Topic:Clinical Pathology
Clinical pathology in horses involves the study and analysis of biological samples to diagnose and monitor diseases and health conditions. This discipline encompasses various laboratory tests and procedures that assess the physiological and biochemical status of equines. Common analyses include hematology, biochemistry, urinalysis, and cytology, each providing insights into different aspects of equine health. Hematology evaluates blood components, such as red and white blood cells and platelets, to identify conditions like anemia or infection. Biochemistry tests measure enzymes, electrolytes, and metabolites to assess organ function and metabolic status. Urinalysis examines urine samples for indicators of renal function and systemic diseases. Cytology involves the microscopic examination of cells from tissues or fluids to detect abnormalities. This page aggregates peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and diagnostic value of clinical pathology in equine medicine.
Sequential measurement of serum amyloid A concentrations in ill hospitalized neonatal foals. In hospitalized foals, limited data are available on the utility of sequential measurement of SAA concentrations and the value of these data in a clinical setting. Objective: To determine serum amyloid A (SAA) concentrations in ill neonatal foals at multiple timepoints during hospitalization, and to evaluate a potential association with systemic inflammatory response syndrome (SIRS) status, blood culture (BC) result, and survival. Methods: Hospitalized ill foals (n = 90, ≤ 14 days). Methods: In this retrospective study, foals were classified based on SIRS criteria: "SIRS" or "NonSIRS," ...
Reference intervals for serum macro- and microminerals in clinically healthy horses in Northwestern Spain: Influence of age, sex, breed and diet. Serum mineral concentrations are key indicators of nutritional status, metabolic function and health in horses; however, contemporary reference intervals (RI) derived from large, well-characterised populations remain scarce. Objective: To establish serum RI for macro- and microminerals in clinically healthy horses in Northwestern Spain and to evaluate the influence of sex, age, breed and diet on mineral status. Methods: Blood samples were collected from clinically healthy horses (n = 211), and serum concentrations of essential macrominerals (calcium [Ca]; phosphorous [P]; magnesium [Mg]; sodiu...
Equine neorickettsiosis: A global perspective of the natural habitat of the bacteria and clinical disease. Equine neorickettsiosis (EN) is an infectious, non-contagious systemic disease of horses caused by the closely related obligatory intracellular bacterial species Neorickettsia risticii and N. findlayensis. Clinical cases are considered endemic in multiple regions across the United States and Canada, as well as in parts of South America, including Uruguay and Brazil. Neorickettsia spp. are obligate endosymbionts of digenean trematodes, which have complex life cycles involving a molluscan first intermediate host, a wide range of invertebrate or vertebrate second intermediate hosts, and a vertebr...
Prolonged wireless measurement of intragastric pH in foals. The pathogenesis of gastric ulceration is not well understood in foals, and its relationship with gastric acidity requires further investigation. A wireless capsule, designed for intraesophageal pH monitoring in humans, was adapted to measure intragastric pH in adult horses. Objective: To (1) determine the feasibility of wireless intragastric pH measurement in foals; (2) determine capsule attachment duration; and (3) describe the intragastric pH profiles recorded. Methods: Eight healthy foals aged 24-98 days. Methods: Prospective interventional study. Capsules were attached to the glandular g...
Unilateral vision loss associated with corneal opacity and posterior lens luxation in the right eye of a Thoroughbred gelding: Case report. A 15-year-old Thoroughbred gelding was presented for examination due to chronic corneal opacity in the right eye, which had been noted for several years. An ophthalmic evaluation revealed dense, irregular corneal opacity; an absence of the direct pupillary light reflex; and a positive dazzle reflex. Fluorescein staining was negative and cytology of a corneal conjunctival swab identified nucleated squamous epithelial cells, but no inflammatory cells. Slit-lamp examination failed to visualize intraocular structure, and the lesion was deemed to be chronic and irreversible. An obstacle-avoidance t...
Obtention and preliminary clinical evaluation of an equine albumin for intravenous administration in adult Colombian Creole Horses (Equus ferus caballus). Albumin is one of the most abundant and physiologically important blood protein in horses due to its ability to regulate vascular volume and transport blood metabolites or drugs. Despite the importance of this protein, in Colombia there is no previous reference of the use of equine albumin in horses as a pharmacological therapy and there is no available any pharmaceutical preparation of this protein to be administrated in horses. This study aims to evaluate for first time the preliminary clinical response of healthy adult Colombian Creole horses after the intravenous administration of an equin...
