"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Lindberg R, Karlsson L.The jejunal mucosa of 4 cases of equine granulomatous enteritis and 2 control horses was investigated by light microscopy and by scanning and transmission electron microscopy. Attention was focused upon changes in mucosal topography and enterocyte morphology in the inflamed mucosa. Structural changes ranged in severity from only a slight thickening and shortening of villi to the appearance of a virtually flat mucosa, upon which crypts opened directly or through shallow cavities encircled by collars of epithelial cells. Between these extremes, the mucosa showed a variety of patterns, all charac...
Allen GP, Yeargan MR, Turtinen LW, Bryans JT.From restriction endonuclease characterization of the DNA of 317 isolates of equine abortion virus (equine herpesvirus-1; EHV-1) from 176 epizootically unrelated outbreaks of equine virus abortion occurring over 24 years in Kentucky, an epizootic pattern and variation of the virus have emerged. Two electropherotypes of EHV-1 (1P and 1B) accounted for greater than 90% of the nonvaccine-related abortion isolates examined. From 1960 to 1981, EHV-1 1P was the predominant isolate circulating in the central Kentucky area and the cause of greater than 80% of EHV-1-related abortions. In 1981, the occu...
Taniguchi K, Mikami S.The vomeronasal organ of both horses and cattle is a tubular structure situated bilaterally at the base of the nasal septum. In frontal plane the shape of its lumen is semilunar to crescent. The sensory epithelium lining the medial wall of the lumen contains receptor, supporting and basal cells with some surface modifications in both species. In the horse, a structure similar to a microprocess was observed among the microvilli of receptor cells. In cattle, a large mass of the cytoplasm of the receptor cell occasionally protrudes to form a bleb-like structure. The supranuclear cytoplasm of the ...
Moorthy AR, Spradbrow PB.
Summary:
During a survey in Queensland in 1974—77 four strains of rickettsia-like organisms were isolated from the respiratory tract of horses, of which two, NS7 and NS68 were isolated from nasal swabs of clinically normal horses and two, KSDH 91 and NSDH 100, from lung samples of slaughtered horses showing gross pathological lesions in the form of acute bronchiolitis and subacute interstitial pneumonia, respectively. The isolates are characterised as rickettsia-like organisms on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacteria...
Hawkes J, Hedges M, Daniluk P, Hintz HF, Schryver HF.Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatl...
Knezevic PF, Fessl L.Thrombosis of the aorta as the cause of intermittent claudication in the horse appears to be rare. Two cases out of about 10 000 horses 1973-1984 are discussed. There are various views on its aetiology, whereby haemodynamic factors and disturbances of coagulation have been mentioned as well as parasites. For treatment surgical methods should be explored in addition to medical procedures. History, diagnosis and the attempt of an aortic thrombectomy in a 12 year old thoroughbred mare are described in this paper. A standardbred stallion was left untreated on owners wish.
Boch J.Babesia infections serologically diagnosed in horses, cattle and dogs in Southern Germany during the last few years are described. 321 sera of horses were examined for specific antibodies to Babesia by means of CFT and IIF in 1984; 18 sera reacted to Babesia equi and 4 to Babesia caballi antigen. In a cattle breeding area in the Western Allgäu 13% of 1616 cattle reacted positive to Babesia divergens antigen using IIF and ELISA; during the grazing season 1982 new latent infections were observed in 25 of 266 calves and heifers. Cases of introduced canine babesiosis are more frequent; 10 of 34 s...
Guerrero J, Newcomb K, Seibert BP, Michael BF.Two controlled tests were conducted in equine foals and yearlings to determine the optimal oral dosage and the duration of activity of closantel for the prevention of Gasterophilus spp larval infections. Additional data were collected on the activity of closantel against Strongylus vulgaris larval infections. In experiment 1, 12 foals and 12 yearlings were equally allocated to 4 experimental groups, and were given oral treatments with closantel at dosages of 0 (nontreated controls), 2, 5, or 8 mg/kg of body weight every 2 months during bot season. The foals and yearlings were allowed to graze ...
Kamerling SG, DeQuick DJ, Weckman TJ, Tobin T.The dose-related effects of intravenously administered fentanyl (0.010, 0.005, 0.0025 mg/kg) and saline were studied in mature performance horses using a rigorous experimental protocol. Fentanyl produced a dose-related prolongation of the skin twitch reflex latency but did not increase the hoof withdrawal reflex latency. Dose related increases in stepping frequency, cardiac and respiratory rats were observed following fentanyl, while changes in rectal temperature and pupil area were not. These data indicate that fentanyl, a prototypic mu-agonist, produces a syndrome characterized by analgesia,...
