Bovine ischaemic teat necrosis (ITN) is a disease affecting the skin of the teats of dairy cows with an unknown aetiopathogenesis. Digital dermatitis (DD)-associated treponemes have previously been suggested as a potential aetiological agent in ITN, although the sample size was small. The current study, using established PCR techniques, aimed to examine the association with the presence of DD-associated treponemes in a large number of ITN samples from a wider geographical area, and surveyed the potential of milk as an infection reservoir. From 95 ITN lesions, 35.8% (n = 34) were positive for at least one DD-associated treponeme compared with only 5.6% (n = 1) of 18 non-lesioned teats from cows with ITN lesions on a different teat using a nested PCR approach. All 10 age- and production-matched control cows were negative for DD-associated treponemes via PCR. No DD-associated treponemes could be detected from foremilk of cows with (n = 19) and without (n = 31) a DD lesion on the hind feet. DD-associated treponemes could be detected via PCR after incubation in milk for up to 2 h. Therefore, milk does not appear to be a competent reservoir for transmission of DD-associated treponemes. Moreover, in the current study DD-associated treponemes were only detected in a subset of ITN samples, so it is unlikely these opportunistic skin-associated pathogens are the major or sole agent of ITN.

In this study 269 swabs collected from 254 ovine foot lesions and 15 apparently healthy ovine feet were screened by PCR for the presence of major lameness causing foot pathogens viz. Treponema species, D. nodosus, F. necrophorum and T. pyogenes with the presumption that ovine foot lesion positive for Treponema species alone or in association with other three pathogens were categorized as contagious ovine digital dermatitis (CODD). While samples positive for D. nodosus alone or its combination with F. necrophorum and T. pyogenes were considered as footrot (FR) and samples in which F. necrophorum or T. pyogenes was found either alone or in combination were considered as interdigital dermatitis (ID). The overall occurrence of Treponema sp. in ovine foot lesions was 48.0%, and ranged from 33 to 58%. In Treponema positive samples D. nodosus, F. necrophorum and T. pyogenes were present in 34 (27.4%), 66 (54.4%) and 84 (68.5%) in contrast to Treponema negative samples in which these were present in 15 (11.1%), 20 (14.12%) and 17 (12.6%) samples, respectively. The data signifies that Treponema sp. are significantly associated with these foot pathogens and their different combinations with Treponema sp. influence the severity of CODD lesion. The identification of Treponema phylotypes was done by sequencing the 16S rRNA gene fragment of ten representative samples. Out of ten sequences, four (Trep-2, Trep-4, Trep-7 and Trep-10) were identical to Treponema sp. phylotype 1 (PT1) that belongs to phylogroup T. refringens-like, one sequence (Trep-1) was genetically close (90% sequence homology) to Treponema brennaborense while five sequences (Trep-3, Trep-5, Trep-6, Trep-8 and Trep-9) matched with uncultured bacterium clones of treponemes forming separate monophyletic group in phylogenetic tree and could represent new digital dermatitis phylogroup presently containing five ovine specific phylotypes. This is the first report on the presence of Treponema phylotypes other than three digital dermatitis (DD) Treponema phylogroups viz. T. phagedenis-like, T. medium/T. vincentii-like, and T. pedis-like that are frequently detected in CODD lesions. Metagenomic analysis of two representative samples revealed the abundance of genus Treponema in CODD lesion while this genus was absent in swab collected from clinically healthy foot suggesting that it might play primary role in producing CODD. These findings may further aid in understanding the etiopathogenesis of CODD and could help to develop appropriate treatment and mitigation strategies to combat the disease.

Keratoma is an aberrant keratin mass thought to originate from epidermal horn-producing cells interposed between the stratum medium of the hoof wall and the underlying third phalanx. The cause is unknown, although the presence of keratomas is frequently associated with chronic irritation, focal infection, or trauma. A total of 167 donkeys with keratomas were presented in this study. The diagnosis of a keratoma was based on clinical signs, radiography, and histopathologic examination. Surgical excision was attempted on all donkeys with lameness unless euthanasia was advised. Histopathologic examination, including Giemsa, periodic acid Schiff, and Young\'s silver special histochemical stains, was performed and showed the presence of fungal hyphae and spirochete bacteria within the degenerate keratin. Polymerase chain reaction (PCR) for treponeme bacteria was performed on 10 keratoma lesions and 9 healthy pieces of hoof (controls). All healthy donkey tissues were negative for the 3 recognized digital dermatitis (DD) treponeme phylogroups, whereas 3 of 10 (30%) donkey keratoma samples were positive for one of the DD treponeme phylogroups. Routine fungal culture and PCR for fungi were performed on 8 keratoma lesions and 8 healthy pieces of hoof (controls). Keratinopathogenic fungi were detected in 1 of 8 (12.5%) keratomas, while only non-keratinopathogenic, environmental fungi were detected in 8 control healthy hoof samples. This is the first time the DD treponemes phylogroup and keratinopathogenic fungi have been detected in keratomas. Further studies are required to assess the significance of this finding.

