Macarena Sanz - Academia.edu (original) (raw)

Papers by Macarena Sanz

Equine Veterinary Journal, 2022

Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a... more Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a common cause of disease and death for foals. The purpose of this narrative review is to summarise recent developments pertaining to the epidemiology, immune responses, treatment, and prevention of rhodococcal pneumonia of foals. Screening tests have been used to implement earlier detection and treatment of foals with presumed subclinical R. equi pneumonia to reduce mortality and severity of disease. Unfortunately, this practice has been linked to the emergence of antimicrobial resistant R. equi in North America. Correlates of protective immunity for R. equi infections of foals remain elusive, but recent evidence indicates that innate immune responses are important both for mediating killing and orchestrating adaptive immune responses. A macrolide antimicrobial in combination with rifampin remains the recommended treatment for foals with R. equi pneumonia. Great need exists to identify which antimicrobial combination is most effective for treating foals with R. equi pneumonia and to limit emergence of antimicrobial-resistant strains. In the absence of an effective vaccine against R. equi, passive immunisation remains the only commercially-available method for effectively reducing the incidence of R. equi pneumonia. Because passive immunisation is expensive, labour-intensive, and carries risks for foals, great need exists to develop alternative approaches for passive and active immunisation.

Objective: 1) To describe the changes that occur in foal lipidomics as a result of aging (birth to 8

BMC Research Notes, 2022

Objective The efficacy of Rhodococcus equi-specific hyperimmune plasma (HIP) is usually evaluated... more Objective The efficacy of Rhodococcus equi-specific hyperimmune plasma (HIP) is usually evaluated in vitro. Anticoagulants (AC) used for plasma collection can negatively impact bacterial replication but their effect on R. equi growth has not been evaluated. The aim of this study was to establish the effect that AC routinely used in veterinary medicine (ACD, K2EDTA, Li Heparin, and Na Citrate) have on in vitro R. equi growth. To assess this, in vitro assays commonly used to test HIP efficacy (direct effect on microorganism and macrophage infection), were performed using each AC and non-treated bacteria. Results There was no direct effect of ACD, Li Heparin or Na Citrate on R. equi growth. These AC significantly (p

Equine Veterinary Journal, 2022

Understanding factors influencing assessment of pain in horses will facilitate communication betw... more Understanding factors influencing assessment of pain in horses will facilitate communication between veterinarians and horse owners. To compare estimates of pain experienced by horses as provided by veterinarians and horse owners and to determine factors associated with individuals who perceive horses to be experiencing extreme pain or minimal pain. Cross-sectional study. Internet-based questionnaires for horse owners and veterinarians included items related to recognition of pain in horses, estimated degree of pain experienced by horses, and demographic information. Variables associated with perception of a high or low degree of pain were investigated using logistic regression analyses. Final data sets included responses from 553 horse owners and 263 veterinarians. Pain scores varied widely and differences in median scores from horse owners and veterinarians were small. Horse owners providing high pain ratings were more likely to have < 10 horses (odds ratio [OR] = 2.0, 95% CI = 1.1 - 3.5) and to not have a college degree (OR = 1.5, 95% CI = 1.0-2.2). Those providing low pain ratings were less likely to own < 10 horses (OR = 0.6, 95% Confidence Interval [CI] = 0.4 - 0.9). Veterinarians providing high pain ratings were more likely to be employed in a mixed animal practice (OR = 2.8, 95% CI = 1.3 - 5.9) and to lack board-certification in a veterinary specialty (OR = 2.1, 95% CI = 1.1 - 4.2). Veterinarians providing low pain ratings were more likely to be male (OR = 2.4, 95% CI = 1.3 - 4.2). The respondent population may be biased because of the method of questionnaire distribution and associated sampling bias. Respondents were primarily from the United States. Assessments of the degree of pain horses are experiencing vary widely among horse owners and equine veterinarians.

