Topic:Clinical Signs
Clinical signs in horses refer to observable physical or behavioral manifestations that may indicate the presence of disease or injury. These signs can include a range of symptoms such as changes in appetite, alterations in gait, abnormal respiratory patterns, or variations in body temperature. Recognizing clinical signs is an integral part of equine veterinary practice, as they provide initial insights into the health status of the animal. Veterinarians rely on these signs to formulate differential diagnoses and guide further diagnostic testing. This page gathers peer-reviewed research studies and scholarly articles that explore the identification, interpretation, and diagnostic value of clinical signs in equine health management.
The Horse with Recurrent Fevers and Infections: Approach to Common Variable Immunodeficiency. Equine common variable immunodeficiency (CVID) is a rare, late-onset, nonfamilial humoral deficiency characterized by B-cell depletion and/or dysfunction resulting in inadequate antibody production and predisposition to recurrent infections. Serum immunoglobulin concentration and peripheral blood lymphocyte immunophenotyping are required to diagnose and characterize CVID in horses. Early recognition of the disease by the equine practitioner is paramount to managing the quality of life for these patients, for whom specific treatment is not yet available and long-term prognosis remains poor. An ...
Immune-mediated Equine Vasculopathies. Immune-mediated vasculopathies occur secondary to infection or another noninfectious stimulus. Potential triggers include heterologous antigens including viruses, injected proteins and drugs; or auto-antigens including immunoglobulins or other endogenous proteins. Although these conditions are rare in horses, immune-mediated vasculopathies can cause considerable morbidity, with variable clinical signs depending on severity and organ system affected. Examples include purpura hemorrhagica, systemic lupus erythematosus, drug-induced vasculitis, paraneoplastic vasculitis, and idiopathic immune-med...
Approach to Inflammatory Bowel Disease. Inflammatory bowel disease (IBD) in the horse encompasses a group of infiltrative gastrointestinal disorders resulting in malabsorption, maldigestion, weight loss, colic, and sometimes diarrhea. The type of IBD can be classified as granulomatous, lymphocytic-plasmacytic, or eosinophilic enterocolitis. The diagnosis of IBD in equids is based on consistent clinical signs and clinicopathologic findings in conjunction with confirmatory histopathology from a gastrointestinal biopsy. Treatment usually consists of a combination of immunosuppressive medications, anthelmintics, and dietary modification...
Is There a Difference in the Prevalence of Gastric Ulcers between Stallions Used for Breeding and Those Not Used for Breeding? Equine gastric ulcer syndrome (EGUS) is a worldwide disease, and includes two different syndromes, Equine Squamous Gastric Disease (ESGD), affecting the squamous mucosa, and Equine Glandular Gastric Disease (EGGD), affecting the glandular mucosa. These two diseases are present in different categories (different activities, ages, etc.) and breeds of horses. The effect of sex on gastric health is not clear: some studies found a higher prevalence of ESGD in geldings and stallions, while others found no influence of sex on the squamous mucosa. The few studies conducted on glandular diseases failed...
Isolation, serological and molecular methods in screening of Burkholderia mallei in East Azerbaijan province, Iran. Glanders caused by Burkholderia mallei is one of the most dangerous zoonotic diseases in solipeds. Clinical diagnosis of this disease in its early stages in horses, is difficult. This study investigated serological and molecular identification of B. mallei in East Azerbaijan province. In the third and fourth quarters of 2020, throughout 2021, and in the first and second quarters of 2022, the complement fixation test (CFT) was performed on 350 horses. The malleination was used to confirm the positive CFT cases. Blood samples were taken for culture and for preparing serums to perform the enzyme-...
Surgical treatment of headshaking by removal of a paracondylar process fragment via modified hyovertebrotomy approach: A detailed anatomical and surgical description in an adult horse. To describe, in detail, the relevant anatomy and surgical approach to access the paracondylar process (PCP) and report its application in a clinical case of headshaking. Methods: A seven-year-old, mixed breed mare. Methods: Experimental study/case report. Methods: A seven-year-old mixed breed mare was presented for investigation of acute onset progressing violent headshaking, resulting in the horse falling on multiple occasions. The horse was highly reactive to palpation over the right PCP. Standing computed tomographic (CT) investigation and ultrasonographic examination of the head detected a...
Expression of IL-10 and TGF-β1 in horses experimentally infected with T. equi merozoites is associated with antibody production but not modulation of pro-inflammatory responses. () is an apicomplexan parasite that causes severe hemolytic anemia in equids. Presently, there is inadequate knowledge of the immune responses induced by in equid hosts impeding understanding of the host parasite relationship and development of potent vaccines for control of infections. The objective of this study was to evaluate the host-parasite dynamics between merozoites and infected horses by assessing cytokine expression during primary and secondary parasite exposure, and to determine whether the pattern of expression correlated with clinical indicators of disease. Our findings showe...
