Oral Palatability Testing of a Medium-Chain Triglyceride Oil Supplement (MCT) in a Cohort of Healthy Dogs in a Non-Clinical Setting

Abstract

The oral palatability of functional foods such as medium-chain triglycerides (MCT) play a crucial role in owner and patient compliance when used as an adjunct in the management of health conditions such as epilepsy. Despite the promising benefits, the palatability of MCT has not undergone a more recent evaluation in dogs. The aim of this study was to assess the palatability and tolerance of short-term, daily supplementation of a 10% metabolic energy based MCT oil volume compared to a tasteless control oil in healthy dogs. An at-home, randomized, double-blinded, controlled single-bowl palatability test with three five-days phases was conducted. Data were collected from nineteen healthy dogs via study visits, feeding diary and eating questionnaires. No difference in the average food intake or intake ratio between food with and without oil supplementation or between the two oil groups was found. The mean food intake time was longer under MCT. In conclusion, MCT oil given as a short-term supplement is well tolerated and palatable in a healthy canine population, with only some changes in eating behaviour. Our results support earlier evidence that MCT oil is a well-tolerated additive in the nutritional management of different diseases such as epilepsy or dementia in dogs.

Keywords: MCT; canine; epilepsy; ketogenic; neurodietetics; nutrition; palatability; supplement; tolerance.

Figure 1

Study protocol: A single-bowl palatability test system. Three periods of five days each were chosen to evaluate the daily supplementation of one commercially available MCT oil for palatability in terms of acceptance and tolerance in comparison to a control oil. Phase 1 constituted to the reference point where no oil was supplemented, phase 2 included the integration of the oil in the feed, and phase 3 was used to observe any long-term effects of the oil post integration. The oil used in the test was randomized and blinded to all participants except the dispensing study nurse. Relevant data to assess MCT oil as a suitable dietary supplement was collected at four study visits.

Figure 2

Food consumption plots. (a) Plot showing the percentage of food consumed in each study phase. (b) Plot showing the food intake ratio per phase (FIR). A calculated FIR of 0.50 represents an equivalent consumption rate. An FIR greater or lower than 0.50 indicates an increase or decrease in the quantity of food consumed, respectively. The FIR of MCT-DS did not exhibit a statistically significant difference when compared to the control-DS throughout all the study phases.

Figure 3

Effects of oil supplementation on the average food intake time (aFIT). (a) Box and whisker plots of the aFIT per study phase measured in seconds. (b) Box and whisker plots of the aFIT differentiated by oil type. The central lines of the box and whisker plots represent the median, while the lower and upper limits of the box represent the 25th and 75th percentiles, respectively, and whiskers represent the minimum and maximum. Two-tailed Wilcoxon tests were conducted to compare aFIT per phase and independent t-test for comparison of both DS types.