• Gillespie A., A. Vanhoudt, L. Benedictus, C.G. McAloon, F. Logan, M. Spaninks, and L. Viora. 2024. A survey of foot disinfection practices for control of bovine digital dermatitis; evaluating solution depth, footbath hygiene, and the potential of footbaths as infection reservoirs for Treponema species. J. Dairy Sci. doi: 10.3168/jds.2023-24108.
• Vanhoudt, A., C. Jacobs, M. Caron, H.W. Barkema, M. Nielen, T. van Werven, and K. Orsel. 2023. Broad-spectrum infrared thermography for detection of M2 digital dermatitis lesions on hind feet of standing dairy cattle. PLoS ONE 18:e0280098. doi:10.1371/journal. pone.0280098.
• Vanhoudt, A., J. Hesseling, M. Nielen, J. Wilmink, R. Jorritsma, and T. van Werven. 2022. M-score and wound healing assessment of 2 nonantibiotic topical gel treatments of active digital dermatitis lesions in dairy cattle. J. Dairy Sci. 105:695–709. doi:10.3168/jds. 2021-20613.
• Strous E., A. Vanhoudt, A. Smolenaars, G. van Schaik, M. Schouten, H. de Pater, B. Roelofs, and M. Nielen. 2021. Observational study on variation of longitudinal platelet counts in calves over the first 14 days of life and reference intervals from cross-sectional platelet and leukocyte counts in dairy calves up to two months of age. Animals 11:347. doi:10.3390/ani11020347.
• Vanhoudt, A., K. Orsel, M. Nielen, and T. van Werven. 2021. An observational study on the management of digital dermatitis through a repeated risk assessment on 19 Dutch dairy herds. J. Dairy Sci. 104:947–956. doi:10.3168/jds.2020-18730.
• Bell, N., and A. Vanhoudt. 2020. Treating and controlling digital dermatitis in dairy cattle. In Pract. 42:554–567. doi:10.1136/inp.m4454.
• Vanhoudt, A., D.A. Yang, T. Armstrong, J.N. Huxley, R.A. Laven, A.D. Manning, R.F. Newsome, M. Nielen, T. van Werven, and N.J. Bell. 2019. Interobserver agreement of digital dermatitis M-scores for photographs of the hind feet of standing dairy cattle. J. Dairy Sci. 102:5466–5474. doi:10.3168/jds.2018-15644.
• Vanhoudt, A., K. van Hees-Huijps, A.T.M. van Knegsel, O.C. Sampimon, J.C.M. Vernooij, M. Nielen, and T. van Werven. 2018. Effects of reduced intramammary antimicrobial use during the dry period on udder health in Dutch dairy herds. J. Dairy Sci. 101:3248–3260. doi:10.3168/jds.2017-13555.
• Mahendran, S.A., R. Booth, L. Beekhuis, A. Manning, T. Blackmore, A. Vanhoudt, and N. Bell. 2017. Assessing the effects of weekly preweaning health scores on dairy calf mortality and productivity parameters: Cohort study. Vet. Rec. 181:196–196. doi: 10.1136/vr.104197.
• Vanhoudt, A., B. Pardon, P. De Schutter, L. Bosseler, C. Sarre, J. Vercruysse, and P. Deprez. 2015. First confirmed case of bovine besnoitiosis in an imported bull in Belgium. Vlaams Diergeneeskd. Tijdschr. 84:205–211.
• Vanhoudt, A., S. van Winden, J.C. Fishwick, and N.J. Bell. 2015. Monitoring cow comfort and rumen health indices in a cubicle-housed herd with an automatic milking system: A repeated measures approach. Ir. Vet. J. 68:12(2015). doi:10.1186/s13620-015-0040-7.

