"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.
Potter K, Anez D.A 17-year-old Quarter Horse mare was examined to determine the cause of a vulvar mass. Differential diagnoses for the swollen, ulcerated tissue included hypersensitivity reaction to insect stings or bites and cutaneous neoplasia. During the next 4 months, the mass enlarged involving the skin of the perineum and ventral aspect of the abdomen with secondary dependent edema of both hind limbs. Histologic examination of biopsy and necropsy specimens revealed changes consistent with a diagnosis of mycosis fungoides (cutaneous T-cell lymphoma). Diagnostic features included invasion of neoplastic lym...
Harris DB, Harris RC, Wilson AM, Goodship A.Muscle ATP loss with exercise has implications both to the causes of fatigue and muscle damage. To study this at the single muscle fibre level, five trained thoroughbred horses performed consecutive 90 second gallops on an inclined treadmill followed by a final gallop to fatigue. Biopsies of the m. gluteus medius were taken at rest, post-exercise and during 24 hour recovery. Blood lactate was 20.0 mmol litre-1 or more, and plasma NH3 300-800 mumol litre-1, following the final gallop. Minimal changes occurred in the plasma markers, CK and AST. ATP loss with exercise was 32.2 (SD 12.2) per cent....
Koepf EK, Hewitt J, Vo H, Macgillivray RT, Burtnick LD.We have generated and characterized the cDNA from equine smooth muscle that encodes gelsolin, an actin-modulating protein. Overlapping cDNA clones synthesized by the reverse transcriptase/polymerase chain reaction and clones isolated from a horse genomic library provided the complete primary structure for the intracellular isoform of gelsolin, while cDNA complemented with protein sequence data produced the full-length primary transcript of the gelsolin isoform found circulating in equine plasma. The deduced amino acid sequences of the intracellular and secreted versions of equine gelsolin infe...
The Journal of heredityMarch 6, 1998
Volume 89, Issue 1 104-106 doi: 10.1093/jhered/89.1.104
Duffield DA, Goldie PL.In a study of 2,786 tobiano and non-tobiano horses involved in paint horse breeding programs throughout the United States, the inheritance of the tobiano color pattern gene was tracked in pedigrees using the tightly linked polymorphic albumin gene. The dominant tobiano allele (T(o)), which produces the tobiano spotting pattern in horses, was in coupling with both AIA and AIB alleles at the albumin locus. The frequency of the T(o):AIA linkage phase among all the homozygous tobiano horses in this study including offspring and parents (N = 127), was 0.08. The T(o):AIB linkage phase was the most f...
Mancebo OA, Verdi JH, Bulman GM.On the basis of positive skin snips for Onchocerca cervicalis microfilariae (MF), 45 horses were chosen from 48 in a total of 257 screened on 12 locations in the northeast Province of Formosa (Argentina), and randomly assigned to two treatment groups of 20 horses each, and a nontreated control group of five horses. On Day 14 post-treatment (PT), skin snip samples in the ivermectin-treated (0.2 mg/kg) group were negative for normal viable microfilariae (MF), while horses in the control group maintained their pretreatment level of infection. On the same Day in the moxidectin-treated (0.4 mg/kg) ...
Monahan CM, Chapman MR, Taylor HW, French DD, Klei TR.Three groups of foals were raised under different management programs in this study: Group 1 (n = 6) and Group 2 (n = 6) were raised with their dams on pasture; Group 3 foals (n = 5) were raised under parasite-free conditions. Mares and foals of Group 1 received daily pyrantel tartrate (PT) treatment with their pelleted feed ration, whereas mares and foals of Groups 2 and 3 received only the pelleted ration. Pasture-reared foals were weaned and moved to a heavily contaminated pasture for 5 weeks. Group 1 foals continued to receive daily PT treatment whereas Group 2 foals received only the pell...
