A retrospective study of the prevalence in equine postmortems of cranial mesenteric arteritis caused by Strongylus vulgaris in Alberta (2010 to 2022).

Background: Strongylus vulgaris is one of the most pathogenic nematodes affecting equids. Larval migration through the cranial mesenteric artery (CMA) with attendant arteritis and thromboembolism can result in fatal non-strangulating intestinal infarction. Once considered a historical disease, recent studies have described the reemergence of this pathogen in several European countries; however, little is known of the current prevalence of S. vulgaris in the Canadian horse population. Objective: To determine the prevalence of active S. vulgaris cranial mesenteric arteritis in horses submitted for postmortem examination to the Diagnostic Services Unit (DSU) at the University of Calgary Faculty of Veterinary Medicine. Animals and procedure: We conducted a retrospective review of all equine postmortem cases submitted to the DSU between July 1, 2010 and June 30, 2022. Over 12 y, 510 horses > 2 mo of age from Alberta were submitted to the DSU for necropsy. Active cases were defined as those with endarteritis and thrombosis in the CMA or its branches. Those cases with only intimal scarring of the CMA were classified as historical. Results: The prevalence of all CMA lesions (both historical and active) over the study period was 17.3% (88/510). Active S. vulgaris cranial mesenteric arteritis was documented in 6.1% (31/510) of equine postmortems and the sequelae of verminous arteritis were the cause of euthanasia or death in 1.5% (8/510) of the cases submitted. Conclusion and clinical relevance: Even after historically intense efforts to eradicate this parasite, the continued effects of S. vulgaris are demonstrated by the results of this study. Strongylus vulgaris should not be regarded as a parasite of the past and verminous arteritis remains an important differential diagnosis for horses in western Canada presenting with mild colic or dull demeanor and anorexia of duration > 24 h. Furthermore, S. vulgaris should be taken into careful consideration when implementing antiparasitic control strategies. Practitioners should remain current on prevention, diagnosis, and treatment of this potentially reemerging and fatal equine disease.

Étude rétrospective de la prévalence lors d'autopsies équines de l'artérite mésentérique crâniale causée par Strongylus vulgaris en Alberta (2010 à 2022). Contexte: Strongylus vulgaris est l'un des nématodes les plus pathogènes affectant les équidés. La migration des larves à travers l'artère mésentérique crâniale (CMA), accompagnée d'artérite et de thromboembolie, peut entraîner un infarctus intestinal non étranglant mortel. Autrefois considérée comme une maladie historique, des études récentes ont décrit la réémergence de cet agent pathogène dans plusieurs pays européens; cependant, on sait peu de choses sur la prévalence actuelle de S. vulgaris dans la population équine canadienne. Objectif: Déterminer la prévalence de l'artérite mésentérique crâniale active à S. vulgaris chez les chevaux soumis pour examen post mortem au Diagnostic Service Unit (DSU), College of Veterinary Medicine, University of Calgary. Animaux et procédure: Nous avons effectué un examen rétrospectif de tous les cas post-mortem d'équidés soumis au DSU entre le 1er juillet 2010 et le 30 juin 2022. Sur 12 ans, 510 chevaux âgés de plus de 2 mois de l'Alberta ont été soumis au DSU pour autopsie. Les cas actifs ont été définis comme ceux présentant une endartérite et une thrombose dans la CMA ou ses branches. Les cas présentant uniquement des cicatrices à l'intima de la CMA ont été classés comme anciens. Résultats: La prévalence de toutes les lésions de CMA (anciennes et actives) au cours de la période d'étude était de 17,3 % (88/510). Une artérite mésentérique crâniale active à S. vulgaris a été documentée dans 6,1 % (31/510) des autopsies équines et les séquelles de l'artérite vermineuse ont été la cause de l'euthanasie ou du décès dans 1,5 % (8/510) des cas soumis. Conclusion et pertinence clinique: Malgré des efforts historiquement intenses pour éradiquer ce parasite, les effets continus de S. vulgaris sont démontrés par les résultats de cette étude. Strongylus vulgaris ne doit pas être considéré comme un parasite du passé et l'artérite vermineuse demeure un diagnostic différentiel important pour les chevaux de l'ouest du Canada présentant des coliques légères ou un comportement abattu et une anorexie de durée > 24 h. De plus, S. vulgaris doit être attentivement pris en compte lors de la mise en œuvre de stratégies de contrôle antiparasitaire. Les praticiens doivent rester informés de la prévention, du diagnostic et du traitement de cette maladie équine potentiellement ré-émergente et mortelle.(Traduit par Dr Serge Messier).

