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.
Tropane alkaloids and toxicity of Convolvulus arvensis. Horses in a few, localized northern Colorado pastures exhibited weight loss and colic. At post mortem, intestinal fibrosis and vascular sclerosis of the small intestine was identified. The pastures where the affected horses grazed were overrun by field bindweed (Convolvulus arvensis). Bindweed from the pasture was found to contain the tropane alkaloids tropine, pseudotropine, and tropinone and the pyrrolidine alkaloids cuscohygrine and hygrine. Laboratory mice readily ate C. arvensis and exhibited a variety of abnormal clinical signs depending on the amount eaten. Similar alkaloids have been f...
Clinical, pathological and epidemiological aspects of flood plain staggers, a corynetoxicosis of livestock grazing Agrostis avenacea. Flood plain staggers, a corynetoxicosis of grazing livestock, occurred on flood plains of the Darling river in northern New South Wales between spring 1990 and autumn 1991, associated with the grazing of Agrostis avenacea with diseased inflorescences. Over this period 1722 cattle, 2466 sheep and 11 horses died on 31 farms. Clinical signs were similar in sheep and cattle, being characterised by intermittent episodes of cerebral convulsion superimposed on varying degrees of cerebellar dysfunction. Pathological changes were variable and non-specific, principally reflecting trauma and the generali...
First recorded outbreak of equine viral arteritis in the United Kingdom. Equine viral arteritis was diagnosed for the first time in the United Kingdom in 1993. The outbreak began on a non-thoroughbred stud in south Nottinghamshire and spread to five other premises through chilled semen used for artificial insemination and from acutely and subclinically infected mares returning home. The outbreak was contained on these six premises by means of voluntary movement restrictions. The most commonly observed clinical signs were typical: pyrexia with depression, and conjunctivitis with periorbital oedema; nasal discharge, and oedema of the distal limbs, prepuce and mammary...
Parasitic dermatoses that cause pruritus in horses. Insect hypersensitivity is the most common cause of equine pruritus. It is a seasonal, highly pruritic dermatosis that is caused by the salivary antigens of biting insects. The most common insects are discussed in terms of the area of the horse affected, clinical signs, therapy, and preventative strategies.
Systemic/topical therapy. Hopefully, the practitioner has obtained a basic broader knowledge of the options available for topical and systemic equine dermatologic therapy. There are many topical and systemic agents that can aid in the treatment of specific skin disease and there are safer alternatives to glucocorticoid therapy. Because equine dermatology is still in its infancy, there is still much to be learned. The practitioner is encouraged to pay close attention to this specialty because it will continue to evolve rapidly.
An overview of equine dermatoses characterized by scaling and crusting. Scaling and/or crusting are common clinical findings associated with equine skin diseases. Scaling and crusting may be associated with pruritic or nonpruritic dermatoses. This article focuses on those conditions that are usually nonpruritic in horses. They include the infectious dermatoses, the keratinization/seborrheic disorders, photosensitization, and the immunologic/inflammatory disorders, including pemphigus foliaceus, equine exfoliative eosinophilic dermatitis and stomatitis, and equine histiocytic dermatitis (sarcoidosis). Clinical signs that help differentiate the various disorders are...
Overview of equine pruritus. Pruritus is a common complaint associated with equine dermatoses. Self-mutilation results in alopecia, excoriations, scaling, and crusting; the aesthetic appearance of the horse is often ruined and the horse may be unfit for riding or showing. This article specifically addresses those pruritic dermatoses caused by allergies, including food allergy/intolerance, atopy and contact allergy, as well as by two ectoparasites, stick-tight fleas and rhabditic mange. The clinical signs, diagnostic tests, and treatment recommendations are discussed for each disorder. Insect hypersensitivity and pruritus ...
Septic cholangiohepatitis and cholangiocarcinoma in a horse. Septic cholangiohepatitis was diagnosed in an 11-year-old Warmblood gelding with a history of intermittent colic and fever. Klebsiella pneumoniae, susceptible to gentamicin, was cultured from the biopsy specimen. However, treatment with gentamicin was unsuccessful, and histologic examination and bacteriologic culture of a biopsy specimen obtained 3 weeks later revealed progression of the hepatic inflammation and yielded growth of gentamicin-resistant K pneumoniae. At this time, several discrete hyperechoic structures, suggestive of biliary calculi, were seen ultrasonographically. A change in a...
