American journal of veterinary research.
Publisher:
American Veterinary Medical Assn.. Schaumburg, Ill. : American Veterinary Medical Association
Frequency: Monthly
Country: United States
Language: English
Author(s):
American Veterinary Medical Association.
Start Year:1940 -
Identifiers
| ISSN: | 0002-9645 (Print) 1943-5681 (Electronic) 0002-9645 (Linking) |
| NLM ID: | 0375011 |
| (DNLM): | A25065000(s) |
| (OCoLC): | 01480202 |
| Coden: | AJVRAH |
| LCCN: | 42050041 |
| Classification: | W1 AM53 |
Corticosteroid-potentiated vascular responses of the equine digit: a possible pharmacologic basis for laminitis. Spirally cut digital arteries and veins were mounted isotonically in organ baths containing oxygenated Krebs' Q-Henseleit solution. Twelve arterial and 12 venous preparations all contracted dose dependently when epinephrine, norepinephrine, serotonin, or histamine were added to the bathing fluid. Addition of hydrocortisone or betamethasone alone did not cause contractions in any of the tissues tested. However, when hydrocortisone or betamethasone was added to vessel strips that were partially contracted (40% to 60% maximal) by epinephrine, norepinephrine, or serotonin, each vessel strip invari...
Survey for infection with Onchocerca cervicalis in horses in eastern United States. This survey was performed to study the prevalence of infection with Onchocerca cervicalis in horses in the eastern United States. In the course of the survey, 121 horses, 1 mule and 1 donkey were examined. Microfilariae were recovered from 74 (61%) of the horses examined. All infected horses showed microfilariae of O cervicalis in the umbilical sample, 62 (84%) were infected in the eyelid and, in 36 (49%), microfilariae had invaded the eye. The mule was unifected and the donkey was infected with O cervicalis.
Ductuli efferentes in the epididymis of boar, goat, ram, bull, and stallion. Dutculi efferentes were studied by microdissection and histologic methods in 2 boar, 6 goat, 5 ram, 25 bull, and 19 stallion epididymides. On the basis of the present findings and the data of others and relating them to the total number of specimens examined in each species, an estimate (narrow range) was made of the minimal-maximal numbers of efferent ductules as follows: dog 13 to 15; cat 14 to 17; boar 14 to 16; goat 18 to 19; ram 17 to 20; bull 13 to 16; and stallion 14 to 17. The histologic appearance of the efferent ductules of the bull, including measurements of their diameter, lumen, a...
Antibody response of horses to Mycoplasma mycoides subsp capri. In horses given whole cultures or cells of Mycoplasma mycoides subsp capri (by subcutaneous and intravenous injections), antibody responses were measured by serologic procedures. During an immunization period of 22 weeks, horses produced an antiserum that was used to identify M mycoides subsp capri by agglutination, complement-fixation, and fluorescent antibody (FA) tests, but not by the growth-inhibition test. Horses that were injected with whole cultures of M mycoides subsp capri responded better than horses that were injected with only cells, ie, antibodies were detectable sooner by agar ge...
Effects of furosemide on plasma volume and extracellular fluid volume in horses. The effects of IV administered furosemide upon plasma volume (PV) and extracellular fluid volume were determined in horses at rest and after exercise. Serum sodium, potassium, chloride, and osmolality determinations were made. Furosemide caused a significant (P less than 0.05) decrease in PV and serum potassium concentrations in resting horses only. Furosemide's effects upon PV and electrolytes were evident longer than its hemodynamic effects.
Venezuelan equine encephalomyelitis vaccine (strain TC-83): a field study. In 1971, more than 370 horses in south Texas were studied with respect to their clinical, virologic, and neutralizing antibody responses to vaccination with Venezuelan equine encephalomyelitis (VEE) strain TC-83. This study confirms reported findings that the vaccine used in the 1971 epizootic in the lower Rio Grande Valley of Texas was safe and efficacious. Vaccinal virus viremia titers were generally below the postulated infection threshold of epizootic vectors. In general, reactions to the vaccine were minimal and transient, with no observed abortions or deaths attributable to use of the va...
