AQHA May-June YB 2024 AQHA Magazine May / June 2024 Year Book | Page 37

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WORDS BY : DR JENNIFER STEWART BVSC BSC PHD EQUINE VETERINARIAN , CEO JENQUINE AND CONSULTANT NUTRITIONIST EQUINE CLINICAL NUTRITION PHOTO BY : TRUDY HOLDEN
WEANING PRESENTS SOME WINDOWS OF OPPORTUNITY – ONCE IN A LIFETIME CHANCES TO PROTECT FUTURE SOUNDNESS , ACHIEVE GENETIC POTENTIAL AND REDUCE THE RISK OF ‘ STABLE VICES ’.
‘ Stable vices ’ also known as ‘ stereotypies ’ are repetitive , seemingly purposeless behaviours such as cribbing , windsucking and weaving . Now recognised as a ‘ disease of domestication ’, because they have never been observed in free-living and feral horses , they occur in 15-40 % of domesticated horses . Weaning as a critical point in development of oral stereotypies - over 65 % of wind-suckers and crib-biters develop the habit within one month of weaning - the same time as diet and environment change . Weaning leaves foals vulnerable to the development of stereotypies and management methods that cause chronic stress are now recognised as the major risk factors .
Crucial in their occurrence are feeds with NSC ( starch + sugar ) over 12 %; meal feeding , low roughage diets , housing / stabling conditions , weaning method and social contact . A 4-fold increase of the incidence of crib biting has been recorded in foals fed starch / sugar concentrates after weaning ( Tables 1 and 2 ). Stable confinement is associated with increased risk of stereotypies compared with paddock weaning . Cribbing and wind-sucking occur most often in stabled horses - although once established the horse may exhibit these behaviours in other places . Recent studies indicate cribbing occurs more frequently in horses that were stable-weaned . At 20 weeks of age , 10.5 % of weanlings on concentrates , low fibre and stabled-weaned demonstrate cribbiting / windsucking .
Another disease that is widely recognised as ‘ man-made ’ is developmental orthopaedic disease . In wild and feral horse populations - where there is no human influence - it is very rare ( around 2 %). Affecting 10 - 65 % of all domestic weanlings , most joint and cartilage lesions are not detectable until the damage causes lameness , joint swelling or xray changes . However , the disease is present long before signs appear and begins during periods of skeletal vulnerability in the foal and weanling .
The term developmental orthopaedic disease ( DOD ) describes skeletal problems in growing horses - limb deformities , bone cysts , contracted tendons , club feet , joint enlargements , wobblers , osteochondritis dessicans ( OCD ) and physitis ( Figures 1 - 3 ). In long yearlings and early 2-year-olds , hock DOD is not uncommon and may present as a decrease in performance .
2024 AQHA YEARBOOK ~ MAY / JUNE ISSUE