Problems in the diagnosis of pituitary adenoma (Cushing’s syndrome) in horses. Thyrotropin releasing hormone (TRH) stimulation tests were carried out on a number of horses, including one clinically affected horse whose age and clinical signs suggested that a pituitary adenoma was most unlikely. The results of these tests indicated that, according to criteria published overseas, the majority of these horses had pituitary adenomas. The fact that clinically normal or affected horses may have marked increases in cortisol concentrations indicates that the TRH stimulation test is not suitable for the diagnosis of pituitary adenoma. Other tests, including alterations in glucose...
Identification of Ehrlichia risticii as the causative agent of two equine abortions following natural maternal infection. Two pregnant mares diagnosed as having equine monocytic ehrlichiosis based on history, clinical signs, and high serum antibody titers to Ehrlichia risticii aborted subsequent to recovery from illness. Mare 1 and mare 2 experienced clinical illness at 120 and 143 days of gestation and aborted at 203 and 226 days of gestation, respectively. The fetuses were expelled in fresh condition, and both mares retained their placentas upon abortion. Gross findings for the fetuses included meconium staining and petechiation of external surfaces. Internally, there was increased volume of feces within the sm...
Arthroscopic surgery for subchondral cystic lesions of the medial femoral condyle in horses: 41 cases (1988-1991). Clinical signs, radiographic and arthroscopic findings, and outcome for 41 horses with subchondral cystic lesions of the medial femoral condyle treated by arthroscopic surgery were reviewed. There were 17. Quarter Horses, 15 Arabians, 8 Thoroughbreds, and 1 Holsteiner, with 28 (68%) of the horses being 1 to 3 years old. For all horses, the owners' complaint was mild to moderate hind limb lameness or an altered gait. Bilateral radiographic abnormalities of the medial femoral condyle were detected in 27 horses. Nineteen of the 27 horses had lesions identified bilaterally at arthroscopic surgery....
Large colon impaction in horses: 147 cases (1985-1991). Medical records from all horses with large colon impaction admitted between 1985 and 1991 were examined. Large colon impaction was diagnosed in 147 of 1,100 (13.4%) horses with colic. One hundred thirty horses were admitted for further evaluation of acute onset of abdominal pain after having been examined and treated by referring veterinarians, and 17 horses that were hospitalized for unrelated medical problems developed large colon impaction. Female horses (92/147; 62.6%) were more commonly affected than males. The age ranged from 1 to 29 years (median, 7.1 years). Mean duration of clinical s...
[Non-invasive patient monitoring in veterinary medicine: pulse oximetry and capnography. II. Capnography]. Capnography measures carbon dioxide concentration or partial pressure of the respiratory gas continuously and non-invasively. The endtidal value is of great diagnostic value, it corresponds approximately to the arterial value, except for ventilation-perfusion-mismatching (horse), shunting (horse), or increased dead-space-ventilation (panting in the dog). Capnography primarily serves for monitoring of spontaneous and artificial ventilation, it is a reliable method for detecting hypo- and hyperventilation. Because metabolism and circulation influence the amount of carbon dioxide eliminated in th...
Clinical, virological and serological responses of donkeys to intranasal inoculation with the KY-84 strain of equine arteritis virus. The clinical, virological and serological responses of seven female donkeys (Equus asinus) to inoculation with the KY-84 strain of equine arteritis virus (EAV), a strain that causes moderate to severe clinical signs in horses, was investigated. In the donkeys, the only clinical signs observed were fever (mainly 3-9 days after inoculation), mild depression in four animals, and a slight nasal or ocular discharge in three. All of the donkeys became infected with EAV as shown by recovery of the virus for periods of up to 14 days from the nasopharynx and buffy coat and, in three out of four donkeys...
