Management of Knuckling in an Ostrich (Struthio camelus) Using a Custom-Made Orthotic Shoe.

A 4-year-old female ostrich (Struthio camelus) developed knuckling on its left foot after a traumatic event. Conservative treatment, rest, and traditional splinting methods failed to resolve the gait abnormality or improve mobility. A dynamic multicomponent orthotic shoe was then custom designed and fabricated with an ultra-high-molecular weight, low-pressure polyethylene polymer (St 1000 DIN16972 TG2) to correct the foot malposition. The affected foot and leg were wrapped with soft padding and the orthosis was attached and secured by nylon belts (Nylon PA [polyamide] 6, a semicrystalline polyamide polymer) with self-locking modified wrench straps. The orthosis immediately prevented knuckling and improved ambulation. After 2 weeks, this shoe was replaced with a modified orthotic shoe of lighter weight to improve kinetics and ease of use by the bird. The modified orthosis dramatically improved ambulation and was left attached to the affected leg for 7 more weeks. Thereafter, the bird was able to ambulate comfortably without the aid of the shoe, even though permanent anatomical changes to the affected leg seemed to restrict its speed of locomotion. The ostrich had another unfortunate traumatic event 10 weeks later, the result of which was knuckling on the contralateral (right) foot. After routine medical and supportive care, the orthosis was then applied to the right foot for a period of 9 weeks. During this period the bird was able to ambulate well, despite having to support the bulk of its weight on the previously affected left limb. At the end of 9 weeks, the orthosis was removed, and the bird was able to ambulate without aid, although the bird's speed of locomotion was considerably reduced. After recovery of its leg problems, the ostrich was confined to a relatively small paddock for the rest of its life.

Acquired equine polyneuropathy of Nordic horses: A conspicuous inclusion body schwannopathy.

Acquired equine polyneuropathy (AEP), formerly also known as Scandinavian knuckling syndrome, is one of the most prevalent polyneuropathies in equids in Norway and Sweden, with more than 400 cases registered since first observations in 1995. Despite geographical clustering and an association to forage feeding, its aetiology remains unknown. Clinically AEP is characterized by knuckling due to dysfunction of metatarsophalangeal extensor muscles. This neuropathological study aimed to gain further insights in the pathobiology of AEP and its underlying aetiopathogenesis. We thereby confirmed that all affected horses suffered from similar large fibre neuropathy, exhibiting conspicuous Schwann cell inclusions in most samples, suggestive of a primary disruption of Schwann cell metabolism leading to inclusion body schwannopathy with secondary inflammatory changes. The degree of nerve pathology was not predictive of clinical outcome.

Long-term follow-up of Norwegian horses affected with acquired equine polyneuropathy.

BACKGROUND: Acquired equine polyneuropathy (AEP), a neurological disease clinically characterised by knuckling of metatarsophalangeal joints, has been described in numerous Nordic horses during the last 20 years. Although clinical recovery has been reported, large-scale data on long-term follow-up of survivors have been lacking. OBJECTIVES: To describe long-term survival of AEP affected horses registered in Norway, with a focus on athletic performance and possible residual clinical signs connected to the disease. STUDY DESIGN: A retrospective cohort study. METHODS: The study includes 143 horses recorded with AEP in Norway from 2000 to 2012, with the follow-up period continuing until 2015. Participating owners of survivors completed a standardised questionnaire, providing information on disease and convalescence, management, performance-level and possible residual clinical signs. To investigate the follow-up of survivors, we performed 2 multivariable linear regression models. RESULTS: The follow-up time of survivors was 1.0-14.5 years (median 5.3, interquartile range 2.5-7.2). Fifty-seven horses survived and all but 3 horses returned to previous or higher level of performance. However, possible disease-related residual clinical signs were reported in 14/57 horses. Forty-nine of the survivors were in athletic use at time of contact. The majority of survivors were categorised with low severity-grades at time of diagnosis and the initial grade was significantly associated with time to resumed training. Only 3 horses had experienced relapse/new attack during the follow-up period. MAIN LIMITATION: Athletic performance was judged by owners, which renders a possible source of bias. CONCLUSIONS: Although AEP is a potential fatal disease, most survivors will recover and return to minimum previous level of athletic performance. Some horses display residual clinical signs, but often without negative effect on performance and relapse of disease is rare.