Boersema JH, Eysker M, van der Aar WM.The reappearance of strongyle eggs in the faeces of horses treated with moxidectin (0.4 mg/kg of body weight) was compared with that in the faeces of horses treated with ivermectin (0.2 mg/kg of body weight). The study was performed from December 1995 till June 1996. Horses were infected naturally in the preceding grazing period. Two groups of 24 horses each were treated with moxidectin and ivermectin respectively at week 0. No side effects were seen after treatment. Horses were housed from week -1 till week 17. From week 17 onwards the horses were on pasture. Faecal samples were taken from ea...
Fernández AS, Larsen M, Nansen P, Grønvold J, Henriksen SA, Wolstrup J.A plot experiment was conducted to investigate the ability of the nematode-trapping fungus Duddingtonia flagrans to reduce the transmission of infective horse strongyle larvae from deposited dung onto surrounding herbage. At three different times during the summer 1995, three groups of horses, naturally infected with large and small strongyles, were fed different doses of D. flagrans spores, while a fourth group of animals served as non-fungal controls. Faeces from all four groups of horses were deposited as artificial dung pats on a parasite-free pasture. Every second week for 8 weeks after d...
Williamson RM, Gasser RB, Middleton D, Beveridge I.The intestinal tracts of 130 horses were examined for infection with Anoplocephala perfoliata at necropsy. Fifty horses (38.5%) harboured the tapeworm, and the site of attachment of each worm was recorded using predetermined anatomical landmarks. The worms were attached in four regions of the gastrointestinal tract: 17% of the worms were found at the ileocaecal junction, 81% on the caecal wall, 1.7% in the terminal ileum and 0.2% in the ventral colon. The severity of lesions produced at the sites of attachment was related to the number of worms attached. Due to the small area of the ileocaecal...
Borgsteede FH, van Beek G.The prevalence of metazoan parasites in the stomach and small intestine was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were young (1.5-3 years) and in good condition. Trichostrongylus axei was the most prevalent parasite species in the stomach (51.4%), followed by Gasterophilus intestinalis (41.4%) and Habronema spp. (4.3%). In the small intestine, Parascaris equorum (28.6%) and Paranoplocephala mamillana (1.4%) were found. The mean worm burden of T. axei was 957 (max. 8502), of G. intestinalis 21 (max. 84), of Habronema spp. 3 (max. 5), and of P. ...
Sahagun-Ruiz A, Waghela SD, Holman PJ, Chieves LP, Wagner GG.A DNA probe from Babesia caballi (Bc1) was selected by antibody screening of a genomic library. The Bc1 probe hybridized specifically to B. caballi genomic DNA. A polymerase-chain-reaction-based assay for B. caballi DNA was developed from primers deduced from the probe nucleotide sequence. An amplified product of 1.6 kb was detected from as little as 500 fg B. caballi template DNA. Sensitivity increased 1000-fold when the biotin-labeled Bc1 probe was hybridized to the amplicons in a Southern blot.
Foster AP, Cunningham FM.Equine eosinophils and neutrophils are believed to play an important part in the protection of horses against parasitic and bacterial invasion. Eosinophils may also play a key role in the pathogenesis of equine inflammatory conditions such as the allergic skin disease, insect hypersensitivity. The factors which stimulate the respiratory burst of equine eosinophils and neutrophils are poorly understood. The first aim of the present study was to determine the effects of the phorbol ester, phorbol myristate acetate (PMA), which is believed to activate intracellular protein kinase C, and opsonised...
Sheoran AS, Sponseller BT, Holmes MA, Timoney JF.Equine strangles, caused by the clonal pathogen Streptococcus equi, is a source of serious economic loss despite the widespread use of commercial vaccines. The anti-phagocytic 58 kDa M-like protein (SeM) is an important protective antigen. The objective of this study was to define differences, if any, between SeM-specific convalescent serum and mucosal IgA and IgG subisotypes and those induced by vaccination with commercial strangles vaccine. SeM-specific opsonophagocytic IgGb was the predominant serum antibody in horses intramuscularly vaccinated or recently recovered from infection. Infectio...