Current insights into equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy. Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disease associated with vitamin E deficiency in the first year of life. It is the second most common cause of spinal ataxia in horses euthanized for neurologic disease. Equine NAD/EDM is characterized by neurologic signs including a symmetric proprioceptive ataxia (> grade 2/5) and a wide-base stance at rest. There are currently no antemortem tests for eNAD/EDM in any breed. Conclusive diagnosis requires postmortem histologic evaluation of the brainstem and spinal cord at necropsy....
Successful hemodialysis treatment of a Quarter Horse mare with silver maple leaf toxicity and acute kidney injury. An adult American Quarter Horse mare presented for pigmenturia and lethargy of 12 hours' duration and was diagnosed with silver maple leaf toxicity. The mare had intravascular hemolysis and azotemia. The mare was treated with a transfusion of whole blood, fluids administered IV, antibiotics, oxygen insufflation, and supportive care. The azotemia persisted despite conventional medical management and hemodialysis was elected. After 2 intermittent hemodialysis treatments over 3 days, the azotemia almost resolved, clinical signs improved, and the mare was discharged. The blood urea nitrogen, c...
Intrahepatic mucinous cholangiocarcinoma with recurrent colic in a horse: case report and literature review of cholangiocarcinoma in horses. A 17-y-old Arabian mare was presented to the Auburn Large Animal Veterinary Teaching Hospital with a long-term history of intermittent mild recurrent colic that responded to medical treatment. CBC revealed mild lymphopenia; serum biochemistry findings were of increased gamma-glutamyl transferase and creatine kinase activities, hyperferremia, hyperglycemia, hypomagnesemia, and hypokalemia. Abdominocentesis was compatible with low-protein transudate. Due to the progression and duration of clinical signs, the owner elected euthanasia. Postmortem examination and histopathology confirmed a cholangi...
Selecting potential biomarkers of plasma proteins in mares with endometritis. Endometritis is a common condition in mares that causes significant economic loss. Lacking obvious clinical signs, the clinical diagnosis of endometritis in mares relies on case-by-case clinical examinations, which can be particularly inefficient in large-scale farms. Therefore, the identification of potential biomarkers can serve as a non-invasive and efficient screening technique for endometritis in mares. Objective: To compare the blood proteome between fertile mares and mares with endometritis to identify biomarkers potentially associated with the development of endometritis and validate t...
Application of the HRE-S to 140 horses with trigeminal-mediated headshaking and the association of clinical signs with diagnosis, therapy, and outcome. Horses with trigeminal-mediated headshaking (TMHS) exhibit different headshaking patterns (HSPs), electric shock-like jerking, signs of nasal irritation, and painful facial expressions. The History Rest and Exercise Score (HRE-S) was developed to objectively clarify the severity of the condition in affected horses. This score considers the history and severity of clinical signs at rest and exercise. This study aimed to assess the frequency of different clinical signs and their individual associations with diagnosis, treatment, and outcome in horses diagnosed with TMHS.The clinical records of h...
Severe orbital hematoma with third eyelid swelling and prolapse following a blind maxillary nerve block in a horse. A 20-year-old quarter horse gelding was presented for routine dental examination. Periodontal disease and luxation of tooth 108 was diagnosed and oral extraction was planned. After an unsuccessful blind maxillary nerve block, it was elected to perform the procedure under total intravenous anesthesia. Following recovery, a focal superficial corneal ulcer, severe retrobulbar swelling, mild exophthalmos, and marked swelling and prolapse of the third eyelid (nictitating membrane) were observed. Clinical signs persisted beyond 48 h despite the use of systemic anti-inflammatories and topical ocular ...
Strongyle egg shedding and egg reappearance periods in horses with pituitary pars intermedia dysfunction. Pituitary pars intermedia dysfunction (PPID) is the most common endocrine disorder of older horses. Immune dysfunction in horses with PPID could increase susceptibility to infectious diseases, including strongyle infections; however, few data are available. The aim of this study was to determine if horses with PPID had increased strongyle faecal egg counts (FEC) compared with control horses, over a fourteen-week period in Victoria, Australia. Clinical signs and plasma adrenocorticotropic hormone (ACTH) concentrations were used to categorise horses into PPID (n=14) or control (n=31) groups. Fae...