Equus caballus papillomavirus Type 7 is a rare cause of equine penile squamous cell carcinomas.

Penile squamous cell carcinomas (SCCs) are common, potentially life-threatening neoplasms of horses. They are well-recognized to be caused by Equus caballus papillomavirus (EcPV) type 2, although EcPV2 cannot be detected in all cases. A 23-year-old standardbred gelding developed multiple penile in situ and invasive SCCs that contained histological evidence of PV infection. By using both consensus and specific PCR primers, these lesions were found to contain EcPV7 DNA, but not DNA from EcPV2 or any other PV type. To determine how frequently EcPV7 is present in equine penile SCCs, specific primers were used to detect EcPV2 and EcPV7 in a series of 20 archived samples. EcPV7 was the only PV detected in one, both EcPV2 and 7 were detected in five, and only EcPV2 was detected in 14 SCCs. EcPV7 DNA was also detected in three of 10 archived oropharyngeal SCCs, although only as a co- infection with EcPV2. This is the first report of EcPV7 causing disease in horses. These results suggest EcPV7 could cause a subset of equine penile SCCs, and this is the first evidence that PV types other than EcPV2 can cause these neoplasms. The detection of EcPV7 in the oropharyngeal SCCs suggests a potential role of this PV type in the development of these SCCs. There were no clinical or histological features that differentiated lesions containing EcPV7 DNA from those containing EcPV2 DNA. If EcPV7 causes a proportion of equine penile SCCs, vaccines to prevent EcPV2 infection may not prevent all equine penile SCCs.

Papillomaviral skin diseases of humans, dogs, cats and horses: A comparative review. Part 2: Pre-neoplastic and neoplastic diseases.

Papillomaviruses (PVs) are well recognized to cause pre-neoplastic and neoplastic diseases in humans. Similarly, there is increasing evidence that PVs play a significant role in the development of pre-neoplastic and neoplastic diseases of the haired skin of dogs and cats, and the mucosa of horses. As the mechanisms by which PVs cause neoplasia are well studied in humans, it is valuable to compare the PV-induced neoplasms of humans with similar PV-associated neoplasms in the companion animal species. In the second part of this comparative review, the pre-neoplastic and neoplastic diseases thought to be caused by PVs in humans, dogs, cats, and horses are described. This includes PV-induced cutaneous plaques, cutaneous squamous cell carcinomas (SCCs) and mucosal SCCs within the four species. The review concludes with a discussion about the potential use of vaccines to prevent PV-induced diseases of dogs, cats, and horses.

Papillomaviral skin diseases of humans, dogs, cats and horses: A comparative review. Part 1: Papillomavirus biology and hyperplastic lesions.

Papillomaviruses (PVs) cause disease in humans, dogs, cats, and horses. While there are some differences, many aspects of the pathogenesis, presentation, and treatment of these diseases are similar between the four species. In this review, the PV-induced diseases of humans are compared to the similar diseases that develop in the companion animal species. By comparing with the human diseases, it is possible to make assumptions about some of the less common and less well-studied diseases in the veterinary species. In the first part of this review, the PV lifecycle is discussed along with the classification of PVs and the immune response to PV infection. The hyperplastic diseases caused by PVs are then discussed; including PV-induced cutaneous, anogenital, and oral warts within the four species.

