Topic:Pyrexia
Pyrexia, commonly referred to as fever, is an elevation in body temperature that occurs as a physiological response to various stimuli, including infection, inflammation, or other underlying medical conditions in horses. It is a common clinical sign observed in equine practice and can indicate the presence of an underlying health issue. The regulation of body temperature is controlled by the hypothalamus, and pyrexia results when this regulatory center adjusts the set point to a higher temperature in response to pyrogens, which can be endogenous or exogenous. Monitoring and assessing pyrexia in horses are important for diagnosing and managing potential health problems. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, mechanisms, and implications of pyrexia in equine health, as well as its role in disease processes and treatment considerations.
Effect of treatment with erythromycin and rifampin during the acute stages of experimentally induced equine ehrlichial colitis in ponies. Sixteen healthy ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocytes. Of the 16 ponies, 15 developed clinical signs of equine ehrlichial colitis. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 7 ponies were treated with 25 mg of erythromycin stearate/kg of body weight and 10 mg of rifampin/kg, given orally every 12 hours for 5 days. The remaining 8 ill ponies served as nontreated controls. All ponies were observed for progression of clinical signs typical of equine ehrlichial colitis. Within 12 hours of initiation of treatment, 4 of the 7 ...
Toxicosis in horses after ingestion of hoary alyssum. Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.
Gastric leiomyosarcoma in a horse. Gastric leiomyosarcoma was diagnosed in a 12-year-old Thoroughbred gelding. The horse was examined because of anorexia, weight loss, and intermittent fever of 1.5 months' duration. Antemortem diagnostic testing was extensive, but a definitive diagnosis could not be reached with noninvasive methods. Exploratory celiotomy confirmed an intra-abdominal mass, and the horse was euthanatized. Necropsy revealed a firm mass associated with the distal portion of the esophagus, cranial two thirds of the stomach, and visceral surface of the liver. The histopathologic diagnosis was leiomyosarcoma.
Hoof and distal limb surface temperature in the normal pony under constant and changing ambient temperatures. Forelimb surface temperatures were continuously monitored in four clinically normal ponies exposed to: (i) constant ambient temperature; (ii) a biphasic change in ambient temperature; and (iii) an incremental increase in ambient temperature. Limb surface temperatures were recorded at the hoof, metacarpus and forearm, and rectal temperature was also measured. Under constant ambient temperature, limb surface temperatures remained relatively constant. A pyrexic episode occurred in one pony under constant ambient temperature conditions and was characterised by an onset phase in which rectal temper...
[Equine monocytic ehrlichiosis (EME), a review]. Serological surveys showed that equine monocytic ehrlichiosis (EME) occurs in the USA, Canada and Europe. The causative agent is Rickettsia Ehrlichia risticii, isolated for the first time in 1984. The clinical features of the disease are sluggishness, anorexia, colic and fever, possibly followed by watery diarrhoea. Complications of an infection with E. risticii are laminitis and abortion. Colitis of the ascending colon may be observed at autopsy. Following a positive serological diagnosis (IgM ELISA) of EME, treatment with oxytetracycline can be initiated. It is also important to restore the ...
Tumor necrosis factor activity in the circulation of horses given endotoxin. Serum and plasma from horses injected with endotoxin was examined for cytotoxic activity. Each of the cell lines, L929 and WEHI 164 clone 13, was sensitive to the cytotoxic effects of equine serum; however, a precipitation artifact caused by the use of isopropanol in the WEHI assay limited the use of this assay to samples containing less than 2 mg of protein/ml. In foals treated with a sublethal IV bolus of 5 micrograms of lipopolysaccharide (LPS)/kg and in adult horses given a low-dose continuous infusion of LPS (30 ng/kg/h for 4 hours), cytotoxic activity was detected in all serum or plasma ...
Correlation of clinical and laboratory data with serum tumor necrosis factor activity in horses with experimentally induced endotoxemia. Serum tumor necrosis factor (TNF) activity was quantitated in 8 horses given an IV infusion of endotoxin (0.03 micrograms of lipopolysaccharide/kg of body weight, from Escherichia coli 055:B5) in 0.9% NaCl solution over 1 hour. Serum TNF activity was likewise measured in 6 horses given only 0.9% sterile NaCl solution at the same rate. The duration of serum TNF activity was determined, and serum TNF activity was correlated with clinical and laboratory changes during the induced endotoxemia. Horses had no serum TNF activity prior to endotoxin administration, but geometric mean serum TNF activity...