Reduction of risk factors for bovine digital dermatitis (BDD) is crucial in current disease control. However, risk factors that might arise especially in mountainous regions are unknown until now, and an adapted BDD control program is consequently missing. The objective of this observational case-control study was to identify farm-level risk factors for BDD in dairy herds in mountainous regions. To investigate predictors for the occurrence of BDD, 100 farms were visited and information about herd characteristics and management practices, potentially relevant explanatory variables for either introduction or establishment of BDD, were gathered by completing a questionnaire with the farmer or herd manager. Within-herd prevalences of BDD assessed during 3 routine claw trimmings with an interval of 6 mo before the survey were used to define cases (BDD within-herd prevalence of ≥26% during each claw trimming) and controls (no BDD cases in each of the 3 routine claw trimmings before the survey). Data were analyzed using 2 separate binomial generalized linear models according to either establishment or introduction of BDD. After prescreening, 15 of 23 explanatory variables were included in the final analysis, which showed 3 variables related to introduction and establishment, each being significantly associated with the occurrence of BDD within a farm. Results of model 1 (i.e., aspects related to BDD introduction) revealed that access to mountain pastures during the summer season (odds ratio, 95% confidence interval: 0.12, 0.04-0.35), participation in dairy shows (0.32, 0.11-0.94), and the number of new animals introduced into the farm during the last 2 yr (1.28, 1.12-1.52) were significantly associated with the occurrence of BDD. Model 2 (i.e., aspects related to BDD establishment) showed that cows kept in freestalls were at higher risk for BDD compared with those kept in tiestalls (20.65, 1.59-649.37). Furthermore, number of days between diagnosis and treatment of a BDD lesion (10.31, 3.55-81.21) and the amount of concentrate feeding (median 5 kg) per cow and day (7.72, 2.46-6.47) were positively associated with BDD occurrence. In conclusion, the findings of this study provide a set of risk factors that are associated with BDD status within herds in mountainous regions. These results may help in development of adapted control programs for BDD in dairy cows.

At a commercial farrow-to-feeder pig system with 2,100 sows in Serbia, lesions resembling porcine ear necrosis syndrome were observed in 80% of the weaned pigs at 45-50 days of age. Pathomorphological examinations were carried out on 10 pigs that had been found dead. The gross lesions ranged from mild, superficial dermatitis to severe, deep inflammation with exudation, ulceration and necrosis. Histopathological examination revealed erosive and ulcerative dermatitis of the pinna with neutrophilic and lymphocytic infiltration and bacterial colonies in the crusts. Staphylococcus aureus (MRSA strain), Staphylococcus hyicus and Streptococcus group C were cultivated from eight, S. hyicus from two ear tissue scraping samples. All 10 samples were positive for treponemes and phylogenetic analysis of two polymerase chain reaction products confirmed the relationship to Treponema (T.) medium/vincentii and Treponema pedis. Treponemes were also detected in seven oral swabs that were analysed to obtain evidence of the transmission of this bacterium by ear biting. The contribution of non-infectious factors to this misbehaviour could not be ruled out as the crude protein concentration of the feed was inappropriate and the climate of the pig house was suboptimal. The concentrations of selected mycotoxins in the feed were not elevated. However, the contribution of both infectious and non-infectious factors to the onset of disease was most probable.

