High Seroprevalence of Lawsonia intracellularis in Thoroughbred Farms in Southern Brazil.

The aim of the present study was to carry out a serological survey to identify the seroprevalence of Lawsonia intracellularis in six Thoroughbred farms in the Southern region of the state of Rio Grande do Sul, Brazil. During 2019 and 2020, blood samples from 686 Thoroughbred horses were obtained from six different breeding farms. Horses were divided into groups according to age: (1) broodmares (>5 years), (2) two-year-old foals, (3) yearlings, and (4) 0-6 months-old foals. Blood samples were collected by venipuncture of the external jugular vein. The detection of antibodies (IgG) against L. intracellularis was performed by Immunoperoxidase Monolayer Assay. The detection of specific antibodies (IgG) against L. intracellularis in the evaluated population was 51%. The highest detection (86.8%) of IgG was in the broodmares category, while the lowest (5.2%) was in foals of 0-6 months of age. Regarding the farms, the Farm 1 had the highest (67.4%) prevalence of seropositivity against L. intracellularis, while Farm 4 had the lowest (30.6%). There was no record of clinical manifestation of Equine Proliferative Enteropathy in the sampled animals. The results of this study show the high seroprevalence of L. intracellularis in Thoroughbred farms in the Southern of Rio Grande do Sul, suggesting a large and continuous exposure to the agent.

Humoral immunity is not altered in overweight pregnant Crioulo mares / Imunidade humoral não é alterada em éguas Crioulas gestantes com sobrepeso

Both pregnancy and obesity can influence significant changes in the immune system. On this basis, the present study proposes to evaluate the humoral immune response of overweight pregnant mares in response to a commercial vaccine. Thirty pregnant Crioulo mares were separated according to body condition score (BCS) into overweight (BCS≥7/9) or lean-control (BCS= 5-6/9). In each group, the animals were subdivided into vaccinated and controls. The mares were vaccinated against EHV-1 in two doses spaced 21 days apart and had their blood collected monthly, for five months, for antibody evaluation. Both vaccinated groups had an increase in specific neutralizing antibodies after the vaccine. However, after the second dose, there was no increase in antibodies in any of the groups. Vaccinated overweight and lean-control mares did not differ at any time point. Therefore, this study demonstrated that obesity does not influence the humoral immune response in pregnant Crioulo mares.(AU)

Tanto a gestação quanto a obesidade podem influenciar o desenvolvimento de alterações significativas no sistema imune, portanto, o presente estudo teve como objetivo avaliar a resposta imune humoral de éguas gestantes com sobrepeso em resposta a uma vacina comercial. Trinta éguas Crioulas gestantes foram separadas de acordo com o escore de condição corporal (ECC) em éguas com sobrepeso (ECC≥7/9) e éguas controles (ECC=5-6/9) e, ainda, em cada grupo, os animais também foram separados em vacinados e controles. As éguas foram vacinadas contra o EHV-1 em duas doses com intervalo de 21 dias, sendo realizadas coletas de sangue mensalmente durante cinco meses para avaliação de anticorpos neutralizantes. Ambos os grupos vacinados tiveram aumento de anticorpos neutralizantes específicos após a vacina, porém, após a segunda dose, não foi observado aumento de anticorpos em nenhum dos grupos. Nenhuma diferença foi observada entre éguas vacinadas com sobrepeso e as éguas controles em nenhum momento. Assim, este estudo demonstrou que a obesidade não é um fator que influencia a resposta imune humoral de éguas Crioulas gestantes.(AU)