Vulvar squamous cell carcinoma associated with Equus caballus papillomavirus type 2 infection in a Japanese mare.

Equus caballus papillomavirus type 2 (EcPV2) infection has been associated with genital squamous cell carcinoma (SCC) development in horses. However, very few reports on EcPV2-associated disease in Asia exist. Our study characterizes pathological and virological features of an EcPV2-associated vulvar SCC from a Japanese mare. Conventional PCR, in situ hybridization, reverse-transcriptase PCR and immunohistochemistry confirmed the presence and distribution of EcPV2 within the lesion and suggested that p53 degradation may not be the mechanism by which this virus induces neoplastic transformation. The complete viral sequence in this Japanese case shows near perfect sequence homology with European reference strains of EcPV2, which may be useful when considering the target for future EcPV2 vaccine development. This report also serves to highlight the importance of EcPV2 in female (vulvar) neoplasia, which is less commonly recognized than EcPV2-induced male (penile or preputial) neoplasia. Finally, the SCC described in this mare was an unusual acantholytic variant that has not been reported previously in horses. It is the first report of EcPV2 identified from genital SCC in Asia and underscores the likely worldwide distribution of this virus and its consistent association with equine genital neoplasia.

Establishment of a Three-Dimensional In Vitro Model of Equine Papillomavirus Type 2 Infection.

There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is etiologically associated with the development of genital squamous cell carcinoma (SCC) and precursor lesions in equids. However, the precise mechanisms underlying neoplastic progression remain unknown. To allow the study of EcPV2-induced carcinogenesis, we aimed to establish a primary equine cell culture model of EcPV2 infection. Three-dimensional (3D) raft cultures were generated from equine penile perilesional skin, plaques and SCCs. Using histological, molecular biological and immunohistochemical methods, rafts versus corresponding natural tissue sections were compared with regard to morphology, presence of EcPV2 DNA, presence and location of EcPV2 gene transcripts and expression of epithelial, mesenchymal and tumor/proliferation markers. Raft cultures from perilesional skin harboring only a few EcPV2-positive (EcPV2+) cells accurately recapitulated the differentiation process of normal skin, whilst rafts from EcPV2+ penile plaques were structurally organized but showed early hyperplasia. Rafts from EcPV2+ SCCs exhibited pronounced hyperplasia and marked dysplasia. Raft levels of EcPV2 oncogene transcription (E6/E7) and expression of tumor/proliferation markers p53, Ki67 and MCM7 expression positively correlated with neoplastic progression, again reflecting the natural situation. Three-dimensional raft cultures accurately reflected major features of corresponding ex vivo material, thus constituting a valuable new research model to study EcPV2-induced carcinogenesis.

Treponema spp. Isolated from Bovine Digital Dermatitis Display Different Pathogenicity in a Murine Abscess Model.

Digital dermatitis (DD) causes lameness in cattle with substantial negative impact on sustainability and animal welfare. Although several species of Treponema bacteria have been isolated from various DD stages, their individual or synergistic roles in the initiation or development of lesions remain largely unknown. The objective of this study was to compare effects of the three most common Treponema species isolated from DD lesions in cattle (T. phagedenis, T. medium and T. pedis), both as individual and as mixed inoculations, in a murine abscess model. A total of 109 or 5 × 108Treponema spp. were inoculated subcutaneously, and produced abscess was studied after 7 days post infection. There were no synergistic effects when two or three species were inoculated together; however, T. medium produced the largest abscesses, whereas those produced by T. phagedenis were the smallest and least severe. Treponema species were cultured from skin lesions at 7 days post infection and, additionally, from the kidneys of some mice (2/5), confirming systemic infection may occur. Taken together, these findings suggest that T. medium and T. pedis may have more important roles in DD lesion initiation and development than T. phagedenis.

Prevalence of Equus caballus Papillomavirus Type-2 Infection and Seropositivity in Asymptomatic Western Canadian Horses.

