Pratt, Stefanie
(2025)
Assessing chronic musculoskeletal pain in horses and the effectiveness of the administration of paracetamol in addition to non-steroidal anti-inflammatories for chronic pain.
MVM thesis, University of Nottingham.
Abstract
Equine lameness is a common problem which affects both equine athletes and geriatric horses, with geriatric horses being at increased risk of lameness (BlueCross, 2018, Ireland et al., 2011). Lameness leads to a shortened working career, increased financial losses and reduction in welfare (Ireland et al., 2012, Marshall et al., 2012). Lameness is also very important to owners, however there is significant under recognition of lameness by owners (Dyson et al., 2017, McGowan et al., 2010). As lameness is a manifestation of pain due to a musculoskeletal injury, when lameness is not recognised horses can continue to be worked leading to compromised welfare (Vinuela-Fernandez et al., 2011). Recognition of musculoskeletal pain relies on assessments including pain scales, subjective lameness grading scales and objective technologies including forceplates, kinematic technology and inertial measurement units. Subjective lameness grading scales have been shown to have marginal agreement between observers especially when considering mild or hindlimb lameness (Dyson, 2011, Hammarberg et al., 2016, Keegan et al., 2010). Objective gait analysis systems may be more reliable especially when considering mild lameness. A narrative review briefly compared both objective and subjective gait analysis systems (Crecan and Peștean, 2023), however there are currently no published systematic reviews which compare the effectiveness of subjective and objective gait analysis.
Once detected, lameness often requires analgesia, with phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID), being most commonly used (De Grauw et al., 2014, Duz et al., 2019, Sabate et al., 2009). However, NSAID use can lead to side effects including gastrointestinal toxicity, with phenylbutazone being the most likely to induce adverse events (Bowen et al., 2020). Paracetamol is used in horses alongside NSAIDs for multi-modal analgesia (Bruniges et al., 2019, West et al., 2011), however to date there are only a few studies published which have investigated its analgesic effect in the horse as a monotherapy (Foreman et al., 2016, Mercer et al., 2023a, Mercer et al., 2023b, Mercer et al., 2022). As a single analgesic at 20mg/kg administered orally, paracetamol has been shown to significantly reduce lameness score and heart rate compared to a control in an inducible acute foot pain model, and was comparable to flunixin meglumine (Foreman et al., 2016). In another acute mechanically induced lameness model, paracetamol at 30mg/kg orally was shown to reduce the lameness score, however 20mg/kg did not (Mercer et al., 2022). This study also compared paracetamol to phenylbutazone, and showed that oral paracetamol at 30mg/kg and oral phenylbutazone at 2.2mg/kg did improve lameness scores compared to the control group, although this occurred at different times post treatment. Mercer et al. (2023a) investigated paracetamol as a monotherapy in horses with naturally occurring chronic lameness and showed that at 30mg/kg orally there was a transient improvement in lameness both subjectively and objectively. Lameness assessments were only performed after administration of 3 weeks of paracetamol at 30mg/kg twice daily orally. Further studies are required to determine the effect of paracetamol on chronic lameness in combination with an NSAID.
This thesis aims to improve our understanding of assessment of chronic musculoskeletal pain in horses and the effectiveness of the administration of paracetamol in addition to an NSAID for chronic pain. The literature review is therefore focused on discussing pain physiology in the horse and how pain is best assessed and recognised. There is a particular focus on musculoskeletal pain recognition including subjective and objective gait assessments. This is followed by a review of NSAID and paracetamol use in the horse. A systematic review was also conducted to review the literature to answer the question ‘In lame horses does objective gait assessment versus subjective gait assessment improve the accuracy of lameness detection?’. Objective and subjective gait analysis techniques were then used to assess the response to the addition of paracetamol treatment in chronically lame horses currently treated with NSAIDs in order to determine whether paracetamol reduced the lameness severity.
| Item Type: |
Thesis (University of Nottingham only)
(MVM)
|
| Supervisors: |
Bailey, James
Burford, John |
| Keywords: |
Equine lameness; Musculoskeletal pain; Horse health; Pain
physiology; Gait analysis techniques; Pain relief |
| Subjects: |
S Agriculture > SF Animal culture |
| Faculties/Schools: |
UK Campuses > Faculty of Medicine and Health Sciences > School of Veterinary Medicine and Science |
| Item ID: |
81409 |
| Depositing User: |
Pratt, Stefanie
|
| Date Deposited: |
24 Jul 2025 04:40 |
| Last Modified: |
24 Jul 2025 04:40 |
| URI: |
https://eprints.nottingham.ac.uk/id/eprint/81409 |
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