(Quercus) both the leaves and acorns of the tree are poisonous. Some horses/ponies may develop an appetite for acorns with serious consequences, however the comsuption of small amounts is probably harmless.
Links:
Contributors:
Jan
Occipital bone
Is at the back of the horse's skull, to which the backbone is attached.
Links:
Contributors:
Jan
Odd-coloured
A horse whose colour cannot be accurately defined as any other official colour. Horses who are odd-coloured often have three or more colours on their body, and are quite rare.
Links:
Contributors:
Ffion
Oesophagus
Amuscular tube from the throat to the stomach situated on the left in the lower part of the neck. It extends through the chest and diaphragm to open into the stomach.
Links:
Contributors:
Jan
Off Side
The right-hand side of a horse
Links:
Contributors:
Jan
Oil Spots (Liver Marks)
Are darker spots which may be found on chestnuts.
Links:
Contributors:
Jan
One Day Event
A modified three day event, it was first held in the UK in 1950 as a nursery for the higher levels. It is now so popular that there is a spring and autumn season. The test consists of dressage, cross-country, and show jumping, the missing elements being the roads, tracks, and steeplechase.
Links:
Contributors:
Jan
Oribatid Mite
A small blind dark-coloured mite which lives in the soil where is digests organic matter. It carries the intermediate form of tapeworm.
Links:
Contributors:
Jan
Os Calcis
Is a pulley (fulcrum) bone providing leverage for the tendons and ligaments of the Tarsus (hock joint).
Links:
Contributors:
Jan
Over
Over Face - asking a horse to jump a fence beyond his ability or stage of training.
Over Reach - a wound, which occurs when a horse treads on the heel of a frontleg with the toe of the hind leg.
Over Bend - a horse that has arched its neck acutely, thereby bringing its head too far into its chest.
