Short communication: Efficacy of copper sulfate hoof baths against digital dermatitis—Where is the evidence?

Abstract

Digital dermatitis is a major problem in modern dairy production because of decreased animal welfare and financial losses. Individual cow treatments are often seen as too time consuming by farmers, and walk-through hoof baths have therefore been used extensively to control digital dermatitis. For decades, copper sulfate hoof baths have been used to treat and prevent digital dermatitis. Copper sulfate has been referred to as the industry gold standard when it comes to hoof-bath chemicals. In several scientific studies testing the efficacy of other hoof-care products, copper sulfate has been used as a positive control, thereby indicating that copper sulfate has a known positive effect. However, this may not be the case. A dilemma may exist between (1) copper sulfate generally being perceived as being effective against digital dermatitis and (2) a possible lack of well-documented scientific evidence of this effect. The objective of this study was to evaluate the existing scientific literature to determine whether the efficacy of copper sulfate used in hoof baths against digital dermatitis has in fact been demonstrated scientifically. A systematic literature search identified 7 peer-reviewed journal articles describing the efficacy of copper sulfate in hoof baths as treatment or prevention of bovine digital dermatitis. Only 2 of the 7 studies compared copper sulfate to a negative control; most studies were relatively small, and often no clear positive effect of copper sulfate was demonstrated. In conclusion, the frequent claim that copper sulfate is widely reported to be effective is supported by little scientific evidence. Well-designed clinical trials evaluating the effect of copper sulfate against digital dermatitis compared with a negative control are needed. Until such studies have been made, the efficacy of copper sulfate in hoof baths against digital dermatitis remains largely unproven.

Associations between biosecurity practices and bovine digital dermatitis in Danish dairy herds

“…Hoof bathing was pointed out as a factor reducing the odds of DD previously (Rodriguez-Lainz et al, 1999); likewise, DD treponemes are mainly isolated from hoof lesions (Evans et al, 2012;Klitgaard et al, 2014;Zinicola et al, 2015). An evaluation of hoof bathing strategies was beyond the scope of this study; however, this should be further investigated, as many treatment regimens failed or were based on clinical trials without control groups (Laven and Logue, 2006;Thomsen et al, 2008b;Thomsen, 2015). Furthermore, chemicals commonly used (e.g., copper sulfate, formalin, glutaraldehyde, and acids) have undesirable side effects, such as irritation to both humans and cows when applied, environmental contamination, and carcinogenic effects (Laven and Logue, 2006;Relun et al, 2013a).…”

“…Preventive and curative measures against DD involve antibiotics and other chemicals applied in hoof baths or topically that are not entirely successful (Laven and Logue, 2006;Thomsen et al, 2008b;Berry et al, 2012;Döpfer et al, 2012;Thomsen, 2015). These strategies may cause environmental contamination and expenses associated with treatments and extra labor (Laven and Logue, 2006;Relun et al, 2013a).…”

Shotgun Metagenomic Sequencing Reveals Functional Genes and Microbiome Associated with Bovine Digital Dermatitis

“…However, Laven and Hunt (2002) [ 8 ] reported that hoof bathing daily for seven days with 5% formalin and 10% CuSO4 was effective in controlling DD [ 8 ]. Although it appears that CuSO4 is effective, most published studies do not include a negative control group [ 42 ]. Here we have identified a higher normalized abundance in the expression of genes associated with resistance to antibiotic and toxic compounds in ADD and IDD, namely copper and zinc.…”

Effectiveness of collective treatments in the prevention and treatment of bovine digital dermatitis lesions: A systematic review

“…However, formaldehyde is carcinogenic and CuSO 4 is toxic for the environment via accumulation in the soil (Ippolito et al, 2010). Moreover, a recent systematic review revealed that the effectiveness of CuSO 4 footbaths against DD is not adequately supported by the evidence (Thomsen, 2015). In addition, new evidence suggests possible genetic resistance to copper and zinc in microbiomes associated with DD lesions (Zinicola et al, 2015).…”