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Topic:Comparative Study
Comparative studies in equine research involve the systematic analysis of different horse breeds, management practices, or physiological responses to identify variations and similarities. These studies are instrumental in understanding how different factors influence health, performance, and behavior in horses. Common areas of comparison include genetic traits, nutritional requirements, disease resistance, and response to training. By evaluating these differences, researchers can develop targeted strategies for breeding, healthcare, and training. This page aggregates peer-reviewed research studies and scholarly articles that focus on the methodologies, findings, and implications of comparative studies in the context of equine science.
Persistent hyperbilirubinemia in a healthy thoroughbred horse. Persistent hyperbilirubinemia and icterus are described in a healthy 4-year-old Thoroughbred horse. Hyperbilirubinemia was not related to food intake and was not associated with evidence of increased hemolysis or with acquired hepatic disease. The hyperbilirubinemia was thought to be a result of inappropriate conjugation of bilirubin rather than any abnormality in bilirubin uptake or excretion. The bilirubinemia in this horse appears most similar to a human syndrome, caused by a familial deficiency of bilirubin-uridine diphosphate glucuronyl transferase.
Neutrophil chemotaxis in the horse is not mediated by a complex of equine neutrophil elastase and equine alpha-1-proteinase inhibitor. Studies have demonstrated that as a result of proteolytic inactivation or complex formation (with neutrophil elastase), human alpha-1-proteinase inhibitor (API) becomes a potent chemoattractant for human neutrophils. The present study aimed to investigate the in vitro chemotactic response of equine neutrophils to an equivalent complex of equine API and neutrophil elastase. No evidence of neutrophil migration was observed towards purified complex derived from equine neutrophil elastase and the Spi 1 isoform of equine API, or to crude mixtures of porcine pancreatic elastase and unseparated equin...
Clinical pharmacokinetics of amikacin in hypoxic premature foals. The pharmacokinetics of amikacin, administered iv at 7 mg/kg, every 8 h, were evaluated over the first 48 h of hospitalisation in 7 critically ill hypoxic premature foals and compared with those in 8 full-term nonhypoxic critically ill neonatal foals. The pharmacokinetic data were used to calculate dosage schedules that would maintain the plasma amikacin concentrations in individual foals within a target range of > or = 15 micrograms/ml but < 30 micrograms/ml for peak values and < or = 3 micrograms/ml for trough values. The results indicated a statistically significant increase in the amikacin...
Development to blastocysts of one- to two-cell equine embryos after coculture with uterine tubal epithelial cells. Development of 1- to 2-cell in vivo fertilized equine embryos cultured with or without uterine tubal epithelial cells (UTEC) was studied. One- to 2-cell embryos (n = 26) were collected surgically from the uterine tubes of pony mares 1 day after ovulation. Four- to 8-cell embryos (n = 9) were collected 2 days after ovulation. Presumptive zygotes and 2-cell embryos were cultured with (n = 17) or without (n = 9) UTEC, and all 4- to 8-cell embryos were cocultured with UTEC as positive controls. Uterine tubal epithelial cells were used as cell suspensions within 2 weeks after initiation of cultures...
Development of a competitive enzyme-linked immunosorbent assay for detection of bovine, ovine, porcine, and equine antibodies to vesicular stomatitis virus. Two competitive (C) enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of antibodies to vesicular stomatitis virus (VSV) in animal sera. The assays are based upon the availability of polyclonal antibodies (PAbs) from mouse ascitic fluids prepared against the New Jersey (NJ) and the Indiana (IN) VSV serotypes. The assays were performed by the immobilization of VSV-NJ and VSV-IN antigens on a solid phase (microtiter plate). Appropriately diluted test serum mixed with an equal volume of serotype-specific PAb was allowed to incubate in the presence of the relevant VSV ant...
Phylogenetic position of Taylorella equigenitalis determined by analysis of amplified 16S ribosomal DNA sequences. The 16S ribosomal DNA sequence of Taylorella equigenitalis (formerly Haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. A phylogenetic analysis of this sequence revealed a phylogenetic position of T. equigenitalis in the beta subclass of the class Proteobacteria apart from the position of Haemophilus influenzae, which belongs to the gamma subclass of Proteobacteria. A close phylogenetic relationship among T. equigenitalis, Alcaligenes xylosoxidans, and Bordetella bronchiseptica was detected; Spirillum volutans and Chromobacterium fluviatile (Iodob...
