Behavioural disorder in a dog with congenital agenesis of the vomeronasal organ and the septum pellucidum

Abstract

A 1.5-year-old, entire male mongrel dog with a bifid nose and primary cleft palate showed aggressiveness towards unknown dogs despite having adequate canine socialisation and the absence of previous traumatic experiences; furthermore, he does not exhibit sexual behaviour towards females in heat. He was previously treated for fear-related aggression towards unknown people and environmental phobia due to poor human socialisation. Pharmacological treatment with fluoxetine and trazodone, together with behaviour modification, was started without success. Therefore, it was decided to repeat medical tests. CT and MRI revealed a rostral middle raphe ossification defect incompatible with the presence of the vomeronasal organ (VNO) and the absence of the septum pellucidum (SP). The dog was presumptively diagnosed with aggressiveness towards unknown dogs due to an organic cause, a congenital anomaly with agenesis of the VNO and SP. This case shows the importance of both structures in the regular intraspecific interactions of dogs.

The vomeronasal system of the wolf (Canis lupus signatus): The singularities of a wild canid

“…Surprisingly, up to this point, there has been limited exploration of the neuroanatomical features of its VNS. Notably, research on VNS in domestic dogs has witnessed substantial growth in the past decade, highlighting its crucial role in shaping the socio‐sexual behaviours of domestic canines (Muñiz‐de Miguel et al., 2023 ), as well as its potential involvement in pathological conditions leading to significant behavioural changes (Asproni et al., 2016 ). Consequently, clinical interest in this sensory system has considerably increased (Dzięcioł et al., 2020 ; Pageat & Gaultier, 2003 ).…”

Sensory Adaptations: Insights into the Vomeronasal System of the Iberian Wolf

“…Surprisingly, to the best of our knowledge, the neuroanatomical features of its vomeronasal system, have remained largely unexplored until now. Notably, research on VNS in domestic dogs has seen a remarkable increase in the last decade, highlighting its crucial role in shaping the sociosexual behaviors of domestic canines (Muñiz-de Miguel et al 2023), but also its potential involvement in pathological conditions that result in significant behavioral changes (Asproni et al 2016). As a consequence, clinical interest in this sensory system has substantially increased (Pageat and Gaultier 2003; Dzięcioł et al 2020).…”

Pheromone Sensing in Mammals: A Review of the Vomeronasal System

“…Despite the presumed regression of the VNS in dogs compared to their wild relatives, the wolves, there is a growing interest in exploring the clinical implications of the VNO in domestic dogs. This has been bolstered by the optimization of an MRI protocol for in vivo visualization of the VNO [371], and the recent identification of a case of canine vomeronasal agenesis, which manifested significant behavioral disorders, such as an inability for sexual discrimination of conspecifics and reduced sexual behavior [372]. Moreover, the use of pheromonotherapy, like the application of dog-appeasing pheromone (DAP) to mitigate symptoms of separation anxiety, including house soiling, vocalizations, and damage [373,374], along with a deepening in the links between VNO inflammation and aggressive behaviors in canids, felids, and livestock [375][376][377][378], has further developed this interest in the dog VNS.…”