Quittor

Quittor used to be more commonly known as 'Gravel'. It is a condition that can affect all horses and ponies and fortunately is not very common today, although in the past it was frequently found in draft horses.
Many people believed that very small stones entered through the sole of the foot and make their way up the inside of the hoof wall and broke out at the top above the coronary band. Hence the term "gravel" or the animal "has been graveled." However, it is bacteria, not minute stones, that causes the disease. Bacteria can enter through the sole of the foot via the minute cracks which can be seen in the structure. Stone bruises to the sole as well as punctures of the tissue are other means of bacterial entrance. It may also enter the white line if the tissue has received some damage. 

Once the bacteria has passed through the sole, it often forms an abscess. This abscess will create substantial pressure in the area and will take the path of least resistance, which is upward through the laminae and soft tissue of the foot, eventually breaking out in the vicinity of the coronary band at the hoofhead. More rarely, the abscess will break through the sole of the foot and drain to the outside, thus relieving the pressure.

As the abscess forms, the first symptom is lameness of the infected foot. The lameness will generally last four or five days becoming increasingly severe until the animal will scarcely bear any weight on the foot but will stand on three legs and keep the affected hoof clear off the ground.

When the lameness is severe, an examination of the coronary band region will reveal a small, hot and painful swelling in the skin of the area. Touching this area will produce great pain for the animal. Sometimes, within a few hours after the formation of the abscess, the pastern or even the whole leg up to the knee or hock becomes swollen. In many of these cases, the lameness is very severe and the animal will have an elevated temperature, be dull, lose its appetite and show an increased thirst.

Veterinary advice is required as it is very important to diagnose and treat any case of pus in the foot as soon as the animal shows the first symptom of lameness. The sole should be cleaned and pressure applied to it by the judicious use of a hoof tester or by tapping the sole with a light hammer. When pressure is applied over the abscess the horse will experience pain and try and remove its foot.. If he abscess is not too deeply seated it can be drained by using the small curved end of a hoof knife to cut a hole through the sole. Often, the abscess is under so much pressure that when you contact it, the pus, often black in colour, will spray out all over the knife and handle.