Cummings JF, Sellers AF, Lowe JE.The distribution of the putative motor excitatory neurotransmitter, substance P, was studied immunocytochemically in the left dorsal colon of four normal control ponies and three ponies with amitraz-induced impaction colic. Substance P-like immunoreactivity in the control ponies was observed in nerve fibres in all layers of the bowel wall and in the nerve cell bodies of the enteric ganglia. The substance P-like immunoreactivity was clearly more intense in the cell bodies of submucosal ganglia than in those of the myenteric ganglia. The internodal nerve strands of the myenteric plexus were very...
Magnuson NS, Perryman LE, Suttle DP, Robinson JL, Mason PH, Marta KM.In an attempt to determine the metabolic defect causing severe combined immunodeficiency (SCID) in horses in which altered purine metabolism has been observed, various parameters of purine and pyrimidine metabolism were evaluated. The activities of nine purine enzymes (adenosine kinase, purine nucleoside phosphorylase, deoxyadenosine kinase, deoxycytidine kinase, 5'-nucleotidase, AMP deaminase, hypoxanthine-guanine phosphoribosyl transferase, and adenine phosphoribosyl transferase were measured in fibroblasts. All activities determined for SCID horses were normal. Uptake of 10 microM adenosine...
Baggot JD, Love DN, Rose RJ, Raus R.The serum concentrations of the aminoglycosides neomycin, kanamycin and streptomycin were determined after intravenous (iv) and intramuscular (im) administration. These values were then related to the minimum inhibitory concentrations (MIC) of a number of equine pathogenic bacteria to determine the duration of therapeutic serum concentrations of the aminoglycosides in the horse. Pharmacokinetic analysis of the data using neomycin as the example revealed a mean (+/- sd) peak serum concentration of 23.2 +/- 10.2 micrograms/ml present at 30 mins, and at 8 h the serum concentration was 2.8 +/- 0.8...
Jaussaud P, Courtot D, Doron P, Guyot JL.Chronopharmacokinetics of intravenous phenylbutazone in the horse was studied with the aim of antidoping control. Among parameters studied, the single one which seemed to depend on circadian rhythm was the elapsed time between the injection and the plasmatic peak. There was no relationship between the injection time and the both parameters: half-life and time required to reach the forensic level of 4 micrograms/ml. This later, and oxyphenbutazone/phenylbutazone ratio, should depend on individual factors. Therefore, the injection time should not be a main parameter for the phenylbutazone evalua...
Becker M.During the last 10 years 268 laparotomies by a midline incision were performed. A high incidence of seromas, fistulas caused by suturing material and wound ruptures were observed. After finding only a small number of publications in the veterinary medicine about wound healing disturbances an analysis of the human medical literature was done. This induced the change of our surgical procedure and suturing technique: The midline incision and surgical management during the laparotomies in 14 horses suffering from colic were performed by a minimized trauma. The abdominal wall was closed layer by la...
Schneider RK, Mayhew IG, Clarke GL.The duration of anesthetic effect and the histopathologic changes resulting from a controlled freeze of the palmar and plantar digital nerves in the horse were evaluated. Two techniques were compared: (i) nerves were frozen by direct application of the cryoprobe after surgical exposure and (ii) nerves were frozen by percutaneous application of the cryoprobe to the overlying skin. Return of skin sensation and ability to detect a stimulus were used to determine return of nerve function. The duration of anesthetic effect was significantly (P less than 0.005) longer for nerves frozen after surgica...
Nakashima M, Noda H, Hasegaea M, Ikai A.We studied the oxygenation of mammalian hemoglobins: mouse (Mus musculus molossinus), rabbit (Oryctolagus cuniculus domesticus), Japanese monkey (Macaca fuscata), man (Homo sapiens), sheep (Ovis aries), llama (Lama glama), pig (Sus scrofa domesticus), cow (Bos taurus domesticus) and horse (Equus caballus), in the absence of 2,3-diphosphoglycerate (DPG) and compared their oxygen affinity in relation to the body weight. The negative correlation between body weight and the oxygen affinity of the whole blood, observed by Schmidt-Nielsen and Larimer (1958), was not observed in the absence of DPG. O...
Doreau M, Martin-Rosset W.Uraemia variations in the heavy breed mare were studied in different situations. A study with 35 mares during an entire grazing season was conducted. The mean uraemia varied between 48.5 and 67.5 mg/100 ml plasma, with season and type of grass. The highest values were found with first-cycle pasture grass. Uraemia was lower with winter diets: 28.6 to 36.0 mg/100 ml. A study using 15 mares fed isonitrogenous diets based on hay or straw, and concentrates offered two different levels, between two months before and 8 days after foaling, showed that the physiological stage had a very moderate effect...