The bronchial tree and lobular division of the horse lung. The lungs of five horses were examined. At present, in veterinary anatomy, the horse lung is divided into the cranial and caudal lobes by the cardiac notch on either side. In addition to these lobes, in the right lung, the accessory lobe is present. However, from the viewpoint of the bronchial ramifications, the horse lung can be divided into the cranial, middle, caudal and accessory lobes bilaterally. The horse lung has four bronchiole systems on either side, dorsal, lateral, ventral and medial. The cranial lobe is formed by the first bronchiole of the dorsal bronchiole system. The middle lob...
Placental and plasma cystine aminopeptidase in pregnant animals. The placental and plasma cystine aminopeptidase (CAP) in pregnant animals was examined on stability after the treatment with L-methionine, ethylene diamine tetra-acetic acid (EDTA) and heat. Inhibitory effects of these treatments on enzyme activities were different among CAPs from the animal species, however, significant correlation in those effects between placental and plasma CAPs was observed. These results suggested that plasma CAP might reflect placental CAP and seemed to be available for estimating maternal gestational conditions.
Equine influenza virus from the 1991 Swedish epizootic shows major genetic and antigenic divergence from the prototype virus. The antigenic properties of H3N8 equine influenza virus from the Swedish epizootic of 1991 differ from those of A/eq 2/Fontainebleau/79 (representative of the Swedish vaccine strain) in hemagglutination inhibition tests. The amino acid sequence of the hemagglutinin (HA) of an isolate from the 1991 outbreak was deduced from the nucleotide sequence and comparison was made to the A/eq 2/Fontainebleau/79 strain. Twenty-three amino acid substitutions were found, 10 mapping onto areas of the HA known to bind antibodies in human H3 influenza viruses. The amino acid changes together with the serologic...
In vitro concentrative accumulation of D-xylose by jejunum from horses and rabbits. Accumulation of D-xylose by jejunal mucosa from healthy horses and rabbits was studied in vitro. When tissue sheets were incubated with 1 mM D-xylose for 60 minutes, mucosa from horses and rabbits accumulated D-xylose against a concentration gradient. There was no accumulation when equine specimens were incubated with 5 mM D-xylose. By comparison, equine jejunum accumulated D-glucose against a concentration gradient when incubated in 5 mM D-glucose. In equine and rabbit jejunum, 13.3 +/- 7.0% and 36 +/- 11.0%, respectively, of accumulated D-xylose was phosphorylated when sheets were incubated ...
Different in vitro metabolism of 7 alpha-methyl-19-nortestosterone by human and equine aromatases. The ability of human and equine placental microsomes to aromatize 7 alpha-methyl-19-nortestosterone (MNT) was studied. Kinetic analysis indicates that MNT shares the androgen-binding site of human and equine placental microsomal aromatases. Human placental microsomal estrogen synthetase had about a 2.5-fold higher relative affinity for MNT than the equine placental enzyme (KiMNT/Km androstenedione of 32 versus 87). However, MNT was not metabolized by human placental microsomes, whereas it was very actively metabolized by equine placental microsomes. Further studies using purified equine cytoch...
Immunocytochemical localization of some turkey pituitary hormones using antisera to human hormones. This study was conducted to determine the crossreactivity of antisera to human prolactin (PRL), adrenocorticotropic hormone (ACTH), and growth hormone (GH) to turkey pituicytes. In addition, crossreactivities of the above antisera and antiserum to turkey GH to pituicytes of turkey, cat, rabbit, horse, owl monkey, and human were evaluated. Results of the immunocytochemical localizations showed that with one exception antisera to human hormones were positive for each species tested. Turkey pituicytes failed to crossreact with antiserum to human GH. Likewise, antiserum to turkey GH failed to cros...
DNA sequence analysis of serologically detected ELA class II haplotypes at the equine DQ beta locus. The genetic diversity at the ELA DQ beta locus was investigated using polymerase chain reaction and DNA sequencing. Based upon serological methods 16 class II homozygous animals were selected and their genomic DNA was used. A DQ beta gene from an equine cDNA library was also sequenced. Our methodology and the similarity between the genomic and the cDNA sequences suggest that the studied locus is expressed on equine lymphocytes. In the predicted amino acid sequence the most extensive variation is located at residues 56-60. The pattern of these five amino acids is strongly correlated to the sero...
