If you have dairy cattle, you’ve most likely experienced animals with udder sores. Typically you find it in the cleft of the udder of older cows or between the udder and one or both rear legs in heifers. Udder edema, bacteria and sometimes mites can all be contributing factors in the cause of udder sores. What you may not have known is that a strain of herpes virus can also be a common factor that leads to udder sores. Bovine herpesvirus type 4 (BHV-4), which is related to IBR (bovine herpesvirus type 1), can be commonly associated with udder sores in dairy cattle, especially in the winter time. Unlike IBR, however, BHV-4 does not have any vaccines to protect against it directly.
In a case presented to the WVDL several years ago, a well-managed, productive dairy herd with about 1700 dairy cows had a 15% incidence of udder sores on the farm. Tissues that were submitted to the diagnostic lab tested positive for BHV-4. Testing also found a high prevalence of bovine leukosis virus in the samples submitted and a suspected synergism between the two viruses leading to more cases of udder sores.
Per the WVDL, since initial testing, the herd implemented a few management strategies that have helped to decrease the incidences of udder sores to less than 1%. Some of the management changes this farm implemented were:
BLV/Leukosis control – through single use of individual needles for all injections and pasteurization of colostrum
Improved bedding quality – by improving recycled sand bedding quality through decreased moisture content, bacterial counts, and decreasing organic matter.
Improved udder health
Aggressive culling of excessive replacements and discontinued use of BST
While these strategies have not been scientifically proven, implementing management strategies that reduces contributing factors such as leukosis, providing external parasite control or reducing udder edema, will help to reduce the prevalence on your farm. Implementing additional strategies that reduce stress, improve udder health and hygiene, and prevent chronic damp conditions can also help to reduce the incidence of udder sores in your herd.