Trommershausen Bowling A, Clark RS.Gene frequencies at 20 blood group and protein polymorphism loci (A, C, D, K, P, Q, U, Al, Tf, Pi, Xk, Es, Gc, PGD, CA, Cat, PGM, AP, Hb and PHI) are given for seven horse breeds in the United States (Thoroughbred, Arabian, Standardbred, Morgan, Quarter Horse, Paso Fino and Peruvian Paso). These data are used to calculate that the battery of tests is at least 96% effective for recognizing incorrect paternity in these breeds. In addition to paternity testing, these tests can be applied to studies of breed relationships.
Tschudi P.The physiological and technical basis of the electrocardiography are shortly explained. The electrodes used for the recording of bipolare thoracal leads, their fixation on the horse, the practical procedure of a ECG-recording, its appearance and variation are described and illustrated. A recommendation for a systematic evaluation and interpretation is being proposed.
Knight DA, Tyznik WJ.Fourteen Quarter Horse foals were used to evaluate the effects of artificial rearing on growth. Seven foals were removed from their dams at 3 d of age and fed a reconstituted 26% crude protein (CP) milk replacer free choice for 1 mo, at which time ad libitum solid feeding began. Controls were weaned from their dams at 2 mo of age and fed a 21% CP concentrate ad libitum until the end of the trial. Variables measured during the 26-wk trial were live body weight, height at the withers and length of body from point of shoulder to point of hip. No significant differences were found between the two ...
Cheevers WP, McGuire TC.Equine infectious anemia (EIA) is a chronic, relapsing infectious disease of horses caused by a nononcogenic retrovirus. Virus persists in infected animals for life and can be reliably detected by serologic tests that measure levels of antibody to the major structural protein of the virus. Periodic virus replication in macrophages leads to an immunologically mediated acute disease characterized primarily by severe anemia. Recrudescence of acute EIA is the result of antigenic variation of the surface glycoprotein of EIA virus. The frequency and severity of clinical episodes of EIA decrease in m...
Skopakoff C.The development of the chewing, lacerative and omnivorous dentition type was confirmed on the base of the author's studies on the dentition of placentalia representatives. The use of vegetable food by the rodents and herbivorous mammals induces an efficient development of molars, absence or reduced number of incisors and canines of the upper jaw and increased number of incisors and absence of canines of the lower jaw, resulting into the proposal of an alteration of the dentition formula for rabbits and for the rest of the rodents (Simplicidentata), for herbivorous and for horses. In beasts of ...
Mettler NE, Fernández AS, Di Santo MI, Pardo DA.Sera from 282 equines from Tandil country and surroundings were investigated searching for hemagglutination inhibition (HI), Complement fixation (CF), and Neutralizing (NT) antibodies against three flavivirus:Ilheus, St. Louis Encephalitis, and Yellow Fever from the Togaviridae family. Sera were collected between 3-20-79 and 11-25-80 from 10 different places in Tandil and Ayacucho countries. Animals ranged from 45 days to 27 years old. Forty nine of them reacted with one or more flavivirus by HI and/or CF tes representing a prevalence of 17.4% for this antigenic complex. Twenty four of them ne...
Sharp DC, Wolfe MW, Cleaver BD, Nilson J.The process of sexual recrudescence in the springtime in mares is characterized by renewal of follicular growth and acquisition of steroidogenic competence. Concomitant with renewal of follicular steroidogenesis is re-establishment of LH biosynthesis and secretion. Research results from our laboratory indicate that increased estradiol and LH secretion occur in close temporal association before the first ovulation of the year. Therefore, the hypothesis tested in this experiment was that estrogen administration to ovariectomized pony mares during the equivalent time of early vernal transition wo...
Doige CE.A midsagittal centrum cleft of T5-6, malformation and fusion of T3-7, intra- and extraspinal cyst, and myelodysplasia were found in a 3-month-old female Arabian foal that had experienced posterior ataxia since birth. Based on studies in other species, ecto-endodermal adhesions early in embryogenesis leading to formation of an enterogenous cyst is the most probable pathogenesis.
Kamphues J, Meyer H, Liebler EM, Johannsen A.Anamnesis and clinical signs of horses form five different stables after ingestion of ionophores are reported and techniques of feed examination are described. Within a few hours or days after feeding of new types or batches of concentrates horses fell ill. They showed colic-like symptoms with intense sweating and ataxia. Most of the sick animals died within a short time span. Samples of the concentrates were analysed and different types and amounts of ionophores were detected. In four cases contamination by monensin in concentrations of less than 5 mg to 679 mg/kg feed were found. One feed sa...