Journal of Swine Health and Production, 2007

Causes of sow and gilt death were appraised with postmortem examinations for 20 weeks (May to Oct... more Causes of sow and gilt death were appraised with postmortem examinations for 20 weeks (May to October) in a 5200-sow herd experiencing higher than expected sow mortality. Complete necropsy fi ndings and data are provided for 107 females. The locomotor, gastrointestinal, reproductive, and urinary systems were affected with lesions presumably causing death; however, lesions affecting the respiratory and circulatory systems also were evident. Sow death was more common during gestation and lactation than in the breeding phase of production. Animals euthanized by farm personnel accounted for approximately 40% of deaths. A group of 88 cull sows was examined at slaughter to discover the distribution of lesions in the surviving population. The proportion of animals with lesions differed between the culled and necropsied sows.

Equine Veterinary Journal, 2021

BACKGROUND Many foals that develop thoracic ultrasonographic lesions as a result of Rhodococcus e... more BACKGROUND Many foals that develop thoracic ultrasonographic lesions as a result of Rhodococcus equi infection heal on their own. However, most of these foals receive antibiotics because foals at risk of developing clinical pneumonia cannot be identified. Untargeted lipidomics is useful to identify candidate biomarkers. OBJECTIVES 1) To describe the changes that occur in foal lipidomics as a result of ageing (birth to 8 weeks) and 2) To compare these results with those observed in foals after experimental infection with R equi. STUDY DESIGN Experimental study. METHODS Healthy newborn foals (n = 9) were challenged with R equi intratracheally the first week of life. Foals were treated with antibiotics if they developed clinical pneumonia (n = 4, "clinical group") or were closely monitored if they showed no signs of disease (n = 5 "subclinical group"). An unchallenged group (n = 4) was also included. All foals were free of disease (transtracheal wash fluid evaluation and culture as well as thoracic ultrasonography) by 8 weeks of life. Plasma lipidomics was determined by LC-MS weekly for the study duration (8 weeks). RESULTS Both ageing and experimental infection altered the foal's plasma lipidome as demonstrated by multivariate statistical analysis. The intensities of 31 lipids was altered by ageing and 12 by infection (p < 0.05). Furthermore, 9 lipids changed by more than 2-fold between clinical and subclinical groups. MAIN LIMITATIONS The number of foals is limited. Foals were experimentally challenged with R equi. CONCLUSIONS Ageing and R equi infection induced changes in the plasma lipidome of foals. These experimental results provide the background for future work in the discovery of earlier biomarkers of R equi pneumonia. Early identification of foals at risk of developing clinical pneumonia is key in order to decrease antimicrobial use and development of resistance.

Journal of Equine Veterinary Science, 2021

Relative to other species, horses seem particularly susceptible to oxidative stress. Plasma album... more Relative to other species, horses seem particularly susceptible to oxidative stress. Plasma albumin plays an important role in preventing oxidative damage, in part due to its methionine (MET) content. Equine albumin is highly unusual in that it contains no MET residues. Whether or not this causes deficient antioxidant capacity in equine plasma relative to that of other species has not yet been explored. The objective of this study was to compare the redox status of equine (no MET) to that of bovine (moderate amount of MET) plasma. Plasma was collected from healthy, nonpregnant Quarter Horse mares (n = 10) and adult, healthy, nonpregnant, dried Holstein cows (n = 15). Measures of total antioxidant capacity and oxidative stress were assessed for each plasma sample using multiple commercially available assays: total antioxidant capacity, thiol detection, thiobarbituric acid reactive substances, and advanced oxidation protein products. Plasma from horses had significantly (P < .05) lower thiol content and thiobarbituric and reactive substances and higher advanced oxidation protein products than plasma from cattle. A difference in total antioxidant capacity was not observed; however, our study was underpowered to establish a meaningful comparison. Based on these findings, the lack of MET in equine albumin appears to translate to a lower antioxidant capacity of equine plasma. Our findings are consistent with previous reports in other species that identify MET as having an important role in the antioxidant capacity of albumin. Our results also highlight the complex system of antioxidant defenses in plasma that counteract the harmful effects of oxidants.