Occurrence of Gasterophilus spp. in weanling foals in southern Brazil

The occurrence of gastrointestinal myiasis caused by Gasterophilus spp. larvae (Diptera: Oestridae) in adult horses has been widely characterized, however data on natural infestation in young foals have been lacking. This observation may be related to the absence of conclusive diagnosis in these individuals, most likely due to logistical or financial constraints. Gastric ulceration is a problem and a significant cause of morbidity in foals, particularly during the weaning stage; therefore, gasterophilosis should be included in the differential diagnosis. The primary purpose of this study was to determine the prevalence of gasterophilosis in 4- to 6-month-old weanling foals. Seventy-one healthy weanling foals were enrolled in the study. Physical assessment blood sampling and was completed in all foals before the commencement of the experiment. Gastroscopy examinations were performed under sedation (Detomidine 0.01 - 0.02 mg/kg) with a flexible endoscope inserted through nasogastric via. The lumen of the stomach was examined in order to search for botflies' larvae. Following gastroscopy, foals were classified into 2 groups based on the presence of Gasterophilus spp. larvae in their stomachs: 1) Infected and 2) Not Infected. Infected foals received a single dose of commercial trichlorfon and albendazole equine oral gel and were stalled for 24 h. The passed feces were thoroughly examined, searching for elimination of larvae. A total of 64% of the foals (n = 45/71) harbored Gasterophilus spp. larvae in the stomach. Mild hyperemia in the gastric mucosa was observed in the attachment sites of the parasites. Physical assessment and hematological parameters' data were analyzed with Shapiro-Wilk normality test. Comparison between groups for clinical signs, hematological parameters and Gasterophilus spp. infection rates were evaluated using the Kruskal-Wallis test or Student's t-test. Statistical significance was set at P < 0.05. There were no statistically significant variations in physical and hematological parameters between foals that were affected and those that were not infected. The larvae found in the feces were subjected to morphological examination, which confirmed the diagnosis of Gasterophilus intestinalis. No systemic clinical indications compatible with Gasterophilus spp. infestation were seen, as described in previous studies of horses infected with the parasite. No botfly eggs were observed in the hair of evaluated foals. During gastroscopy, mild hyperemic lesions in the gastric mucosa were observed in the larvae fixation sites. Although no changes in clinical or hematological parameters were noted, the confirmation of parasite presence is a cause for concern due to horses' tolerance for low infestation levels and poor diagnosis. Additionally, the presence of this myiasis in foals may be a significant stressor during the weaning period and should be included in the differential diagnosis of recurring abdominal pain. Furthermore, infected foals might be a reservoir for the parasite and, contribute to the elimination and spread of the larvae in the environment. Thus, inclusion of young horses in deworming protocols targeted to botfly larvae is needed. This is the first report of Gasterophilus intestinalis myiasis in foals in Brazil. Further research is necessary to fully understand the epidemiology and prevalence of this condition in young horses in Brazil, based on the findings of this study.(AU)

Peripheral blood markers of sepsis in foals born from mares with experimentally induced ascending placentitis.

BACKGROUND: Neonatal sepsis is a leading cause of neonatal death during the first-week postfoaling. Despite recent advancements in the diagnosis and treatment of sepsis in the newborn foal, the non-specific clinical signs and subtle nature of this disease may result in delayed diagnosis until severe progression of the disease; thus, early detection of sepsis remains critical for a favourable outcome. This study aimed to identify early blood markers as predictive of sepsis on foals. METHODS: Thirty-five foals were allocated into three groups: healthy control foals (n=7) and foals born from mares with placentitis: septic foals (n=9) and non-septic foals (n=19). Blood samples were obtained immediately after foaling and at 12, 24 and 48 hours. All samples were assessed for glucose, lactate, triglycerides, total cholesterol, urea, creatinine, total solids, fibrinogen, gamma-glutamyl transferase (GGT), serum amyloid A (SAA) and alpha-fetoprotein (AFP) concentrations. RESULTS: At foaling, glucose and GGT concentrations were lower in septic foals (P<0.001). Of interest, SAA, AFP, creatinine and total cholesterol were higher in septic foals at parturition (P<0.05). At 12 hours, lactate, triglycerides and total cholesterol concentrations were higher in septic foals. When evaluated at 24 and 48 hours, higher concentrations of SAA and AFP were found in placentitis foals than in the control group. CONCLUSIONS: Total cholesterol and lactate appear to be suitable markers for sepsis during the first 24 hours postpartum. Septic foals displayed altered energy metabolisms as determined by increased triglycerides and cholesterol concentrations, hypoglycaemia at birth and reduced activity of the GGT and increased lactate and urea concentrations. Sepsis was associated with high concentrations of SAA and AFP.