The cDNA sequence of horse transferrin. The cDNA sequence of horse transferrin was determined by sequencing clones isolated from a horse liver cDNA library and clones obtained by PCR. The 2305 bp horse transferrin cDNA sequence included part of the 5' untranslated region and extended to the poly(A) tail. It had 80% sequence identity with the human transferrin cDNA, and encoded a protein of 706 residues, including a signal sequence of 19 amino acids. The horse transferrin sequence had the duplicated structure and conserved iron binding and cysteine residues which are characteristic of the transferrin family.
Are tapeworms associated with equine colic? A case control study. Faeces samples from 116 horses with colic and 115 non-colic cases were assayed by a centrifugation/floatation method for the presence of tapeworm eggs. Analysis of these data failed to demonstrate an association between tapeworm infection and colic of all types. The data were further analysed according to anatomical site of the lesion causing colic. The risk of ileocaecal colic was increased in the presence of tapeworms. Age, breed and sex were evaluated as possible confounding factors but had no association with the incidence of colic. This study suggests an association between tapeworms and ...
Effect of sucralfate on healing of subclinical gastric ulcers in foals. The effect of sucralfate on healing of subclinical gastric ulcers and gastric inflammation was investigated in twelve 6- to 7-month-old foals. Foals with endoscopically evident gastric lesions on day 0 were assigned to 1 of 2 groups, on the basis of mucosal inflammation and number and severity of ulcers, to create groups of foals with approximately equal severity of lesions. None of these foals had clinical signs of gastroduodenal ulcer disease. Groups were assigned to receive sucralfate (22.0 mg/kg of body weight) or corn syrup for 14 days, PO, every 8 hours. On day 15, gastroscopic examinati...
Plasma constituents during incremental treadmill exercise in intact and splenectomised horses. Six intact and 6 splenectomised mares were given an incremental exercise test on a treadmill to examine the fluid and electrolyte changes associated with exercise and the role of the spleen in these changes. Blood samples were obtained at rest and at the end of each 1-min step of the test. Exercise at 7 m/sec caused significant (P 0.05) in either group (intact = 2.7%; splenectomised, = 3.5%). This appears to be the first record of substantial changes of these constituents during short-term exercise, even before the onset of visible sweat losses. The changes in the concentration of plasma prot...
Pathogenicity of a thymidine kinase-deficient mutant of equine herpesvirus 1 in mice and specific pathogen-free foals. Both intranasal (i.n.) and intracerebral (i.c.) inoculation of mice with wild-type equine herpesvirus type 1 (wt EHV-1) caused clinical signs and mortality. Virus could be recovered from target organs (turbinates, lungs and blood) for several days. By contrast, the thymidine kinase (TK)-deficient deletion mutant PR1 produced markedly less clinical disease following both i.n. and i.c. inoculation, and, in particular, no mortality occurred. PR1 did, however, establish productive infections following either route of inoculation. High titres of virus were recovered from target organs although viru...
Effect of stabling on bronchoalveolar cells obtained from normal and COPD horses. Bronchoalveolar lavages (BAL) were performed before and after 3 weeks of housing in 5 horses suffering from COPD and 5 normal horses. In the two groups, the total number of cells recovered remained unchanged after stabling. The most common cell populations in BAL fluid of control animals were alveolar macrophages (46.4%) and lymphocytes (44.9%). The percentage of neutrophils increased after stabling from 8.7% to 27.6%. In COPD horses, lymphocytes predominated (40.7%) in animals at pasture with neutrophils increasing from 29.4% to 71.6% after stabling. After fractionation by Percoll density gra...
Binding of stallion spermatozoa to the equine zona pellucida after coculture with oviductal epithelial cells. The objective of this study was to determine whether coculture of stallion spermatozoa and mare oviductal (uterine tubal) epithelial cells induced sperm cell capacitation in vitro. Capacitation as determined by zona binding and chlortetracycline staining of the sperm cells was compared for stallion spermatozoa: (1) incubated with medium alone (negative control), (2) treated with calcium ionophore A23187 (positive control) or (3) cultured with mare oviductal epithelial cells (OEC) for 4 h. Chlortetracycline staining patterns of sperm cells bound to the zonae were used to group spermatozoa as un...
