Ramos, D., Yazbek, K.V., Brito, A.C., Georgetti, B., Dutra, L.M., Leme, F.O. and Vasconcellos, A.S., 2024. Is It Possible to Mitigate Fear of Fireworks in Dogs? A Study on the Behavioural and Physiological Effects of a Psychoactive Supplement. Animals, 14(7), p.1025.
Fear of fireworks is a common and widespread problem worldwide for dogs, it affects the welfare of both dogs and owners. Many vets and behaviour professionals increasingly recommend neutraceuticals and herbal remedies, who have limited scientific backing behind them.
In this study, behavioural and stress reactions of firework-fearful dogs were evaluated, in response to a supplement made of tryptophan, valerian, and passiflora, or a placebo. In participant dogs receiving either the supplement or the placebo, fear responses to fireworks decreased, and their general behaviour improved during treatment.
In a randomised, double-blinded, placebo-controlled study, 44 dogs (25 in the “supplement” group and 19 in the “placebo” group) completed a long-term continuous treatment with either a supplement made of tryptophan, valerian, and passiflora or a placebo, including two real exposures to fireworks (on 2020 Christmas and 2021 New Years’ Eve, after 42 and 48 days of treatment, respectively).
Behavioural (measured by LSSS—Lincoln Sound Sensitivity Scale and PANAS—Positive and Negative Activation scale, as rated by the owners) and stress (measured via salivary cortisol measures) reactions were evaluated. Significantly greater fear decrease (LSSS) was recorded in the “supplement” dogs, as compared to the “placebo” group.
Cortisol dosages on New Year’s Eve (“noisy” night) were in line with behavioural results; “supplement” dogs showed a smaller increase in the stress response from 22:30 to 00:30 h on New Year’s Eve and a greater decrease in their stress response from 02:30 h to 10:30 h on New Year’s Day compared to “placebo” dogs. Smaller cortisol levels were also shown by “supplement” dogs than “placebo” dogs on a controlled “quiet night” (27th December). Owners’ rates on PANAS remained stable during the whole period of therapy for both groups. The evaluated supplement, a combination of tryptophan, valerian, and passiflora, showed satisfactory results and rare side effects when treating dogs fearful of fireworks.
The effect of the supplement on the stress response of the participant dogs went beyond the firework exposure. Dogs in the “supplement” group showed smaller salivary cortisol levels than dogs in the “placebo” group during the “quiet night”. Since the week between Christmas and New Year constitutes a festive period and there were rainy days/nights around this time, it might be that stressors present on the “quiet night” were mild noises. Alternatively, cortisol increase on the “quiet night” might be due to the collection procedure per se. In any case, the supplement also acted by somehow mitigating the stress response arising from minor disturbing stimuli present even on an apparently calm night.
Improvement in the placebo group was not unexpected, given the “placebo effect” on the owners’ part, which can be very high in behavioural studies, as also noted by. Furthermore, the “Task Force Against Fireworks”, which owners followed to a high degree, likely contributed to their dogs’ improved behaviours during Christmas and New Year’s Eve. According to Riemer, even less robust recommendations such as environmental modifications and ad hoc counterconditioning using valuable items, as included in our instructions, can be very effective in decreasing fear of fireworks.
In humans, research has shown that tryptophan can be a determinant in mood, cognition, and behaviour, and results of clinical trials have shown its efficacy for moderate psychiatric disorders; for a review, see. In veterinary behaviour medicine, tryptophan has shown inconsistent results and studies on valerian and passiflora are lacking. The studied supplement, a combination of tryptophan, valerian, and passiflora, has shown evidence of satisfactory results after 42 days of regular daily use, with a further decline in the dogs’ fear of noise after 48 days of use. Further therapy using this supplement should start at least one-and-a-half months ahead of the fearful noisy event, and ideally in combination with environmental management and ad hoc counterconditioning using valuable items.
The studied supplement, a combination of tryptophan, valerian, and passiflora, was found to induce both behavioural and physiological correlates of fear reduction (with relatively infrequent side effects) when used to treat dogs suffering from fear of fireworks. For maximum results, this pharmacological treatment should be combined with behavioural recommendations, such as environmental modifications and ad hoc counterconditioning using valuable items.