This article is from the Dogs Agility FAQ, by J L Gauntt with numerous contributions by others.
Not every dog should be doing agility and may become injured or
aggravate a pre-existing condition if the owner does not perform some
pre-screening before entering the phase of intensive training. The
pre-screening should at a minimum consist of hip, elbow, and eye
Veterinarians should be informed what is planned for the dog and the
dog should be radiographed for both hip & elbow dysplasia. The owner
should reconsider their plans for agility if the dog is rated anything
less than 'Fair'. Unobstructed vision is also critical.
Because agility is a fairly new type of dog competition, it is not
unusual for a veterinarian to be unaware of the requirements for
agility. In this case, it is very helpful for the owner to have
available a short video (2-3 minutes long) of a dog performing the
equipment; this will give the veterinarian an idea of the physical
requirements necessary for the sport. Both the owner and veterinarian
should be particularly sensitive to the dog's weight. What is a good
healthy weight for a pet dog with normal activity expectations may be
too heavy for agility training and competition. Poor performance or
injuries, which can include muscle strains and other soft tissue
injuries, are nearly always due to the 'weekend athlete syndrome' --
i.e. the dog is overweight and/or not conditioned properly.
On-going conditioning separate from the equipment training is vital to
keeping the dog's agility performance high and injury-free. Weight
bearing exercise is the most appropriate; for example walks
interspersed with short sprints condition both the dog and the
handler. Long distance, low to the ground games of ball and/or frisbee
are particularly helpful for building the dog's cardiovascular and/or
muscular capacity. Swimming can also be beneficial for improving
cardiovascular & muscular capacity.
The agility obstacles that require the most conditioning (particularly
for international style agility) are the jumps. In order for a dog to
be able to safely engage in the amount of jumping required for both
agility training and competition, the dog must not only possess the
proper cardiovascular and muscular structure, he must possess the
necessary skeletal structure as well. Skeletal conditioning is
performed slowly over time by spending at least 6-9 months of training
at low jump heights; this minimizes impact to the bones and yet
induces the rather slowly growing bones to thicken and develop the
strength needed at the correct points to withstand the impact of
landing after jumping. These months of low jump training are a good
time for a handler to work on developing the dog's command vocabulary.
Once this conditioning period is accomplished, the jumps can then be
systematically raised in training until the dog's full jump height is
reached and actual competition can be considered.
Some on-going physical maintenance of the dog is necessary as well in
order to prevent injury whether in training or competition. In
particular, nails must be kept trimmed back at all times so that they
do not catch on the equipment or impede the dog's traction. Some
sacrifice in dog appearance must be accepted in those breeds which
have a lot of hair over or about the eyes; this hair must be kept
trimmed or tied back so as not to interfere with the dog's vision.