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.
Can Acute Neurological Disease Cause Cardiomyopathy in Horses? In human medicine, neurological diseases have been associated with transient cardiac abnormalities. In horses, myocardial disease is rarely diagnosed and has been associated with a wide variety of causes. The aim of this article is to describe three horses with no previous cardiac disease, which all developed severe cardiomyopathy following neurological disease. A 5-year-old Shetland pony stallion was diagnosed with cardiomyopathy with arrhythmias following an episode of seizures caused by an accidental intra-arterial xylazine injection. A 20-year-old crossbred mare was hospitalised for an ope...
apEvaluation of circulating microRNAs in plasma from horses with non-strangulating intestinal infarction and idiopathic peritonitis. Non-strangulating intestinal infarctions (NSII) associated with Strongylus vulgaris infection and idiopathic peritonitis (IP) share similar clinical presentation but require different treatment approaches. Horses with NSII need surgical intervention, while idiopathic peritonitis cases can be successfully treated with antimicrobials. A correct diagnosis is thus crucial, but because the two diseases overlap in clinicopathological features, differentiation is difficult in clinical practice. MicroRNAs (miRNAs) are non-coding RNAs that exhibit measurable changes in abundance in tissues and circulat...
How to perform abdominocentesis and interpret abdominal fluid in equine patients. To describe and demonstrate the collection of abdominal fluid from a standing, sedated equine patient. Unassigned: 1 healthy university-owned animal was used for abdominocentesis demonstration. Images from various clinical cases from the University of Illinois Veterinary Teaching Hospital are shown. Unassigned: Under standing sedation, a 10 X 10-cm area is clipped and aseptically prepared on the most dependent portion of the abdomen to the right of midline. One to 2 mL of 2% lidocaine is instilled subcutaneously and into the abdominal musculature at the abdominocentesis site. A stab incision i...
Presumptive Lyme disease-associated eosinophilic synovitis in a horse. A 1-year-old American Quarter horse was presented with acute onset of right hind lameness. On physical examination, there was synovial effusion of the right tarsocrural joint. Synovial fluid cytology revealed a marked eosinophilic synovitis. Serology indicated evidence of acute and chronic infection with Borrelia burgdorferi, although PCR of the synovial fluid was negative. The filly was treated with phenylbutazone and oxytetracycline, and repeated synovial cytology indicated improvement. The filly was discharged with a prescription of minocycline for 30 days. Despite initial improvement, recu...
Long-Term Firocoxib Use in Horses. Many horses receive firocoxib over multiple years, and studies evaluating hematologic and biochemical values in these animals are lacking. Objective: To describe the hematologic and biochemical values of horses receiving long-term firocoxib. Methods: A total of 79 horses receiving long-term firocoxib and 153 horses not receiving long-term firocoxib and not presenting for a specific medical problem. Methods: Retrospective study comparing horses receiving firocoxib (F group) and no firocoxib (NF group). Signalment, hematologic, and biochemical values were compared between the two groups. Simple ...
First report on equine papillomavirus type 1 in Arabian horses in Saudi Arabia: Clinical, histopathological, and molecular characterization. Equine papillomavirus type 1 (EcPV-1) causes cutaneous papillomatosis in horses, which is characterized by benign, proliferative epithelial lesions. Despite its global presence, the prevalence and characterization of EcPV-1 in Arabian horses in Saudi Arabia have not been previously reported. Unassigned: This study is the first to identify and comprehensively analyze EcPV-1 in four Arabian horses presenting with multiple raised, verrucous lesions around the muzzle and lips. Unassigned: This study involved clinical examination, skin biopsy collection, histopathological examination, and molecular...
Patent Urachus and Associated Comorbidities in 101 Newborn Foals: A Retrospective Study. Patent urachus is a common disease in newborn foals. However, despite its frequency, studies investigating symptoms, comorbidities, treatment and prognosis in a large number of affected foals have rarely been conducted. This study aimed to describe the clinical symptoms, laboratory diagnostic findings and prognosis of foals with patent urachus. Data from 101 foals with a patent urachus from 2006 to 2017 were analysed. Patent urachus occurred at a frequency of 7.8% of all foals up to the 14th day of life during the study period. More colts (74.3%) than fillies (25.7%) were affected. In those wi...
