The recognition of pain and learned behaviour in horses which buck

Bucking behaviour in horses is potentially dangerous to riders. There is limited information about how bucking behaviour should be investigated by veterinarians. The objectives of this article are to define bucking behaviour, to review the literature relating to bucking and allied behaviours in horses and describe personal observations and to describe an approach to clinical investigation and management strategies. A literature review from 2000 to 2020 was performed via search engines and additional free searches. A buck is an upward leap, usually in addition to forward propulsion, when either both hindlimbs or all four limbs are off the ground with the thoracolumbosacral region raised. Bucking often occurs as a series of such leaps and different manifestations include ‘pronking’, ‘bronking’ and ‘fly bucking’. Causes include excitement, exuberance, defensive behaviour associated with fear, learned behaviour through negative reinforcement or a reaction to musculoskeletal pain. Specific causes of pain include an ill-fitting saddle or girth, thoracolumbar pain, girth region pain, sternal or rib injury, neuropathic pain, sacroiliac joint region pain, referred pain and primary hindlimb lameness. Any of these may be compounded by a rider who is fearful, poorly balanced or crooked. Determination of the underlying cause requires a comprehensive clinical assessment, including assessment of saddle fit for horse and rider and suitability of the horse–rider combination. In some horses, identification of a primary source of pain allows targeted treatment and resolution of pain, but careful retraining is crucial. An understanding of learning behaviour is required for successful rehabilitation. It was concluded that identification of the cause of bucking may enable treatment of primary pain which, when combined with retraining, results in management of bucking behaviour. However, in a minority of horses, dangerous bucking behaviour cannot be reliably resolved, requiring retirement or euthanasia of the horse.     

Crooked tail carriage in horses: Increased prevalence in lame horses and those with thoracolumbar epaxial muscle tension or sacroiliac joint region pain

The relationship between lameness and crooked tail carriage (CTC) in horses is unclear. The objectives of this study were (i) to determine the association between CTC and lameness; (ii) among lame horses, to determine associations between CTC and lameness diagnosis, saddle slip, thoracolumbar range of motion (ROM), epaxial muscle tension and pain, and sacroiliac joint region (SIJR) pain, and (iii) to determine whether abolition of lameness and SIJR pain by diagnostic anaesthesia modified CTC. In this study, 520 lame and 170 nonlame sports horses were examined for CTC and other characteristics by one clinician (S.J.D.). All horses were evaluated when ridden. Lame horses were also assessed in hand and on the lunge. Crooked tail carriage, its direction, lameness, musculoskeletal and tack-related parameters were recorded as binary variables and analysed using 2 × 2 contingency tables. Sacroiliac joint region pain was diagnosed using local anaesthesia. Standard errors are shown in square brackets. 32.5% of lame horses had CTC, compared with 5.3% of nonlame horses (odds ratio = 8.6 [confidence intervals 4.4, 16.7]; P = 2×10⁻¹²). Of 169 lame horses with CTC, 103 (60.9% [3.8%]) held their tail to the left. There was no association between the side of the predominant lame limb and CTC direction. However, CTC was more common (P = 0.005) in horses with hindlimb lameness (35.7% [2.4%], N = 401) compared with forelimb lameness (21.0% [4.1%], N = 100). Crooked tail carriage was associated with SIJR pain (P = 0.0007) and thoracolumbar epaxial muscle tension (P = 0.0007), but not with saddle slip, reduced thoracolumbar ROM or thoracolumbar epaxial muscle pain. Limitations of the study included the facts that nonlame horses were a convenience sample and lameness assessment, other clinical observations and determination of the presence of CTC were subjective, with potential for bias. Video recordings and photographs are available for verification of tail position. It was concluded that CTC is more prevalent in lame horses than nonlame horses. There is a positive association between CTC and hindlimb lameness, SIJR pain and thoracolumbar epaxial muscle tension.