edian, and often in the lateral,
lacunae. The organ is wasted and fissured, the horn in the depths of the
lacunae softened and easily detachable, and portions of the sensitive frog
often laid bare.

With a bad thrush lameness is present, the frog itself is tender to
pressure, and often there is considerable heat and tenderness of the heels
and the coronet immediately above. More especially is this noticeable after
a journey.

It is, perhaps, more common in the hind-feet than in the fore, and more
often met with in heavy draught animals than in nags. The hind-feet are, of
course, more open to infection by reason of their being constantly called
upon to stand in the animal discharges in the rear of stable standings,
while it is a well-known fact that heavy animals have their stables kept
far less clean, and their feet less assiduously cared for, than do animals
of a lighter type.

In a nag-horse with thrush of both fore-feet lameness becomes sometimes
very great. The gait when first moved out from the stable is feeling
and suggestive of corns, while progress on a road with loose stones is
sometimes positively dangerous to the driver.

_Treatment_.--When this condition has arisen, as it often does, from want
of counter-pressure of the frog with the ground, this pressure must be
restored after the manner described when dealing with the treatment of
contracted foot (see p. 125) either by the use of tip or bar shoes, or by
suitable pads and stopping.

So far as direct treatment of the lesion itself is concerned, the first
step is to carefully trim away all diseased horn and freely open up the
lacunae in which the discharge has accumulated. Good results are then often
arrived at by poulticing, afterwards followed up by suitable antiseptic
dressings. With us a favourite one is the Sol. Hydrarg. Perchlor. of Tuson,
used without dilution. Others use a dry dressing, and dust with Calomel,
with a mixture of Sulphate of Copper, Sulphate of Zinc and Alum, or with
Subacetate of Copper and Tannin.

With restoration, so far as is possible, of the frog functions, and with
careful dressing, a cure is nearly always obtained.

6. CANKER.

_Definition_.--Under this unscientific, yet expressive term, is indicated a
chronic diseased condition of the keratogenous membrane, commencing always
at the frog, and slowly extending to the sole and wall, characterized by a
loss of normal function of the horn secreting cells, and the discharge o