An investigation of the role of Fusarium moniliforme in duodenitis/proximal jejunitis of horses. Duodenitis/proximal jejunitis syndrome (DPJ) is a small intestinal disease of horses that is associated with depression and copious gastric reflux. Since an infectious cause for DPJ remains unsubstantiated, these studies were designed to investigate the possible role of Fusarium moniliforme toxins in this disease. Fusarium moniliforme was isolated by culturing 2 samples of feed that had been fed to horses with clinical signs of DPJ. These isolates (AU 2/3) were subsequently grown concurrently on autoclaved corn and their toxicity evaluated in a feeding trial utilizing horses. Isolates of F mon...
Tenotomy of the tibial insertion of the semitendinosus muscle of two horses with fibrotic myopathy. Two horses with fibrotic myopathy of the semitendinosus muscle are described. The report deals with the aetiology, clinical signs and diagnosis of the condition, and discusses the different surgical techniques described in the literature. Tenotomies were performed on both horses. Excellent results were obtained in the horse in which only the semitendinosus muscle was affected, but in the horse in which the semimembranosus and gracilis muscles were also involved the results were less satisfactory.
Cauda equina syndrome, diskospondylitis, and a paravertebral abscess caused by Rhodococcus equi in a foal. A 4-month-old male Quarter Horse was referred for evaluation of urinary incontinence. Physical examination revealed clinical signs consistent with cauda equina syndrome. Radiography revealed diskospondylitis of S2 through S4. Infected bone was surgically curretted, and drainage was established for an associated paravertebral abscess. Rhodococcus equi was isolated from specimens of bone and from fluid samples obtained from the paravertebral abscess. Bethanechol was administered to stimulate urination. Erythromycin and rifampin were administered for 120 days. The foal's neurologic dysfunction re...
Equine parafilariosis in Iran. From March to September 1991, horses (n = 1567), donkeys (n = 112) and mules (n = 96) were examined for equine parafilariosis by random sampling from different areas of Iran. The clinical signs of equine parafilariosis were observed in 136 cases of two northern areas (1.4% and 41.3% infection rate) and one northeastern area (6.3% infection rate). Most of the infected cases were confirmed by laboratory findings. All infected cases were followed up to establish the epidemiological features. The results suggest that there is one enzootic area in Iran, the Caspian coast and Persian Turkman steppes...
[Case report: polycythemia in a horse]. A 13 year old Thoroughbred gelding was presented with a history of a single episode of collapse during mild exercise. Clinical examination revealed a high packed cell volume (PCV) of 72%, a haemoglobin concentration of 24.9 g/l and 15.2 millions erythrocytes/microliters. Despite continuous intravenous infusion therapy with large volumes, the PCV never decreased to a physiological level. The animal showed a normal appetite and no signs of discomfort or syncope. Arterial blood gas values were in the normal range as well as the concentration of erythropoietin (measured by radioimmunoassay, RIA). ...
Response of ponies to adjuvanted EHV-1 whole virus vaccine and challenge with virus of the homologous strain. Five yearling ponies were vaccinated with inactivated Equid herpesvirus type 1 (EHV-1) in Freund's complete adjuvant as a double emulsion and revaccinated 6 weeks later with EHV-1 in Freund's incomplete adjuvant. These ponies and three age-matched controls were challenged intra-nasally after a further 6 weeks with homologous live virus and monitored clinically, biologically and serologically. After challenge, clinical signs were mild in both groups. No cell-associated viraemias were detected in vaccinated ponies. Vaccination induced high levels of complement-fixing (CF) and virus-neutralizing ...
Outbreak of larval cyathostomiasis among a group of yearling and two-year-old horses. Larval cyathostomiasis was diagnosed as the cause of an outbreak of illness in a group of five young horses. One had the typical clinical signs of larval cyathostomiasis--sudden onset diarrhoea, weight loss, ventral abdominal oedema and pyrexia, but the other four suddenly started to lose weight rapidly and had limb and ventral abdominal oedema and pyrexia, in the absence of diarrhoea. Large numbers of cyathostome larvae were found in the faeces. Four of the five horses recovered after being treated with anthelmintics and steroids.
Examination of the equine patient with gastrointestinal emergency. Clinical examination of the equine patient with acute abdominal pain should identify the affected body system and yield a provisional diagnosis. Determination of signalment, history, physical examination, and basic laboratory tests should assist in classification of the gastrointestinal disorder and direct the therapeutic plan. Determination of the definitive diagnosis of abdominal pain based on clinical examination is not crucial. For a successful outcome, efforts should be directed toward early recognition of the need for surgery and treatment of cardiovascular compromise in horses with seve...
