Veterinary advice should be sought from your local veterinarian before applying any treatment or vaccine. Not sure who to use? Look up veterinarians who specialize in poultry using our directory listing. Find me a Vet
Valgus-varus Deformity
Other Names: Twisted Leg, Angular Bone Deformity
Valgus-varus deformity (VVD), often referred to as "twisted legs" is the deviation of the long bone (tibia) that causes the bird to develop a 'hocks-out/feet-in' (varus) or a 'hocks-in/feet-out' (valgus) stance. Varus refers to deviation of the medial side of the tibia and valgus is when the deviation is towards the lateral side. As the chicken grows, the deviation of the bone gets worse and can cause bending and rotation of the metatarsus bone.
The condition occurs frequently in the cornish breed (fast-growing "broilers") and in chicks given feed intended for commercial broilers. It usually starts to develop when the chick is between 2 to 7 weeks of age but can be seen as early as day 6.
Chickens affected by this deformity are more at risk of developing a slipped tendon or leg fracture, due to the increased pressure placed on the deformed leg. In one study, 60% of birds affected with severe valgus developed slipped tendon. Once this occurs, the chicken may be physically incapable of getting up from its abnormal, twisted leg-like position. Without intervention, these chickens will eventually starve to death from inability to reach water or food, or from getting trampled to death by other flock members.
Case 1: Angular limb deformity in a Flamingo Three hand-raised American flamingo chicks and one hand-raised Chilean flamingo developed valgus angular limb deformities of the proximal tarsometatarsal bone. All flamingos underwent surgical correction to unequally retard the growth plate using transphyseal bridging. Positive profile pins were placed in the proximal epiphysis and distal to the growth plate in the metaphysis on the convex side of the affected tarsometatarsus. Various banding techniques were used in each flamingo to create tension. Three of the four flamingos responded in 7-14 days with correction or slight overcorrection of the valgus limb deformity. The fourth flamingo's leg deformity did not improve for reasons thought to be related to improper implant placement. Growth plate retardation by transphyseal bridging proved successful in correcting valgus limb deformity of the proximal tarsometatarsus. This technique may be considered as an option for correction of angular limb deformities of the proximal tarsometatarsus in flamingos less than 90-120 days of age. Ref
Le Bihan-Duval, E., Beaumont, C., & Colleau, J. J. Genetic parameters of the twisted legs syndrome in broiler chickens. Genetics Selection Evolution (1996)