The neutrophil-to-lymphocyte ratio is associated with disease severity and infectious etiologies of colitis in horses presenting with acute colitis. To evaluate associations between the neutrophil-to-lymphocyte ratio (NLR), nonsurvival, illness severity, and infectious etiologies. Unassigned: This was a retrospective multicenter study that included 100 healthy horses and 444 horses presenting with acute diarrhea to 5 equine referral hospitals. Inclusion criteria were diarrhea duration < 48 hours, complete hemograms, and outcome data. Illness severity was assessed using systemic inflammatory response syndrome. The results of pathogen testing for Salmonella spp, equine coronavirus, Clostridium spp, and Neorickettsia risticii/findlayensis ...
Prognostic Significance of Erythrocyte Sedimentation Rate for Survival in Equine Colic. Accurate early prognostic assessment is a central aspect of clinical decision-making in horses presenting with colic. Despite the availability of multiple clinical and laboratory parameters, reliable biomarkers that provide useful information at the time of admission remain limited. The erythrocyte sedimentation rate is a non-specific indicator of systemic inflammation that has recently been validated for automated point-of-care use in horses. Its behaviour in equine colic has not been previously characterised. This study included 85 horses admitted for colic at two university referral hospita...
miRNAS and target genes are regulated post-training in quarter horse athletes. In the context of Brazilian equestrian sports, the Quarter Horse (QH) breed has the third largest population of registered horses and stands out for its numerous abilities in various disciplines. Studies on equine health and athletic performance parameters are scarce, especially involving molecular markers. Objective: This study aimed to investigate the differential expression of microRNAs and target genes involved in metabolic pathways of exercise and to assess hematological and clinical changes in 10 horses (Equus caballus Linnaeus) of the QH breed under different physiological conditions. H...
Effects of sample storage time and temperature on equine complete blood counts. Equine blood samples are often collected in uncontrolled, distant environments and stored for later analysis. Objective: This study aimed to determine how sample storage methods influence complete blood count (CBC) parameters, hypothesizing that temperature and time elapsed from collection to analysis would affect CBC parameters. Methods: Blood samples were collected from 10 healthy Quarter Horse mares (age: 13 ± 4.5 years old) and stored in EDTA tubes at room temperature (22°C), above ice (8°C), refrigerated (4°C), or in contact with ice (2°C). The IDEXX ProcyteDx was used to obtain CBCs...
Wrong turns, right career: an accidental journey into equine surgery. From average school reports to a surgical residency in the USA and running a 17-vet practice, this is the unplanned route Phil Cramp took to finding a career he loves.
Two cases of primary hepatic neoplasia in young horses: Diagnostic challenges and clinical implications. Primary hepatic neoplasms are rare in horses and often have a poor prognosis due to non-specific clinical signs and delayed diagnosis. This report describes two cases of primary hepatic neoplasia in young horses. The first case was a yearling Hanoverian filly presenting with non-specific clinical signs, including poor weight gain and inappetence, ultimately diagnosed with hepatoblastoma based on ultrasonographic findings and histopathological examination. The second case was a three-year-old Polish Sport Horse stallion that died suddenly, with post-mortem examination revealing advanced cholang...
Clinical and laboratory evaluation in horses submitted to intracecal fluid therapy administered in two different rates. Two routes of administration for electrolyte solutions are commonly used in horses with fluid, electrolyte, and acid-base imbalances: intravenous and nasogastric. Despite the frequent use of these routes, there are situations in which they cannot be applied. In such cases, intracecal fluid therapy represents a viable alternative, as this route enables the administration of enteral electrolyte solutions even in animals lacking normal anterior gastrointestinal function. This study aimed to evaluate the effects of a neutral hypotonic enteral electrolyte solution administered intracecally at two d...
Evaluating the Biochemical and Haematological Safety of the Histoplasma capsulatum var. farciminosum ‘8ZH’ Vaccine in Foals. Epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum (HCF), is a neglected equine fungal disease lacking effective vaccines. The newly developed inactivated '8ZH' vaccine requires safety validation in the target species. Objective: To evaluate the biochemical, haematological and clinical safety of the inactivated HCF '8ZH' vaccine in foals. Methods: A controlled, single-blinded study was conducted on 30 clinically healthy foals (4-6 months), randomized into vaccinated (n = 15) and control (n = 15) groups. Vaccinated animals received a 5 mL intramuscular dose (...
Full Clinical Pathological and Bacteriological Investigation of a Giant Nasal Polyp Associated With the Developing Apex of the Permanent Fourth Premolar (Triadan 108) in a 3-year-old Connemara Filly: A Case Report. A 3-year-old Connemara X filly was referred to a UK equine hospital for further investigation of unilateral nasal discharge and facial swelling. Diagnostic imaging documented the presence of a heterogenous, soft tissue opacity with areas of focal mineralisation within the right paranasal sinuses, completely obliterating the nasal cavity, in addition to endodontic disease and significant periapical pathology associated with the right permanent fourth premolar (Triadan 108). Subsequent histopathologic examination confirmed the mass as a fibro-inflammatory polyp.