Integration of machine learning and viscoelastic testing to improve survival prediction in horses experiencing acute abdominal pain at a veterinary teaching hospital. Viscoelastic coagulation testing (VCT) identifies subclinical disruption of coagulation homeostasis and may improve prognostication, particularly for patients with severe systemic inflammation or shock. Machine learning (ML) algorithms may capture complex relationships between clinical variables better than linear regression (GLM). Objective: To evaluate the utility of ML models incorporating VCT and clinical data to predict survival outcomes in horses with acute abdominal pain. Methods: Retrospective observational cohort study. Methods: VCT (VCM Vet™) was performed on 57 horses with acute a...
Chronic idiopathic myopathy in Icelandic horses: A case series. Exertional myopathies are recognised as a cause of poor performance in equines. In Icelandic horses presenting reduced performance and/or multi-limb lameness, no specific myopathy has been identified. Objective: To characterise the clinical presentation and histopathological findings in muscle biopsy samples from Icelandic horses demonstrating poor performance. Methods: Case series. Methods: Phenotypic characteristics, clinical examination and diagnoses of 17 Icelandic horses were studied. All horses had a resting serum creatine kinase (CK) and aspartate transaminase activities measured, and C...
Sorghum poisoning in ruminants and horses: a review. We reviewed the history, epidemiology, clinical signs, pathology, pathogenesis, treatment, control, and prophylaxis of Sorghum poisoning in livestock. Economic losses in the livestock industry associated with sorghum have been reported since the 19th century. Hyperacute/acute poisoning associated with cyanide (HCN) or nitrate/nitrite frequently occurs in ruminants that consume high quantities of growth and regrowth sorghum after drought, followed by rainfall, respectively. Chronic cystitis-ataxia syndrome primarily affects horses after weeks of grazing on sorghum pastures, while congenital art...
Population pharmacokinetics and clinical evaluation of intravenous acetaminophen and its metabolites in Andalusian horses. To date, no intravenous pharmacokinetics (PK) studies have assessed acetaminophen or its major metabolites (acetaminophen-glucuronide and acetaminophen-sulphate) in horses. The influence of sex on acetaminophen metabolism in horses is unclear, and Monte Carlo simulations have not been applied to explore potential clinical applications. This study aimed to determine the intravenous PK and safety of acetaminophen in Andalusian horses at 10 and 20 mg/kg, evaluate sex as a covariate, and simulate clinical regimens. Twenty mares and twenty stallions received intravenous acetaminophen, and plasma ...
Management of an Equine Herpesvirus-1 Outbreak During a Multi-Week Equestrian Event. The present study reports on the management of an EHV-1 outbreak at a large, multi-week equestrian event with ongoing showing. Within a 48 h period, 8 horses out of a cohort of 38 horses from the same trainer displayed elevated rectal temperatures ranging from 38.4 to 39.0 °C. Initial testing using a point-of-care PCR assay detected EHV-1 in 2/8 horses, with the results being confirmed at a later time by qPCR. As a precautionary measure and because of the inability to isolate the entire at-risk population, the 38 horses were relocated to an equine facility outside the equestrian event for dai...
Characteristics of the Mare-Uterine-Culture-Based Bacterial Composition Using Practical Clinical Evaluation Methods. Uterine health is paramount to fertility in broodmares and for the success of a breeding project, and the Lusitano breed is no exception. This study aimed to characterize the mare uterine microbiota using practical clinical evaluation methods. Mares were examined by transrectal palpation and ultrasonography, followed by the collection of samples by one of three different techniques: uterine lavage, biopsy, or swab. The results of cytology, histology, microbiology, and antimicrobial susceptibility testing were recorded, and statistical analyses were performed. Inflammation was present in 42.2% ...
The Effect of Vaccination Status on Total Lymphocyte Count in Horses Affected by Equine Herpes Virus-1 Myeloencephalopathy. Equine herpesvirus 1-induced myeloencephalopathy has a significant impact on the equine industry. Nevertheless, the clinical variables that may affect the severity of the disease are still under investigation. The objective of this research is studying the relationship between the level of lymphopenia and vaccination status with the severity of the disease in horses at an event, considering whether they had been correctly vaccinated or not prior to exposure to EHV-1. Ten horses were admitted to a veterinary teaching hospital following an equine herpesvirus myeloencephalopathy outbreak during a...