Oral presentations

• A cross-sectional study of footbath hygiene and the application of footbathing for control of bovine digital dermatitis on dairy farms. 2023. European Buiatrics Congress 2023, Berlin, Germany.
• Bovine digital dermatitis: Trick or treat. 2022. 21st International Symposium & 13th International Conference on Lameness in Ruminants, Minneapolis, USA.
  M-score and wound healing assessment of two non-antibiotic topical gel treatments of active digital dermatitis lesions in dairy cattle. 2022. European Veterinary Conference Voorjaarsdagen, Amsterdam, the Netherlands.
• Interobserver agreement of digital dermatitis M-scores for photographs of hind feet from standing dairy cattle. 2019. 20th International Symposium & 12th International Conference on Lameness in Ruminants, Tokyo, Japan.
• Udder health in the Netherlands after the introduction of the guideline on antibiotic dry cow therapy. 2018. Symposium Droogstand op maat, Wageningen, the Netherlands.
• The enforced transition from blanket dry cow therapy to selective dry cow therapy in the Netherlands: An evaluation of the effect on udder health parameters. 2017. European Veterinary Conference Voorjaarsdagen, Amsterdam, the Netherlands.
• Monitoring cow comfort and rumen health on a farm with an automated milking system. 2015. National Veterinary Congress of the Dutch Royal Veterinary Orginazation KNMvD, Utrecht, the Netherlands.

Scientific posters

• An observational study on managing digital dermatitis through risk assessment and veterinary advice on 19 Dutch dairy herds. 2022 World Buiatrics Congress, Madrid, Spain.
• Topical treatment of active digital dermatitis lesions with an enzyme alginogel or copper and zinc chelates gel fail to achieve high cure rates to M0 within 10 days. 2022 World Buiatrics Congress, Madrid, Spain.
• Farm workers are exposed to substantial levels of formaldehyde on dairy farms. 2022. 21st International Symposium & 13th International Conference on Lameness in Ruminants, Minneapolis, USA.
• A risk assessment alone is insufficient to decrease the digital dermatitis prevalence on dairy herds. 2022. 21st International Symposium & 13th International Conference on Lameness in Ruminants, Minneapolis, USA.
• Development of an online training tool for the M-score of bovine digital dermatitis lesion. 2022. 21st International Symposium & 13th International Conference on Lameness in Ruminants, Minneapolis, USA.
• Automated on-farm detection of M2 lesions with infrared thermography is unlikely. 2022. 21st International Symposium & 13th International Conference on Lameness in Ruminants, Minneapolis, USA.
• Can less be more in dry cow therapy? A message from the Netherlands. 2018. Total Dairy Seminar. Stratford-upon-Avon, UK.
• Variations in clinically relevant behaviours in a zero-grazed voluntary-milking Holstein herd. 2013. Britisch Catte Veterinary Association Annual Congress. Harrogate, UK.

PhD Thesis: Diagnosis, treatment, and control of bovine digital dermatitis in dairy cattle. 2023.

Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.

This thesis focuses on the detection, prompt effective treatment, and control of digital dermatitis on dairy herds. In Chapter 2, an overview of the status quo on management of digital dermatitis on dairy herds is given. In Chapter 3 we demonstrated that experienced scorers are well able to differentiate between photographs of feet affected by digital dermatitis and photographs feet unaffected by digital dermatitis. On the other hand, they were less able to identify specific lesion stages, including the M2 and M4 stage which are considered important stages regarding clinical impact and infection reservoir, respectively. In Chapter 4 we concluded that infrared thermography (IRT) is unlikely to be suited for automated identification of feet affected by digital dermatitis due to the poor associations between maximum temperature of the plantar pastern region and the presence of M2 lesions or digital dermatitis lesions in general. In Chapter 5 we demonstrated that topical treatment of active, often painful, digital dermatitis lesions with a copper and zinc chelates gel (coppergel) and bandage outperformed an enzyme alginogel and bandage in M-score improvement, with the majority of lesions transitioning to the chronic, often not painful, state. In contrast, treatment with the alginogel achieved improved wound healing progress compared with the coppergel. However, neither the coppergel nor the alginogel achieved high cure rates to healthy skin. In Chapter 6 we illustrated that a standalone identification of risk factors for digital dermatitis together with associated advice to control these risk factors is insufficient to decrease the prevalence of digital dermatitis in dairy herds. Chapter 7 concludes this thesis with a general discussion providing a reflection on insights gained and suggestions for future research on the diagnosis, treatment, and control of digital dermatitis in dairy herds. Read the thesis