Welfare

Infection or Injury? Simplifying the Lameness Issue

ANALYSIS - Lameness is an expansive topic with a wide range of causes. This means any attempt to simplify diagnosis and treatment is hugely helpful.

16 May 2014

2 minute read

North America

South Dakota stockmen have been advised that a cow limping across a yard is doing so for one of two reasons – infection or injury.

Footrot, Laminitis, Hairy Heel Warts, toe ulcers and abscesses all sit in the infection category.

In the injury category are hoof cracks, degloving, dislocated joints and penetration from foreign objects.

However, Professor Russ Daly, State Veterinarian at South Dakota State University says that there can be blurred lines.

“Occasionally, a lame cow will have had an infection following an injury, where lameness bridges the gap,” says Prof Daly.

“Toe abscesses are the result of infection, however they occur in response to an insult to the tips of the toes.”

Abrasion often occurs on hard concrete or when loading or processing animals, he adds.

A similar problem - toe ulcers - result from bleeding infection at the white line area of the toe, where the hoof meets the sole.

However, this tends to have more to do with diet than injury, explains Prof Daly.

Subclinical acidosis is a potential trigger which is why farmers should scrutinise youngstock when on high concentrate rations.

And Prof Daly adds: “Along that line, acidosis - whether obvious or subclinical - is a major contributor to Laminitis in feedlot calves, as well as occasionally in adult beef cattle.”

The lameness stems from a separation of hoof wall and underlying bone and is typically a mistake in feed delivery.

The most common of all infections, according to Prof Daly is foot rot or “infectious pododermatitis”.

This is caused by Fusobacterium necrophorum, amongst others, and is common in housed, feedlot and pasture systems.

“All of the bacterial species are commonly found in soil and animal manure,” he says.

“When the protective barrier of the skin is breached by these bacteria due to constant wet conditions or by abrasions, the bacteria causes a painful, necrotic infection between the toes.”

An entirely different bacteria is responsible for Hairy Heel Warts. Prof Daly says that, while not the major cause of lameness, Hairy Heel Warts have been grabbing the headlines, particularly in beef circles.

“This is a very contagious condition, but how the disease starts in an animal is a bit unclear,” he adds.

“Bacteria in the spirochete family can be demonstrated in the characteristic warts of this disease, but there may be other factors that enable the infection to take hold.”