Peritonitis in adult horses: a review of 21 cases. The clinical signs in 21 adult horses affected by peritonitis (unassociated with gastrointestinal rupture or surgical interference of the abdomen) included colic (18 cases), pyrexia (15 cases), weight loss (six cases) and diarrhoea (five cases). The diagnosis was based on a nucleated cell count in peritoneal fluid greater than 10(10)/litre. Haematological abnormalities (either neutropenia or neutrophilia) were present in 17 animals, and hyperfibrinogenaemia was identified in 14. Twelve of the 21 horses survived after intensive antibiotic therapy; the other nine were destroyed either at explora...
Epidemiologic study of salmonellae shedding in the feces of horses and potential risk factors for development of the infection in hospitalized horses. A study was designed to identify epidemiologic factors associated with the development and spread of salmonellae in horses in a veterinary teaching hospital, through a case-control study and a longitudinal follow-up prospective study. In the case-control study, 44 horses shedding salmonellae in feces were compared with 99 control horses not shedding salmonellae in feces; regarding breed, sex, age and initial diagnosis, none of the odds ratios for study factors was significant. The factors found to be associated with fecal shedding of salmonellae in the prospective study included diarrhea at th...
Haematological measurements as an aid to early diagnosis and prognosis of respiratory viral infections in thoroughbred horses. In late November 1988 large numbers of thoroughbred horses in training in Hong Kong developed a transient pyrexia with, in some cases, the clinical signs of viral respiratory disease. Serial blood samples for haematological examination were taken from 10 of the horses which were stabled in six different blocks. They had developed a high temperature within three days of each other and subsequently seroconverted to equine herpes virus 1 (EHV1). The absolute monocyte count was more than 0.5 x 10(9)/litre in all 10 within the first five days, and nine of them had a high neutrophil/lymphocyte ratio...
One way protection between equid herpesvirus 1 and 4 in vivo. Two groups each of six sibling ponies were exposed to sequential infections with equid herpesvirus 1 or 4 (EHV-1 or EHV-4) at four or five month intervals. Two exposures to EHV-4 did not significantly reduce virus shedding or pyrexia when the ponies were subsequently exposed to EHV-1. However, two sequential infections with EHV-1 completely protected against challenge with EHV-4. Virus neutralising antibody in each group did not increase until 21 days after primary exposure and was subtype specific. However, complement fixing antibody rose within seven days after inoculation with EHV-1, and 14...
Experimental infection of ponies with equine influenza (H3N8) viruses by intranasal inoculation or exposure to aerosols. Infection of seronegative Welsh mountain ponies was established by intranasal instillation or exposure to nebulised aerosol of egg grown H3N8 viruses. Pyrexia and coughing were noted following intranasal instillation and high titres of virus were recovered from the nasopharynx. Exposure to aerosol resulted in more severe clinical signs characterised by high temperatures, dyspnoea, anorexia and coughing; lower levels of virus were recovered from the nasopharynx. The severity of clinical signs and the kinetics of virus shedding were dose-related with the minimal infectious dose being 10(2)EID50/...
Haemodynamic, pathological, haematological and behavioural changes during endotoxin infusion in equine neonates. The purpose of this study was to evaluate the effects of experimentally induced sublethal endotoxaemia in equine neonates. Four foals, between two and five days of age, were infused intravenously with 0.5 microgram/kg bodyweight of Salmonella typhimurium endotoxin (LPS) over a 5 h period. A four-day-old and a five-day-old foal, similarly infused with sterile isotonic saline, served as controls. Clinical signs were monitored, blood samples obtained for evaluation of selected haematological and biochemical parameters; and haemodynamic parameters were recorded hourly during the infusion, as well ...
[Clinical changes after intravenous administration of endotoxin in the horse]. The results of a study conducted to determine the clinical changes in 4 experimentally-induced cases of endotoxaemia in the horse are reported on. Endotoxaemia was induced by injecting commercially available E. coli 055:B5 lipopolysaccharide intravenously at a dose of 1 microgram kg-1. The parameters that were monitored include general behaviour, rectal temperature, heart rate, respiratory rate and quality, pulse quality, mucous membrane colour, capillary refill time, appearance of the faeces and the presence of laminitis. Increases in rectal temperature, respiratory and heart rate, capillary ...
Fever of unknown origin in the horse: a review of 63 cases. Fever of unknown origin (FUO) is a syndrome characterised by prolonged, unexplained fever associated with non-specific signs of illness such as lethargy, inappetence and weight loss. This paper reviews the details of 63 horses affected by FUO. The cause was found to be infection in 43 per cent of the cases, neoplasia in 22 per cent, immune-mediated diseases in 6.5 per cent and miscellaneous diseases in 19 per cent; the cause remained undiagnosed in 9.5 per cent.