Prevalence and factors associated with Leishmania spp. and Toxoplasma gondii infections in apparently healthy horses in Eastern Spain. Leishmaniasis and toxoplasmosis are two of the most common parasitic zoonoses. Leishmaniasis is endemic to 98 countries around the world, whereas toxoplasmosis is widely distributed throughout the world, causing significant health expenditure. Horses can play a relevant role in the transmission of the disease, being a silent reservoir, as clinical signs are not common. Serum samples from 166 horses living in eastern Spain (Mediterranean basin) were analysed to determine the presence of antibodies against Leishmania spp. and T. gondii by ELISA (Enzyme-linked Immunosorbent Assay.) The risk facto...
Endometrial expression of antimicrobial peptides as markers of subclinical endometritis in mares. Endometritis is a major cause of subfertility in mares. Multiparous old mares are more susceptible to developing endometritis given that ageing is associated with an altered immune response and with inadequate physiological uterine clearance after breeding, which can lead to degenerative changes in the endometrium. Molecules such as antimicrobial peptides (AMPs) have been proposed as endometritis markers in the equine species. Methods: Cross-sectional. Objective: To investigate the endometrial expression of defensin-beta 4B (DEFB4B), lysozyme (LYZ) and secretory leukocyte peptidase inhibitor (...
First report of Besnoitia bennetti in Irish donkeys: an emerging parasitic disease in Europe. This is the first report of Besnoitia bennetti in donkeys in Ireland. B. bennetti, an apicomplexan protozoan parasite specific to equids, is an emerging pathogen in Europe. This parasite forms chronic intracytoplasmic cysts in cells of the mesenchymal lineage, mainly fibroblasts, in the skin, sclera and mucosa. Clinical signs in affected equine hosts vary from mild to severe debilitating disease. Little is known of the phylogeny, epidemiology or transmission of B. bennetti infection in donkeys, mules or horses. Methods: Two cases of besnoitiosis in donkeys are presented. Both donkeys were born...
Retrospective Study of 25 Cases of Acorn Intoxication Colitis in Horses between 2011 and 2018 and Factors Associated with Non-Survival. The aim of this study is to describe clinical data associated with acorn intoxication and to find variables associated with survival. Data from horses presented at CISCO-ONIRIS from 2011 to 2018 with a diagnosis of acorn intoxication were included. Diagnosis was based on the following: season, the presence of acorns in the environment, clinical and hemato-biochemical parameters suggestive of a digestive/renal disease, the co-morbidity of companion animals, and post-mortem findings. Statistical analysis was completed using Student's t-test for mean comparisons and a Chi-square test for group co...
Improved quality of life and pain relief in mature horses with osteoarthritis after oral transmucosal cannabidiol oil administration as part of an analgesic regimen. The aim of this study was to evaluate the effect of oral cannabidiol (CBD) administration in addition to a conventional analgesic protocol on the clinical signs of 20 horses with mild joint osteoarthritis. The horses were randomly assigned to either the control group (C group) or the cannabidiol group (CBD group). Both groups were treated with phenylbutazone for 5 days. The CBD group received 0.03 mg/kg cannabidiol in hemp oil orally once daily for 14 days in addition to phenylbutazone treatment. All subjects were monitored for clinical parameters, oxidative status and blood counts. Pain...
Fetal maceration and partial retention of fetal bones in 2 mares. Pregnancy loss after Day 40 in mares usually results in the expulsion (abortion) of the fetus and placental membranes. However, fetal retention within the uterus is also a possible outcome, leading to either fetal mummification or maceration. Fetal maceration is septic decomposition of fetal tissues within the uterus following failure of expulsion. It requires the presence of bacteria and oxygen within the uterus, likely originating from an open cervix, and results in tissue autolysis, leaving only fetal bones remaining in the mare. Fetal maceration is a rare complication of pregnancy in mares...
Effects of β-Glucan Supplementation on LPS-Induced Endotoxemia in Horses. β-glucan is part of the cell wall of fungi and yeasts and has been known for decades to have immunomodulating effects on boosting immunity against various infections as a pathogen-associated molecular pattern that is able to modify biological responses. β-glucan has been used in rat models and in vitro studies involving sepsis and SIRS with good results, but this supplement has not been evaluated in the treatment of endotoxemia in horses. This study aims to evaluate the effects of preventive supplementation with β-glucan in horses submitted to endotoxemia by means of inflammatory response m...
Fatal West Nile Virus Infection in Horse Returning to United Kingdom from Spain, 2022. We report fatal West Nile virus (WNV) infection in a 7-year-old mare returning to the United Kingdom from Spain. Case timeline and clustering of virus sequence with recent WNV isolates suggest that transmission occurred in Andalusía, Spain. Our findings highlight the importance of vaccination for horses traveling to WNV-endemic regions.
