DEXO contains 0.1 mg / ml dexmedetomidine hydrochloride( equivalent to 0.09 mg dexmedetomidine per ml). This low-dose preparation is prescribed to relieve general and sound-induced anxiety in dogs while keeping the animal alert. Dose-dependent side effects include decreases in HR and rectal temperature, and peripheral vasoconstriction.
The time to maximal blood concentration( Tmax) is 36 min, and the half-life is 30 min to 3 hours, with repeat administration recommended after 2 hours when needed, up to a maximum of five doses [ 17, 19 ]. DEXO has previously been shown to reduce clinical signs in dogs associated with stress from noise [ 20 ], car travel [ 19 ] and veterinary clinic visits [ 21 ].
Aptus Relax food supplement
Aptus Relax( Orion Pharma Animal Health)( hereafter referred to as FSAR) is marketed as a supplementary chew feed to be given to dogs or cats facing unpleasant situations, such as a veterinary visit, separation from their owner, travel / transport, the introduction of a new family member, thunder or fireworks, to contribute to calm and balanced behaviour. The chews contain vitamin B1, L-tryptophan, green tea powder( containing L-theanine) and Colostrum Calming Complex.
The amino acids L-theanine and tryptophan are common in supplementary feeds. L-theanine is found in green tea and has been shown to increase alpha activity in the brain [ 22 ] and decrease stress-related signs [ 23 ]. Its structure is similar to that of glutamate and it can thus bind to glutamate receptors and block excitatory neurotransmission. L-theanine may reduce fear in dogs when they are introduced to new people, as well as reducing fear of sounds in dogs. Tryptophan acts by converting to 5-hydroxytryptophan, a step in the formation of serotonin. To the authors ' knowledge, no scientific studies have been performed on the effects of FSAR.
Dogs that are bred and raised with insufficient human socialisation( low-accustomed dogs, hereafter referred to as LADs) are assumed to be more prone to more intense stress reactions in relation to clinical examinations. The population of dogs minimally accustomed to human interaction is substantial, for example, in shelters, with so-called puppy farms and rescues creating a persistent inflow. Reducing visit-associated stress might prove particularly valuable for this subset of dogs, and the means needed to achieve it may differ compared with the general canine population.
In the authors ' veterinary educational settings, beagles bred on site for educational purposes are highly socialised and adapted to human interactions, and are trained for participating in clinical examinations. However, a recently acquired group of newly imported dogs exhibited the traits of LADs from having been bred in a specialised research breeding facility. In the course of their early training and preparation for participation, it was possible to evaluate the effects of different treatments on LADs under very controlled settings, which would be hard to achieve elsewhere. The similarity of these dogs in their breed, age, weight, early experiences and previous training allowed us to design a study with minimal intraindividual variation compared with a sample of LAD patients from clinics or shelters.
This crossover study was designed with the dual aim of compiling more data on LADs under stress in general and evaluating the effect of interventions specifically for the studied group of beagles under training at the authors ' institution. The aim was to determine the possible stress-reducing effect of treatment with DEXO and FSAR in dogs minimally accustomed to human interaction, during a clinical examination.
The null hypothesis of the study was that DEXO or FSAR does not achieve a reduction in the RR, HR, mean arterial pressure( MAP) or rectal temperature compared with a placebo, and / or increase the willingness of dogs to participate and interact with a veterinary nurse( VN) during a clinical examination.
Learning outcomes
• Recognise that visiting veterinary clinics can be stressful for dogs
• Understand that stress complicates examination, diagnosis and treatment, and increases the risk of injuries
• Identify dexmedetomidine as a drug that, in an oromucosal gel formulation, can be used as a PVP
• Understand that dexmedetomidine lowers certain physiological variables, indicating reduced stress levels
Materials and methods
Study design
The study design was a single-blind crossover study that investigated the effect of DEXO or FSAR, versus placebo, in six dogs( not pictured) undergoing a simulated clinical examination. The dogs were randomised into a fixed order of treatment.
Two baseline treatments were performed using only placebo, one at the start of the study and the other at the end of the study. Dogs acted as their own controls.
The study was conducted on six healthy beagles that were imported with the intention of serving as teaching animals at the Swedish University of Agricultural Sciences( SLU).
20 Veterinary Nursing Journal