- Email: [email protected]
Laminitis 911
Abstracts / Journal of Equine Veterinary Science 31 (2011) 562-609 [17] Treiber K, Carter R, Gay L, et al. Inflammatory and redox status of ponies with a history of pasture-associated laminitis. Vet Immunol Immunopathol 2009;129:216-20. [18] Weiss DJ, Evanson OA, Green BT, Brown DR. In vitro evaluation of intraluminal factors that may alter intestinal permeability in ponies with carbohydrate-induced laminitis. Am J Vet Res 2000;61:858-61. [19] Bergen WG, Wu G. Intestinal nitrogen recycling and utilization in health and disease. J Nutr 2009;139:821-5. [20] King C. Equine anatomy in perspective: an integrative view of equine musculoskeletal anatomy. In Proceedings, 3rd International Symposium on Rehabilitation and Physical Therapy in Veterinary Medicine, 2004; pp. 89–93.
609
[21] Rose NS, Northrop AJ, Brigden CV, Martin JH. Effects of a stretching regime on stride length and range of motion in equine trot. Vet J 2009;181:53-5. [22] Floyd AE. Environmental management of the severely laminitic horse. In: Floyd AE, Mansmann RA, editors. Equine Podiatry. Elsevier Health Sciences; 2007. p. 359-67.
Laminitis 911 Margaret Duprey – Moderator – Panel Discussion
Workshops The effects of environment on the horse’s hoof Brian Hampson School of Veterinary Science, The University of Queensland
Take-Home Message: Although feral horses living and traveling on hard substrates appear to have robust feet modified by the environment and able to withstand locomotion over hard surfaces, there are some negative consequences associated with this lifestyle. Introduction: It has been proposed that the feral-horse foot is a benchmark model for foot health in all horses and can be used as a guide to optimize care of the domestic horse's feet. The adoption of this model by some groups has shifted the focus of hoof trimming away from the traditional farriery model to a tendency toward excessive removal of the bearing border of the distal hoof wall and sculpting the foot in the shape of the popular feral hoof model. However, the paradigm model for the feral horse foot was obtained from limited studies of desert-dwelling feral horses, and it may not represent the general appearance of feral horse feet across a range of habitats. The external appearance of the typical desert-dwelling feral horse's foot appears aesthetically pleasing, with little visible pathology. However, the foot morphology and foot health of feral horses has not been formally investigated in detail. The objective of this study was to investigate the effect of varying environments (from alpine to sandy desert) on foot morphology, foot health, and related parameters in feral horses in Australian and New Zealand. The aim was to investigate important aspects of feral horse ecology that relate to foot morphology and function in order to improve our understanding of the interaction between ecology and foot variables. Materials and Methods: Fourteen separate studies of feral horses in Australia and New Zealand, ranging in subject numbers from 12 to 100 horses, were performed to investigate the genetic structure, travel profiles, nutritional parameters, foot morphology, and foot health in populations of feral horses from various environments. Results: There was a profound effect of environment on the feral horses' feet. The gross morphology of the feet was affected by a combination of substrate (footing) and the distance that horses traveled. Travel distance was determined by the separation between water and food sources in the habitat. Each environment studied produced a unique foot type in terms of general appearance, foot morphology, and foot health. There were marked differences in some conformation parameters between the feral horses in the current study and domestic horses from previous studies.
As mentioned in the first abstract, a total of 377 gross abnormalities were identified in 97 of 100 left forefeet studied (97%); only 3/100 (3%) left forefeet had no discernible pathology. The type and severity of abnormality varied between populations. Of the populations surveyed by histopathology, the incidence of chronic laminitis ranged from 40% to 93%. There appeared to be a balance between hoof capsule wear and growth rate in the hard-substrate environments. Consequently, hoof capsules were short and often worn to the level of the peripheral sole. In the softer-footing environments, growth rate exceeded wear, allowing the hoof wall to grow long and flared. There were signs of pathology, such as ungual cartilage calcification and traumatic laminitis, consistent with concussive changes in the feet of horses living on hard footing. Some feet from high-travel populations appeared to have overuse changes such as excessive hoof wall wear. A combination of high travel and hard substrate was associated with the more serious foot pathologies observed. Discussion: Given this moderate evidence of suboptimal foot health in feral horses, it may be inappropriate to use the feral horse's foot as the benchmark for equine foot health. Previous observers and proponents of the “natural” foot model were apparently unaware of this inner pathology when they made recommendations for domestic foot care, such as the promotion of solar loading and excessive beveling of the distal hoof wall. This collection of feral horse studies highlights the importance of using empirical methodology, a large sample size, thorough investigation, and independent, blinded observations to obtain data for use in the guidance of hoof care practices. The standard of using the “natural” foot model as the optimal morphometric model on which to base foot trimming practices may need to be reconsidered. Conclusions and Clinical Relevance: This study identifies the negative long-term implications of substrate and movement on foot health. Care needs to be taken in choosing one environment over another because the consequences may be harmful. Although feral horses living and traveling on hard substrates appear to have robust feet that are modified by the environment and able to withstand locomotion over hard substrates, the current study suggests that there are some negative consequences associated with this lifestyle. However, it is also possible that the hard-substrate foot type, because of its robust nature and biomechanical function, allows the feral horse to withstand significant foot pathology without showing overt lameness, thus assisting the horse to survive in extreme environments. In light of this observation, further research is required to fully understand the impact of various models of hoof care and footing on the health and well-being of domestic horses.