Compounded oral doxycycline in late-term pregnant mares: pharmacokinetics, fetoplacental diffusion, and neonatal safety. Doxycycline is widely used in equine medicine, yet data on its pharmacokinetics and safety during late gestation are scarce. We investigated the pharmacokinetics, fetoplacental diffusion, and safety of compounded oral doxycycline in late-term pregnant mares. In the first experiment, six mares at 300 days of gestation received a single oral dose (10 mg/kg), and plasma concentrations were measured using LC-MS/MS. Pharmacokinetic analysis using non-compartmental and compartmental models showed rapid absorption, with a mean Cmax of about 6000 ng/mL reached within 0.8 h and a terminal half-life ...
Sequential changes in serum protein profiles in pregnant Spanish purebred mares. This study investigates sequential changes in serum protein fractions during gestation in 31 pregnant Spanish Purebred mares compared to 15 non-pregnant control. Total serum proteins (TSP) were measured using the Biuret method, while albumin (ALB), total globulins (tGLOB), and their subfractions (α₁, α₂, β₁, β₂, γ-GLOB) were analyzed by agarose gel electrophoresis. Pregnant mares showed significant changes in serum protein profiles throughout gestation. TSP and tGLOB concentrations increased from mid to late pregnancy (months 6-11), while ALB concentrations declined between months...
Preliminary assessment of the leukocyte coping capacity as a point of care marker in horses with stress associated diseases. Stress represents a serious health and welfare concern; however, its objective assessment remains difficult. The equine gastric ulcer syndrome (EGUS) and orthopedic diseases that cause pain are among stress associated diseases in equine medicine. The leukocyte coping capacity (LCC) quantifies oxygen radical generation of neutrophil granulocytes which is altered under stress. Therefore, LCC could be a novel biomarker for stress in horses and we hypothesized that horses with stress associated diseases would have lower LCC values in comparison to horses without these diseases. Methods: In this ob...
A novel dataset of 2,362 equine fecal microbiomes from veterinary teaching hospitals across three countries reveals effects of geography and disease. Horses and other equids are reliant on the gut microbiome for health, and studies have reported associations between certain clinical conditions and features of the fecal microbiome. However, research to date on the equine fecal microbiome has often relied on small sample sizes collected from single and relatively localized geographic regions. Previous work also largely employs single timepoint analyses, or horses selected based on limited health criteria. Results: To address these limitations and expand our understanding of the core microbiome in health, and the changes associated with advers...
Treatment evaluation using ultrasonographic scanning of the spleen in Arabian horses affected by babesiosis. Equine babesiosis is a widespread protozoan disease in Saudi Arabia. The most common finding of clinical babesiosis is splenomegaly, which can be detected using non-invasive splenic ultrasonography. Unassigned: This study aimed to investigate changes in the spleen size in horses infected with babesiosis using ultrasonography before and after treatment. Unassigned: This study employed 15 male and female Arabian horses. Each animal was examined clinically for clinical signs, and blood samples were collected in plain tubes to detect antibodies against . The spleens of healthy and affected horses ...
Thyroid Disease in Horses-Retrospective Case Series on Patients Examined for Thyroid Disease in an Equine University Clinic (2009-2024). Thyroid diseases in horses are rare and pose challenges for veterinarians due to the complexity of clinical and diagnostic approaches. This retrospective case series describes cases of equine thyroid disease in a referral hospital population. Files of horses examined for suspected thyroid disease at an equine university clinic between 2009 and 2024 were reviewed. Data from nine horses examined for suspected thyroid disease, including signalment, clinical presentation, laboratory results, imaging findings, fine needle aspirates, biopsies, diagnoses, and treatments, were summarised. Diagnoses in...
Lipid-rich abdominal fluid mimicking chyloabdomen in a horse. We report here a case of lipid-rich abdominal fluid in a 31-y-old Arabian gelding with acute colic. Abdominocentesis yielded opaque, yellow-to-orange peritoneal fluid with an elevated triglyceride concentration (42 g/L, RI: <0.10 g/L; fluid:serum triglyceride ratio 11.4, RI: <1.0). A second abdominocentesis performed 3 d later revealed clear fluid, suggesting transient chyloabdomen. Despite medical management, the horse developed respiratory distress secondary to pharyngeal edema and was euthanized. Autopsy identified a large omental lipoma and severe ulcerative gastritis, but no effusion....
Clinical signs, clinical pathology and outcomes in horses infected naturally with equine encephalosis virus. Equine encephalosis (EE) is caused by an Orbivirus from the family Sedoreoviridae and is thus similar to African horse sickness (AHS) and Bluetongue viruses (BTV). These viruses are transmitted by Culicoides midges. Equine encephalosis can infect horses, donkeys and zebras sub-clinically while only horses develop clinical disease. The vector's distribution is climate-dependent with evidence for circulation in Southern Africa, the Middle East and India. Global warming could facilitate the expansion of this distribution and consequently the potential spread into Europe should not be overlooked. ...
