Changes

==Description==

==Description==

Photosensitisation is an abnormal reaction of the skin to sunlight due to the presence of a photodynamic agent in the dermis. It is

Photosensitisation is an abnormal reaction of the skin to sunlight due to the presence of a photodynamic agent in the dermis. It is

primarily a condition of sheep, cattle and horses but other species may also be susceptible.  

primarily a condition of sheep, cattle and horses but other species may also be susceptible.  

The condition can be divided into two categories, primary and secondary photosensitisation. Primary photosensitisation occurs due to the normal ingestion of lush green plants containing photodynamic agents. Secondary (hepatogenous) photosensitisation is the most commmon type of photosensitivity seen in animals and occurs as a result of liver or bile duct damage. The photosensitising agent, phylloerythrin accumulates in the blood, body tissues and skin due to insufficient conjugation and excretion by the liver. This accumulation in the skin leads to absorption and release of UV light, leading to a phototoxic reaction.

The condition can be divided into two categories, primary and secondary photosensitisation. Primary photosensitisation occurs due to the normal ingestion of lush green plants containing photodynamic agents. Secondary (hepatogenous) photosensitisation is the most commmon type of photosensitivity seen in animals and occurs as a result of liver or bile duct damage. The photosensitising agent, phylloerythrin accumulates in the blood, body tissues and skin due to insufficient conjugation and excretion by the liver. This accumulation in the skin leads to absorption and release of UV light, leading to a phototoxic reaction.