Wagner B, Brandt K, Sheoran A, Holmes MA, Deegen E, Leibold W.The functional properties of different immunoglobulin isotypes in equine recurrent uveitis (ERU) has not been investigated yet. Here, we describe the quantitative determination of total immunoglobulin levels and isotype differentiation in the vitreous of four horses with ERU as compared to that of seven healthy horses. In contrast to almost equal amounts of total immunoglobulin in the vitreous of both groups, remarkable differences were found: All four of the horses with ERU had significantly higher IgA contents in their vitreous as compared to the control group. However, the other isotypes mo...
Konkle DM, Nelson KM, Lunn DP.An outbreak of cryptosporidiosis occurred at a veterinary hospital, involving multiple species, including humans. The index case was an infected dairy calf that presented with diarrhea. Several other cases of cryptosporidial diarrhea subsequently developed during a 1-month period. The key features of this outbreak were the multiple species affected, the increased morbidity in immunocompromised neonates, and the failure of implemented control measures to contain the disease.
Hammer EJ, Tulleners EP, Parente EJ, Martin BB.To evaluate laryngeal function by means of videoendoscopy during high-speed treadmill exercise in racehorses with grade-III left laryngeal hemiparesis at rest and to determine outcome of treatment. Methods: Retrospective study. Methods: 26 racehorses. Methods: Videoendoscopy of the larynx was performed while horses were at rest and exercising on a treadmill. Horses were classified as having grade-IIIA, -IIIB, or -IIIC laryngeal hemiparesis on the basis of the degree of arytenoid cartilage abduction maintained during exercise. Postoperative racing performance was determined by evaluating race r...
Ramirez S, Wolfsheimer KJ, Moore RM, Mora F, Bueno AC, Mirza T.The objectives of this study were to determine if phenylbutazone decreased serum thyroxine (TT4) and free thyroxine (FT4) concentrations using radioimmunoassay and equilibrium dialysis techniques in horses, and, if so, an additional objective was to determine the duration of this decreased concentration once phenylbutazone administration was discontinued. Serum TT4 and FT4 concentrations were determined before and after administration of 4.4 mg/kg of phenylbutazone i.v. bid for 5 days. Treatment with phenylbutazone caused a significant decrease in TT4 and FT4 concentrations (P < .05). Serum...
O'Rielly JL, Bertone AL, Genovese RL.A four-year-old Standardbred gelding was examined because of vague right hind limb lameness of 3 to 4 months' duration. Results of physical examination, radiography, and scintigraphy were indicative of a chronic comminuted fracture of the proximal portion of the right fibula. A cancellous bone graft was placed in the fracture site, and 3 months later, the fracture appeared to be healed radiographically. Fractures of the fibula are rare in horses and should not be confused with normal anatomic discontinuities that result in a bi- or tripartite appearance of the fibula on radiographs. Because th...
Beyer MJ, Freestone JF, Reimer JM, Bernard WV, Rueve ER.Five thoroughbred foals (4 fillies and 1 colt), all in good to excellent body condition, ranging in age from 4 days to 5 weeks at the time of onset of signs, were presented to 2 Kentucky equine hospitals from 1992 through 1996. All 5 foals presented with tachycardia, hyperhidrosis, diarrhea or a recent history of diarrhea, and muscle rigidity or stiff gait. Four of the 5 foals presented for recumbency, seizure-like activity with opisthotonos, or pronounced extensor muscle rigidity. All 5 foals were hypocalcemic. All foals either died or had euthanasia performed. None responded to oral calcium ...
Thomas AD, Bowater IC, Vine JH, McLean JG.To determine whether a drug detected in the blood or urine of a racing animal could have penetrated through the skin from a topically applied preparation. Methods: Blood and urine of dogs and horses were analysed after topical administration of three common nonsteroidal anti-inflammatory preparations. Methods: Dimethylsulphoxide was analysed using a gas chromatograph with a flame photometric detector. Phenylbutazone, its metabolites and lignocaine were analysed using a gas chromatograph with a mass selective detector. Results: Dimethylsulphoxide, phenylbutazone and lignocaine were detected in ...
