The prevalence of hoof diseases in cattle has increased in Norway, alongside growing herd sizes and the transition towards free-stall housing systems. Just 20 years ago, bovine digital dermatitis (BDD) was virtually unheard of in this country. Today, the disease has been detected in around 10% of Norwegian cattle herds undergoing routine hoof trimming, though the true prevalence is likely significantly higher. BDD is a contagious infection that causes painful skin lesions, most commonly found in the heel bulb area of the hoof, just above the interdigital cleft. Lesions may also appear in front of or within the cleft itself. While most BDD-positive herds in Norway currently report few and mild cases, experience from other countries shows that the disease can spread rapidly and lead to more severe lesions.
Sheep can also be affected by a similar condition called contagious ovine digital dermatitis (CODD). Lesions usually develop at the coronary band – the junction between the skin and the hoof – and can progress to the point where the entire hoof capsule detaches. This results in severe lameness and poses significant animal welfare concerns. CODD is widespread in the UK and was first detected in Sweden in 2019, but has never been reported in Norway.
The primary cause of both BDD and CODD is bacteria of the genus Treponema, which are difficult to culture and occur in several disease-associated variants. The painful lesions caused by these infections reduce animal welfare and, if the disease becomes established in a herd, can lead to significant production losses. Despite these serious consequences, no commercial diagnostic test is currently available. Diagnosis still relies on clinical signs, which increases the risk of both misdiagnosis and underreporting. Rapid and accurate diagnosis is crucial to prevent introduction of disease into new herds and to limit its spread.
In the research project Diginostics, we identified two dominant Treponema variants in Norwegian cattle affected by BDD. These variants were significantly more prevalent in diseased animals compared to healthy ones, and there were clear differences between herds with and without BDD. We also demonstrated that swab samples from hooves provide results comparable to biopsies, making the sampling process simpler, less invasive and more animal friendly.
Based on these findings, we have developed a PCR-based test that detects the two most important bacterial variants. The test has been validated using samples from several counties, and results indicate that five samples per herd are sufficient to determine infection status. This provides a practical tool for disease surveillance and infection control. Further validation through testing in additional herds, including beef cattle, as well as environmental sampling, will enhance the test’s reliability and help assess its suitability for diagnosing individual animals.
In sheep, samples from lesions resembling CODD revealed a completely different bacterial flora compared to what has been found in the UK, and no CODD-associated Treponema were detected. These findings support the assumption that CODD is still not present in Norway. At the same time, they highlight the importance of continued surveillance and maintaining import restrictions. If the test proves capable of detecting CODD in other countries, it could also serve as a tool for import control.
The project has also contributed to the development of a hoof health status feature within the Norwegian Animal Health Recording System (DHP), providing farmers and advisors with better oversight of hoof health in the herds. The hoof health status, displayed as either green or red, is based on documented cases of BDD and interdigital phlegmon, as well as the registration of routine hoof trimming in a trimming chute. The purpose is to support biosecure live animal trade, in accordance with industry guidelines.
The results from Diginostics provide a valuable foundation for improving animal welfare, enabling more targeted infection prevention, and promoting greater sustainability in Norwegian cattle production. The new test, together with our increased knowledge of the bacterial flora in Norwegian cattle herds, will serve as the foundation for continued collaboration with the industry, aiming to establish a more robust national decision-making tool for managing BDD.
Prosjektet har gitt ny og viktig kunnskap om digital dermatitt (BDD) hos storfe i Norge, og har etablert et solid faglig grunnlag for videre overvåking og bekjempelse av sykdommen. Identifiseringen av to dominerende Treponema-fylotyper (PT1 og PT6) og utviklingen av en PCR-basert test representerer et betydelig gjennombrudd. Testen gir mulighet for rask og spesifikk påvisning av BDD på besetningsnivå, og har potensial til å forbedre både diagnostikk og smitteforebygging i norsk storfenæring.