Immunolocalization of Leptin and its Receptor (ObR-b) in Equine Placenta at Term and Plasma Level Measurement in the Late Gestation.

Placental tissues from humans, rodents, and farm animal contain leptin and its receptor. Expression of leptin has already been described in horses, although there is no description about immunolocalization of leptin and its receptor. The aim of the present study was to investigate the presence and distribution of leptin and ObR-b in the equine placenta at term by immunofluorescence staining, and the changes on plasma leptin concentrations during late gestation. The present study involved eight Criollo-type mares carrying healthy pregnancies. Blood samples were collected during the third trimester of gestation, at foaling, and at 24 hours after foaling. Leptin concentrations were analyzed via radioimmunoassay. Plasma leptin concentrations did not change from the 8th to the 10th month of gestation and displayed a discrete decrease 24 hours after parturition (P = .07). The expression of leptin and ObR-b was observed in the cytoplasm of pseudostratified epithelial cells in the areolar region and in the epithelium of microcotyledons. Also, leptin receptor was allocated in the apical surface of the cells. The presence of leptin and its receptor (ObR-b) in the placenta of mares at term supports an endocrine and autocrine/paracrine action of leptin within this organ.

Development of a weight-estimation model to use in pregnant criollo-type mares / Modelo para estimativa de peso em éguas gestantes mestiças crioulas

ABSTRACT: The aims of this study were: 1) to compare the tape weight and associated weight-estimation formula to evaluate weight gain in pregnant mares, and 2) to develop a mathematical model to estimate the weight of pregnant mares using body measurements. Thirty-four criollo-type mares were evaluated every two weeks during the middle and late pregnancy. The mares were weighed on a livestock scale, and we estimated body weight using tape weights and an associated body-weight estimation formula. Also, heart-girth circumference (heartgirth) and abdominal circumference were measured; the latter at the 12th intercostal space (12th ICS) and 18th rib (18th Rib), to use in a mathematical model to estimate the weight of pregnant mares. Observations were divided into three periods of pregnancy: 5th to 7 h month, 7th to 9 h month, and 9th to 11th month. Mares in late pregnancy showed an increase in actual weight and an increase in 12th ICS and 18th Rib measurements. Tape weight and body-weight estimation formula underestimated the weight of pregnant mares. However, the regression model using heart-girth circumference, 12th ICS, and 18th Rib measurements showed high correlation (r2 = 0.87, P<0.001) with actual weight. Finally, the alternative methods usually used in horses are not accurate to estimate body weight in pregnant mares. In conclusion, the regression model Y=-540.143 + (heartgirth x 3.068) + (12th ICS x 1.278) + (18th Rib x 0.944) can be used to estimate body weight in pregnant mares from the 5th to 11th months of pregnancy.

