White Line Disease in Horses

White Line - is it a Disease?

White Line Disease is the term applied to a problem affecting the health of the horse’s hoof. The external hoof wall may appear brittle and dry. The firm horn tissue of the hoof becomes crumbly and cottage-cheese like, and deterioration begins. The condition becomes obvious in the horse’s foot as the hoof wall separates from the laminae.

This separation:

• reduces the weight-support system of the hoof and hoof wall
• opens the foot of the horse up to further infection
• can cause lameness and lead to complications developing in the hoof.

White Line Disease - What Causes it?

The destructive agents in whiteline diease were originally grouped together under the general term of ’anaerobic bacteria’ - bacteria who thrive in conditions where there is no oxygen.

More recently, there has been increasing support for the possibility that the destructive agents are one or more types of fungus that may be working alone, or together with the bacteria.

Questions still to be fully answered include to what degree bacteria and/or fungi are responsible for white line disease. Also still to be determined is specific identification of the culprits.

Ongoing research by veterinary faculties and farrier support groups is continually updating the knowledge base relating to hoof care and diseases of the hoof. A limited study conducted into white line disease at Cornell University with 4 control and 5 infected hooves gave results indicating the presence of fungi, and the absence of bacteria.

Whether the cause of the white line separation is bacteria or fungi, the horse owner still faces the same problem: hooves that are being eaten away by a destructive agent. His question is not likely to be ’How do I spell that biological fungus name?’ but rather: ’My horse has white line disease - What can I do about it?’

Whiteline Disease - Being Pro Active

Preventive action is a positive first step, and team work pays off.

• Owner - conscientious preventive action
• Owner and Farrier - careful observation of the horse
• Farrier and Vet - co-ordinated specific treatment as in the case study.

The bacteria/fungi are opportunistic, and will enter the foot through the smallest of openings, often invisible to the human eye.

Risk factors that can contribute to whiteline disease developing in horses could include

• excess damp and humidity. The horse’s hoof is hygroscopic (absorbs moisture). A moist hoof expands more readily.
• stress after laminitis,
• the presence of an injury in the hoof,
• long toes on the hoof - causing stress and the possibility of separation at the juncture of hoof wall and sole.
• an excess of inappropriate hoof care products applied to a hoof
• poor nutrition, resulting in poor health of the hoof
• insufficient stable management leading to a lack of cleanliness.