Pozio E, Tamburrini A, Sacchi L, Gomez Morales MA, Corona S, Goffredo E, La Rosa G.Routine examination for Trichinella infection by artificial digestion of 5-g samples of muscle tissue revealed the presence of muscle larvae in one out of 28 horses imported from Romania to an abattoir in Italy. The parasite, identified as Trichinella spiralis by the polymerase chain reaction, showed a reproductive capacity index of 68 in Swiss mice. Light microscope examination of 200 nurse cell-larva complexes showed that 22% of them were calcified and that the capsules of the non-calcified nurse cells were 17.5-27.5 microns (s = 22.67 microns) thick and had very few cellular infiltrates. Th...
Mohan K, Muvavarirwa P, Pawandiwa A.Among the Actinobacillus spp. only A. lignieresii represents a homogenous and well studied taxon. However, haemolytic and non-haemolytic strains of A. equuli and A. suis are also isolated from a wide range of diseases in a variety of hosts. These isolates often pose problems in definitive identification. Consequently, several studies have been published, emphasizing the need for detailed studies to reclassify various members of this genus and also to assess their disease significance. We isolated 48 strains of Actinobacillus from clinical cases in horses, cattle, sheep, cat, pigs and ostrich. ...
Leifsson PS, Olsen SN, Larsen S.This paper is the first report of systemic tuberculosis involving the eyes in a horse. The animal lost condition and gradually became increasingly blind in both eyes; it was eventually euthanased. The pathological findings included bilateral, mycobacterial granulomatous uveitis with unilateral retinal detachment and necrosis, and disseminated, mycobacterial granulomatous foci in the myocardium, lungs, bronchial lymph nodes, kidneys, liver, pancreas, colon and visceral serosal surfaces, with the most extensive lesions in the myocardium. The mycobacteria were identified as Mycobacterium avium.
Deluca TH, Patterson Iv WA , Freimund WA, Cole DN./ Various types of recreational traffic impact hiking trails uniquely and cause different levels of trail degradation; however, trail head restrictions are applied similarly across all types of packstock. The purpose of this study was to assess the relative physical impact of hikers, llamas, and horses on recreational trails. Horse, llama, and hiker traffic were applied to 56 separate plots on an existing trail at Lubrecht Experimental Forest in western Montana. The traffic was applied to plots at intensities of 250 and 1000 passes along with a no-traffic control under both prewetted and dry t...
BMC research notesNovember 8, 2012
Volume 5 626 doi: 10.1186/1756-0500-5-626
Boudko SP, Ishikawa Y, Lerch TF, Nix J, Chapman MS, Bächinger HP.Hyperelastosis cutis is an inherited autosomal recessive connective tissue disorder. Affected horses are characterized by hyperextensible skin, scarring, and severe lesions along the back. The disorder is caused by a mutation in cyclophilin B. Results: The crystal structures of both wild-type and mutated (Gly6->Arg) horse cyclophilin B are presented. The mutation neither affects the overall fold of the enzyme nor impairs the catalytic site structure. Instead, it locally rearranges the flexible N-terminal end of the polypeptide chain and also makes it more rigid. Conclusions: Interactions of th...
Vervuert I, Klein S, Coenen M.The aim of this study was to investigate the effects of fat supplementation on postprandial glycaemic and insulinaemic responses in horses fed a corn meal. Four horses were fed three different diets: (1) cracked corn (CC), (2) cracked corn with soybean oil (CC+SBO), and (3) cracked corn with fish oil (CC+FO). Each diet was adjusted so there was a starch intake of 2 g/kg bodyweight (BW) and an intake of 0.2 mL/kg BW of FO and SBO. The increases in mean plasma glucose and insulin concentrations, peak values, and areas under the curve were similar for all diets (time P<0.05, diet not significa...
