggregometry to determine whether this technique could accurately identify dogs that responded to the low-dose aspirin regimen.
RESULTS Of the 16 dogs, 13 had turbidimetric and conventional impedance aggregometry results that were decreased by > 25% from baseline on days 3 and 7, and 4 and 7 dogs had PFA closure times > 300 seconds on days 3 and 7, respectively. The median urine 11-dehydro-thromboxane B2 concentration–to–creatinine concentration ratio decreased by 49% between days 1 and 7. Turbidimetric aggregometry results were correlated with conventional impedance aggregometry results. There was poor agreement between the turbidimetric aggregometry and PFA results. The multiple-electrode impedance aggregometry protocol failed to reliably detect aspirin-induced platelet dysfunction. In vitro incubation of platelet-rich plasma with acetylsalicylic acid followed by turbidimetric aggregometry did not predict whether dogs responded to the low-dose aspirin regimen.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the response to a low-dose aspirin regimen varied among healthy dogs. (Am J Vet Res 2016;77:174–185)