Equus caballus papillomavirus type 2 (EcPV-2) has been recognized as a potential cause of a subset of genital squamous cell carcinomas (SCCs) in horses. In the current study, we measured EcPV-2 seropositivity in 50 healthy horses from Western Canada, and these were compared to a herd of horses with known EcPV-2 exposure. Second, the presence of EcPV-2 DNA was measured using EcPV-2-specific PCR (polymerase chain reaction), performed on a variety of tissues collected at necropsy from 70 horses that lacked any history, gross, or histologic evidence of neoplasia or papillomavirus-associated disease. EcPV-2-specific RNA in situ hybridization (R-ISH) was performed on PCR-positive samples to identify the specific tissues infected. The prevalence of asymptomatic infection with EcPV-2 in Western Canadian horses was 20/70 (29%). Exposure to EcPV-2 as measured by seropositivity was 18/50 (36%). EcPV-2 positivity by anatomic location, as measured by R-ISH, was as follows: penis 10/29 (35%), vulva 5/34 (15%), eyelid 8/68 (12%), oral mucosa 7/65 (11%), skin from muzzle 7/68 (10%), and retropharyngeal lymph node 2/64 (3%). The youngest horses with EcPV-2 infection, based on PCR, were fetuses, suggesting for the first time that vertical transmission of EcPV-2 occurs in horses. The current study observed an increased prevalence of EcPV-2 as compared to previous studies. We suggest that this difference is due to our use of biopsies in place of superficial swabs. We propose that EcPV-2 infection in asymptomatic horses is more common than previously reported and that the virus' role in equine genital SCCs may be more complex than originally thought.

Prevalence and Prognostic Impact of Equus caballus Papillomavirus Type 2 Infection in Equine Squamous Cell Carcinomas in Western Canadian Horses.

Equus caballus papillomavirus type-2 (EcPV-2) has been proposed as a causal factor in equine genital squamous cell carcinoma (SCC). This study had 2 objectives: first, calculate the frequency of papillomavirus (PV) and EcPV-2 infection in papillomas, carcinomas in situ (CIS), and SCCs in Western Canadian horses; and second, determine if EcPV-2 status of equine SCCs is associated with overall survival (OS). EcPV-2 status of 115 archived tissue samples, spanning 6 years, was determined using broad spectrum (MY09/11) and EcPV-2-specific polymerase chain reaction (PCR) assays, EcPV-2-E6/E7 chromogenic RNA in situ hybridization (R-ISH), and amplicon sequencing. A retrospective survey gathered data on history, outcome, breeding, treatment, and rationales of referring veterinarians when managing PV-associated diseases. Histologic grade and completeness of surgical margins of SCCs were also considered. EcPV-2 DNA was identified in 10/58 (17%) SCC, 8/27 (30%) papillomas, 0/5 CIS, and 0/11 lesions identified as "other." Overall, 18/101 (18%) of these lesions were positive for EcPV-2. EcPV-2 was identified in 10/35 (29%) SCCs arising from genital tissues but in 0/22 SCCs from other locations. There was no association between breeding history and EcPV-2 status of genital SCCs. EcPV-2 status of genital SCCs was not associated with OS (P = .76). The strongest negative predictors of OS were a lack of treatment (P < .01) and recurrence post-treatment (P < .01). Weaker predictors of OS included older age at time of diagnosis (P = .02). Completeness of margins at surgical excision, concurrent disease, treatment type, anatomic location of the SCC (anogenital vs other), and histologic grade of the SCC did not influence OS (P > .1).

Cathelicidins Mitigate Staphylococcus aureus Mastitis and Reduce Bacterial Invasion in Murine Mammary Epithelium.

