Impact of canine epilepsy on judgement and attention biases

Abstract

Idiopathic epilepsy (IE) is the most common chronic neurological condition in dogs, characterised by recurrent seizure activity and associated with negative behavioural and cognitive changes. We hypothesised that IE would negatively impact putative affective state, with dogs with IE exhibiting a more pessimistic judgement bias and more negative attention bias than controls. Dogs were tested in a previously-validated spatial judgement bias task, and a novel auditory attention bias task testing attention to sounds with different valence or salience (neutral, novel pre-habituated, threatening). Sixty-eight dogs (IE = 33, Control = 35) were tested, of which n = 37 acquired the spatial discrimination and responses to judgement bias probes were tested (IE = 19, Control = 18), and n = 36 were tested for responses to sounds (IE = 20, Control = 16). Study groups did not significantly differ by age, sex, breed or neuter-status (p > 0.05). Main effects of study group were not significant in judgement bias (F_1,102 = 0.20, p = 0.658) or attention bias tasks (F_3,102 = 1.64, p = 0.184). In contrast with our hypotheses, there was no evidence that IE altered cognitive biases in this study population; however, dogs with IE were significantly more likely to be unable to learn the spatial discrimination task (p = 0.019), which may reflect IE-related cognitive deficits. Developing methods to test affective state without excluding cognitively impaired individuals is a future challenge for animal welfare science.

Figure 1

Schematic of the judgement bias task setup. The distance from the starting location to each bowl location was 4 m, with each of the five target locations equidistant from each other over a total of 3 m.

Figure 2

Schematic of the population and sub-population of dogs recruited to the study, and number of dogs included in analyses for each behavioural task. Percentage of dogs remaining in the study at are reported for each stage of the study by study group.

Figure 3

Mean latencies (± SE) for dogs to reach each bowl location in the judgement bias test. Pairwise Dunn-Bonferroni test significant differences (p < 0.05) were found between locations that do not share any of the same letter superscripts.

Figure 4

Mean latencies (± SE) for dogs to reach the baited bowl following different sound types being played in the attention bias test. Pairwise Dunn-Bonferroni test significant differences (p < 0.05) were found between sounds that do not share any of the same letter superscripts.