Food for Thought: A Study on Canine Eating Behaviour
Natalie Leong, Tiara Safaei
Crofton House
Floor Location : S 045 D

Currently, one of the largest concerns within the veterinary community is animal welfare. Amongst veterinary clinics, different methods are used to restrain animals: one of the most controversial being scruffing. This technique of holding animals by their scruff (the loose skin at an animal’s nape) mimics the maternal practice of carrying offspring by the scruff. In the animal community, scruffing is a popular method for restraining cats. This procedure is defended as an effective method of calming animals and successfully restraining them in order to perform medical procedures, such as basic exams, vaccinations, and diagnostic procedures. However, it was unclear whether dogs illicit the same response as cats, and canine scruffing is rarely used.

There are many conflicting perspectives on the subject of canine scruffing. For instance, it can be seen as a display of dominance (when dogs fight they often target each other’s scruffs), which could trigger an adverse reaction. However, scruffing could conversely trigger a soothing response, which is favourable in a veterinary setting. In order to determine the impact of scruffing on dog behaviour, a study was conducted on a random sample of dogs through the collection of quantitative and qualitative indicators of distress. Because scruffing stimuli can activate the autonomic nervous system, quantitative data was recorded in terms of dog cardiac rhythm. Heart rate has a direct relationship with the autonomic nervous system: heart rate will increase if the sympathetic division is activated, conversely heart rate will decrease if the parasympathetic division is activated.

In order to record heart rate, a photoplethysmogram (PPG) was designed and developed. The PPG employs a low-intensity infrared light and photodiode sensor to detect changes in blood volume by measuring the amount of light reflected from blood vessels at each moment in time and generating a cardiac rhythm. This data was tested for normality by using the Shapiro-Wilk test and histograms. The data was then analyzed using the chi-square test to determine if scruffing has a statistically significant impact on heart rate, which was noted as a qualitative indicator of anxiety and stress level. Additionally, a pre-survey was taken by the owners to determine information about their pet (age, gender, and scruffing exposure) to test against the cardiac data using simple linear regression. On this univariate level, the linear regression was used and analyzed to determine if any patterns or trends emerged when only one factor was considered, therefore checking for interaction between these variables.

In a veterinary office, agitation is especially common among dogs, and can negatively impact the effectiveness of a veterinary procedure, or in some cases even have a negative effect on the procedure’s outcome. By determining whether scruffing has a statistically significant effect on dogs’ heart rates in a controlled environment, a conclusion can be drawn regarding whether or not scruffing is a viable method of restraining dogs in a veterinary environment.