RESUMO: Este estudo teve como objetivos: 1) comparar a utilização dos métodos alternativos fita de pesagem e peso metabólico em éguas gestantes e; 2) desenvolver um modelo matemático para estimar o peso de éguas gestantes, baseado em medidas corporais. Trinta e quatro éguas foram avaliadas quinzenalmente durante o terço médio e final da gestação. Foi realizada a pesagem em balança comercial; a mensuração com a fita de peso para equinos; o cálculo do peso metabólico; as medidas de perímetro torácico (Ptorac); a mensuração abdominal no décimo segundo espaço intercostal (12EI) e na décima oitava costela (18Cost). As observações foram divididas em três períodos gestacionais: Período de 5 a 7 meses, Período de 7 a 9 meses e Período de 9 a 11 meses. As éguas demonstraram incremento no peso na balança e na mensuração abdominal no 12EI e 18Cost no terço final da gestação. A utilização da fita de pesagem e o cálculo de peso metabólico subestimaram o peso na balança em éguas gestantes. O modelo de regressão utilizando o Ptorac, 12EI e 18Cost apresentou alta correção (r2=0,87; P<0,001) com o peso na balança. Observou-se que os métodos alternativos de pesagem, usualmente utilizados, não apresentaram a mesma eficiência em éguas prenhes. Pode-se concluir que o modelo de regressão Y=-540,143+(Ptorac X 3,068) + (12EI X 1,278) + (18Cost X 0,944) pode ser utilizado para mensurar o peso em éguas gestantes a partir do 5º mês de gestação.

Histomorphometry of the placental vasculature and microcotyledons in Thoroughbred mares with chronic laminitis.

The objective of this study was to assess the placental vasculature and microcotyledons in pregnant mares with chronic laminitis. Twenty-six pregnant mares were enrolled in the study, 13 had chronic laminitis (Laminitis Group) and 13 were healthy mares (Healthy Group). Arterial systolic pressure and heart rate were measured in the last 30 days of gestation. After foaling, the fetal membranes were grossly evaluated and samples were harvested for histopathologic examination. All mares had digitalized images taken from chorioallantois for histomorphometry analyses (software-NIH ImageJ). Images were assessed for: (i) arterioles from the allantoic region: total and lumen vascular diameter and vascular wall thickness; (ii) microcotiledonary and capillary area/field. Mares in the Laminitis Group showed hypertension, shorter gestational length, lower placental weight and lower birthweight (p < 0.05) foal in comparison with mares in the Healthy Group. Laminitis mares had a reduction of vascular lumen diameters in the uterine body and pregnant horn (p < 0.05), vascular wall thickening in the pregnant horn (p < 0.05) and smaller capillary area/field in the microcotyledons of uterine body and pregnant horn (p < 0.05). In conclusion, pregnant mares with chronic laminitis presented signs of hypertension syndrome, and vascular abnormalitities in placental vessels such as reduction in the vascular lumen and capillary area in the microcotyledones, and thickening of the vascular wall. Foals born from mares with chronic laminitis showed lower birth weight and shorter gestation lengths.

Oral single dose of allopurinol in thoroughbred foals born from mares with placentitis / Administração de alopurinol por via oral de dose única em potros nascidos de éguas com placentite

ABSTRACT: The aim of this study was to evaluate the effects of Allopurinol in foals born from mares with placentitis. Twenty foals were assigned into two groups: Healthy foals (n=10), born from healthy mares and Placentitis foals (n=10), born from mares with placentitis. Five foals from each group were randomly assigned to a treatment or control group. Treatment groups received Allopurinol (40mg kg-1 orally six hours after birth). Blood samples were collected for estimation of hematological variables and serum concentration of calcium, chloride, creatinine, phosphorus, glucose, lactate and magnesium. Placentitis foals presented leukopenia and neutropenia when compared with Healthy foals, at birth. The white blood cell (WBC) count was lower in the Placentitis foals untreated at 12 hours. No adverse effects related to the use of Allopurinol were detected. Treated Placentitis foals showed higher serum calcium and glucose levels within 12 hours than untreated Placentitis foals. Administration of Allopurinol PO in foals born from mares with placentitis did not result in adverse effects and can help in stabilizing serum calcium and glucose levels.

