Papillomatous digital dermatitis and associated risk factors in US dairy herds

The effect of claw trimming on the hoof health of Swedish dairy cattle

A 2-year experiment on the effect of claw trimming on hoof health was performed in 77 Swedish dairy herds (3444 dairy cattle) selected on herd size, breed composition and membership in the official milk-recording scheme. In the autumn, cows within each herd were blocked according to breed, parity and stage of lactation and allocated to two treatments: autumn trimming (AT) or no autumn trimming (NAT). Outcome variables were claw measurements and prevalence of hoof lesions and lameness (measured at spring trimming) and the need for hoof treatments between scheduled trimmings. At spring trimming, NAT cows had longer and shallower claws than AT cows. The average net growth of the toe wall was greater for AT than for NAT cattle, with a marked variation between housing systems. Most hoof lesions present at AT had disappeared at the subsequent spring trimming. Controlled for clustering by herd-within-year and for the effects of individual-and herd-level covariates, AT cattle at spring trimmings had significantly lower odds of lameness (OR=0.66) and of haemorrhages of the sole or white-line (OR=0.86), sole ulcer (OR=0.59) and white-line fissure or double sole (OR=0.71)-but not of moderate-to-severe heel-horn erosion or dermatitis (OR=0.96). Acute hoof treatments between claw trimmings were more common in the NAT group (OR=2.02).

Effect of lameness on milk yield in dairy cows

OBJECTIVE

To examine the relationship between lameness and milk yield in dairy cows.

DESIGN

Cohort study.

ANIMALS

531 dairy cows.

PROCEDURE

Cows affected with lameness were classified into 1 of 3 groups on the basis of type of diseases or lesions observed, including interdigital phlegmon (foot rot), papillomatous digital dermatitis (foot warts), or claw lesions. Cows not affected with lameness were classified as healthy. From Dairy Herd Improvement Association records, 305-day mature equivalent milk yield data were collected at the end of lactation or when the cow left the herd. Milk yield was compared between cows affected with lameness and healthy cows.

RESULTS

167 (31%) cows were affected with lameness during lactation. Lame cows had claw lesions (60%), papillomatous digital dermatitis (31%), or interdigital phlegmon (9%). Milk yield in lame cows with interdigital phlegmon (mean, 17,122 lb) was significantly less, compared with healthy cows (19,007 lb).

CONCLUSIONS AND CLINICAL RELEVANCE

In this herd, interdigital phlegmon was associated with a 10% decrease in milk production. Lame cows with claw lesions or papillomatous digital dermatitis produced less milk than healthy cows, but the difference was not significant.

Effect of lameness on the calving-to-conception interval in dairy cows

OBJECTIVE

To examine the relationship between lameness and the duration of the interval from calving to subsequent conception in lactating dairy cows.

DESIGN

Cohort study.

ANIMALS

837 dairy cows.

PROCEDURE

Cows affected with lameness were classified into 1 of 4 groups on the basis of types of disease or lesions observed, including foot rot, papillomatous digital dermatitis, claw lesions, or multiple lesions. Cows not affected with lameness were classified as healthy. Time from calving to conception was compared between lame cows and healthy cows.

RESULTS

254 (30%) cows were affected with lameness during lactation. Most lame cows (59%) had claw lesions. Lame cows with claw lesions were 0.52 times as likely to conceive as healthy cows. Median time to conception was 40 days longer in lame cows with claw lesions, compared with healthy cows. Number of breedings per conception for lame cows with claw lesions was significantly higher than that for healthy cows.

CONCLUSION AND CLINICAL RELEVANCE

Claw lesions were the most important cause of lameness, impairing reproductive performance in dairy cows, as indicated by a higher incidence of affected cows and a greater time from calving to conception and a higher number of breedings required per conception, compared with healthy cows.

Diseases of the digital soft tissues

This article reviews diseases of the digital soft tissues, including digital dermatitis, interdigital dermatitis, interdigital phlegmon, and interdigital hyperplasia. The clinical signs and diagnosis, epidemiology and pathogenesis, etiology, and treatment and prevention of each disease are discussed.

Biosecurity on dairy operations: hazards and risks

The objective here was to present a model for considering biosecurity related to infectious diseases on US dairy operations using a risk assessment framework. With the example of an important dairy cattle pathogen (Mycobacterium paratuberculosis), I followed risk assessment steps to characterize risks related to the use of certain management practices and possible risk reduction within an infectious disease biosecurity program. Biosecurity practices focus on the prevention of introduction of these pathogens to the dairy, and estimates of the risks associated with introduction of different sources of cattle are presented. In addition, biosecurity practices also limit the transmission of these pathogens within an infected dairy operation, especially those focused on sick cow management, calving area management, and manure management. Recent information from the National Animal Health Monitoring System (NAHMS) Dairy 96 Study indicates that many of these practices have not been adopted on US dairy operations, indicating both risk of disease and opportunity for animal health improvement.