Ved å inkludere svaberprøver som et alternativ til biopsier, har prosjektet bidratt til å gjøre prøvetakingen mer skånsom, praktisk og kostnadseffektiv. Dette øker sannsynligheten for at metoden tas i bruk i felt. Sammenligning av svaberprøver og biopsier fra samme lesjoner viste at begge metodene fanget opp de samme bakteriene som er assosiert med BDD. Dette styrker tilliten til svaberprøver som et pålitelig diagnostisk verktøy. Muligheten for å benytte svaberprøver legger også til rette for en mer objektiv og standardisert diagnostikk. I tillegg stilles det ikke like strenge krav til grundig rengjøring av klauven for å kunne påvise BDD-smitte i form av typisk lesjon, ettersom de aktuelle bakteriene fanges opp med svaberprøve – i hvert fall på besetningsnivå.
Testresultatene vil kunne integreres i klauvstatus i Dyrehelseportalen (DHP), og dermed gi produsenter og rådgivere et bedre beslutningsgrunnlag for smittesikker livdyromsetning og styrket dokumentasjon av dyrehelse. Den nye kunnskapen om genetisk variasjon og utbredelse av Treponema gir et viktig grunnlag for videre forskning og metodeutvikling, inkludert mulig bruk av testen på individnivå og i kjøttfebesetninger. På lengre sikt kan prosjektets resultater bidra til redusert forekomst av BDD, bedre dyrevelferd, lavere behandlingskostnader og økt bærekraft i storfeproduksjonen.
Prosjektet har også gitt ny og verdifull kunnskap om CODD-liknende lesjoner hos sau. Analyser av prøver fra slike lesjoner viste en bakterieflora som skiller seg markant fra det som er rapportert i Storbritannia, og ingen CODD-assosierte Treponema-arter ble påvist. Dette styrker antakelsen om at CODD fortsatt ikke forekommer i Norge. Funnene har dermed direkte betydning for nasjonal beredskap og understreker behovet for videre overvåking og opprettholdelse av dagens importrestriksjoner.
Dersom den utviklede PCR-testen viser seg å være egnet til å påvise CODD hos sau i andre land, kan den også få en viktig funksjon som verktøy i importkontroll og smitteforebygging. Dette gir prosjektet en potensiell effekt utover norsk storfeproduksjon, med relevans for småfe og internasjonal handel med livdyr.
Forankringen i næringen og det tette samarbeidet med sentrale aktører legger til rette for at resultatene kan få varig effekt gjennom implementering i bransjeretningslinjer og beslutningsverktøy. På sikt kan dette bidra til en mer målrettet og effektiv forvaltning av smittsom klauvsykdom i Norge.
“Diginostics” shall develop a diagnostic test (DD-test) for rapid detection of cattle and sheep suffering from bovine digital dermatitis (BDD) and contagious ovine digital dermatitis (CODD), respectively. The tests will be implemented in a risk management system.
Bovine digital dermatitis (BDD) is a severe disease of the skin of the cattle foot, was first described in 1974. The disease is endemic in the dairy cattle population in most parts of the world, despite this, laboratory based diagnostic tools are not yet available.
CODD is a severe, but relatively new disease, first described in the UK in 1997, it is already endemic in the UK and it was found in Sweden in 2019. CODD has never been observed in Norwegian sheep and hence it is of great importance to maintain this situation.
The DD-test will be based on a polymerase chain reaction (PCR) targeting common gene sequences in the bacterial genus, Treponema, associated with BDD and CODD. “Diginostics” will be based on ongoing research on BDD in Norway and Denmark, and on CODD in Sweden and the UK.
To meet the challenge with the increase of BDD in Norway, a risk management system for safe trade of cattle will be developed in parallel to the development of the diagnostic test. The risk management part will consist of a combination of data from the DD-test, and risk assessments and clinical registration by claw trimmers. A national guideline will be developed which include descriptions of economic measures (sanctions) to encourage the will to register and share data for safe trade in livestock.
“Diginostics” will generate new knowledge about digital dermatitis in cattle and sheep, initiate new measures to control the disease, and reduce the occurrence in Norwegian livestock. It will enhance the effectiveness of the work that the industry is doing and increase the positive effects of planned measures like screening, controlling and potentially future eradication of the BDD in the Norwegian cattle population.