Bradbury LA, Archer DC, Dugdale AH, Senior JM, Edwards GB.A horse which had had a caecal impaction for 10 days was treated by means of an ileocolostomy [corrected] but failed to respond satisfactorily. Before a second laparotomy was performed it was observed to have dislodged the extension set from a jugular catheter and air was heard being sucked into the vein. It became very agitated but was anaesthetised again and the impaction was removed through an incision in the apex of the colon [corrected] After recovering from the anaesthesia it developed severe signs of pruritus which subsided only after 12 hours. These signs were considered most likely to...
Montgomery JB, Hamblin B, Suri SS, Johnson LE, New D, Johnston J, Kelly J, Wilson DG, Singh B.Ischemia followed by reperfusion leads to release of toxic molecules into the circulation, and these molecules may cause injury in remote organs such as the lung. Horses commonly suffer from episodes of intestinal ischemia-reperfusion (IR) due to intestinal twisting/strangulation followed by repair. Because there is no evidence of lung injury associated with IR in horses, we designed a study to characterize the intestinal IR-associated lung inflammation and determine the effect of lidocaine on lung inflammation in IR horses. Lung tissues were collected from non-anesthetized (n=4) and anestheti...
Rahnama S, Spence R, Vathsangam N, Baskerville CL, Bailey SR, de Laat MA, Anderson ST, Pollitt CC, Sillence MN.Although it is understood that equine endocrinopathic laminitis can be triggered by high concentrations of insulin, it is unclear whether this represents a direct action on lamellar tissue via insulin receptors (InsR), an interaction with IGF-1 receptors (IGF-1R), or some other, indirect action. This uncertainty is because of the reported scarcity of InsR in lamellar tissue and the low affinity of insulin for equine IGF-1R. In the present study, the effects of insulin and IGF-1 (as a positive control) were examined using lamellar explants isolated from the hooves of healthy horses and incubate...
Moore RM, Muir WW, Cawrse M, Bertone AL, Beard WL.Twenty-four horses were randomly allocated to 3 groups. Horses were anesthetized, subjected to a ventral midline celiotomy, and the large colon was exteriorized and instrumented. Group-1 horses served as sham-operated controls. Group-2 horses were subjected to 6 hours of low-flow colonic arterial ischemia, and group-3 horses were subjected to 3 hours of ischemia and 3 hours of reperfusion. Baseline (BL) samples were collected, then low-flow ischemia was induced by reducing ventral colonic arterial blood flow to 20% of BL. All horses were monitored for 6 hours after BL data were collected. Bloo...
Lea RG, Stewart F, Allen WR, Ohno I, Clark DA.Endometrial tissue from the gravid uterine horn of pregnant mares was examined by northern analysis and in situ hybridization for mRNA that hybridized to cDNA and RNA probes generated from a mouse TGF-beta 2 1.2 kb cDNA clone. The mouse cDNA probe hybridized to characteristic TGF-beta 2 mRNA transcripts on a northern blot of total RNA isolated from horse endometrium collected at day 45 of gestation. Two major 4.0 and 3.5 kb transcripts and possibly a minor 1.6 kb transcript were observed, consistent with specific hybridization to equine TGF-beta 2 mRNA. By in situ hybridization, riboprobes tra...
Nixon AJ.An arthroscopic technique for examination and surgical treatment of conditions of the shoulder joint was evaluated in eight normal horses and two horses with osteochondrosis lesions. A single arthroscope entry point caudal to the infraspinatus tendon allowed inspection of the cranial, lateral, and caudal surfaces of the shoulder joint. With the humeral head and glenoid cavity distracted by a curved forceps, the entire cartilage surface of the shoulder could be examined. The caudomedial portion of the humeral head was seen better with a 70 degree angled arthroscope. Instruments for intra-articu...
