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Restraint for hoof trimming
Barb Frey, DVM and Yvonne Sprey
BF: Portec Australia Pty Ltd, P.O. Box 331, Belmont WA 6104
Australia; email: bfportec@highway1.com.au. YS: Pigz Consultancy,
Woodside Road, Oxford, Canterbury, New Zeland
Sow lameness and the associated pain
and discomfort are underestimated as contributors to reproductive
losses and premature culling. For example, 18% of sows removed
during a national sow wastage study were culled for lameness.1
Many causes of lameness have been documented.2 A proportion
of these are attributable to hoof lesions such as overgrowth,
corns, and hoof abscesses. Such lesions may be associated with
floor type, poor hygiene, conformation, injury, or lack of exercise.
However, they may be treated or prevented by corrective trimming,
as illustrated in Figures 1-6. The economics of this procedure
will be dictated by the cost of replacement stock and the value
of culls.
Equipment
Hoof knives are not recommended except for paring out a localized
lesion. The main tool to use for hoof trimming is either a one-handed
pair of nippers, or a two-handed pair (such as those used for
cattle) with an assistant holding the hoof. Ear protection and
leather gloves are recommended.
Restraint
Chemical restraint is usually only required when facilities
or available assistance preclude manual restraint, the extent
of the lesion requires prolonged effort, the animal is a pet,
or the owner prefers it. It is difficult to trim a foot squarely
when an animal is recumbent.
Problems with restraint include:
- fearful pigs accustomed to aversive handling. Such pigs are
also difficult to restrain chemically;
- leg elevated too high or pulled out to the side too far for
the animal's comfort. This throws off its center of balance and
it struggles in fear of falling. This also encourages it to lean
its weight on the handler. It tires more quickly, as well;
- when the animal's head is free, it struggles. Swine have
a lot of strength in the neck and weight in the head, which needs
to be firmly elevated to square its center of balance;
- when the head is restrained uncomfortably or too high, it
can throw off its balance;
- slippery floor;
- many lamenesses are bilateral, especially when they are related
to conformation flaws. An animal can simply be more lame on one
leg than the other. This makes it painful to bear all its weight
on the other leg. I suspect this is the problem with most pigs
that struggle despite quiet handling and firm supportive restraint.
Such animals often 'go lame' in the opposite limb a few weeks
after trimming the affected side. For this reason, I always check
both.
The most important thing is having a person to support the
pig. It really makes all the difference. Done properly, trimming
takes little time for simple hoof overgrowth. Timely correction
of hoof overgrowth and mild lesions in younger stock can reduce
culling due to lameness.
    
References
1. Paterson RA, et al. Investigations into death and excessive
culling of sows in Australian pig herds. Proc Aus Assoc Pig
Vet. 1996: 65-70.
2. Dewey CE, et al. Clinical and postmortem examination of
sows culled for lameness. Can Vet J. 1993;34:555-6.
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