Placebo effect in canine epilepsy trials.
BACKGROUND
The placebo effect is a well-recognized phenomenon in human medicine; in contrast, little information exists on the effect of placebo administration in veterinary patients.


OBJECTIVE
Nonpharmacologic therapeutic effects play a role in response rates identified in canine epilepsy trials.


METHODS
Thirty-four dogs with epilepsy.


METHODS
Meta-analysis of the 3 known prospective, placebo-controlled canine epilepsy trials. The number of seizures per week was compiled for each dog throughout their participation in the trial. Log-linear models were developed to evaluate seizure frequency during treatment and placebo relative to baseline.


RESULTS
Twenty-two of 28 (79%) dogs in the study that received placebo demonstrated a decrease in seizure frequency compared with baseline, and 8 (29%) could be considered responders, with a 50% or greater reduction in seizures. For the 3 trials evaluated, the average reduction in seizures during placebo administration relative to baseline was 26% (P = .0018), 29% (P = .17), and 46% (P = .01).


CONCLUSIONS
A positive response to placebo administration, manifesting as a decrease in seizure frequency, can be observed in epileptic dogs. This is of importance when evaluating open label studies in dogs that aim to assess efficacy of antiepileptic drugs, as the reported results might be overstated. Findings from this study highlight the need for more placebo-controlled trials in veterinary medicine.
Muñana
K R
KR
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA. karen_munana@ncsu.edu
Zhang
D
D
Patterson
E E
EE
D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use; D001965:Bromides / Q000627:therapeutic use*; D004032:Diet / Q000662:veterinary; D004283:Dog Diseases / Q000178:diet therapy / Q000188:drug therapy*; D004285:Dogs; D004827:Epilepsy / Q000178:diet therapy / Q000188:drug therapy / Q000662:veterinary*; D016014:Linear Models; D010634:Phenobarbital / Q000627:therapeutic use*; D015990:Placebo Effect; D017680:Potassium Compounds / Q000627:therapeutic use*
D000927:Anticonvulsants; D001965:Bromides; D017680:Potassium Compounds; C039004:potassium bromide; D010634:Phenobarbital