Orthopaedic disease in the foal should be considered separately from that in the adult for a number of key reasons: a) musculoskeletal components are immature and very sensitive to trauma; b) the potential for growth should be protected to prevent long term disability; c) the immune system is also immature, leading to a different pattern of disease from the adult animal. It should also be remembered that in many instances the foal was being bred for commercial reasons and the balance between emotional and economic factors will need to be discussed thoroughly with the client. In principle foal examination is identical to that involving the adult. Usually it is easier to lead the mare up and down and allow the foal to follow her. It is however very unusual for a foal to trot in a consistent manner in a straight line! Most foals also object to being handled and even from a young age kick very accurately. Also when handling foals it is worth remembering that in general they do not have any sense of self-preservation and will continue to struggle even to the point of damaging themselves. 

Very common, either as a result of a kick from the mare, another foal or excessive exercise, or the mare standing on the foal.

- long bone fracture

- pelvic fracture

- physeal fracture

- pedal bone fracture

 -sesamoid bone fracture 

Not uncommon (metacarpal/metatarsal three diaphysis; Bischofberger et al. (2009), proximal tibial physis), should be considered in any severely lame foal. Long bone fracture fixation is a more realistic option in a foal compared to an adult due to their lower body weight, the relative increase in strength of the implants and their intrinsic healing capabilities. However fracture fixation in foals does present a different set of possible complications, including growth disturbances and flexural tendon laxity. If a long bone fracture is suspected it is worth talking to a referral institute before assuming the fracture is irreparable. Additionally optimal limb immobilisation can seriously affect outcome of these cases. Postsurgical infection is more common in foals. 

Reported to be common, prognosis very dependent on whether there is acetabular involvement. Conservative management is generally recommended.

Physeal fracture: 

These fractures are very common due to the delicate nature of the cartilage in this region. They are classified using the Salter Harris method (see small animal notes). It is important that they are recognised early and optimally managed to reduce growth disruption. Differentiating a fracture from infection is not always easy but of crucial importance. 

Common, prognosis good (different from adult horses). 

Fracture of the proximal sesamoid bone(s) 

Can be uniaxial or biaxial, single limb or multi limb. Believed to be due to excessive exercise running after the mare (first time in the field for both of them), commonly occurs between 2 weeks and 2 months, can be basilar or apex, commonly comminuted, conservative management possible, or wire cerclage, may develop elongated bone. 

Osteochondrosis

subchondral bone cysts 

angular limb deformities

flexural limb deformities

Characterised radiographically by radiolucent areas of bone often accompanied by a thin well demarcated rim of sclerotic bone. Usually occur in the subchondral bone underlying a weight bearing surface of the articular cartilage E.g. medial femoral condyle, phalanges. Clinical signs include lameness ± joint effusion. Lameness in young horses (1-3 years) usually occurs at onset of training. Diagnosis confirmed with radiography ± ultrasound. Treatment involves arthroscopically guided disruption of cyst lining and injection with corticosteroids (Wallis et al. (2008)). Good prognosis in young horses.

This is a common condition in foals and refers to when the limb has a deviation in the frontal plane i.e. the leg will bend either inwards (varus deformity) or outwards (more common, valgus deformity). Congenital and acquired forms are recognised.

- congenital

- acquired 

Periarticular ligamentar laxity or hypoplasia of the cuboidal bones of the carpus or tarsus. Malformation of the diaphysis of the long bones (rare). Intrauterine malpositioning, Mare nutrition (iodine deficiency in Canada)(Teratogens). 

Above lesions only apparent as growth accelerates; asymmetrical growth at the physis. A careful clinical examination to identify exact site of deviation, often need to confirm radiographically. Radiographs not always precise. Often together with rotational deformities. Treatment depends on cause.

Neonate: If deviation due to periarticular laxity or cuboidal bone collapse, limb should be straightened using padded bandage/cast. Leave out foot to correctly load limb. Restrict exercise. Care with bandaging as foals skin very delicate.

Older foal: Deviation due to growth asymmetry. Partially restrict exercise (cattle court), monitor diet to avoid overweight/rapid growth, check Cu, Zn, Ca, P levels in diet. Foot care. Check for lameness. Valgus deformities: medial extension shoes, Varus deformities: lateral extension shoes. Support the side bearing most weight

Persistent deformities due to asymmetric growth. If deformity does not respond to conservative management or is severe surgical treatment is required (ideally within 4 weeks for fetlocks, 4 months carpus, tarsus). 

Growth acceleration - Periosteal transection and elevation: 

Performed on the short side of the bone i.e. the side towards which the limb is bent. The periosteum is stripped from the physis on one side of the bone and then replaced. Unsure of mechanism of growth acceleration (ligament removal?). Using this procedure it is not possible to over correct the lesion. 