RESUMO: Este estudo teve por objetivo avaliar os efeitos da administração por via oral de Alopurinol em potros nascidos de éguas com placentite. Vinte potros foram divididos em dois grupos: potros saudáveis (n=10), nascidos de éguas sem placentite, e potros placentite (n=10), nascidos de éguas com placentite. Cinco potros de cada grupo foram selecionados aleatoriamente para compor o grupo tratado ou controle. Os grupos tratados receberam Alopurinol (40mg kg-1 PO na sexta hora de vida). Foram coletadas amostras sanguíneas para realização de análise hematológica e avaliação das concentrações séricas de cálcio, cloretos, creatinina, fósforo, glicose, lactato e magnésio. Os potros placentite apresentaram leucopenia e neutropenia, comparado com os potros saudáveis no momento do nascimento. O grupo placentite não tratado apresentou leucopenia no momento 12 horas. Não foram observados efeitos adversos relacionados ao uso do Alopurinol. O grupo placentite tratado apresentou maiores concentrações de cálcio e glicose em relação ao grupo placentite não tratado, nas 12 horas. A administração de Alopurinol por via oral em dose única em potros nascidos de éguas com placentite não resultou em efeitos adversos e pode ter contribuído para a estabilização dos níveis de cálcio e glicose.

Vitrification of equine oocytes with a polyvinyl alcohol after in vitro maturation with equine growth hormone and insulin-like growth factor-I.

BACKGROUND: In vitro fertilization (IVF) procedures are limited by the inability to mature equine oocytes on in vitro methods. OBJECTIVE: The aim of this study was to evaluate structural integrity of equine oocytes subjected to vitrification with a synthetic polymer (PVA). METHODS: The effect of eGH and its relationship with IGF-I on in vitro maturation (IVM) were evaluated. Compact cumulus oocytes complexes (n=122) were cultured in TCM-199 with eGH, IGF-I or eGH+IGF-I for 30h at 38.5C in air with 5 % CO2. Oocytes were fixed after IVM or subjected to the vitrification protocol. Cryopreserved oocytes were exposed to 1.4M DMSO+1.8M EG+1 percent PVA for 3min, and then transfer to 2.8M DMSO+3.6M EG+0.6M sucrose+1 % PVA for 1min. After rewarming, oocytes were evaluated by confocal microscopy. RESULTS: Maturation rates of oocytes were not significant different among groups (P > 0.05), however eGH+IGF-I group can develop the assessment of resumption of meiosis (MI+MII = 86.7 %). CONCLUSION: The oocyte did not show morphological alterations. The use of PVA-copolymer may represent a potential alternative for vitrification of equine oocytes after IVM.

Isolamento de Arcanobacterium pyogenes de granuloma actinomicóide em bovino / Isolation of Arcanobacterium pyogenes of actinomycotic-like granuloma in a cow

Foi observada em um bovino com suspeita de lechiguana, uma lesäo arredondada de consistência dura na regiäo sub-mandibular que media 12x11x7cm. Foram realizadas biópsias cirúrgicas para estudos bacteriológico e histológico, teste de tuberculinizaçäo intra-dérmico e coleta de sangue, a fim de realizar o teste de imunodifusäo radial para o diagnóstico de lechiguana. Posteriormente, foi realizada eutanásia e necropsia do animal. No resultado das biópsias, näo se obteve isolamento bacteriano e o estudo histológico näo foi conclusivo. Os testes de tuberculinizaçäo e de imunodifusäo apresentaram resultado negativo. Na necropsia, constatou-se que a lesäo consistia de um nódulo, formado por uma cápsula de tecido conjuntivo envolvendo uma massa esbranquiçada com grânulos amarelados de até 3mm de diâmetro. Através de histologia, constataram-se piogranulomas multifocais, com um infiltrado de neutrófilos circundando rosetas formadas por colônias bacterianas no centro e corpúsculos de Splendore-Hoeppli na periferia; ao redor desse infiltrado purulento observaram-se células epitelióides e tecido fibroso infiltrado por linfócitos. Arcanobacterium pyogenes foi isolado em cultura pura do material obtido na necropsia. Conclui-se que A. pyogenes poderia ter participaçäo na etiologia de granuloma com características clínicas e patológicas semelhantes à lechiguana, tuberculose e actinobacilose.