Renal Lipidosis in Horses and Donkeys: 25 Cases (2008-2022). Renal lipidosis is a well-documented histologic finding in humans and small animals with renal and metabolic disorders, but it is not well described in equids. Objective: To describe the signalment, clinicopathologic indices, and postmortem findings of equids with a histologic diagnosis of both hepatic and renal lipidosis (HL + RL) and compare them to cases with hepatic lipidosis only (HL). Methods: Equids with necropsy findings of renal or hepatic lipidosis (state diagnostic lab) between 2008 and 2022. Methods: Retrospective case-control study. Signalment, history, necropsy diagnosis, and...
The diagnostic accuracy of the Brix refractometer in determining mare colostrum with high and low immunoglobulin G concentrations. Foals, that receive poor-quality colostrum, are exposed to a risk of failure of transfer of passive immunity. The Brix refractometer can be used for the estimation of the immunoglobulin (IgG) concentration of mare colostrum, yet there is a scarce literature available on Brix refractometer thresholds for use in the detection of mare colostra with high and low IgG concentrations. Objective: This study aimed to assess the diagnostic accuracy of the Brix refractometer in determining mare colostra with IgG concentrations of <50g/L, <60g/L, >80g/L, >100g/L and >125g/L. Methods: Two hundred and seven...
Association Between Adrenocorticotropic Hormone Concentration and Clinical Signs of Pituitary Pars Intermedia Dysfunction in Swiss and Austrian Equids. There remains a scarcity of data concerning the relationship between the clinical signs associated with PPID and plasma ACTH concentrations. Objective: Report the frequency of clinical signs in the study cohort and identify individual clinical signs or combinations of clinical signs associated with high ACTH concentrations. Methods: Two hundred eighty equids were examined by private veterinarians. Methods: A cross-sectional study of animals with clinical suspicion of PPID was conducted between August and November. Private practitioners completed an online questionnaire reporting detailed infor...
ESTABLISHING REFERENCE INTERVALS FOR SERUM INFLAMMATORY MARKERS AND INVESTIGATING THEIR STORAGE STABILITY AND CLINICAL UTILITY IN ASIAN WILD HORSES (EQUUS FERUS PRZEWALSKII) UNDER MANAGED CARE. Acute phase proteins (APPs) are commonly used in domestic equine practice, where they rise rapidly in response to inflammation and decrease soon after resolution. This response provides useful information to identify, monitor, and prognosticate a variety of inflammatory conditions. Asian wild horses (Equus ferus przewalskii) are an endangered relative of the domestic horse, and APP reference intervals (RI) and clinical utility in this species are not well documented. This study used serum samples from clinically healthy Asian wild horses under managed care to establish RI for serum amyloid A (...
Systemic, hemodynamic and neurological effects of caudal epidural administration of Neosaxitoxin in horses. The present study was conducted to evaluate the safety and the long-lasting anesthetic properties of Neosaxitoxin (NeoSTX) when injected into the intercoccygeal space in standing horses. A group of eighteen (n = 18) healthy client-owned mature crossbreed horses were enrolled in this study. Caudal epidural injection was ascertained by two methods, the "hanging drop" technique and radiographs. Horses were allocated into three groups (n = 6) each group receiving different dosages of NeoSTX. To assess the onset of action and duration of anesthesia, six horses received 20 μg in 2 mL, six 20...
Metabolomic and proteomic stratification of equine osteoarthritis. Equine osteoarthritis (OA) is predominantly diagnosed through clinical examination and radiography, leading to detection only after significant joint pathology. The pathogenesis of OA remains unclear and while many medications modify the disease's inflammatory components, no curative or reversal treatments exist. Identifying differentially abundant metabolites and proteins correlated with osteoarthritis severity could improve early diagnosis, track disease progression, and evaluate responses to interventions. Objective: To identify molecular markers of osteoarthritis severity based on histolog...
Campylobacter jejuni hepatitis in a horse: case report and literature review. spp. can cause gastroenteritis, hepatitis, bacteremia, and abortions in domestic animals and humans. Some spp. are zoonotic. To our knowledge, hepatitis caused by has not been reported in horses. Here we present a case of acute necrosuppurative hepatitis caused by infection in a 3-y-old gelding, and we review the literature on infections in various animal species. The horse had a one-week history of weight loss and weakness before becoming recumbent and dying. Grossly, the liver had rounded edges and was mottled. There were ecchymoses on the gastric serosa, and a large amount of mucoid, p...