Fecal shedding of Campylobacter and Arcobacter spp. in dairy cattle

Campylobacter jejuni, Campylobacter coli, and Arcobacter spp. were detected in feces of healthy dairy cows by highly specific multiplex-PCR assays. For C. jejuni, at this one-time sampling, cows from 80.6% of farm operations (n = 31) and 37.7% of individual dairy cattle fecal samples (n = 2,085) were positive. Farm management factors were correlated with prevalence in herds in which >25% of cows were positive for C. jejuni. Statistical significance was set at a P of 0.20. Using these criteria, application of manure with broadcast spreaders (P = 0.17), feeding of whole cottonseed or hulls (P = 0.17) or alfalfa (P = 0.15), and accessibility of feed to birds (P = 0.17) were identified as possible risk factors for C. jejuni infection. C. coli was detected in at least one animal in 19.4% of operations and 1.8% of individual cows (n = 2,085). At the herd level, use of broadcaster spreaders was not a risk factor for C. coli infection. For Arcobacter, cows from 71% of dairy operations (n = 31) and 14.3% of individual dairy cattle fecal samples (n = 1,682) were positive. At the herd level, for Arcobacter spp., feeding of alfalfa (P = 0.11) and use of individual waterers (P = 0.19) were protective. This is the first description of Arcobacter spp. in clinically healthy dairy cattle and the first attempt to correlate their presence with C. jejuni.

Efficacy of oxytetracycline for treatment of papillomatous digital dermatitis lesions on various anatomic locations in dairy cows

OBJECTIVE

To evaluate efficacy of topical treatment with oxytetracycline solution among dairy cows with papillomatous digital dermatitis (PDD) lesions on the interdigital cleft, heels, or dewclaw.

DESIGN

Clinical trial.

ANIMALS

70 dairy cows from a single herd.

PROCEDURE

On the basis of anatomic location of PDD lesions, cows were allocated into 1 of 3 groups (interdigital cleft [n = 14], heels [30], or dewclaw [26]) and treated topically with oxytetracycline solution. Cows were examined 14 and 30 days after initial treatment. During each examination, pain and lesion size scores were recorded.

RESULTS

On the basis of pain and lesion size scores, oxytetracycline appeared significantly less effective among cows with lesions on the interdigital cleft than for cows with lesions on the heels or the dewclaw. Number of cows with signs of pain or visible lesions after treatment was significantly higher for cows with lesions on the interdigital cleft than for cows with lesions on heels or the dewclaw.

CONCLUSIONS AND CLINICAL RELEVANCE

Anatomic location of PDD lesions has an effect on the efficacy of topical treatment with oxytetracycline solution in dairy cows affected with PDD. Cows with lesions on the interdigital cleft were less likely to respond to treatment, compared with cows with lesions on the heels or the dewclaw.

Efficacy of two modified nonantibiotic formulations (Victory) for treatment of papillomatous digital dermatitis in dairy cows

A field trial was conducted to compare the efficacy of the original and two modified formulations of Victory and oxytetracycline among dairy cows affected with papillomatous digital dermatitis. Seventy-eight cows with papillomatous digital dermatitis lesions were randomly allocated to one of four treatment groups (A, B, C, D). Cows in group A (n = 19) were treated with an oxytetracycline solution; cows in group B (n = 22) were treated with the original formulation of Victory containing soluble copper, peroxide compound, and a cationic agent; cows in group C (n = 17) were treated with a modified formulation of Victory containing reduced soluble copper and peroxide compound but increased levels of cationic agent; and cows in group D (n = 20) were treated with a modified formulation of Victory containing levels of soluble copper and cationic agent equivalent to the original formulation but with reduced concentrations of peroxide compound. Cows were examined 7, 14 and 28 d after initial treatment; during each examination, pain and lesion scores were recorded. The modified nonantibiotic formulation used in cows in group C appeared to be the most effective for treatment of papillomatous digital dermatitis. Proportions of cows with signs of pain were significantly lower among cows in group C, compared with cows in group A. Similarly, pain scores were significantly lower among cows in treatment group C, compared to cows in group A. The 2 low efficacy of oxytetracycline was an unexpected result b and may have clinical implications associated with possible antibiotic resistance in dairy cows affected with papillomatous digital dermatitis.