Staphylococcus aureus, an important cause of mastitis in mammals, is becoming increasingly problematic due to the development of resistance to conventional antibiotics. The ability of S. aureus to invade host cells is key to its propensity to evade immune defense and antibiotics. This study focuses on the functions of cathelicidins, small cationic peptides secreted by epithelial cells and leukocytes, in the pathogenesis of S. aureus mastitis in mice. We determined that endogenous murine cathelicidin (CRAMP; Camp) was important in controlling S. aureus infection, as cathelicidin knockout mice (Camp-/- ) intramammarily challenged with S. aureus had higher bacterial burdens and more severe mastitis than did wild-type mice. The exogenous administration of both a synthetic human cathelicidin (LL-37) and a synthetic murine cathelicidin (CRAMP) (8 µM) reduced the invasion of S. aureus into the murine mammary epithelium. Additionally, this exogenous LL-37 was internalized into cultured mammary epithelial cells and impaired S. aureus growth in vitro We conclude that cathelicidins may be potential therapeutic agents against mastitis; both endogenous and exogenous cathelicidins conferred protection against S. aureus infection by reducing bacterial internalization and potentially by directly killing this pathogen.

Murine and Human Cathelicidins Contribute Differently to Hallmarks of Mastitis Induced by Pathogenic Prototheca bovis Algae.

Prototheca bovis (formerly P. zopfii genotype-II) is an opportunistic, achlorophyllous alga that causes mastitis in cows and skin disease in cats and dogs, as well as cutaneous lesions in both immunocompetent and immunosuppressed humans. Antifungal medications are commonly ineffective. This study aimed to investigate innate immune responses contributed by cathelicidins to P. bovis in the mammary gland using a mastitis model in mice deficient in the sole murine cathelicidin (Camp). We determined P. bovis caused acute mastitis in mice and induced Camp gene transcription. Whereas, Camp-/- and Camp+/+ littermates had similar local algae burden, Camp+/+ mice produced more pro-inflammatory cytokines, TNF-α, and Cxcl-1. Likewise, Camp+/+ bone marrow-derived macrophages were more responsive to P. bovis, producing more TNF-α and Cxcl-1. Human cathelicidin (LL-37) exhibited a different effect against P. bovis; it had direct algicidal activity against P. bovis and lowered TNF-α, Cxcl-1, and IL-1ß production in both cultured murine macrophages and mammary epithelial cells exposed to the pathogenic algae. In conclusion, cathelicidins were involved in protothecosis pathogenesis, with unique roles among the diverse peptide family. Whereas, endogenous cathelicidin (Camp) was key in mammary gland innate defense against P. bovis, human LL-37 had algicidal and immunomodulatory functions.

Prototheca zopfii genotype II induces mitochondrial apoptosis in models of bovine mastitis.

Prototheca zopfii is an alga increasingly isolated from bovine mastitis. Of the two genotypes of P. zopfii (genotype I and II (GT-I and -II)), P. zopfii GT-II is the genotype associated with acute mastitis and decreased milk production, although its pathogenesis is not well known. The objective was to determine inflammatory and apoptotic roles of P. zopfii GT-II in cultured mammary epithelial cells (from cattle and mice) and murine macrophages and using a murine model of mastitis. Prototheca zopfii GT-II (but not GT-I) invaded bovine and murine mammary epithelial cells (MECs) and induced apoptosis, as determined by the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay. This P. zopfii GT-II driven apoptosis corresponded to mitochondrial pathways; mitochondrial transmembrane resistance (ΔΨm) was altered and modulation of mitochondrion-mediated apoptosis regulating genes changed (increased transcriptional Bax, cytochrome-c and Apaf-1 and downregulated Bcl-2), whereas caspase-9 and -3 expression increased. Apoptotic effects by P. zopfii GT-II were more pronounced in macrophages compared to MECs. In a murine mammary infection model, P. zopfii GT-II replicated in the mammary gland and caused severe inflammation with infiltration of macrophages and neutrophils and upregulation of pro-inflammatory genes (TNF-α, IL-1ß and Cxcl-1) and also apoptosis of epithelial cells. Thus, we concluded P. zopfii GT-II is a mastitis-causing pathogen that triggers severe inflammation and also mitochondrial apoptosis.

