Targeted lipidomics showed altered serum phosphatidylcholine levels in fearful dogs.

Fearfulness accounts for most disorders affecting family dogs, who generally experience several behavioral traits, including trembling, hiding, flinching at noises, panting, or ears held back. Intense and persistent exposure to threatening situations might escalate to phobia, which easily makes patients more prone to inter- and intra-specific aggression. Factors like pain, adverse environment, and poor nutrition, as well as medical conditions, may contribute to the onset and severity of fear, although molecular pathways underlying such a dysfunctional emotional status are not yet fully understood. Among them, growing evidence highlighted the importance of lipid dynamics in mood-related disorders, both in humans and animals. Accordingly, lipids are the main components of brain structure, facilitating neuronal activities, including energy storage, signaling, and membrane integrity. In the present work, we identified a distinct lipidomic pattern significantly altered in the serum of fearful dogs, characterized by the differential abundance of several lipid species, primarily phosphatidylcholines. This predominance of phosphatidylcholine dysregulation underscores the central role of membrane phospholipid metabolism in canine fear behavior and suggests that lipid dysmetabolism is associated with behavioral disorders in companion animals. Collectively, our data pave the way for a deeper characterization of the impact of lipid dysregulation upon mood-related dysfunctions in dogs and for identifying diagnostic biomarkers in veterinary practice to cope with this behavioral disorder.