Equine ovarian aromatase: evidence for a species specificity. Mare granulosa cells and cyclic corpus luteum microsomes are reported to aromatize 19-norandrogens more efficiently than androgens. However, 16 alpha-hydroxytestosterone and epitestosterone were not aromatized by the equine corpus luteum microsomal estrogen synthetase. These results indicate that the equine aromatase system would be different from the human placental microsomal estrogen synthetase, which aromatizes 16 alpha-hydroxyandrogens and epitestosterone but not 19-norandrogens. Furthermore, our data show that the rates of aromatization of androgens and 19-norandrogens were not additive ...
Ground reaction force patterns of Dutch Warmbloods at the canter. Ground reaction force (GRF) patterns from 20 clinically sound Dutch Warmbloods were recorded at the right fore-leading canter, and a standard horse was composed. These GRF data for the standard can be used for evaluation of jumping horses. The GRF patterns were asymmetric for all 4 limbs. The leading right forelimb decelerated the body. The trailing left forelimb propelled the body and decelerated it slightly. The trailing left hind limb propelled, and the leading right hind limb contributed to deceleration and propulsion. Referred to the maximal vertical load of the leading right forelimb, th...
Risk factors associated with equine motor neuron disease: a possible model for human MND. Equine motor neuron disease (EMND), a newly described neurodegenerative disease, bears a striking resemblance to progressive muscular atrophy (PMA) in humans. We present a comparison of the equine and human diseases and the results of a case-control study conducted to identify intrinsic factors associated with EMND. Cases included all horses with a confirmed diagnosis of EMND diagnosed in the United States since 1985 (32 cases). Controls included horses diagnosed with either cervical stenotic myelopathy, equine degenerative myeloencephalopathy, or protozoan myelitis at the Veterinary Teaching ...
Racing performance of standardbreds after conservative and surgical treatment for tarsocrural osteochondrosis. A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC-affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presen...
Plasma cell myeloma in the horse. A case report and literature review. Plasma cell myelomas in horses have been reported infrequently. Data from 10 cases, 9 from the literature and 1 new case, are used to characterize the disease in the horse. Hot-blooded horses (7/10), specifically Quarter Horses (4/10), were most often affected. Median age at diagnosis was 11 years (range, 3 mo-22 yr) and both male (5) and female horses (5) were represented equally. Clinical findings included weight loss (6/8), anorexia (4/8), fever (4/8), limb edema (4/8), pneumonia (3/8), rear leg paresis/ataxia (3/8), epistaxis (3/8), palpable lymphadenopathy (2/8), and bone pain (2/8). Anem...
Nutrient intake of horses in thoroughbred and standardbred stables. Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighted at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean +/- sd. The estimated body weight of TB horses was 493 +/- 34 kg and 437 +/- 32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0 +/- 2.4 kg and SB tra...
[M-mode echocardiography in dressage horses, class S jumping horses and untrained horses]. Heart structures of 45 warmblooded horses were measured by M-mode-echocardiography. The current training level of 15 dressage horses (group I) and 15 show-jumping horses (group II) was category "S". In the third group were 15 untrained horses. Four standardized transducer positions were determined for the m-mode echobeam, calibrated according to the two-dimensional real time technique. End systolic and end diastolic diameters of left ventricle, right ventricle, aortic root, interventricular septum and left ventricular wall, as well as motion pattern of heart wall, mitral valve and aortic valve...
Effect of oestradiol on oxytocin-stimulated prostaglandin F2 alpha release in mares. The objective of this study was to clarify the role of oestradiol in luteal function by examining its effect on the oxytocin stimulation of 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) concentrations in cyclic mares. In the first experiment, three groups of mares (4 per group) were given a bolus injection of 17 alpha-oestradiol (1 mg), oestradiol (1 mg) or vehicle on days 7, 9, 11, 13 and 15 of the cycle. Six hours later the mares were challenged with 10 iu oxytocin intravenously and frequent blood samples were taken from 15 min before to 15 min after for measurement of PGFM. Results sh...
