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The classic laminitis stance, where a horse or pony stands with its front feet ahead of its body, was found in fewer than half of the active laminitis cases in a major British study.
The researchers said the stance did not prove to be a useful discriminator between laminitis and other causes of lameness.
Horse owners in particular were urged to take care not to rely on this clinical sign when trying to ascertain whether their horse had laminitis, despite it being widely publicised as how laminitis appeared.
The study team set out to compare the prevalence of selected clinical signs in laminitis cases and lame control horses that were not laminitic. The researchers found that no individual sign was present in every case of laminitis.
Participating vets completed a checklist of laminitis-associated clinical signs identified by literature review before the study looked at the nuts and bolts of how they discriminated laminitis from other causes of lameness.
Cases were defined as horses or ponies with veterinary-diagnosed, clinically apparent laminitis. The controls were horses and ponies with any lameness other than laminitis.
Analysis by Dr Claire Wylie, from Rossdales Equine Hospital and her colleagues from a range of institutions linked laminitis prevalence with specific combinations of clinical signs.
In all, information was gathered on 588 laminitis cases and 201 lame control horses.
The researchers, writing in the journal, Veterinary Record, reported that lameness in both front limbs proved to be the best discriminator among the vets, with 92 per cent of animals with this clinical sign being diagnosed with laminitis. If, in addition, the horses or ponies had an elevated digital pulse, 99 per cent were identified as laminitic.
The study reported that five clinical signs stood out in laminitis, with a difference in prevalence of greater than 50 per cent. They were a reluctance to walk; a short, stilted gait at walk; difficulty turning; shifting weight; and an increased digital pulse.
The presence of a flat or convex sole significantly enhanced clinical diagnosis of laminitis, but these were characteristic of the chronic phase of the disease only.
The paper concluded that improved evaluation of the clinical signs shown by laminitic horses examined by first-opinion vets would lead to equine welfare improvements, as the best recoveries occurred in animals undergoing intensive treatment within several hours of the appearance of the disease.
The study is the first epidemiological laminitis research to use decision-tree analysis, providing the first evidence base for evaluating clinical signs to differentially diagnose laminitis from other causes of lameness.
The researchers were variously affiliated with Rossdales Equine Hospital in Newmarket, the Animal Health trust, the Royal (Dick) School of Veterinary Studies and the Roslin Institute at the University of Edinburgh, and the Royal Veterinary College.
Decision-tree analysis of clinical data to aid diagnostic reasoning for equine laminitis: a cross-sectional study
C. E. Wylie, D. J. Shaw, K. L. P. Verheyen, J. R. Newton.
Veterinary Record 2016; 178:420 doi: 10.1136/vr.103588
The abstract can be read here.