Characterization of a soft-tissue infection model in the horse and its response to intravenous cephapirin administration. A soft-tissue infection model was created in eight horses by infecting subcutaneous tissue chambers with Streptococcus zooepidemicus organisms. Responses of the horses to the infections were determined by monitoring changes in the complete blood count and body temperature and by following changes in the cytology and protein content of the tissue chambers. Systemic reactions to the infections included a mild neutrophilia, mild pyrexia and mild anemia. There was a marked influx of neutrophils and protein into the chambers after they were seeded with bacteria and chamber neutrophil viability decr...
Diagnosis of avian tuberculosis in a horse by use of liver biopsy. A 15-month-old Appaloosa colt had pyrexia, weight loss, diarrhea, and dependent edema. Abnormal laboratory findings included anemia, hypoalbuminemia, and hyperglobulinemia. Activities of liver-specific enzymes in this colt were high. Analysis of a liver biopsy specimen resulted in a presumptive diagnosis of tuberculosis. We recommend that liver biopsy be used as a diagnostic procedure if the differential diagnosis in a horse includes avian tuberculosis or granulomatous enteritis, especially if serum activities of liver-specific enzymes are high.
Disease features in horses with induced equine monocytic ehrlichiosis (Potomac horse fever). Fifty-five horses were inoculated IV and/or SC with materials containing Ehrlichia risticii, ie, infected whole blood, buffy coat cells, or cell culture, to study clinical and hematologic features of equine monocytic ehrlichiosis (Potomac horse fever). Major clinical and hematologic features of induced E risticii infection were biphasic increase in rectal temperature with peak increases of 38.9 C and 39.3 C on postinoculation days (PID) 5 and 12, respectively; depression; anorexia; decreased WBC count (maximal decrease of 47% on PID 12); and diarrhea from PID 14 to PID 18. Increased WBC count ...
Treatment of bacterial endocarditis in a horse. Using echocardiography, mitral valve bacterial endocarditis was diagnosed in a yearling Thoroughbred filly with a history of periodic fever and intermittent hind limb lameness. Streptococcus sp were isolated from blood, and the filly was treated with penicillin, resulting in a bacteriologic cure. Severe mitral regurgitation developed secondary to scarring of the valve, which resulted in the filly's death. A poor prognosis usually is indicated in horses with bacterial endocarditis, as bacteriologic cures are infrequent and severe valvular insufficiency often develops.
Pathogenicity for horses of original Sagiyama virus, a member of the Getah virus group. Sagiyama virus is a member of the Getah virus group. Its pathogenicity for horses was examined. All the horses infected with the original 4 strains of Sagiyama virus (M6/Mag 33, Mag 121, Mag 132 and Mag 258) developed pyrexia ranging from 39.0 to 40.0 degrees C. Other clinical signs, characterized by eruptions, edema in the hind legs, enlargement of the submandibular lymph node and mild leukopenia, were also manifested. Viremia occurred 1-4 days post-inoculation (p.i.). Virus was recovered from spleen, liver, lung and various lymph nodes of a horse autopsied on Day 4 p.i. The maximum titer of ...
Sero-epizootiological study of racehorses with pyrexia in the training centers of the Japan Racing Association. A sero-epizootiological study was conducted on horses which showed clinical pyrexia at two training centers, each of which maintained 1, 200 to 2, 100 racehorses for training, of the Japan Racing Association. It continued from 1980 to 1985 to clarify the cause of pyrexia, so that measures might be considered for the prevention of infectious disease. A total of 3, 849 horses were found to be affected with pyrexia for the 6 years. Of them, 2, 852 horses were tested to equine herpesvirus type 1 (EHV-1), equine rhinovirus type 1 (ERhV-1), rotavirus and equine adenovirus (EAdV) by collecting paired...
Plasma lysozyme activity of Polish primitive horses under physiological conditions and in experimental fever. The normal level of plasma lysozyme of 9 Tarpane-like horses was 0.922pg/ml. This was
calculated from determinations performed 5 times in a period of 14 months. Observations on the
normal plasma level of lysozyme in the horse revealed marked variations in individual animals, as well
as in the whole group and in the mean values calculated for individual horses. The model for the
subsequent studies was an experimental fever evoked by the administration of E. colz LPS in a dose of
0.1 pg/kg body weight. Blood samples from the jugular vein were taken just before LPS injection, and
then for 8...
