HM Medical Clinic

Digital dermatitis

Authored by the
DIGITAL DERMATITIS (HEEL WART)
Digital dermatitis (DD) is a multi-
factorial superficial dermatitis of the
digital skin of cattle. The most
common site is the palmar/plantar
interdigital ridge of the foot—
especially the rear feet (Figure 1),
but other sites include the skin of the
interdigital cleft, the heel, sometimes
under-running the sole, and the
dorsal aspect of the coronary band
(Figure 2), where they may be
associated with a vertical wall crack.
Figure 1. Typical granulomatous
Necrotic lesions of the anterior udder
appearance to a DD lesion at the
have also been associated with the
plantar aspect of the interdigital
Figure 2. An atypical DD lesion
located on the dorsal aspect of the
coronary band.
Early lesions are erosive, circular or
oval with clearly demarcated raised
borders. Lesions may become red
Once introduced via the addition of Constant moisture and low oxygen ten- and granular or develop filiform
new cattle to the herd, DD spreads rap-idly, especially among the first and sec- sion are required for infection to occur, papillae (Figure 3) which are
ond lactation animals.
suggesting that wet, manure contami- associated with the papillomatous
nated conditions are a pre-requisite for form—known as the hairy heel wart.
Spirochetes from the genus Treponema the organism(s) to penetrate the skin have been identified consistently from The lesions are very painful due to
lesions. However, DD has not been cre- exposure of nerve endings, and
ated experimentally using any of the Younger cattle appear to be moreaffected than older animals, and some many have a characteristic odor
organisms identified alone, only byusing an exudate from active DD cattle never develop lesions, suggesting believed to be caused by break
lesions. The disease therefore appears a degree of resistance. New cases are down of keratin and secondary
to be multifactorial in nature, requiring observed more commonly in early lacta- infectious, immune and environmental tion, suggesting that immune suppres- sion around calving time may be a factorin the pathogenesis.
Important Things to Know About Digital Dermatitis
Other Predisposing Factors
Conformation may predispose individu- DD is a multifactorial disease with infectious, immune and environmental als to infection, with low heel heights increasing the likelihood of disease.
Spirochetes from the genus Treponema are believed to be the infectious The disease is more common in free stall Lesions typically occur on the plantar aspect of the interdigital cleft and may housing compared to tie stall and straw be ulcerative, granulomatous or papillomatous in nature bedded barns, and within free stall Topical antibiotic treatment is effective Foot hygiene and foot bath management are important aspects of control

Digital Dermatitis (Heel Wart) continued
can be soaked into a gauze swab and fate (5–10%), formalin (2–5%), and wrapped on the lesion.
commercial chemicals containing qua-ternary ammonium compounds, organic A number of non-antibiotic commercial- acids, and other disinfectants. Recently, ly available alternatives exist that may several new products which serve to also be active topically for the treat- activate copper sulfate have been ment of individual cows.
released which allow lower concentra- Parenteral antibiotics may be indicated tions (2%) to be used.
for severe lesions, especially those onthe dorsal aspect of the claw, but they It is essential that the volume of the are secondary to topical treatments and foot bath is known so that the correct should not be used alone. In severe amount of chemical may be used to pro- cases, a NSAID may also be indicated.
vide the appropriate final concentration.
The volume in gallons may be calculated Figure 3. A severe DD lesion with
from the formula; length × width × filiform papillae typical of the
depth (in inches) divided by 231.
papillomatous form of the disease
Animals should respond quickly to treat-ment. Wraps should be removed after Foot baths should be at least 8 feet long barns, use of automatic scrapers appears 3–4 days when the lesion can be checked and 5 inches deep and as wide as the to increase the risk by making cows step for signs of healing (drying, darkening alley way that they are located in. They through large waves of manure as they and absence of pain). Lesion recurrence are commonly placed in the return lanes progress through the pen. rate 7–15 weeks after treatment may be from the parlor or in a transfer lane.
high (60% has been reported).
Whatever the location, the alley must DD appears to have been recognized be wide enough to provide an alternate with increasing frequency in beef cattle route around the bath when it is not in including feedyards and animals similar- use. Wash baths sited in front of the ly housed in dry lot conditions.
Hygiene is the most important control treatment bath are optional, but if measure for DD. Reducing exposure to used, there should be a 6 foot gap in Care should also be taken with regard manure and avoiding chronic wetting of between them, to prevent carry over of to movement and use of trimming the foot are paramount in reducing the wash solution into the treatment bath, equipment between farms, and ade- risk of DD. Factors which improve leg and dilution of the chemical. The floor quate disinfection is essential.
hygiene include freestall pen design of the bath should be non-slip, but not (2-row pens have 20% more surface too rough or ridged as this will prevent area than 3-row pens), grooming of cows from wanting to walk through it.
corrals to avoid wet areas, reducing A range of topical antibiotics are effec- stocking density, frequent manure Foot bath frequency is determined by tive, but all are extra-label uses in North removal from alleyways by scraping or leg hygiene and the extent of the DD America requiring records of use. The flushing at least three times per day, problem in a herd. In highly contami- lesion should be cleaned and dried and and maintenance of watering and feed- nated situations, bathing twice daily for the antibiotic applied with a dressing or ing areas to avoid mud accumulation.
at least 5 days per week is necessary, topical spray.
Foot baths will help clean and disinfect whereas in cleaner more hygienic condi- the interdigital skin and are an integral tions a bath run once per week may be For topical spray treatments, oxytetracy- part of DD control for most dairy herds.
cline (mixed at 10–25mg/ml) or lin- Note that foot baths should not be used comycin (mixed at 1–8mg/ml) are effec- to treat active lesions—they are meant Because of the susceptibility of early lac- tive when mixed with distilled or deion- to control the spread of infection by tation animals, foot bathing should ized water in a 2–4 liter agricultural regular disinfection in much the same begin in the close-up period and be sprayer and applied once or twice daily way that we use teat dipping to control aggressively implemented in early lacta- for 5–7 days. Alternatively, the prepared the spread of mastitis pathogens. A tion. AABP
solution of antibiotic (50–100 mg/ml range of different products are effective oxytetracycline or 8 mg/ml lincomycin) including copper sulfate (5%), zinc sul-

Source: http://cdrf.org/wp-content/uploads/2012/06/AABP-Digital-Dermatitis.pdf