Relationships between type of hoof lesion and behavioral signs of lameness in Holstein cows housed in Canadian tiestall facilities

Sensitivity and specificity of mobility scoring for the detection of foot lesions in pasture-based Irish dairy cows

Lameness is an important production disease in dairy cows worldwide and has detrimental effects on cows' welfare, production, and reproductive performance, thus affecting the sustainability of dairy farming. Timely and effective detection of lameness allows for effective treatment, minimizing progression of disease, and maximizing the prognosis of recovery. Mobility scoring (MSc) is a 4 point (0-3) visual lameness scoring system that is the industry standard in several countries. However, few studies have examined the sensitivity (Se) and specificity (Sp) of MSc to detect foot lesions. The aim of this observational study was to determine the Se and Sp of MSc to detect foot lesions in dairy cattle in a pasture-based system. Five hundred ninety-five primi- and multiparous cows were randomly selected from 12 commercial Irish dairy farms and recruited for the study. Recruited cows were mobility scored and passed through a foot-paring crate where all 4 feet were lifted for examination. The team recorded the anatomical location and severity of any foot lesions present based on appearance only. Then, based on the type and severity of the lesions present, cows were classified according to 3 case definitions case definition 1: Any lesion present; case definition 2: Moderate lesions present (excluding minor lesions expected to have a low probability of affecting gait); and case definition 3: Severe lesions present (only including lesions most likely to result in a detectable gait abnormality). Sensitivity and Sp of MSc was calculated based on a threshold of MSc ≥2, defined as impaired (MSc = 2) or severely impaired (MSc = 3) mobility for each of the 3 case definitions, at the overall level and disaggregated by parity. The overall cow-level lesion prevalence based on the case definition 1 was 0.54 with significant between-herd variation. The overall Se and Sp of MSc for the detection of foot lesions were 0.18 and 0.96, 0.35 and 0.94, 0.43 and 0.94 for the case definitions 1, 2, and 3, respectively. Our findings showed poor Se, but high Sp of MSc for the detection of cows with foot lesions in a pasture-based system.

Local and Systemic Inflammation in Finnish Dairy Cows with Digital Dermatitis

Digital dermatitis is a disease of the digital skin and causes lameness and welfare problems in dairy cattle. This study assessed the local and systemic inflammatory responses of cows with different digital dermatitis lesions and compared macroscopical and histological findings. Cow feet (n = 104) were evaluated macroscopically and skin biopsies histologically. Serum samples were analyzed for acute phase proteins (serum amyloid A and haptoglobin) and pro-inflammatory cytokines (interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha). Cows with macroscopically graded active lesions (p = 0.028) and non-active lesions (p = 0.008) had higher interleukin-1 beta levels in their serum compared to healthy cows. Interleukin-1 beta serum concentrations were also higher (p = 0.042) when comparing lesions with necrosis to lesions without necrosis. There was no difference when other cytokine or acute phase protein concentrations in healthy cows were compared to those in cows with different digital dermatitis lesions. A novel histopathological grading was developed based on the chronicity of the lesions and presence of necrosis and ulceration. The presence and number of spirochetes were graded separately. In the most severe chronic lesions, there was marked epidermal hyperplasia and hyperkeratosis with necrosis, deep ulceration, and suppurative inflammation. Spirochetes were found only in samples from necrotic lesions. This study established that digital dermatitis activates proinflammatory cytokines. However, this did not initiate the release of acute phase proteins from the liver. A histopathological grading that takes into account the age and severity of the lesions and presence of spirochetes was developed to better understand the progression of the disease. It is proposed that necrosis of the skin is a result of ischemic necrosis following reduced blood flow in the dermal papillae due to pressure and shear stress caused by thickened epidermis, and that the spirochetes are secondary invaders following tissue necrosis.

Efficacy of quaternary ammonium salt-based disinfectant or chelated copper-zinc footbath solution in the treatment of digital dermatitis on one research dairy farm in Taiwan

BACKGROUND

Footbaths can be used to manage digital dermatitis (DD), a common cause of lameness in dairy cattle. Copper sulfate and chelated copper-zinc (CZS) solutions in footbaths are potentially harmful to the environment.

HYPOTHESIS/OBJECTIVES

To determine if a quaternary ammonium salt-based disinfectant (QASD) footbath is as effective as a chelated CZS solution in controlling DD in dairy cows.

ANIMALS

Fifty-one lactating Holstein cows were randomly assigned to one of two treatment groups, with DD status based on the M-stage scoring system and locomotion score balanced between treatment groups.

MATERIALS AND METHODS

The groups were treated with a 1% QASD or a 2.5% chelated CZS. Footbaths were performed once per week for 15 weeks. Logistic regression was used to analyse clinical improvement. All cows received appropriate medical treatment for DD and other hoof diseases.

RESULTS

Clinical improvement rates were 67% in the QASD group and 38% in the CZS group (p = 0.03). Logistic regression analysis showed that the odds (95% confidence interval) for clinical improvement rate in the CZS group were 0.30 (0.095-0.948) times that of the QASD group (p = 0.04). The M0 score in the QASD and CZS groups increased significantly (p < 0.05) at the end of the 15 week study period. In the QASD group, the proportion of M2, M3 and M4 scores were significantly decreased (p < 0.05).

CONCLUSION AND CLINICAL RELEVANCE

Over a 15 week period, QASD for footbathing was associated with a lower prevalence of active DD lesions than when using CZS.