Bovine digital dermatitis (BDD) is a common infectious disease of digital skin in cattle and an important cause of lameness worldwide, with limited treatment options. It is of increasing global concern for both animal welfare and food security, imposing a large economic burden on cattle farming industries each year. A polytreponemal etiology has been consistently identified, with three key phylogroups implicated globally: Treponema medium, Treponema phagedenis, and Treponema pedis. Pathogenic mechanisms which might enable targeted treatment/therapeutic development are poorly defined. This study used RNA sequencing to determine global differential mRNA expression in primary bovine foot skin fibroblasts following challenge with three representative BDD treponemes and a commensal treponeme, Treponema ruminis. A pro-inflammatory response was elicited by the BDD treponemes, mediated through IL-8/IL-17 signaling. Unexpectedly, the three BDD treponemes elicited distinct mechanisms of pathogenesis. T. phagedenis and T. pedis increased abundance of mRNA transcripts associated with apoptosis, while T. medium and T. pedis increased transcripts involved in actin rearrangement and loss of cell adhesion, likely promoting tissue invasion. The upregulation of antimicrobial peptide precursor, DEFB123, by T. phagedenis spirochaetes may present a microbial ecological advantage to all treponemes within BDD infected tissue, explaining their dominance within lesions. A commensal, T. ruminis, significantly dysregulated over three times the number of host mRNA transcripts compared to BDD treponemes, implying BDD treponemes, akin to the syphilis pathogen (Treponema pallidum), have evolved as \"stealth pathogens\" which avoid triggering substantial host immune/inflammatory responses to enable persistence and tissue invasion. Immunohistochemistry demonstrated increased IL-6, IL-8, RND1, and CFB protein expression in BDD lesions, confirming in vitro fibroblast observations and highlighting the system\'s value in modeling BDD pathogenesis. Several unique shared gene targets were identified, particularly RGS16, GRO1, MAFF, and ZC3H12A. The three key BDD Treponema phylogroups elicited both distinct and shared pathogenic mechanisms in bovine foot skin; upregulating inflammation whilst simultaneously suppressing adaptive immunity. The novel gene targets identified here should enable future vaccine/therapeutic approaches.

BACKGROUND: Bovine digital dermatitis (BDD) is an infectious foot disease found commonly in dairy herds. Foot-trimming is an important husbandry procedure for reducing the ensuing lameness; however, epidemiological, and microbiological studies have identified this as a risk activity for transmitting BDD. Three disinfectants have previously been identified in laboratory work as effective for removing viable BDD-associated Treponema spp., from hoof knife blades. The present study enrolled 133 dairy cattle with BDD lesions, and swabbed hoof knife blades before and after foot-trimming, and after knife disinfection with one of three disinfectants (1:100 FAM30®, 2% Virkon® and 2% sodium hypochlorite) to assess their efficacy under field conditions.
RESULTS: Detection of BDD treponeme phylogroup DNA was undertaken by direct PCR of swabs, and viable treponemes were detected by PCR of swab cultures after 6 weeks\' incubation. Where hoof knives did not contact the lesion, BDD-associated treponemes were detected after foot-trimming in 12/22 (54.5%) cases by direct PCR and 1/22 (4.5%) cases by PCR of cultured organisms. Where contact was made with the lesion, 111/111 (100%) samples taken after trimming were positive by direct PCR and 47/118 (39.8%) were positive by culture PCR. Viable organisms were identified in cultures from lesion stages M2, M3, M4 and M4.1. No viable organisms were detected after disinfection of hoof knives.
CONCLUSIONS: Hoof knives post-trimming were frequently contaminated with BDD-associated treponeme DNA. Viable organisms were identified in cultures whether contact had been made between hoof knife and lesion or not, although contact clearly increased the frequency of detection of viable organisms. The three disinfectants tested were effective for removing viable organisms. The disinfection protocol used in this study should therefore be considered reliable for adoption as standard industry practice.

BACKGROUND: Bovine digital dermatitis (BDD) is a painful infectious foot disease of cattle, and much evidence implicates a pathogenic role for treponemes. This study measured the survival of BDD treponemes on hoof knife blades and tested the efficacy of relevant disinfectants under laboratory conditions.
METHODS: Two strains of BDD treponemes were applied to hoof knife blades under aerobic conditions. Swabs were taken at different time points (10 minutes, one hour, two hours, four hours and 18 hours) and again after 20-second disinfection time with one of five disinfectants. Swabs were used directly for nested PCR to detect treponemes or inoculated for anaerobic growth, and subsequently examined using phase contrast microscopy and PCR.
RESULTS: BDD treponeme DNA was detectable by nested PCR at all survival time points, and these organisms were culturable from hoof knives for two hours after exposure under aerobic conditions in the laboratory. Three of the five disinfectants-1 per cent volume per volume (v/v) FAM30®, 2 per cent weight per volume (w/v) Virkon® or 2 per cent (v/v) sodium hypochlorite-were effective at preventing visible growth of treponemes following 20-seconds contact, and 1 per cent (v/v) FAM30® also prevented detection of treponemes by PCR.
CONCLUSIONS: Treponeme viability of two hours under aerobic conditions suggests BDD treponemes could be transmitted between cows on hoof knives. It is therefore important to apply a disinfection protocol during foot-trimming; the authors have identified three common disinfectants that may be suitable.

