First evidence for an association between joint hypermobility and excitability in a non-human species, the domestic dog

Jonathan Bowen,James A Serpell,Jaume Fatjó,Eldin Leighton,Andrea Bulbena-Cabré,Antoni Bulbena

doi:10.1038/s41598-019-45096-0

Abstract

There is a well-established relationship between joint hypermobility and anxiety in humans, that has not previously been investigated in other species. A population of 5575 assistance dogs were scored for both hip hypermobility and 13 behaviour characteristics using previously validated methods. Our results suggest a positive association between hip joint hypermobility and emotional arousal in domestic dogs, which parallel results found in people.

Highlights

Since our first observation of the strong association between anxiety and joint hypermobility[1], in people, a number of additional studies in clinical and non-clinical groups have supported the association between joint hypermobility syndrome (JHS) and anxiety, and with underlying features such as affective reactivity[2,3,4,5,6]
It has been proposed that anxiety could be linked to pain and a greater perception of joint instability in human patients with JHS8
We selected the domestic dog (Canis familiaris) as a candidate species as it presents physical health problems related to JHS and experiences naturally occurring behavioural disorders that show face validity, and potential homology, with previously defined psychiatric disorders in humans[10]

Summary

Lower Upper

Conformation or structure of the hip; only extension of the joint under anesthesia. The resulting Distraction Index (DI) is primarily a measure of the extensibility of the ligament of the head of the femur (ligamentum teres), and of hip joint hypermobility. The Seeing Eye is a philanthropic organisation with a large database of guide dogs that are routinely assessed for both hypermobility of the hip joint and behaviour traits through the use of PennHip and C-BARQ. This provided us an excellent opportunity to study the association between both conditions in a population of 5575 dogs in a non-invasive manner. With regard to behavioural traits, higher scores for excitability and aggression towards familiar dogs were associated with belonging to the high hypermobility cluster (see Table 2 for a summary of the BLR results).

Attention sensitivity problems Excitability seeking Chasing Energy

Methods

Findings

Additional Information