A Well-Balanced Hoof Is The Best Defense Against White Line Disease

Extra stress makes a hoof more susceptible to this fungus.

Warco van de Halhoeve was diagnosed with white line disease two years ago, and the promising young show jumper spent most of a year recovering.
   
“In his first year at grand prix he has won two World Cup [qualifiers] and was second in another,” said his rider, Ali Nilforushan of San Diego, Calif. “He’s an amazing, great horse.”
   
White line disease was not suspected at first, but it ended up sidelining him for eight months. “The horse wasn’t really lame, though he once in a while favored that foot. He’d be fine and then off a little,” said Nilforushan.
   
Warco van de Halhoeve’s hoof was cut almost all the way up to the coronet band to get rid of all the diseased tissue.
   
“Thank God the farrier was able to get all of it by the second time. We then had to wait for it to grow down,” said Nilforushan. “Every day we were squirting antibiotics into the hoof and keeping it dry. He couldn’t walk or do anything; he basically had to just stay in his stall for months.”
   
Nilforushan started riding the gelding again in March of 2006. “He’s 9 years old now, and this was his first year in the top level, so he’s just hitting his prime,” said Nilforushan, who purchased the 18-hand Belgian Warmblood as a 6-year-old. 
   
“Warco van de Halhoeve is by Darco, the same [sire] as [McLain Ward’s 2004 and 2008 Olympic horse] Sapphire. He is sound now and totally perfect,” said Nilforushan, who became the first rider from Iran to go to the Olympic Games, in 2000. His long-term goal is the 2010 World Equestrian Games (Ky.) and the 2012 Olympic Games (London).

Where Does It Comes From?

White line disease is a progressive infection and subsequent separation of the hoof wall—with the wall coming loose from the foot. This problem usually starts at the bottom of the hoof and travels upward as this area becomes hollowed out.
   
Scott Morrison, DVM, a farrier and veterinarian at Rood And Riddle Equine Hospital in Lexington, Ky., described white line disease as an ascending fungal infection of the white line. The technical term for this is onychomycosis, which means fungal infection of the nail, a similar condition in humans.
   
“Several studies have shown that the pathogen in white line disease is a fungus. It’s an opportunistic pathogen, which means the tissue must be somewhat damaged already in order for this fungus to invade. The fungus may become established in an old abscess tract or an area where the white line is stretched or flared due to a dish in the toe of the foot,” said Morrison.
   
A hoof that’s out of balance and under additional stress can be at risk.
   
“If there’s a flare or hoof capsule distortion, the white line may be stretched, and a small fissure or opening may occur. Fungi can invade those fissures in the white line and set up shop. The hoof wall is three layers, the stratum externum, the stratum medium, and stratum internum. The fungi usually attack the inner portion of the stratum medium—the thick, pigmented part—and the horn produced by the terminal papillae,” he said.
   
The bottom part of this layer can be seen as the white line—between hoof wall and sole—when you pick up the bare foot.