McDonough P, Kindig CA, Ramsel C, Poole DC, Erickson HH.In healthy man, conditions that change muscle O2 delivery affect the achievable maximum rate of O2 uptake as well as the metabolic (e.g. lactate threshold, LT) and gas exchange (e.g. gas exchange threshold, Tge) responses to incremental exercise. Inclined (I) compared to level (L) running increases locomotory muscle EMG at a given speed in the horse, indicative of elevated metabolic demand. To our knowledge, the effect of treadmill incline on VO2,max, LT and Tge has not been addressed in the exercising quadruped. We used blood sampling and breath-by-breath expired gas analysis to test the hypo...
Rizk A, Hamed M.Fractures of the rostral mandible in horses are the most common type of jaw fractures. The present study was performed for stabilization of rostral mandibular fracture with cerclage wire. In a retrospective case series, six client-owned horses with unilateral mandibular fractures were admitted to our clinic and suffered from a major gingival wound at rostral part of mandible. Rostral mandibular fracture was diagnosed through clinical examination and radiography. Fractured region was repaired by cerclage wire under the effect of general anesthesia and wires were maintained for 6-12 weeks. The r...
Keg PR, van den Belt AJ, Merkens HW, Barneveld A, Dik KJ.The influence of regional nerve blocks on lameness resulting from tendon injury was studied in six horses. Tendonitis was induced in the midmetacarpal region of the Superficial Digital Flexor Tendon (SDF), Deep Digital Flexor Tendon (DDF) and the Suspensory Ligament (SL) through collagenase injections. The results were evaluated through sequential clinical examinations, ultrasonographic imaging and kinetic gait analysis (force plate) during a period of 144 days post injury and subsequently compared with gross and microscopic findings. The lameness corresponding to the SDF and DDF tendon lesion...
Tokushige H, Kushiro A, Okano A, Maeda T, Ito H, Wakuno A, Nagata SI, Ohta M.Alfaxalone has a number of pharmacological properties which are desirable for constant rate infusion (CRI). Previously, the co-administration of alfaxalone and medetomidine is shown to be suitable for short-term anesthesia in horses. However, the use of alfaxalone-medetomidine CRI with inhalational anesthesia under surgical procedures have not been investigated in clinical cases. The aim of the present study was to evaluate the clinical efficacy of alfaxalone-medetomidine CRI in sevoflurane-anesthetized Thoroughbred racehorses undergoing arthroscopic surgery. Sevoflurane requirement, cardiovas...
Kalamanova A, Anderson BH, Cust AR, Fulton IC.There are several skin grafting methods described in the human and animal literature. Currently, there are five types of free grafts used in horses: pinch and punch grafts, split and full-thickness sheet or mesh grafts and tunnel grafts. Published methods of tunnel grafting describe the use of alligator forceps. The alligator forceps create a poor tunnel and are excessively traumatic to the granulation bed. This technique utilised a 13G Jamshidi needle that was placed across the granulation bed and created a uniform tunnel. The Jamshidi needle was atraumatic to the granulation bed increasing t...
Votion D, Vandenput S, Duvivier H, Art T, Lekeux P.A method is proposed (1) to create inhalation to perfusion ratio (I/Q) images from equine lung scintiscans and (2) to analyse these I/Q images. This method was applied to five healthy horses in order to establish reference ranges of I/Q distribution pattern. Computed I/Q images were divided in three regions based on the activity due to the inhalation (I) versus perfusion (Q) procedure. For each region a regional mismatching factor (Iri), i.e. the I/Q of the region, and an intraregional mismatching factor (Lri), which expresses the variability of pixels' I/Q within the region, were calculated. ...
Ho EN, Wan TS, Wong AS, Lam KK, Schiff PJ, Stewart BD.Bromide is a sedative hypnotic. Due to its potential use as a sedative or calmative agent in competition horses, a method to control bromide is needed. Colorimetric method had been employed in the authors' laboratory from 2003 for the semi-quantification of bromide in equine plasma samples. However, the method was found to be highly susceptible to matrix interference, and was replaced in 2008 with a more reliable inductively coupled plasma-mass spectrometry (ICP/MS) method. Equine plasma was protein-precipitated using trichloroacetic acid, diluted with nitric acid, and then submitted directly ...