Whey Protein and Its Components Lactalbumin and Lactoferrin Affect Energy Balance and Protect against Stroke Onset and Renal Damage in Salt-Loaded, High-Fat Fed Male Spontaneously Hypertensive Stroke-Prone Rats.

BACKGROUND: Whey protein (WH)-enriched diets are reported to aid in weight loss and to improve cardiovascular health. However, the bioactive components in whey responsible for causing such effects remain unidentified. OBJECTIVE: We determined the effects of whey and its components [α-lactalbumin (LA) and lactoferrin (LF)] on energy balance, glucose tolerance, gut hormones, renal damage, and stroke onset in rats. METHODS: Male spontaneously hypertensive stroke-prone (SHRSP) rats (age 8 wk) were fed isocaloric high-fat (40% kcal) and high-salt (4% wt/wt) diets (n = 8-10/group) and randomized for 8 wk to diets enriched as follows: control (CO): 15% kcal from egg albumin, 45% kcal from carbohydrate; WH: 20%kcal WH isolate + 15% kcal egg albumin; LA: 20% kcal LA  + 15% kcal egg albumin; or LF: 20% kcal lactoferrin + 15% kcal egg albumin. Measurements included energy balance (food intake, energy expenditure, and body composition), stroke-related behaviors, brain imaging, glucose tolerance, metabolic hormones, and tissue markers of renal damage. Data were analyzed by linear mixed models with repeated measures or 1-way ANOVA. RESULTS: Diets enriched with WH, LA, or LF increased survival, with 25% of rats fed these diets exhibiting stroke-associated morbidity, whereas 90% of CO rats were morbid by 8 wk (P < 0.05). The nephritis scores of rats fed WH-, LA-, or LF-enriched diets were 80%, 92%, and 122% lower than those of COs (P = 0.001). The mRNA abundances of renin and osteopontin were 100-600% lower in rats fed WH-, LA-, or LF-enriched diets than in COs (P < 0.05). Urine albumin concentrations and albumin-to-creatinine ratios were 200% lower in rats fed LF-enriched diets than in COs (P < 0.05). Compared with COs, rats fed LF-enriched diets for 2-3 wk had food intake decreased by 29%, body weight decreased by 13-19%, lean mass decreased by 12-19%, and fat mass decreased by 20% (P < 0.001). Relative to COs, rats fed WH and LA had food intake decreased by 10% (P < 0.1), but COs had 12-45% lower weight than rats fed LA- and WH-enriched diets by 3 wk (P < 0.01). Compared with COs, rats fed WH-enriched diets increased energy expenditure by 7%, whereas, rats fed LA-enriched diets had energy expenditure acutely decreased by 7% during the first 4 d, and rats fed LF-enriched diets had energy expenditure decreased by 7-17% throughout the first week ( P < 0.001). Rats fed LA- and LF-enriched diets had blood glucose decreased by 14-19% (P < 0.05) and WH by 9% (P = 0.1), relative to COs. Compared with COs, rats fed LF had GIP decreased by 90% and PYY by 87% (P < 0.05). CONCLUSION: Together, these findings indicate that whey and its components α-lactalbumin and lactoferrin improved energy balance and glycemic control, and protected against the onset of neurological deficits associated with stroke and renal damage in male SHRSP rats.

Oxytetracycline reduces inflammation and treponeme burden whereas vitamin D3 promotes ß-defensin expression in bovine infectious digital dermatitis.