609
[21] Rose NS, Northrop AJ, Brigden CV, Martin JH. Effects of a stretching regime on stride length and range of motion in equine trot. Vet J 2009;181:53-5. [22] Floyd AE. Environmental management of the severely laminitic horse. In: Floyd AE, Mansmann RA, editors. Equine Podiatry. Elsevier Health Sciences; 2007. p. 359-67.
Laminitis 911 Margaret Duprey – Moderator – Panel Discussion
Workshops The effects of environment on the horse’s hoof Brian Hampson School of Veterinary Science, The University of Queensland
Take-Home Message: Although feral horses living and traveling on hard substrates appear to have robust feet modified by the environment and able to withstand locomotion over hard surfaces, there are some negative consequences associated with this lifestyle. Introduction: It has been proposed that the feral-horse foot is a benchmark model for foot health in all horses and can be used as a guide to optimize care of the domestic horse's feet. The adoption of this model by some groups has shifted the focus of hoof trimming away from the traditional farriery model to a tendency toward excessive removal of the bearing border of the distal hoof wall and sculpting the foot in the shape of the popular feral hoof model. However, the paradigm model for the feral horse foot was obtained from limited studies of desert-dwelling feral horses, and it may not represent the general appearance of feral horse feet across a range of habitats. The external appearance of the typical desert-dwelling feral horse's foot appears aesthetically pleasing, with little visible pathology. However, the foot morphology and foot health of feral horses has not been formally investigated in detail. The objective of this study was to investigate the effect of varying environments (from alpine to sandy desert) on foot morphology, foot health, and related parameters in feral horses in Australian and New Zealand. The aim was to investigate important aspects of feral horse ecology that relate to foot morphology and function in order to improve our understanding of the interaction between ecology and foot variables. Materials and Methods: Fourteen separate studies of feral horses in Australia and New Zealand, ranging in subject numbers from 12 to 100 horses, were performed to investigate the genetic structure, travel profiles, nutritional parameters, foot morphology, and foot health in populations of feral horses from various environments. Results: There was a profound effect of environment on the feral horses' feet. The gross morphology of the feet was affected by a combination of substrate (footing) and the distance that horses traveled. Travel distance was determined by the separation between water and food sources in the habitat. Each environment studied produced a unique foot type in terms of general appearance, foot morphology, and foot health. There were marked differences in some conformation parameters between the feral horses in the current study and domestic horses from previous studies.
As mentioned in the first abstract, a total of 377 gross abnormalities were identified in 97 of 100 left forefeet studied (97%); only 3/100 (3%) left forefeet had no discernible pathology. The type and severity of abnormality varied between populations. Of the populations surveyed by histopathology, the incidence of chronic laminitis ranged from 40% to 93%. There appeared to be a balance between hoof capsule wear and growth rate in the hard-substrate environments. Consequently, hoof capsules were short and often worn to the level of the peripheral sole. In the softer-footing environments, growth rate exceeded wear, allowing the hoof wall to grow long and flared. There were signs of pathology, such as ungual cartilage calcification and traumatic laminitis, consistent with concussive changes in the feet of horses living on hard footing. Some feet from high-travel populations appeared to have overuse changes such as excessive hoof wall wear. A combination of high travel and hard substrate was associated with the more serious foot pathologies observed. Discussion: Given this moderate evidence of suboptimal foot health in feral horses, it may be inappropriate to use the feral horse's foot as the benchmark for equine foot health. Previous observers and proponents of the “natural” foot model were apparently unaware of this inner pathology when they made recommendations for domestic foot care, such as the promotion of solar loading and excessive beveling of the distal hoof wall. This collection of feral horse studies highlights the importance of using empirical methodology, a large sample size, thorough investigation, and independent, blinded observations to obtain data for use in the guidance of hoof care practices. The standard of using the “natural” foot model as the optimal morphometric model on which to base foot trimming practices may need to be reconsidered. Conclusions and Clinical Relevance: This study identifies the negative long-term implications of substrate and movement on foot health. Care needs to be taken in choosing one environment over another because the consequences may be harmful. Although feral horses living and traveling on hard substrates appear to have robust feet that are modified by the environment and able to withstand locomotion over hard substrates, the current study suggests that there are some negative consequences associated with this lifestyle. However, it is also possible that the hard-substrate foot type, because of its robust nature and biomechanical function, allows the feral horse to withstand significant foot pathology without showing overt lameness, thus assisting the horse to survive in extreme environments. In light of this observation, further research is required to fully understand the impact of various models of hoof care and footing on the health and well-being of domestic horses.