Epiglottitis in horses: 20 cases (1988-1993). Epiglottitis was diagnosed and treated in 20 horses (13 Thoroughbreds and 7 Standardbreds) over a 5-year period. Eighteen horses were used for racing, and 2 Standardbreds were broodmares. Primary clinical signs were exercise intolerance, respiratory noise, and coughing. The most common endoscopic diagnosis made by referring veterinarians was epiglottic entrapment (11 horses). In 19 horses, endoscopic evaluation at admission revealed mucosal ulceration and thickening of the lingual surface of the epiglottis. Other endoscopic findings included dorsal displacement of the soft palate (14 horses), ...
Ventricular tachycardia and myocardial dysfunction in a horse. Ventricular tachycardia develops less frequently than supraventricular dysrhythmias and generally is more indicative of cardiac disease. The horse in this report had clinical signs of lethargy and hypophagia and was determined to have sustained ventricular tachycardia. Echocardiography was a valuable diagnostic tool and revealed an echodense area in the left ventricle that had subnormal ventricular performance. A primary heart problem of an inflammatory nature was suspected. The horse responded favorably to treatment with lidocaine, antimicrobials, and aspirin, as well as stall rest. The horse...
Resistance of castrated male horses to attempted establishment of the carrier state with equine arteritis virus. Twelve geldings all became infected when inoculated intranasally with the KY-84 strain of equine arteritis virus (EAV), a strain previously shown to be capable of establishing the carrier state in the stallion. With the exception of one animal that showed no effects other than pyrexia, all of the geldings developed clinical signs characteristic of equine viral arteritis (EVA). The geldings were febrile for varying periods within the range of 2-10 days after inoculation. Viraemia occurred from day 2 onwards, for periods varying from 9 to at least 19 days. Nasal shedding of virus began 2-4 days ...
Experimentally-induced synovitis as a model for acute synovitis in the horse. The use of extremely small dosages of intra-articular E. coli lipopolysaccharide (LPS) endotoxin can create a model of synovitis that mimics acute synovitis in horses. Dosages of 5000 ng, 25 ng, 0.5 ng, 0.25 ng, 0.17 ng and 0.125 ng per joint were injected into various joints of a total of 6 horses. The dose response of LPS on clinical signs and synovial fluid parameters was evaluated at baseline and 12, 24, 36 and 48 h after LPS injection. Peripheral venous blood analysis was performed at baseline and at 0, 4, and 12 h after LPS injection. Dosages greater than 0.5 ng/joint resulted in clinica...
Presence of African horse sickness virus in equine tissues, as determined by in situ hybridization. In a retrospective study, a negative-sense digoxigenin-labeled RNA probe, corresponding to the gene encoding nonstructural protein-1 of African horse sickness virus (AHSV) serotype 4, was applied to formalin-fixed, paraffin-embedded tissue taken from horses in the terminal stages of infection with AHSV. Fifteen infected ponies and one noninfected control were studied. Ponies exhibited a range of clinical signs and lesions. Thirteen ponies were infected with serotype 4, one with serotype 1, and one with serotype 2. Ponies were monitored clinically and euthanatized when severely clinically ill. ...
[Equine infectious arteritis: molecular biology, epidemiology and preventative measures]. After a brief historical account of the outbreak of infectious arteritis of horses which occurred in 1984 in Kentucky (United States of America), the author reports on the present state of knowledge concerning the organisation of the genome of the virus. Clinical signs of the disease are described, as well as modes and routes of transmission. Finally, currently-available vaccination procedures are discussed and their value is assessed.
Quantitation of alpha-1 proteinase inhibitor in the pulmonary epithelial lining fluid of horses with chronic obstructive pulmonary disease. The concentration of alpha-1 proteinase inhibitor (API) was measured in the pulmonary epithelial lining fluid (PELF) of horses with chronic obstructive pulmonary disease (COPD) while they had clinical signs and while they had none. The concentrations of total protein, albumin and API were significantly higher in the PELF of animals with clinical signs of COPD. The correlation between albumin and API in the PELF suggested that most of the API was derived from the serum.