Cerebellar abiotrophy in a quarter horse foal. Cerebellar abiotrophy is a neurodegenerative disease that affects the Purkinje cells of the cerebellum, resulting in premature neuronal death. In horses, its occurrence has been reported mainly in the Arabian breed as a congenital mutation inherited in an autosomal recessive manner. The objective of this study was to describe the case of cerebellar abiotrophy in a Quarter Horse foal. An 8-day-old foal was treated after presenting signs of ataxia, hypermetria, difficulty maintaining a standing position, and decreased menace response. The foal was hospitalized for 26 days, received treatment wit...
Suspected chlorfenapyr poisoning in a horse. Chlorfenapyr is a pesticide that interferes with mitochondrial function, leading to cell death and mortality. Although poisoning is primarily documented in humans and dogs, it can result in severe clinical signs, including sweating, respiratory distress, and neurological dysfunction. This report describes the clinical and laboratory findings of a horse with suspected accidental intoxication with chlorfenapyr. A 4-year-old Quarter Horse mare was referred to the veterinary hospital with signs of excessive sweating, hyperthermia, tachypnea, muscle fasciculation, and fearful facial expression. The...
Can Arterial Blood Gas, Electrolyte and Acid-Base Analysis at Admission be Used to Predict Survival to Hospital Discharge for Different Causes of Colic? Predicting outcome in horses presenting with colic remains challenging. Objective: To test whether arterial blood samples in horses admitted for colic predict outcome to hospital discharge for different colic types. Methods: Arterial blood samples collected on admission from 358 horses undergoing medical or surgical management of colic were evaluated for pH, PaO, PaCO, Na, K, iCa, Cl, HCO (P), HCO (P, set), Base (B), Base (ecf) and anion gap. Categories were small intestinal non-strangulating (SINS) or strangulating (SIS) lesions, large colon non-volvulus (LCNV) or volvulus (LCV), small colo...
Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) in Icelandic Horses in Germany: A Correlation Between Clinical and Radiographic Findings. Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a widespread dental disease with an unknown aetiology, mainly affecting the incisors and canine teeth of senior horses. Being clinically asymptomatic in early stages but progressively destructive and painful in many cases highlights the need for improvements in early diagnosis of EOTRH. This study describes how clinical and radiological findings correlate with distinguishing EOTRH-specific symptoms from non-specific findings. Clinical and radiographic examinations of the rostral oral cavity were performed in 154 Icelandic hor...
Nonexertional Rhabdomyolysis. Although horses most commonly develop exertional rhabdomyolysis, there are numerous causes for nonexertional rhabdomyolysis (nonER) that pose a serious health threat to horses. Their etiologies can be broadly categorized as toxic, genetic, inflammatory/infectious, nutritional, and traumatic and a variety of diagnostic tests are available to discern among them. This study discusses causes of nonER as well as diagnostics and treatments that are specific to each etiology. General treatment of acute rhabdomyolysis is covered in detail in the study in this issue on sporadic and recurrent exertional...
Clinical Examination of the Muscle System. The equine muscle system is complex and prone to a large range of hereditary and acquired diseases that often have overlapping clinical signs with orthopedic, neurologic, and other disorders. Obtaining a clinical history that fully outlines the client concerns and any known information about the disorder and following with a comprehensive physical examination and screening clinical pathology tests are fundamental to achieve definitive diagnosis. A methodical and comprehensive approach aids accurate diagnosis and development of an optimal treatment and management plan. This article describes th...
Sporadic and Recurrent Exertional Rhabdomyolysis. Horses are particularly susceptible to developing exertional rhabdomyolysis (ER) characterized by muscle stiffness, pain, and reluctance to move. Diagnosis requires establishing abnormal increases in serum creatine kinase activity when horses exhibit clinical signs. The 2 main categories of ER include sporadic ER arising from extrinsic causes and chronic ER that arises from intrinsic continuous or episodic abnormalities in muscle function. This article focuses on treatment of acute ER and causes and management of sporadic ER. Differential diagnoses for chronic ER as well as the pathophysiology...
Myofibrillar Myopathy. Myofibrillar myopathy (MFM) is characterized by segmental disarray of myofibrils and ectopic accumulation of a protein called desmin. Previously thought to be a glycogen storage disease, MFM is now recognized as a stand-alone myopathy. Endurance Arabians with MFM usually present with exertional rhabdomyolysis (MFM-ER) at the end of races, elevated serum muscle enzymes, and myoglobinuria. Warmblood horses with MFM (MFM-WB) usually present with pain-associated behaviors such as exercise intolerance, reluctance to engage hind quarter muscles, shifting lameness and normal serum muscle enzymes. Bot...