achieve the angle and support the foot that may tend to land unevenly,
particularly in show horses. In a recent study however, we found that neither
the lateral extension shoe nor the rolled toe shoe with elevated heels had a
consistent effect on the position of the point of zero moment (point of force) of
the foot during stance, on the orientation of the hindlimbs during flight nor on
the clinical lameness of these horses, thereby questioning their efficacy.
Anti-inflammatory medication
Anti-inflammatory therapy is required to resolve or control the pain resulting in
lameness. Generally, the best plan is to do the minimum required to keep the
horse effectively in work, because more treatment will probably be required
eventually. Each horse is different and requires discovery of an effective
treatment schedule. A starting point includes systemic phenylbutazone (2.2
mg/kg, BID), which can be continued for an extended period of time in most
horses or given only when the horse is worked.
Intra-articular corticosteroids
Intra-articular medication with corticosteroids (40-80 mg methylprednisolone,
6-12 mg bethamethasone or 6-12 mg triamcinolone acetonide) is more
predictably successful in rendering horses sound, although reported success
rates vary from 35% to 70% of horses injected being improved (Labens et al.
2007; Byam-Cook et al. 2009). Medical treatment is best selected for those
horses that have minimal radiological changes and combined with a program
of controlled walking together with alterations of the shoeing.
Therapeutic concentrations of methylprednisolone have been measured in
both the TMT and DIT joints following injection of the TMT joint only (Serena
et al. 2005). However, clinical impressions suggest strongly that both joints
(TMTJ + DITJ) must be injected concurrently for optimal effect and to avoid
unexpected treatment failures.
When the horse responds poorly to initial treatment with intra-articular
steroids, a second injection 3 to 4 weeks later may be more effective. Using
triamcinolone (6 mg/ joint) for the first injection and scheduling a second
injection with 80 mg methylprednisolone makes sense in horses for which
long-term pain control is needed. A period of reduced activity after medication
usually improves the result; the rest period has subjectively varied from 5 to
14 days in show horses.
Tiludronate
Tiludronate inhibits osteoclast activity and has been used in horses with distal
tarsal pain. In a limited double-blind clinical trial of 8 horses with lameness
confirmed to originate in the distal tarsal joints given 1 or 2 single IV doses, 1
horse improved (Dyson 2004). More recently, a larger study using 86 horses
showed an average improvement of 2 (out of 10) lameness grades in horses
treated with an infusion of tiludronate and a controlled exercise regime, which
was significantly better than the improvement seen in horses in the placebo
group (Gough et al. 2010). However, it was considered difficult to separate the
effect of tiludronate from the effect of the controlled exercise regime in
improving lameness. Clodronate, a new bis-phosphonate has become
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February
2016
East
London
Convention
Centre,
East
London,
South
Africa
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