Shellow JS, Jackson SG, Baker JP, Cantor AH.Twenty mature geldings, averaging 535 kg, were used to determine the influence of dietary selenium (Se) on the blood levels of Se and Se-dependent glutathione peroxidase (SeGSH-Px) activity in the horse. Horses were randomly assigned within breed to four treatments consisting of five horses each and fed a basal diet containing .06 ppm of naturally occurring Se. Diets were supplemented with .05, .10 and .20 ppm Se, as sodium selenite. Blood was drawn for 2 wk before, and for 12 wk following, the inclusion of supplement Se in the diets. Whole blood and plasma Se concentrations and plasma SeGSH-P...
Pollard D, Grewar JD.Police-recorded road injury data are frequently used to approximate injury risk for different road user groups but a detailed analysis of incidents involving ridden horses has not previously been conducted. This study aims to describe human injuries resulting from interactions between ridden horses and other road users on public roads in Great Britain and identify factors associated with severe to fatal injuries. Police-recorded road incident data involving ridden horses (2010-2019) were extracted from the Department for Transport (DfT) database and described. Multivariable mixed-effects logis...
Merlin A, Ravinet N, Sévin C, Bernez-Romand M, Petry S, Delerue M, Briot L, Chauvin A, Tapprest J, Hébert L.Cyathostomins are considered as the most prevalent and pathogenic parasites of grazing horses. The development on pastures of the free-living stages of these gastrointestinal worms is particularly influenced by outdoor temperature. Understanding the bionomics of free-living stages is an important prerequisite to implement mathematical models designed to assess the parasitic risk for grazing equids. The aim of this study was to assess the effect of 3 constant temperatures under laboratory conditions (10 ± 1 °C, 23 ± 2 °C, 30 ± 2 °C) and one fluctuating temperature under outdoor c...
Richter MC, Bayly WM, Keegan RD, Schneider RK, Weil AB, Ragle CA.To determine the cardiovascular and respiratory effects of water immersion in horses recovering from general anesthesia. Methods: 6 healthy adult horses. Methods: Horses were anesthetized 3 times with halothane and recovered from anesthesia while positioned in lateral or sternal recumbency in a padded recovery stall or while immersed in a hydropool. Cardiovascular and pulmonary functions were monitored before and during anesthesia and during recovery until horses were standing. Measurements and calculated variables included carotid and pulmonary arterial blood pressures (ABP and PAP respective...
Oliver JW, Held JP.Thyrotropin (thyroid stimulating hormone; TSH) stimulus to thyroid cells of horses and dogs resulted in increased serum triiodothyronine (T3) concentrations that were detected earlier than those of thyroxine (T4). Doubling of the base-line T3 values in horses was detected 0.5 hours after injection of 5 IU of TSH IV, with peak response of 5 times base-line value detected 2 hours after injection. Doubling of T4 values in horses was noticed between 2 and 3 hours, with the peak response of 2.4 times base-line value at 4 hours after injection of TSH. Doubling of base-line T3 values in dogs in respo...
Hansen PJ, Asbury AC.The release of opsonins into the uterine lumen of mares susceptible or resistant to endometritis was examined after intrauterine inoculation of a filtrate of Streptococcus culture fluid or vehicle. Uterine flushings were collected at 0.5 hour before and 2, 4, 6, 8, and 24 hours after inoculation on day 2 or 3 of estrus and on day 7 or 8 after ovulation. Amounts of opsonins in flushings were quantified as the H2O2 produced by leukocytes incubated with flushings-opsonized bacteria, compared with H2O2 produced by leukocytes incubated with nonopsonized bacteria. Opsonin values in flushings increas...