Digital dermatitis (DD), a common ulcerative disease of the bovine foot causing lameness and reducing productivity and animal welfare, is associated with infection by spirochete Treponema bacteria. Topical tetracycline, the most common treatment, has inconsistent cure rates; therefore, new therapeutic options are needed. We compared effects of topical oxytetracycline and vitamin D3 on innate immunity in DD-affected skin. Cows with active DD lesions were treated topically with oxytetracycline or vitamin D3 and skin biopsies were collected from lesions. Tissue samples were examined histologically, transcriptional expression of pro-inflammatory cytokines, Toll-like receptors (TLRs), and host defense peptides assessed, and the presence of specific treponeme species determined. Effects of treatments at a mechanistic level were studied in a human keratinocyte model of treponeme infection. Oxytetracycline promoted hyperplastic scab formation in ulcerated DD lesions and decreased transcriptional expression of Cxcl-8 (neutrophil chemoattractant). Oxytetracycline also reduced numbers of Treponema phagedenis and T. pedis and enhanced Tlr2 mRNA expression. Vitamin D3 did not modify expression of cytokines or Tlrs, or bacterial loads, but enhanced transcription of tracheal antimicrobial peptide (Tap), a key bovine ß-defensin. Combing oxytetracycline and vitamin D3 provides complementary clinical benefits in controlling DD through a combination of antimicrobial, immunomodulatory, and pro-healing activities.

Paving the way for more precise diagnosis of EcPV2-associated equine penile lesions.

BACKGROUND: There is growing evidence that equine papillomavirus type 2 (EcPV2) infection is causally associated with the development of equine genital squamous cell carcinomas (SCCs). Early stages of disease present clinically as plaques or wart-like lesions which can gradually progress to tumoural lesions. Histologically these lesions are inconsistently described as benign hyperplasia, papilloma, penile intraepithelial neoplasia (PIN), carcinoma in situ (CIS) or SCC. Guidelines for histological classification of early SCC precursor lesions are not precisely defined, leading to potential misdiagnosis. The aim of this study was to identify histologic criteria and diagnostic markers allowing for a more accurate diagnosis of EcPV2-associated equine penile lesions. RESULTS: A total of 61 archived equine penile lesions were histologically re-assessed and classified as benign hyperplasia, papilloma, CIS or SCC. From these, 19 representative lesions and adjacent normal skin were comparatively analysed for the presence of EcPV2 DNA and transcripts using PCR and RNA in situ hybridisation (RISH). All lesional samples were positive by EcPV2 PCR and RISH, while adjacent normal skin was negative. RISH analysis yielded signal distribution patterns that allowed distinction of early (hyperplasia, papilloma) from late stage lesions (CIS, SCC). Subsequently, the 19 lesions were further assessed for expression of p53, Ki67, MCM7 and MMP1 by immunohistochemistry (IHC). All four proteins were expressed in both normal and lesional tissue. However, p53 expression was up-regulated in basal keratinocyte layers of papillomas, CIS and SCCs, as well as in upper keratinocyte layers of CIS and SCCs. MCM7 expression was only up-regulated in upper proliferating keratinocyte layers of papillomas, CIS and SCCs. CONCLUSION: This study proposes combining a refined histological protocol for analysis of equine penile lesions with PCR- and/or RISH based EcPV2-screening and p53/MCM7 IHC to more accurately determine the type of lesion. This may help to guide the choice of optimum treatment strategy, especially at early stages of disease.

Assessing the Efficacy of Ventilation of Anesthetized Neonatal Calves Using a Laryngeal Mask Airway or Mask Resuscitator.

Calves that have undergone a dystocia are often hypoxic and acidemic, which can result in reduced vigor and subsequent mortality. Methods of field resuscitation of apneic newborn calves are often ineffective and therefore underutilized. This proof-of-concept study aimed to determine the efficacy of the laryngeal mask airway (LMA) as well as the current industry standard method of ventilation, the McCulloch Calf Aspirator/ Resuscitator (MMR) for positive pressure ventilation of neonatal calves. Five LMA models of various sizes were first tested in cadaver heads to assess anatomical fit. Three LMA models in two sizes each were then tested in two anesthetized calves to determine the model best suited to ventilate calves. Next, the selected LMA and the MMR were both assessed for efficacy of ventilation. Six anesthetized calves had hypoventilation induced by administering alfaxalone intravenously. Calves were ventilated for 3 min with the LMA, allowed a brief washout period, then given a second administration of alfaxalone prior to ventilation with the MMR. Serial arterial blood gas analyses were performed prior to ventilation (baseline), at 1, 2, and 3 min during ventilation, and 1 min after ventilation had ceased. Success of ventilation was assessed by monitoring partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), bicarbonate ( HCO 3 - ), pH, L-lactate, and hemoglobin saturation (SaO2) in arterial blood. A one-way ANOVA for repeated measures with Bonferroni correction was used to assess the efficacy of ventilation of each device compared to baseline. For the LMA, PaO2, SaO2, and pH were significantly higher than baseline throughout ventilation and PaCO2 was significantly lower than baseline at 1 min of ventilation. For the MMR, PaO2 and SaO2 were significantly higher and PaCO2 and HCO 3 - were significantly lower than baseline for 1 to 2 min of ventilation. This proof-of-concept study showed the LMA is an effective means of ventilating neonatal calves, as was the MMR.