Growth retardation - Transphyseal bridging 

Surgical implants (figure of 8 wire or mini plate or staples) can be placed across the physis on the side that is growing too rapidly. Used only in severe cases as it is possible to over correct. Take implants out before limb is totally straight.

Can use both techniques on the same limb if severe deviation is present. These measures only work while an appreciable degree of growth is occurring at the physis. 

Limb deviation in the sagittal plane. Only in some cases contracted tendons. Congenital and acquired forms recognised.

- congenital

- acquired  

Congenital flexural deformities 

Uterine malpositioning, toxic/viral insults during embryonic life

Limbs held in permanent flexion, wide range of severity. Evaluate which joints involved. Could be arthrogryposis. May improve with weight bearing; intravenous oxytetracycline (2-4gms/foal IV) in first 48hrs; physiotherapy; corrective foot trimming, reduce heels, consider toe extensions. Bandaging will induce musclelaxity and prevent skin damage. 

Acquired flexural deformities 

Rapid growth, imbalance between growth of between bones and tendinous unit. Excessive calorific intake/nutritional imbalances. Reduced weight bearing in the limb, often associated with lameness/physitis 

Flexor deformity of the distal interphalangeal joint (club foot) 

Usually develops 6w-6m of age. Boxy upright foot, broken back hoof pastern axis. Can develop very rapidly. Type 1 dorsal hoof wall still slopes cranially (prox to distal), type 2 hoof wall past the upright i.e. slopes caudally. Unilateral or bilateral

Conservative management in mild cases; dietary restriction; NSAIDS; controlled exercise; rasp down heels and place toe extension. Can try bandaging, but usually successful in early cases only. Surgical treatment in severe or progressive cases

Type 1: desmotomy of the accessory ligament of the deep digital flexor tendon (ALDDFT).

Type 2: deep digital flexor tenotomy, usually viewed as a salvage procedure. 

Can be very rapid in onset and very variable in degree of flexion. Can be unilateral or bilateral. Forelimb or hindlimb. Conservative as for DIPJ condition, except raised heel shoes.

Surgery. Must perform careful palpation to see which tendons under most tension as can involve SDFT and DDFT. Desmotomy of ALDDFT or ALSDFT or both. Often unsuccessful. SDFT tenotomy is a salvage procedure. 

Inflammation and disruption of growth in the physeal regions. Causes: overload, over-exercise, rapid growth. Firm, often painful swelling of the physeal areas. Often in distal radius and tibia, also distal MT/C 3. Flaring of the growth plates gives the long bones a typical "hour glass" shape. This usually occurs around the time of growth plate closure. Rapidly growing, heavy animals are most commonly affected. Associated lameness is usually mild in degree and may be intermittent and in multiple limbs. Osteochondrosis may be associated. Radiographically the physis is widened and irregular. The outline of the bone is disrupted, with lipping and flaring of the physeal region. Differentiate from septic physitis, a separate, much less common condition, which causes a profound lameness (see later). Most cases of physitis are self-limiting. Treatment is required if condition is painful or is suspected to be causing secondary growth disturbance leading to angular or flexural limb deformities. Treatment is aimed at eliminating the inflammation of the physis. Exercise reduction is important. The dietary energy intake of these foals should be reduced to slow the growth rate. Care with NSAIDS due to gastric ulceration, add antiulcer medication. 

Commonly seen in premature or dysmature foals, presenting clinically with various angular limb deformities following uneven loading of a dysmature skeleton. Identified radiographically as incomplete ossification of the carpal or tarsal bones. If less than 30% of the cartilage skeleton has ossified then prognosis for athletic activity is hopeless. Management consists of sleeve cast application and stall rest until skeleton matures sufficiently to tolerate normal weight bearing forces. 

Septic arthritis

Septic tenosynovitis

Septic osteitis

Septic osteomyelitis

Septic physitis 

•   Clinical examination will give a high index of suspicion. Severe lameness, foal maybe systemically ill, joints or physes hot, swollen, painful.

•   Radiography, very useful in chronic cases, less useful in acute, if subchondral bone involved prognosis is poorer, ultrasonography, useful in assessing contribution of articular and periarticular swellings, looking for periarticular abcessation.

•   Synoviocentesis

•   Blood analysis (WBC, Immuneglobulins, Blood culture). 

0. Antibiotics: systemic, intra-articular, intraosseous, regional perfusion. Joint lavage. Supportive therapy (Plasma). Immune mediated synovitis is recognised as a consequence of Rhodococcus equi infection.