Papillomatous digital dermatitis in Chilean dairies and evaluation of a screening method

• Published in: Preventive veterinary medicine Vol. 37; no. 1; pp. 197 - 207
• Main Authors: Rodriguez-Lainz, Alfonso, Melendez-Retamal, Pedro, Hird, David W, Read, Deryck H
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-12-1998
• Subjects: Animals; BOVIN LAITIER; Cattle; Cattle Diseases - diagnosis; Cattle Diseases - epidemiology; Cattle – microbiological diseases; CHILE; Chile - epidemiology; CHILI; DAIRIES; DAIRY CATTLE; DERMATITE; DERMATITIS; Digital dermatitis; DISEASE SURVEYS; ENCUESTAS SANITARIAS; ENQUETE PATHOLOGIQUE; Female; Foot Dermatoses - diagnosis; Foot Dermatoses - epidemiology; Foot Dermatoses - veterinary; GANADO DE LECHE; Lameness; Lameness, Animal - epidemiology; Mass Screening - methods; Mass Screening - veterinary; Papillomatous digital dermatitis; PLANTAS LECHERAS; Prevalence; Reproducibility of Results; USINE LAITIERE; Chile; Digital dermatitis; Lameness; Cattle – microbiological diseases; Papillomatous digital dermatitis
• ISSN: 0167-5877; 1873-1716
• DOI: 10.1016/S0167-5877(98)00091-9

Outbreaks of papillomatous digital dermatitis (PDD) have been reported from many countries, but there is little information on prevalence and geographic distribution of the disease. Our objectives were to describe prevalence of PDD on dairies belonging to the two main dairy-producer associations in Chile, and to evaluate a milking-parlor screening method for detection of PDD in dairy cows. First, a self-administered questionnaire was sent to all 214 association dairy managers. Seventy percent of the 119 respondents had observed PDD on their dairies. About 83% of the 63 responding managers had first seen PDD during the previous 10 years. Subsequently, a random sample of 43 dairies stratified by association was selected from the total 214 for PDD screening. During milking, we inspected cows' feet for PDD lesions; 91% of dairies had cows affected by PDD; median PDD prevalence for milking cows in dairies was 6.1%. Finally, in one dairy, PDD screening at the parlor was compared to PDD diagnosis by inspecting restrained cows in a chute. The screening method had a sensitivity of 0.72, and a specificity of 0.99. This study demonstrated that PDD was widespread on study dairies in Chile. The screening test presented can be used as a cost efficient method to estimate prevalence of PDD either on individual dairies or in large-scale surveys.