Success of different therapies for bacterial endometritis in stud farm practice. Bacterial endometritis is a major problem in equine reproduction usually treated with antibiotics, however reports of success rates are scarce. This study collected data from mares diagnosed with intrauterine bacterial growth and compared the outcome of different therapies for bacterial endometritis in German stud farm practice. Data on mares with positive uterine culture results were collected retrospectively in veterinary practices (n = 5; 2018-2022). Information relating to 30 factors (mare, diagnostics, therapy, pregnancy rate) of bacterial endometritis cases (n = 772) were recorded an...
An investigation of the prevalence of equine filariosis in North and Northeast of Iran. Worldwide, equines are affected by equine filariosis, an endemic vector-borne disease caused by heterogenous parasitic nematodes. The main objective of this study was to determine the prevalence of filarial infection among horses in the North and Northeast of Iran. Between October 2021 and July 2022, 145 equine blood samples were investigated, of which 49 cases were from the northeast and 96 were from the north of Iran. Blood samples were taken for microfilariae using Knott's method. Out of 145 blood samples, only 2 cases (1.37%) from northern Iran were positive for microfilaria of , and no po...
Pulmonary aspergillosis in a horse: a case report. Respiratory diseases considerably affect equine athletes, being the second most common cause of poor performance. Among these diseases, fungal pneumonia in horses, caused specifically by Aspergillus spp., is relatively rare but potentially fatal. Fungal pneumonia typically affects horses exposed to fungal elements due to environmental factors, immunosuppression, or previous debilitating illnesses. Treatment is complex, with minimal success due to late diagnosis and serious concomitant underlying diseases. The choice of medication depends on the site of infection, the fungal species involved, a...
Development and evaluation of a test strip for the rapid detection of antibody against equine infectious anemia virus. Equine infectious anemia (EIA) is a contagious disease of horses caused by the equine infectious anemia virus (EIAV). The clinical signs at the acute phase include intermittent high fever, thrombocytopenia, hemorrhage, edema, and anemia. The clinical signs at chronic and relapsing subclinical levels include emaciation and progressive weakness. Surviving horses become lifelong carriers because of the integration of the viral genome into that of the host, and these horses can produce and transmit the virus to other animals. This increases the difficulty of imposing practical control measures to ...
Osteoarthritis of the coxofemoral joint in 24 horses: Evaluation of radiography, ultrasonography, intra-articular anaesthesia, treatment and outcome. Few case reports describe equine coxofemoral joint osteoarthritis (CFJOA). Objective: To evaluate diagnostic findings and outcome of horses with CFJOA and to provide a score facilitating radiographic assessment. Methods: Retrospective case series. Methods: History, clinical signs, ultrasonographic, radiographic and intra-articular anaesthesia findings, treatments, outcome, and necropsy results of horses with CFJOA presented between 2002 and 2023 were collated. Radiographic findings were categorised to develop a radiographic score which was applied by two masked examiners. Intra- and inter-obse...
α-Casozepine supplementation shows no effect on foals’ growth and cortisol levels before and after weaning. The goal of this study was to determine whether oral administration of α-casozepine (Zylkene) supplementation decreases the risk of disease in foals, as measured through salivary cortisol levels, temperature, clinical signs of disease, and body weight before and after weaning. Methods: 20 Thoroughbred foals were observed over 10 weeks, beginning 14 days prior to the time of weaning. Methods: Experimental foals were randomly selected and given α-casozepine daily for 10 weeks, while the controls received a placebo with the same frequency as the experimental group. The average daily height and ...
Lumbar vertebral bone density is decreased in horses with pituitary pars intermedia dysfunction. Pathological fractures have been reported in equids with pituitary pars intermedia dysfunction (PPID) but their prevalence and pathogenesis is unknown. Objective: To compare: (1) bone mineral density (BMD) in weight bearing and nonweight bearing bones in PPID+ equids and aged and young PPID- controls; and (2) biomechanical properties of the fourth lumbar vertebral body in PPID+ equids and aged PPID- equids. Methods: Case-control study: five PPID+ equids and six aged and four young PPID- control horses. Methods: PPID status was based on clinical signs and necropsy examination of the pituitary g...
Equine dermatitis outbreak associated with parapoxvirus. Parapoxviruses (PPV) cause skin and mucous membrane lesions in several animal species, and of the five recognized PPVs, at least three are zoonotic. Equine PPV (EqPPV) is the sixth one initially described in humans in the United States and later in a severely sick horse in Finland in 2013-2015. In 2021-2022, a large-scale pustulo-vesicular pastern dermatitis outbreak occurred in horses all over Finland. This study aimed at analysing the outbreak, identifying and describing the causative agent, describing clinical signs, and searching for risk factors. EqPPV was identified as a probable causati...