Digital Dermatitis

Category: Dairy

Digital Dermatitis

What is it?

  • Infectious hoof diseases are caused by bacterial infections of the skin around the hoof.
  • There are 3 main lesions:
    • Digital Dermatitis (aka Heel Warts) 
    • Foot Rot (Interdigital Necrobacillosis or Phlegmon)
    • Heel Horn Erosion
  • Digital Dermatitis

Foot Rot (Phlegmon)

  • Heel Horn Erosion

What causes it?

  • Digital Dermatitis is a multifactorial disease with a strong bacterial component.
  • Amongst the bacteria involved, a Gram-negative spirochete bacteria called Treponema sppappear to be necessary for the disease to occur.
  • There is a genetic susceptibility to chronic infection which appears common in the Holstein breed.

Chronic exposure to moisture and manure is a prerequisite for the disease – hence it is more common in confinement housed cattle, especially in freestalls with automatic scrapers

 

Digital Dermatitis Lesion Classification

M0
Normal

 M1
Subclinical active stage (<20 mm)

 

M2 Clinical Active Stage >20mm

M3 Healing Stage

M4 Chronic Stage

M4.1 Active Stage

Digital Dermatitis Dynamics

How do we treat it?

  • We have to identify cows with active stages of digital dermatitis (M2 and M4.1) as soon as possible by weekly active surveillance of cows in the parlor or at the feed bunk before they become lame.
  • Active lesions need to be treated with a topical antibacterial.
  • Efficacy of treatment of chronic stages of the lesion (M4) is poor.

 

 

A topical antibacterial is applied with or without a light wrap. Use of ~2000 mg tetracycline powder mixed with 6ml propylene glycol is effective but use is EXTRA-LABEL and should be administered under guidance from the Veterinarian of Record (VOR). A milk withhold period may be required.

 

How do we prevent it?

Prevention of digital dermatitis is dependent upon:

  • Breeding heifers that are resistant to chronic disease.
  • Using in-feed trace mineral supplements to enhance the resistance of the epidermis to infection in heifers.
  • Limit the spread by treating active lesions as soon as they occur.
  • Routine use of an antibacterial footbath.
  • Improve foot hygiene

 

 

Footbath Best Practices

  • Use a well designed footbath to optimize transfer of antibacterial to feet
  • Locate a mixing station adjacent to the footbath for safe handling of chemicals
  • Start a regime once a day for 4 days per week and adapt based on outcome
  • Use an antibacterial with proven efficacy that DOES NOT DAMAGE THE SKIN DEFENCE – maintain pH>3.0
  • Use the bath as long as it is effective ~ 100-300 cow passes
  • Don’t forget the dry cows and heifers!