BACKGROUND: Several young bulls in a beef farm showed large, foul-smelling skin lesions in the plantar region of the coronary band and in the interdigital space. Some of the animals also had a painful, warm swelling in the palmar fetlock area. All bulls were lame (score 4/5), the most severely affected animal had a lameness score of 5/5. Initial local treatment was unsuccessful, therefore the animals received parenteral antimicrobial treatment leading to improvement of clinical signs and weight bearing in most animals. However, several animals were slaughtered prematurely due to severe foot lesions. The diverse clinical picture did not allow for diagnosing one specific claw affection without further diagnostic investigations. Histopathological and bacteriological examinations confirmed the diagnosis of digital dermatitis (DD) in combination with an interdigital phlegmon, whereby five of the seven examined specimens were positive for one or more Treponema spp. Treponemes belong to the spirochetes, the ones commonly involved in DD in dairy cows include Treponema medium, Treponema phagedenis and Treponema pedis. The last two species were detected in the present cases. The clinical findings and results of diagnostic investigations indicate that a severe form of DD complicated by a secondary infection and interdigital phlegmon caused an outbreak of severe lameness in young bulls in a beef farm. Single or combined claw diseases can be associated with severe losses not only in dairy but also in beef herds.
BACKGROUND: In einem Mastbestand zeigten mehrere Jungbullen, vornehmlich an den Hinterbeinen im Bereich des plantaren Kronsaums bis in den Interdigitalspalt reichend, teils grosse stinkende Läsionen. Einige Tiere wiesen zu dem eine Schwellung im Fesselbeugebereich auf, welche vermehrt warm und sehr schmerzhaft war. Die Tiere waren lahm (L4/5), der am stärksten betroffene Mastbulle zeigte eine schwere Lahmheit (L5/5). Die Behandlung erfolgte anfänglich lokal, doch wegen des ausbleibenden Behandlungserfolgs wurden die Tiere parenteral mit einem Antibiotikum behandelt, was bei den meisten Tieren eine Verbesserung der Symptome und der Gliedmassenbelastung zur Folge hatte. Trotzdem mussten mehrere Tiere aufgrund der schwerwiegenden Veränderungen frühzeitig der Schlachtung zugeführt werden. Infolge des vielfältigen klinischen Bildes konnten die Veränderungen nicht ohne weiterführende diagnostische Abklärungen einer bestimmten Klauenerkrankung zugeordnet werden. In der histopathologischen wie auch in der bakteriologischen Untersuchung wurde die Diagnose Dermatitis digitalis (DD) in Kombination mit einer Zwischenklauenphlegmone bestätigt, wobei fünf der sieben untersuchten Tupferproben positiv für eine oder mehrere Treponema spp. waren. Die Treponemen gehören zu den Spirochäten, und zu denen, die am häufigsten an der DD bei Milchkühen beteiligt sind, Treponema medium, Treponema phagedenis und Treponema pedis. Die beiden letztgenannten Arten konnten in unseren untersuchten Proben nachgewiesen werden. Die Klinik und die Probenresultate weisen bei diesem Ausbruch von schwerer Lahmheit in einem Grossviehmastbetrieb auf das Vorliegen einer schweren Form von DD mit einer Sekundärinfektion und Entwicklung einer Zwischenklauenphlegmone hin. Klauenerkrankungen, einzeln oder in Kombination, können auch in Mastbetrieben zu schweren Verlusten führen.
BACKGROUND: Plusieurs jeunes taureaux dans une exploitation d’engraissement ont présenté, en particulier aux membres postérieurs, des lésions étendues et malodorantes au niveau plantaire de la couronne, qui s’étendaient jusqu’à l’espace interdigital. Certains animaux présentaient une enflure chaude et très douloureuse dans le pli du boulet. Les animaux étaient fortement boiteux (4/5), le taureau le plus atteint présentait une boiterie très sévère (5/5). Un traitement initial local a été mis en place, cependant, en l’absence de succès thérapeutique, les animaux ont été ensuite traités par voie parentérale avec un antibiotique, ce qui permis de réduire la sévérité du tableau clinique et d’améliorer la charge des membres atteints. En raison de la gravité des lésions, plusieurs animaux ont toutefois dû être abattus prématurément. Au vu de la diversité du tableau clinique, la maladie n’a pas pu être attribuée à une maladie des onglons particulière sans clarification supplémentaire du diagnostic. Un diagnostic de dermatite digitale en combinaison avec un phlegmon interdigital a été confirmé par l’analyse histopathologique ainsi que l’examen bactériologique: cinq des sept écouvillons examinés étaient positifs pour un ou plusieurs Treponema spp. Dans la famille des spirochètes, Treponema medium, Treponema phagedenis et Treponema pedis sont les tréponèmes le plus souvent impliqués dans la dermatite digitale chez les vaches laitières. Les deux germes mentionnés en dernier ont été mis en évidence dans les échantillons prélevés sur les taureaux d’engraissement décrits ici. L’image clinique et les résultats d’analyses des échantillons examinés suggèrent qu’une forme sévère de dermatite digitale compliquée par une infection secondaire et le développement d’un phlegmon interdigital s’est développée lors de l’épidémie de forte boiterie observée dans une exploitation d’engraissement. Les maladies des onglons, individuellement ou en combinaison, peuvent donc occasionner des pertes importantes dans les exploitations d’engraissement.
BACKGROUND: Diversi giovani tori in un allevamento di animali da ingrasso, hanno mostrato lesioni estensive e maleodoranti a livello del cercine coronario plantare e nello spazio interdigitale, in particolare a livello degli arti posteriori. Alcuni animali mostravano un gonfiore caldo e particolarmente dolente distalmente agli unghielli. Gli animali presentavano un’importante zoppia (4/5) ed il toro più colpito presentava una grave zoppia (5/5). Il trattamento topico delle lesioni non ha prodotto risultati soddisfacenti e un trattamento antibiotico parenterale è quindi stato utilizzato. Quest’ultimo ha portato ad un miglioramento del quadro clinico e una diminuzione della zoppia. Tuttavia diversi animali sono stati macellati in anticipo a causa della gravità delle lesioni. A causa della diversità del quadro clinico, non è stato possibile attribuire le lesioni ad una malattia specifica degli unghioni senza ulteriori esami diagnostici. Gli esami istopatologico e batteriologico hanno confermato la diagnosi di dermatite digitale associata ad un flemmone interdigitale. Cinque dei sette campioni esaminati erano positivi per uno o più Treponema spp. Tra le spirochete, Treponema medium, Treponema phagedenis e Treponema pedis sono i treponemi più spesso coinvoltoi nella dermatite digitale nella vacca da latte. I due ultimi sono stati ritrovati nelle lesioni dei tori da ingrasso qui descritti. Il quadro clinico ed i risultati degli esami complementari suggeriscono una forma atipica e severa di dermatite digitale complicata da un’infezione secondaria e lo sviluppo di un flemmone interdigitale. Le patologie podali, individuali o in associazione, possono causare gravi perdite economiche negli allevamenti da ingrasso.

