438 DISEASES OF THE HORSE’S FOOT 
Even this is such as to at first occasion no alarm, being 
intermittent and slight, and only very gradually becoming 
marked. In a few cases, however, lameness will come on 
suddenly, and is excessive from the commencement. It is 
the lameness, slow in its onset, intermittent in its character, 
and gradual in its progress, however, that is ordinarily 
characteristic of navicular disease. 
The animal is taken out from the stable sound, with just 
a vague suspicion, perhaps, that he moved a bit stiffly. 
While out he is thought by his driver or rider to be going 
feelingly with one foot or with both. Even this is not 
marked, and the driver has some difficulty in assuring 
himself whether or no he really observed it, or whether it 
was but imagination. 
On the return home the limb is examined, and nothing 
abnormal is to be found. The leg is of its normal appearance, 
and neither heat nor tenderness is to be observed in it or in 
the foot. On the following day the animal again is sound, 
and the lameness of the previous day is put down to a slight 
strain or something equally simple. The patient is then, 
perhaps, rested for a day or two. When next he is worked 
he again moves out from the stable sound, but again during 
the going gives the driver the unpleasant impression that 
something is amiss; and so the case goes on. One day 
the owner fears the animal is becoming seriously enough 
affected to warrant him in calling in his veterinary surgeon ; 
the next he is confidently assuring himself that nothing is 
wrong. 
Perhaps the animal is now rested for a week or two, or 
even for a month or two, hoping that this will put him 
sound. Immediately on commencing work, however, the 
same symptoms as before assert themselves, and the 
veterinary surgeon is called in. 
With a history such as we have given the veterinarian’s 
suspicions are aroused. He has the animal trotted, and 
may notice at this stage that there is an inclination to go 
on the toes, that the lame limb or limbs are not put forward 
freely, and that progression is stilty and uncertain ; it is 