Bioanalytical Uncertainty Assessment of Ultra-High-Performance Liquid Chromatography-High Resolution Mass Spectrometry Method for Caffeine and Lidocaine in Equine Antidoping: A Dual Perspective on Bottom-up and Top-Down Approaches. The quality of quantitative results in bioanalysis requires not only a validated analytical method but also a rigorous estimation of measurement uncertainty. This study examines the challenges associated with the implementation of two distinct approaches in equine anti-doping control for the assessment of uncertainty associated with an ultra-high-performance liquid chromatography-high resolution mass spectrometry quantitative method for caffeine and lidocaine in horse urine. The bottom-up approach, based on the ISO Guide to the Expression of Uncertainty in Measurement (ISO GUM), was compared t...
Intraocular Tumors in Horses: Diagnosis, Tumor Classification, Oncologic Assessment and Therapy. Intraocular neoplasia in horses is rare and only few case reports and small case series exist. Intraocular neoplasia has various clinical signs and includes important differential diagnoses in ocular disease. This narrative review of the current literature aims to provide a clinically relevant overview and classification of intraocular tumors in horses and adds a comparative oncological perspective concerning diagnosis, treatment and future considerations. The available clinical and imaging examination techniques allow for a reliable and differentiated investigation of the tumor, even in the s...
Complications in the Critically Ill Equine Patient. Complications in critically ill equine patients are often related to the underlying disease process but can also be a consequence of diagnostic and therapeutic interventions. Complications can be specific to the affected organ or body system; however, in critically ill patients, they frequently affect the vasculature, acid-base, electrolyte, and fluid balance, energy homeostasis, and coagulation, with systemic consequences. Infrequent monitoring, late detection, failure to adapt therapies, hematologic and biochemical abnormalities, coagulopathies, and systemic inflammation can all contribute t...
Bridging Breeds: Transcriptomic Insights into Immune Traits of Yili, Thoroughbred, and Kazakh Horses. Studying the genetic characteristics and molecular mechanisms of immune regulation in horses is of great significance for protecting their genetic resources, improving breeding strategies, and enhancing their disease resistance, thereby ensuring their healthy performance in both sports and production. Objective: This study investigates the genetic characteristics and molecular mechanisms underlying immune regulation in Yili horses, comparing them with Thoroughbreds and Kazakh horses. Methods: Blood samples from each breed were analyzed for physiological, biochemical, and immune indices alongsi...
Computer-Aided Diagnosis of Equine Pharyngeal Lymphoid Hyperplasia Using the Object Detection-Based Processing Technique of Digital Endoscopic Images. In human medicine, computer-aided diagnosis (CAD) is increasingly employed for screening, identifying, and monitoring early endoscopic signs of various diseases. However, its potential-despite proven benefits in human healthcare-remains largely underexplored in equine veterinary medicine. This study aimed to quantify endoscopic signs of pharyngeal lymphoid hyperplasia (PLH) as digital data and to assess their effectiveness in CAD of PLH in comparison and in combination with clinical data reflecting respiratory tract disease. Endoscopic images of the pharynx were collected from 70 horses clinic...
The predictive ability of blood-based biomarkers to detect bacteremia in hospitalized neonatal foals. Early and accurate identification of septicemia in neonatal foals improves survival. In human medicine, the neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-monocyte ratio (NMR), monocyte-to-lymphocyte ratio (MLR), and plasma cell-free DNA (cfDNA) aid in early bacteremia detection. This study evaluated the diagnostic utility of these markers in conjunction with other clinical and hematological parameters in hospitalized foals < 5 days old to predict positive blood culture at admission and to distinguish between Gram-positive, Gram-negative, or polymicrobial bacteremia. A total of 391 foal...
Retrospective Evaluation of Neutrophil-to-Lymphocyte Ratio in Horses That Required Emergency Laparotomy: 341 Cases of Noninfectious Causes of Gastrointestinal Colic (2019-2024). To (1) compare total nucleated cell count (TNCC) and neutrophil-to-lymphocyte ratio (NLR) at admission between horses with medically managed, large intestinal (LI) and small intestinal (SI) surgical colic; (2) compare TNCC and NLR between survivors and nonsurvivors; and (3) investigate associations between TNCC, NLR, surgical intervention, and outcome. Methods: Case-control study. Methods: Single, academic institution. Methods: A total of 341 adult horses diagnosed with noninfectious medical or surgical colic. Results: Admission TNCC did not differ between the medical and combined surgical gro...