Digital dermatitis (DD) is the number one cause of lameness among dairy cows around the world, but some herds are saying “no” to these painful lesions with a “zero tolerance” policy that works.
Manage it like mastitis
Let’s start managing DD like we do mastitis. As a dairy producer, would you ever accept a 25 to 40 percent herd incidence rate for mastitis? Not only would it be tough to pay the bills, but you would really start to question your management skills.
You would be tearing your equipment apart and phoning every udder specialist and milking equipment specialist, reviewing employee milking procedures and doing whatever you could to get to the root of the problem. So why do we accept these rates for DD? As consumers demand better animal welfare, processors are putting cow comfort and hoof health targets in place at the farm level. Now is the time to be proactive, not reactive.
Antibiotics and alternative treatments
Another concern consumers are passing onto milk processors is antibiotic use. In the case of both DD and mastitis, prevention and management on the front end can significantly reduce the need for drug intervention later. However, some severe situations warrant judicious antibiotic use to effectively and correctively treat a painful disease.
Research shows the success of tetracycline as a safe and effective DD treatment. According to the veterinary feed directive, application of this antibiotic is allowable, contingent upon mandatory veterinarian involvement in the treatment, protocol and record-keeping.
Little is known about the efficacy of tetracycline alternatives to treat DD, including new products and “recipes” on the market. Buyers must beware, as there is no regulated testing of these non-antibiotic products.
However, the tried-and-true method for getting DD under control doesn’t come in a bottle; it comes down to the basics: adhering to a management protocol for identifying, treating and preventing lesions.
DD management protocol
Getting DD to a manageable state is possible, and I’ve seen success on dairies using this protocol. Sara Pederson of Farm Dynamics in the United Kingdom performed a case study with these steps to demonstrate it is practical and doable on any farm.
1. Identifying all infected animals in the herd with a simplified M-stage score: uninfected, infected, healing, dormant, recurring (Figure 1)
2. Blitz treatment of all infected animals
3. Prevention with improved hygiene and proper footbath design and protocols
4. Monitoring with regular foot inspection for recurring and new lesions (daily or weekly)
Identifying can be done easily and quickly in the milking parlor or along the feedbunk with the M-scoring system on the DD Check app (available free on iTunes) or with a simple yes-or-no infection score. All infected animals then can be taken to the trim chute for a topical tetracycline treatment approved by the farm vet.
If wraps are preferred, they need to be removed within six to 12 hours after application. The treatment will be ineffective after that point, and the wrap just becomes a lameness risk factor and provides a perfect environment for a recurring lesion to begin.
During this treatment process, these animals should not be allowed through a footbath until the lesion is at the healing stage (Figure 2).
Many farms do not have a chute, so if treatment is not being performed on a scheduled trim day, a responsible topical antibiotic treatment can be performed on-farm with results in one to three treatments (Figure 3).
A blitz treatment protocol has several benefits. Primarily, the infected cow is the main reservoir for the bacteria in the environment causing the infection. Some research shows the bacteria that causes DD only survives for 24 hours in manure slurry.
By only treating the noticeable, painful lesions, other cows with undetected lesions go untreated, thus constantly supplying bacteria in the environment. Further, when a cow with an ulcerated lesion walks through a footbath filled with copper sulphate or another caustic product, the bacteria burrow deeper into the skin and the infected cow becomes a chronic carrier. This results in an increased number of proliferated lesions, like in Figure 4.
Follow a footbath protocol
Once all lesions reach the healing stage, continue running footbaths for the whole herd, including the animals in the dormant or healing stage. The products with the most proven success and trials are a 2 to 5 percent copper sulphate solution or a 1 to 3 percent formalin solution. My gold standard is copper sulphate, as there is less risk of chemical burn and employee safety and health risks associated with formalin.
Continue monitoring the herd and, when lesions become small and few, copper sulphate can be substituted with a cheaper alternative like feed-grade salt or laundry soap. The number of alternative solution baths is farm-dependent. A set time to monitor the herd for new or recurring lesions is critical, and any lesions need to be treated promptly.
Footbath design and placement is more critical than the solution choice. The bath needs to be long enough to ensure two to three dunks with each foot, roughly 10 to 12 feet. Cows prefer walking through a narrow bath, and this design saves cost and product. Some large farms prefer a longer, wider bath. The goal is multiple dunks and efficient use of product.
Set herd benchmarks
Dairy farmers often ask what is an acceptable level of DD in a herd. Ideally, that number is zero, but a good goal is less than one new or recurring lesion per 100 cows per month. Benchmarking can be helpful to set and reach new goals to minimize lesion occurrence. Remember, with every untreated ulcerated lesion, another cow increases the bacteria reservoir within your barn.
This makes an environment difficult to control and usually costs more in products, time dealing with lame cows and more frequent outbreaks. I would strongly suggest your benchmark be to not accept any more new or recurring lesions per month than you accept cows infected with mastitis per month. Have employees “look” for DD lesions daily, just as they look for mastitis at every milking.
One final note: Just as all mastitis treatments need to be proven with independent trials and research, so do footbath and DD treatment products. Solid udder health programs have allowed some herds to reduce antibiotics as part of the dry cow treatment protocol. The same can be achieved with DD.
Achieving minimal – and even zero – antibiotic treatments for DD is possible, but it’s not the result of a “magic bullet” product. It is the result of managing the current problem and an ongoing prevention strategy. All my clients who have decided to adopt zero tolerance for DD wish they had done so sooner. Prevention can be cheap, and we need to stop looking for the miracle cure to get back to the basics of happy, healthy cows.
4 steps for a successful footbath protocol
1. Use 2 to 5 percent copper sulphate solution with an added acidifier to achieve a starting pH of 3 to 3.5.
2. Refresh the footbath solution if pH rises to 5 to 5.5.
3. Ideal frequency: five to seven days per week.
4. Achieve appropriate feet and leg hygiene: Ensure clean cross alleys and water trough areas, appropriate stall bedding material, and lower the size of the “manure wave” in front of scrapers to less than one stride for a cow to walk over.