A Differential Innate Immune Response in Active and Chronic Stages of Bovine Infectious Digital Dermatitis.

Digital dermatitis (DD) commonly associated with Treponema spp. infection is a prevalent infectious bovine foot disease characterized by ulcerative and necrotic lesions. Lesions associated with DD are often classified using the M-stage scoring system, with M0 indicating healthy heel skin and M4 indicating chronic lesions. Current treatments utilizing antimicrobials or chemical footbaths are often ineffective and rarely cure DD lesions. Understanding the function of the innate immune response in the pathogenesis of DD will help to identify novel therapeutic approaches. In this study, the expression of the local innate host defense peptides cathelicidins and ß-defensins was investigated in cows with DD and associated with the presence of treponemes and inflammatory reactions. Samples from active ulcerative DD lesions (M2) had considerable epidermal neutrophilic infiltration and increased gene expression of ß-defensin tracheal antimicrobial peptides compared to control skin. Samples from acute lesions also had elevated local Cxcl-8 and TLR4 gene expression and abundant treponemes as identified by direct visualization, immunohistochemistry, and culture. Conversely, the anti-inflammatory peptide IL-10 was elevated in skin from chronic (M4) lesions, whereas bovine cathelicidin myeloid antimicrobial peptide 28 (Bmap-28) was increased in skin from oxytetracycline-treated M2 lesions. Experiments using cultured human keratinocytes challenged with Treponema spp. isolated from clinical cases of bovine DD showed that structural products from treponemes are able to initiate the innate immune response, in part through TLR2 signaling. These findings indicate that neutrophil influx, Cxcl-8, and ß-defensin are key markers of active DD. Cathelicidins and IL-10 seem important in response to treatment or during the chronic proliferative stages of the disease.

Equine Endometrial Explants Undergo Significant Degenerative Changes in Culture.

This study evaluated equine endometrial explants following 12, 24, and 48 hr in culture. Measurement of an indicator of cell death in explant supernatant, light microscopy, and gene expression of biomarkers of endometrial function and cellular stress were used to compare the effect of six different media on explant viability and morphology. Viability of explants was assessed indirectly through measuring LDH activity in the culture supernatant. Regardless of culture medium composition, a significant increase in LDH activity was observed within 12 hr of culture, indicating occurrence of cell damage. Morphological analysis through light microscopy revealed degenerative changes occurring within 12 hr and, after 48 hr, there is nearly complete loss of luminal and superficial glandular epithelium and diffuse detachment of deep glandular epithelium. Transcript abundance of prostaglandin-endoperoxide synthase 2 (PTGS2), estrogen receptor 1 (ESR1), and vascular endothelial growth factor (VEGF) was assessed as biomarkers of endometrial function. A marked increase in PTGS2 and VEGF expression occurred; ESR1 displayed more or less steady expression levels. Above-described changes were seen irrespective of cell culture medium used. The marked increase in expression in PTGS2 expression presents a limitation to using endometrial explants in the current culture system to study aspects of endometrial function such as the inflammatory response to insemination. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:148-153, 2018. © 2017 Wiley Periodicals, Inc.