Inhibition of calcium absorption in ponies fed diets containing oxalic acid. The effects of dietary oxalic acid on absorption, excretion, and retention of calcium was determined in Shetland ponies in 2 experiments. In each experiment, the results of feeding a control diet consisting of oats, molasses, and a complete pelleted horse ration were compared with those of feeding the control diet plus 1% oxalic acid. The diets contained 0.6% calcium in the 1st experiment and 0.45% calcium in the 2nd experiment. Oxalic acid increased the fecal excretion of calcium and decreased calcium absorption. The endogenous fecal excretion of calcium determined in the 1st experiment, usin...
Common membrane neoantigens on bovine papilloma virus-induced fibroma cells from cattle and horses. Cultured cells from bovine papilloma virus (BPV)-induced fibroblastic tumors and normal dermis of cattle, horses, and hamsters were examined for cell membrane or internal neoantigens, using the indirect immunofluorescence technique. Sera from cattle and horses bearing BPV-induced fibromas cross reacted with cell membranes of tumor, but not with normal dermal cells of both species. The reaction could be blocked with homologous, but not heterologous, serum of these 2 species. Immunofluorescence was not detected with sera from hamsters bearing BPV-induced sarcomas if incubated with bovine, equine...
Increased plasma bromide concentration in the horse after halothane anesthesia. A long-lasting increase of the plasma bromide concentration was found in 25 horses after clinical halothane anesthesia. The plasma bromide concentration was significantly (P less than 0.005) increased at the end of anesthesia. In 18 horses, peak values were reached between 48 and 72 hours after anesthesia. Eighteen days after horses had been anesthetized, the plasma bromide concentration remained significantly (P less than 0.005) increased. Significant correlation was not found between the total dose of halothane and the plasma bromide concentration. In 1 horse reanesthetized with halothane 4 ...
Cardiopulmonary effects of narcotic agonists and a partial agonist in horses. The cardiopulmonary effects of the narcotic agonists morphine, meperidine, oxymorphone, and methadone and of the partial agonist pentazocine were examined in the pain-free adult horse. The drugs produced dysphoric followed by euphoric effects. Increases in heart rate, arterial blood pressure, and cardiac output were observed in all horses with all drugs. Arterial blood pressure remained increased even after heart rate and cardiac output had returned to base-line values. Respiratory rate generally remained unchanged or increased shortly after drug administration and then decreased insignificant...
Electromagnetic blood flowmeters and flow probes: theoretic and practical considerations. Electromagnetic blood flowmeters and flow probes are used to measure blood flow in blood vessels throughout the circulatory system. The principle of this measuring device is based on laws of electromagnetic induction discovered in the 19th century. The instrument has been predominantly used in research, but is presently used in human cardiovascular units to measure blood flow in blood vessels, and in prosthesis in conjection with cardiovascular surgical procedures. Electromagnetic flow equipment provides the most accurate measurement (in vivo) of blood flow available, both for acute and chroni...
Pathogenicity of equine herpesvirus: in vivo persistence in equine tissue macrophages of herpesviuus type 2 detected in monolayer macrophage cell culture. Equine macrophages from the mammary glands of a yearling filly and an 18-year-old barren nonlactatind mare formed cell monolayers in continuous cultures. There was absence of viral cytopathic effect (CPE) in early cell culture passages. The cells from the early cell culture passages having no CPE failed to show evidence of virus or viral antigen by electron microscopic and immunofluorescence studies. Foci of CPE first appeared in the monolayer cell cultures from the filly and the mare in the 3rd and the 4th serial passages respectively, and the CPE increased on subsequent serial passages. Equi...
Critical tests of the anthelmintic febantel in the horse: activity of a paste formulation alone or with a trichlorfon paste. Critical tests were carried out in 10 horses to evaluate the antiparasitic activity of febantel given alone or with trichlorfon. Paste formulations were administered intraorally at dose levels of 6 mg of febantel (active ingredient)/kg and 35 mg of trichlorfon (active ingredient)/kg. In 5 tests with febantel alone, removal of 100% was recorded for mature or immature Parascaris equorum from 2 infected horses. Strongylus vulgaris from 4 infected horses, S edentatus from 5 infected horses, and mature Oxyuris equi from 1 infected horse; and removal of 96% was recorded for small strogyles from 1 ho...
