Despite recent increased attention to improving the experience for pets and their caregivers during visits to veterinary clinics, many dogs still show signs of being fearful and/or anxious when visiting the practice. Such behaviour by patients can impede a thorough veterinary examination and increase risk of injury to staff and owners. Furthermore, over time, if dogs have repeated exposure to fear- or anxiety-inducing experiences, their fear or anxiety is likely to worsen due to sensitisation. It has been suggested that prescribing anxiolytic mediation may help to prevent or treat fearful or anxious behaviour in canine patients in a clinical setting.
An oromucosal gel formulation of dexmedetomidine is currently licensed in the UK for the alleviation of acute noise anxiety in canine patients. A recent study conducted by Korpivaara and colleagues in Finland investigated the effect of dexmedetomidine gel in alleviation of canine fear and anxiety during minor veterinary or husbandry procedures including vaccination, blood sampling, routine radiography and ultrasonography, suture removal and nail clipping.
Canine patients presenting to one of seven veterinary clinics in Finland were invited to participate in the randomised, double-blind, placebo-controlled, parallel-group, multicentre, clinical-field study. To be eligible for inclusion, dogs had to be at least 16 weeks old, weigh between 2-50kg, have a history of being fearful or difficult to handle, and had to be considered healthy or with mild systemic disease in accordance with the American Society of Anaesthesiologists. Dogs had to attend an initial screening visit and a treatment visit within 2 weeks of one another.
The eligible dogs were randomly assigned to receive dexmedetomidine 0.1mg/g oromucosal gel at a dosage of 125μg/m2 or 250 μg/m2, or placebo gel. The dogs’ owners were instructed to administer a single dose of treatment on the mucosa between the check and gum in a stress-free environment 45-60 minutes prior to the scheduled appointment. The two dosages of dexmedetomidine oromucosal gel and the placebo gel were compared for efficacy and clinical safety.
Seventy-six client-owned dogs were included in the study; 27 received dexmedetomidine gel at a dosage of 125μg/m2, 24 at a dosage of 250 μg/m2, and 23 dogs received the placebo gel. The investigator’s ability to perform the intended procedure was considered excellent for 40.7% of the dogs in the dexmedetomidine 125μg/m2 group, 33.3% in the dexmedetomidine 250 μg/m2 group, and 4.3% in the placebo group (p=0.03).
The ability to perform the procedure was significantly better with both doses of dexmedetomidine separately and combined when compared with the placebo. This is potentially indicative that the lower dose is sufficient to produce an anxiolytic effect. This may be an important clinical finding given that the number of dogs with abnormal heart sounds increased in the 250 μg/m2 dexmedetomidine group from zero at the screening visit to 5 dogs (20.8%) at the treatment visit. In addition, there were two events of mild bradycardia detected in the higher dose group. Conversely, in the dexmedetomidine 125 μg/m2 group, the number of dogs with abnormal heart sounds increased from three to four dogs and in the placebo group from one to two dogs.