There is little evidence of the efficacy of artificial polymers for controlling bovine digital dermatitis (BDD) as a major problem of intensive dairy productions worldwide. We therefore aimed to compare salicylic acid (SA)-based paste with a polyurethane (PU) wound dressing on a German Holstein dairy farm over a maximum 56-d period. On d 0, 109 ft with active BDD lesions from 109 cows were randomly assigned to two treatment groups: (1) SA group received a topical SA-containing paste and (2) PU group was treated with a PU wound dressing. Dressing changes were performed according to manufacturer\'s instructions until clinical cure (transition from active M1 or M2 to non-active M4 or healed M0 stages), whereby a clinical scoring of lesions was additionally conducted. Data from 100 ft could be analyzed (nSA = 54; nPU = 46). There was a significant reduction of the lesion score over time within each group (SA: d 0-d 14; PU: d 0-d 28, p < .05). Score differences between first (d 0) and second (SA: d 7; PU: d 14) as well as between first and third (SA: d 14; PU: d 28) evaluation did not differ significantly (p > .05). The proportion of clinically cured cows was higher in SA than in PU on d 14 (96.3 vs. 32.6%) as well as on d 28 (100 vs. 54.3%) after initial treatment (p < .05). Analysis of survival to cure in a Cox regression model showed that hazard ratio (HR) was higher for SA with PU as baseline (HR: 6.324, 95% CI: 3.625-11.033, p < .05). However, while BDD scores at enrollment did not differ between treatments (p > .05), PU had a significantly lower final BDD score (p < .05). In conclusion, evidence on the efficacy of PU bandages to treat BDD lesions is provided and further studies on bacteriological cure as well as recurrence rates are needed.