Direct colorimetric determination of serum arginase in various domestic animals. A direct colorimetric method for the determination of serum arginase activity in various domestic animals is described. Serum arginase activity in healthy mature dogs, cats, horses, cattle, sheep, and pigs ranged from 0 to 14 IU/L. Serum arginase activity increased considerably in these animals during experimental hepatic damage induced by oral administration of carbon tetrachloride.
Evaluation of xylazine, guaifenesin, and ketamine hydrochloride for restraint in horses. A combination of intramuscular xylazine plus intravenous guaifenesin and ketamine hydrochloride was evaluated as a method for chemical restraint and casting of the adult horse. This drug combination provided safe and rapid induction of the horse and uneventful recovery from lateral recumbency. Cardiopulmonary function remained within base-line values for the adult horse, although cardiac output, arterial blood pressure, and arterial partial pressure of oxygen were decreased from base-line values. Xylazine, guaifenesin, and ketamine hydrochloride provided safe induction to general anesthesia wi...
Quantitative study of the decussating optic axons in the pony, cow, sheep, and pig. A quantitative study of optic axons in the optic tracts of several species was performed to determine the number and percentage of optic axons that decussate. Animals were prepared by unilateral ocular enucleation, and light microscopic techniques were employed to count the fibers. The mean number of fibers projecting from a single eye was 732,119 for the pony, 1,041,739 for the cow, 534,755 for the sheep, and 442,629 for the pig. The mean degree of crossover at the chiasm was 80.8% in ponies, 82.9% in cattle, 88.9% in sheep, and 87.8% in pigs.
Pathologic changes and pathogenesis of Parascaris equorum infection in parasite-free pony foals. Parasite-free pony foals (n = 10) were infected orally with 1000,000 Parascaris equorum embryonated eggs. One pony foal each was euthanatized on days 1, 3, 5, 7, 11, 16, 23, 27, 42, or 80 after infection. Foals infected for more than 7 days showed signs of coughing, anorexia, rough coat, and weight loss. Cellular changes in the blood were mild anemia, marked eosinophilia, and leukopenia. Gross postmortem lesions included hemorrhage, edema, and white-to-yellow necrotic foci (0.5 to 1.00 mm) in lungs, liver, and bronchial and hepatic lymph nodes. Microscopically, the liver was hemorrhagic and ha...
Potency of halothane-N20 in the horse. The minimal alveolar concentration (MAC) of halothane which just prevented purposeful movement in response to electrical stimulation was determined in 11 young, healthy, unpremedicated horses breathing oxygen (O2) or nitrous oxide (N2O) and O2. Ventilation was controlled during these MAC studies. The arterial PO2 was always greater than 90 mm of Hg and the average PaCO2. range was 36 to 40 mm of Hg. The MAC for halothane in O2 was 0.93 vol %. Alveolar N2O concentrations of 25% and 50% reduced the halothane MAC about 12% and 25%, respectively. In 8 of these horses, the cardiovascular effects of...
Evaluation of delayed hypersensitivity responses in normal horses and immunodeficient foals. Delayed hypersensitivity (DH) responses of normal and immunodeficient horses were evaluated with antigens [dinitrochlorobenzene (DNCB), keyhole limpet hemocyanin (KLH)] and phytolectins [phytohemagglutinin (PHA), concanavalin A (Con A)]. Immunologically normal horses sensitized with 5 daily applications of 2 mg of DNCB developed positive skin reactions upon challenge with 0.4 mg of DNCB. The delayed onset of the reaction and the predominately mononuclear cell infiltration at the test site indicated these were DH reactions. Normal horses sensitized with 500 microgram of KLH and challenged with ...
Equine grass sickness: serologic evidence of association with Clostridium perfringens type A enterotoxin. Clostridium perfringens type A enterotoxin seroneutralization was carried out on sera from 50 horses recovered from grass sickness and from 100 other horses with no record of having had the disease. Of the affected horses, 70% had seroneutralizating titers higher than 1:64, half of these being equal or higher than 1:128. More than 88% of the horses with no record of grass sickness had titers lower than 1:64. These data support the theory of association between C perfringens type A toxins and grass sickness.