Omental fibrosarcoma in a horse. A 13-year-old Thoroughbred mare had a 2-week history of weight loss and intermittent fever. Examination of abdominal and pleural fluid revealed peritonitis and pleuritis. Ultrasonography of the ventral abdominal midline revealed an intra-abdominal mass. Exploratory celiotomy was performed, but the mass was not surgically excisable. The mare was euthanatized and necropsied. Histologically, the mass was determined to be a fibrosarcoma of omental origin.
Suppurative splenitis and peritonitis in a horse after gastric ulceration caused by larvae of Gasterophilus intestinalis. A 12-year-old Thoroughbred mare, with a history of anorexia, dramatic weight loss, fluctuating pyrexia and intermittent diarrhoea after an episode of colic, was presented for examination with depression, emaciation and ataxia. Thoracic and abdominal paracenteses yielded copious quantities of inflammatory exudate. Palpation per rectum revealed an enlarged spleen. The primary alterations in haematology included a severe leucocytosis with a left shift, and a hyperproteinaemia characterised by hypoalbuminaemia and hypergammaglobulinaemia. Post-mortem examination revealed a low grade pleurisy and p...
An induced synovitis disease model in ponies. The effects of intra-articular injection of small amounts of E. coli lipopolysaccharide (LPS) into the intercarpal joint of 5 ponies were studied. The LPS induced predictable changes all of which were analogous to acute bacterial infection, except that the development of signs occurred sooner after the LPS injection, and subsided within 36 hours. Fever was monophasic and peaked at 5-7 hours. The ponies exhibited depression, reduced or absent appetite, increased pulse and respiration rates, and lameness. The lameness became evident between 1 and 2 hours after injection, at which time warmth, ar...
Clinical and hematologic variables in ponies with experimentally induced equine ehrlichial colitis (Potomac horse fever). The clinical and hematologic variables of 10 ponies with experimentally induced equine ehrlichial colitis (EEC; syn: Potomac horse fever) were studied for a 30-day period (6 ponies) or until death (4 ponies). The earliest clinical sign indicative of EEC was fever (rectal temperature exceeding 39 C). All ponies became depressed (CNS) at various times during the disease, and 90% of the ponies developed diarrhea between 9 and 15 days after infection was induced. The most significant hematologic change was an increase in plasma protein concentration after the onset of fever (P less than 0.05). The...
Enterocolitis caused by Ehrlichia sp. in the horse (Potomac horse fever). Potomac horse fever was reproduced in 15 ponies by transfusion of whole blood originally from two natural cases and subsequently from ponies infected by the transfusions. Incubation periods varied from 9 to 15 days. Affected ponies developed varying degrees of fever, diarrhea, anorexia, depression, and leukopenia. Eleven affected ponies were killed, three died in the acute phase of the disease, and one did not show clinical signs. The most consistent post-mortem findings were fluid contents in the cecum and large colon, and areas of hyperemia (of inconstant degree and distribution) in mucosae ...
Deficiency of the contact phase of intrinsic coagulation in a horse. A 16-year-old gelding was examined because of weight loss, inappetence, and intermittent fever of 2 months' duration. Preliminary laboratory findings revealed anemia, hypoproteinemia, thrombocytopenia, and prolongation of the activated partial thromboplastin time. A deficiency or inhibition of coagulation factor XI, factor XII, or high molecular weight kininogen was diagnosed. This defect was not associated with a bleeding diathesis, but should be considered as a cause of prolongation of the activated partial thromboplastin time.
California serogroup virus infection in a horse with encephalitis. A 4-fold or greater seroconversion to the snowshoe hare serotype of the California serogroup of viruses in a horse with acute encephalitis was demonstrated by hemagglutination-inhibition, complement-fixation, and neutralization tests. The horse had a mild fever, was ataxic, had a head tilt, and was observed to circle. Chloramphenicol, dexamethasone, and B complex vitamins were administered and the horse recovered. The snowshoe hare virus is a recognized human pathogen, but it has not been associated with disease in horses. It is unknown whether horses play a role as amplification hosts for the...
Standardization of an experimental disease model of Streptococcus zooepidemicus in the equine. A reproducible experimental disease model in horses using Streptococcus zooepidemicus was developed. An intravenous challenge dose of 1 X 10(10) colony-forming units (CFU), followed 24 h later with another challenge of 1 X 10(8) CFU of Strep. zooepidemicus produced the desired disease model. The disease was characterized by depression, pyrexia, anorexia, abnormal lung sounds, inflammation of joints, moderate to severe lameness, gradual loss of condition and emaciation. The effects of the disease on hematology, serum chemical profile and different protein fractions were studied. The disease sta...