J P O'Connell, K E Lawrence, H Taylor, G Orbell, M E Bestbier, K Crowley, H Hunt
{"title":"An outbreak of ischaemic teat necrosis in a dairy herd in Taranaki, New Zealand.","authors":"J P O'Connell, K E Lawrence, H Taylor, G Orbell, M E Bestbier, K Crowley, H Hunt","doi":"10.1080/00480169.2024.2392687","DOIUrl":null,"url":null,"abstract":"<p><strong>Case history: </strong>In spring 2021, on a seasonally calving, pastorally based, Taranaki dairy farm, 12 first-calving heifers (≤ 30 days post-calving) developed similar dry, red to black, crusting lesions on the medial aspect of the teat udder junction extending down the medial teat. Some cows had multiple teats affected. Treatment was initially unrewarding and did not slow the progression of the disease. Overall, 8/12 cows recovered, and 4/12 cows were culled, with three of the cows culled after a teat sloughed and the fourth after surgical amputation of a teat. Outbreaks of the same condition, on the same farm but affecting fewer animals, occurred in spring 2022 (n = 6) and spring 2023 (n = 3).</p><p><strong>Clinical findings: </strong>An initial scab-like or crusting lesion progressed to resemble a thick eschar consisting of very dry and hard dead tissue. The unaffected areas of the teat felt normal but immediately under the dead tissue, there was a warm, firmer area consistent with an inflammatory reaction. Removing the scab led to profuse bleeding, with no visible bed of granulation underneath the scab. There was no leaking of milk in those cows that lost a teat, and no smell to the lesions themselves. Serology and virology ruled out the involvement of bovine alphaherpesvirus (BoHV-2) bovine gammaherpesvirus (BoHV-4), orthopoxviruses (cowpox) and parapoxviruses (pseudocowpox). Histopathology of an affected and surgically amputated teat showed multifocal erosion and ulceration of the epidermis, covered by a thick serocellular crust. In areas of ulceration, there were numerous neutrophils, and the dermis was expanded by granulation tissue with variable numbers of neutrophils, eosinophils, and lymphocytes around small blood vessels.</p><p><strong>Diagnosis: </strong>Based on the similarity of the history, presentation, and histopathological changes to those described for a novel disease reported in the UK, a diagnosis of ischaemic teat necrosis (ITN) was made.</p><p><strong>Clinical relevance: </strong>If ITN is an emerging condition in New Zealand and becomes as prevalent as it has in the UK, clinicians will be confronted with a significant new welfare problem in dairy cows. Anecdotally, there have been reports of other ITN outbreaks in New Zealand, and the Ministry for Primary Industries would be interested in collating reports from other New Zealand veterinarians.</p>","PeriodicalId":19322,"journal":{"name":"New Zealand veterinary journal","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Zealand veterinary journal","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1080/00480169.2024.2392687","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/8/26 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Case history: In spring 2021, on a seasonally calving, pastorally based, Taranaki dairy farm, 12 first-calving heifers (≤ 30 days post-calving) developed similar dry, red to black, crusting lesions on the medial aspect of the teat udder junction extending down the medial teat. Some cows had multiple teats affected. Treatment was initially unrewarding and did not slow the progression of the disease. Overall, 8/12 cows recovered, and 4/12 cows were culled, with three of the cows culled after a teat sloughed and the fourth after surgical amputation of a teat. Outbreaks of the same condition, on the same farm but affecting fewer animals, occurred in spring 2022 (n = 6) and spring 2023 (n = 3).
Clinical findings: An initial scab-like or crusting lesion progressed to resemble a thick eschar consisting of very dry and hard dead tissue. The unaffected areas of the teat felt normal but immediately under the dead tissue, there was a warm, firmer area consistent with an inflammatory reaction. Removing the scab led to profuse bleeding, with no visible bed of granulation underneath the scab. There was no leaking of milk in those cows that lost a teat, and no smell to the lesions themselves. Serology and virology ruled out the involvement of bovine alphaherpesvirus (BoHV-2) bovine gammaherpesvirus (BoHV-4), orthopoxviruses (cowpox) and parapoxviruses (pseudocowpox). Histopathology of an affected and surgically amputated teat showed multifocal erosion and ulceration of the epidermis, covered by a thick serocellular crust. In areas of ulceration, there were numerous neutrophils, and the dermis was expanded by granulation tissue with variable numbers of neutrophils, eosinophils, and lymphocytes around small blood vessels.
Diagnosis: Based on the similarity of the history, presentation, and histopathological changes to those described for a novel disease reported in the UK, a diagnosis of ischaemic teat necrosis (ITN) was made.
Clinical relevance: If ITN is an emerging condition in New Zealand and becomes as prevalent as it has in the UK, clinicians will be confronted with a significant new welfare problem in dairy cows. Anecdotally, there have been reports of other ITN outbreaks in New Zealand, and the Ministry for Primary Industries would be interested in collating reports from other New Zealand veterinarians.
期刊介绍:
The New Zealand Veterinary Journal (NZVJ) is an international journal publishing high quality peer-reviewed articles covering all aspects of veterinary science, including clinical practice, animal welfare and animal health.
The NZVJ publishes original research findings, clinical communications (including novel case reports and case series), rapid communications, correspondence and review articles, originating from New Zealand and internationally.
Topics should be relevant to, but not limited to, New Zealand veterinary and animal science communities, and include the disciplines of infectious disease, medicine, surgery and the health, management and welfare of production and companion animals, horses and New Zealand wildlife.
All submissions are expected to meet the highest ethical and welfare standards, as detailed in the Journal’s instructions for authors.