Journal of the American Veterinary Medical Association, 2019

OBJECTIVE To describe the use of non-contrast-enhanced CT to identify deep digital flexor (DDF) t... more OBJECTIVE To describe the use of non-contrast-enhanced CT to identify deep digital flexor (DDF) tendinopathy in horses with lameness attributed to pain in regions distal to the metatarsophalangeal or metacarpophalangeal joints. DESIGN Retrospective case series. ANIMALS 28 client-owned horses. PROCEDURES Medical records were searched to identify horses that underwent non-contrast-enhanced CT with or without high-field MRI as part of an evaluation for lameness localized to areas distal to the metacarpophalangeal or metatarsophalangeal joint in ≥ 1 limb. Horses were included in the study if they had ≥ 1 DDF tendon lesion (DDF tendinopathy) identified. Signalment, lameness examination findings and response to perineural anesthesia, imaging modality, anesthetic agents and duration of anesthesia, and imaging findings were recorded. Data were summarized descriptively. RESULTS Bilateral imaging was performed for all horses, irrespective of unilateral or bilateral lameness. Nine of 28 horses underwent both CT and MRI, and all DDF tendon lesions identified by one modality were identified by the other. Of 48 limbs with DDF tendinopathy, 46 (96%) had core lesions and 35 (73%) had dorsal border irregularities. Median anesthesia time for CT and CT followed by MRI was 15 and 110 minutes, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that non-contrast-enhanced CT was useful for identifying DDF tendinopathy in horses with lameness localized to the phalangeal regions, and this was supported by consistency of findings in a subset of horses that underwent MRI. Further research is needed to confirm these results.

Journal of Equine Veterinary Science, 2020

Abstract Equine coronavirus (ECoV) is a known cause of fever, anorexia, and lethargy in adult hor... more Abstract Equine coronavirus (ECoV) is a known cause of fever, anorexia, and lethargy in adult horses. Although there are multiple reports of ECoV outbreaks, less is known about the clinical presentation of individual horses during a nonoutbreak situation. The purpose of this study was to describe the clinical presentation of horses diagnosed with ECoV infection that were not associated with an outbreak. Medical records of all horses admitted to Washington State University, Veterinary Teaching Hospital, during an 8-year period were reviewed (2010–2018). The five horses included in this study were older than 1 year of age, were diagnosed with colitis, tested positive for ECoV using real-time polymerase chain reaction, and were negative to other enteric pathogens. Interestingly, 4 of 5 horses had moderate to severe diarrhea, 3 had abnormal large colon ultrasonography, 2 had transient ventricular tachycardia and 2 had clinicopathologic evidence of liver dysfunction. ECoV should be included as a differential diagnosis for individual horses presenting with anorexia, fever, lethargy, and colitis. Early identification of ECoV cases is key to implement appropriate biosecurity measures to prevent the potential spread of this disease.

Veterinary Record, 2019

Rhodococcus equi is the most common cause of pneumonia in young foals. Pneumonic foals are an imp... more Rhodococcus equi is the most common cause of pneumonia in young foals. Pneumonic foals are an important source of environmental contamination as they shed higher amounts of R. equi in their faeces than unaffected foals. As R. equi-specific hyperimmune plasma (HIP) lessens clinical pneumonia, we hypothesise that its use would result in decreased faecal shedding of R. equi by foals. Neonatal foals were either given HIP (n=12) or nothing (n=9, control) shortly after birth and were then experimentally infected with R. equi. Faeces were collected before and on weeks 2, 3, 5 and 7 after infection. Presence of virulent R. equi was tested using qPCR. There was strong evidence of an association between HIP administration and a decrease in faecal shedding of virulent R. equi (P=0.031 by Pearson chi-squared test). Foals in the control shed significantly more R. equi (colony-forming units/ml) than foals that received HIP (P=0.008 by Mann-Whitney rank-sum test). While our study is the first to r...