Nyquist NF, Burri L, Jensen RB.Supplementation with marine-derived n-3 long-chain polyunsaturated fatty acids (LC PUFAs), eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) is linked to beneficial health effects in both humans and horses. Krill oil (KO), which is extracted from the Antarctic krill (Euphausia superba), is well documented as a safe and biologically available dietary supplement in humans and several animal species, but there is a lack of documentation regarding its effect as a dietary ingredient for horses. The objective of this study was to test whether KO as a dietary supplement h...
Walker N, Cater M, Bourg B, Devall H, Sarver M.Due to the increased awareness of animal welfare issues and sensitized attitudes throughout society, youth animal projects provide a unique opportunity to assess and impact youth understanding and attitudes regarding animal welfare. Animal ethics training is not an uncommon requirement for participants in 4-H livestock programs. However, participants in 4-H horse projects are not universally held to the same standard. The purpose of this study was to assess youth knowledge, attitudes, and confidence in understanding of equine welfare at the 4-H state horse show, as well as to determine the bel...
van Muiswinkel K.Based on three clinical cases, the history and the clinical and radiological aspects of osteochondrosis in horses are discussed. The prognosis, therapy and consequences with regard to athletic soundness and use for breeding are described.
Moore RM, Couto CG, Muir WW, Moore BR, Kociba GJ.Twenty-four horses were randomly allocated to 3 groups. All horses underwent a ventral midline celiotomy, and the large colon was exteriorized and instrumented. Group-1 horses served as sham-operated controls, group-2 horses underwent 6 hours of colonic ischemia, and group-3 horses were subjected to 3 hours of ischemia and 3 hours of reperfusion. Baseline blood samples were collected, then low-flow colonic ischemia was induced in horses of groups 2 and 3 by reducing colonic arterial blood flow to 20% of baseline. All horses were monitored for 6 hours. Citrated systemic venous (SV) blood sample...
Bowman KF, Dix LP, Riond JL, Riviere JE.Pharmacokinetics of ampicillin sodium (11 mg/kg), gentamicin sulfate (2.2 mg/kg), and combination ampicillin sodium-gentamicin sulfate were determined for serum and synovia of healthy horses given single-dose IV injection and were not found to be different from those from other reports; however, a prolonged terminal gamma-phase for gentamicin (8,498 +/- 1,842 minutes) in serum of horses was found to exist. Pharmacokinetic interaction between combination ampicillin sodium-gentamicin sulfate was not observed int he serum or synovia. Prediction of ampicillin sodium or gentamicin sulfate concentra...
Mang L, Li JL, Shi YF.Mitochondrial DNA D-Loop varied region 400 bp sequence variations in 4 Chinese Mongolian horses and 4 External Thoroughbred horses were analyzed in this experiment. The results showed that the average nucleotide mutational rate of mtDNA D-Loop varied region in 4 Chinese Mongolian horses was 3.69%, while External Thoroughbred horses were 4.00%. Three types of mutations including transition, transversion and deletion were all found in the investigated mtDNA D-Loop regions, of which transition was the most frequent. Nucleotide mutational loci were abundant, length mutations were found and great d...
Lee HF, Lee JD, Lee YC.In course of immunizing horses with snake venoms, tetanus and diphtheria toxoids, a new serum component, T-globulin, was formed and migrated between the beta- and gamma-globulins. The T-globulin content was parallel with the antibody titre after the middle course of immunization. There were many components in snake antivenin and T-globulin was composed of most of those components. The components of diphtheria T-globulin were the same as those of crude antitoxin and tetanus T-globulin except one precipitin.
Friedrich A, Hagedorn HW, Schulz R.Due to their marked antiinflammatory effect, synthetic corticosteroids are used to mask illness, especially lameness in horses. The detection of these drugs in equine body fluids requires accurate methods, particularly where misuse of corticosteroids is suspected. Gas chromatography/mass spectrometry (GC/MS) is well established as a reliable technique for the identification of drugs in biological fluids. Using GC/MS, we determined dexamethasone levels in horse urine and serum after intravenous application of a therapeutic dose. Dexamethasone was detectable, in serum for up to six hours, and in...
Eysker M, Vercruysse J.The epidemiology, chemotherapy and control of strongylus infections in the horse are discussed. The annual cycle of various species are stated. In addition the anthelmintics available for treatment and control and the occurrence of anthelmintic resistance are referred to. Finally the options for control under various management conditions (little if any grazing; extensive grazing; intensive grazing) are discussed.