Splayleg or Rotational Leg Deformity in Birds

Splayleg or rotational leg deformities in birds can involve various tissue types in the stifle, femur (upper thigh), tibiotarsus (main bone of the bird’s leg), and tarsometatarsus (large bone in lower leg of bird).  It is possible to treat or repair this condition but the treatment or repair needs to be done as soon as possible in a young bird.

Rotational leg deformity, or splayleg, can describe many deformities of the legs of young birds.  These deformities can include ligaments and angular deformities of various skeletal components of the bird’s legs.

Splayleg or rotational deformities can present in both young and older pet birds and these are some of the things which may be noticed in your pet bird:

• Reluctance to stand
• Trembling of legs when standing
• Reluctance to walk
• Impaired gait
• Bending, bowing or rotation of impaired leg
• One or both legs may be affected

Types 

This malady of birds can be divided into several categories.  The categories listed below apply specifically to the Psittacine family, but they can be applied, to some degree, to other species as well:

• Congenital/developmental - Includes beak abnormalities, constricted toe syndrome, choanal atresia (closed, constricted or absent slit in roof of mouth), metabolic bone disease [MBD], crypto-ophthalmia (refers to deformity of upper lateral eyelid) and splayleg
• Husbandry/nutritional - These diseases result from nutritional deficiencies and enclosure insufficiencies like inadequate support and substrate materials 
• Infectious - These types can be either viral or bacterial or both
• Parasitic - Offending parasites can be picked up through contact via oral/fecal route

While the actual causes of splayleg or rotational deformity in birds are not well documented, there are some risk factors which have been found to at least contribute, if not cause, this condition in birds.  Here are some of those risk factors:

• Nutritional deficiencies - Dietary components are probably the most common - this risk factor can include birds of any age, not just young birds or hatchlings (metabolic bone disease (MBD) is caused by a calcium-phosphorus imbalance in the bird’s diet or inherited from the parents in the case of a hatchling or young bird, sometimes a vitamin D deficiency also can cause lower levels of calcium)
• Husbandry - This category includes elements of the bird’s environment like incubators, insufficient support and substrate in enclosures, hatching facilities and activities, nesting areas, and injuries sustained from parents during nesting process
• Viral and bacterial infections present in the parents and flock
• Parasites which can infest a bird of any age via the oral/fecal route

When any of the above symptoms are noted, be sure to call your veterinary professional as soon as possible so that diagnosis and treatment can begin promptly.  When your vet assesses your bird, he will need a complete history from you which outlines feeding, breeding, hatching and nesting specifics as well as any behaviors or changes you have noted and how long these behaviors and changes have been displayed.  Your vet will do a thorough physical examination of the afflicted bird and will likely need to order some laboratory testing, utilizing various blood, fluid and tissue samples.  When the lab reviews the samples, they will be looking not only for values of calcium/phosphorous ratio and vitamin D primarily but also for any comprehensive blood panel component which may be out of the norm for your bird species.  

The lab will also be looking at the microbiological components of the flora in the digestive tract for clues (this is done by testing the bird’s excrement). Since splayleg and rotational leg deformity involves the skeletal system, radiographic imaging (x-ray) will also likely be employed to look at the structure of the long bones in the legs of your bird.  Depending on what other signs and symptoms are found in the diagnostic process, CT imaging might also be utilized, especially if the condition is afflicting an older bird as opposed to a young bird or hatchling.

Once your veterinary professional has gathered the necessary and available diagnostic information regarding your bird, he will develop a treatment plan appropriate to the cause of the splayleg, its stage of development and the your bird’s age.  That treatment plan may encompass a variety of treatments, some of which are listed below:

• Nutritional changes required to bring the levels of vitamin D, calcium and phosphorous back in line
• Husbandry changes for the hatchling or young bird which may incorporate changing the structure of the nesting areas to allow better support for the bird (suspension devices to allow the legs to straighten)
• “Hobbling” with a non-adhesive material with support structure to help maintain appropriate alignment
• Adjusting the nesting area to prevent parents from sitting too tightly on the baby
• Changes in the substrate in the nestbox or brooder
• Exercising the bird
• Adjusting the climate (temperature and humidity levels) in the brooder 
• Surgical repair of the deformed limb
• In the case of infectious and parasitic causes, medications may need to be administered to treat those causes as well

Recovery of your bird from splayleg or rotational leg deformity will depend on the age and the cause of the condition.  The younger a bird is when the deformity is noted and treated, the better the prognosis.  While the bird is young, the long bones in the legs may still be growing and may still be pliable enough to make the appropriate correction utilizing the best method determined to be available.  

Nutritional and husbandry changes made at this level will help to strengthen the bones as they develop.  You can’t help genetics but you can certainly be watchful of your hatchlings to catch developmental deficiencies and deformities as early as possible so that appropriate medical care can be given.  In the case of your older birds, nutritional and husbandry changes can correct many of the causes of this condition.