bluuebunny/crossref_metadata_2025 huggingface dataset:
Histamine inhalation provocation test: Method to identify nonspecific airway reactivity in equids
Authors: Klein Hans-J. , Deegen Eckehard
Published: February 2025

After inhalation of increased concentrations of histamine solutions, equids had a decrease in dynamic compliance (Cdyn) and an increase in airway resistance, work of breathing, and maximum intrathoracic differences in pressure. Because the change in Cdyn correlated best with the inhaled histamine concentrations, airway reactivity was assessed by the decrease in Cdyn. With the use of linear regression, histamine concentrations were calculated; this resulted in a 35% reduction of Cdyn and these concentrations were defined as 35% provoking concentration Cdyn.

The histamine inhalation provocation test was carried out in 40 equids. Nonspecific airway hyperreactivity was not present in equids that did not have clinical signs of respiratory tract disease, but it was present in 25% of the equids with low-grade lung disease and in all equids with severe lung disease.
Histochemical staining characteristics of normal horse skeletal muscle
Authors: Andrews Frank M. , Spurgeon Thomas L.
Published: February 2025

The histologic and histochemical staining characteristics of the triceps brachii (long head), extensor carpi radialis, gluteus medius, vastus lateralis, biceps femoris, semimembranosus, semitendinosus, and extensor digitorum longus muscles of 8 Thoroughbreds, 2 Quarter Horses, 1 Arabian, 1 Paso Fino, and 1 Shetland Pony are described. Muscle fiber morphology, staining distribution and intensity, amount of im connective tissue, number of im blood vessels and IM nerves, calcium-activated adenosine triphosphatase activity (CaATPase), percentage of fibertype population, percentage of relative fibertype area, mean fiber diameter, nonspecific esterase activity, alkaline phosphatase activity, and acid phosphatase activity were evaluated, using 10 common histochemical and histologic stains.

Two fiber types (I, II) and 3 subtypes (IIA, IIB, IIC) were observed, using CaATPase-, nicotinamide-adenine dinucleotide-tetrazolium reductase-, periodic acid-Schiff hematoxylin-, and nonspecific esterase-stained frozen serial muscle sections. Type I muscle fibers in general had low CaATPase activity, high oxidative capacity, low glycogen capacity, and low esterase activity. Type IIA muscle fibers had high CaATPase activity, intermediate oxidative capacity, high glycogen concentration, and high esterase activity. Type IIB fibers had high CaATPase activity, low oxidative capacity, high glycogen concentration, and a high esterase activity. Type IIC muscle fibers had high CaATPase activity, high oxidative capacity, variable glycogen concentration, and high esterase activity. Type II (IIA and IIB) muscle fibers predominated in the muscles.

The percentage of muscle fiber population, mean minimal muscle fiber diameter, and percentage of relative muscle fiber area were determined for each sampled muscle. Type IIA and IIB muscle fibers predominated in the percentage of muscle fiber population and percentage of relative muscle fiber area. Type IIB muscle fibers had the greatest minimal fiber diameter, type IIA muscle fibers had intermediate minimal fiber diameter, and type I muscle fibers had the smallest minimal fiber diameter. Phe percentage of relative muscle fiber area was less variable (P ≤ 0.05) than the percentage of muscle fiber population. Mean muscle fiber diameter did not significantly differ between breeds.

Alkaline and acid phosphatase activities were at low levels in all muscles biopsied and were limited to the im connective tissue fibrocytes, macrophages, and capillaries.

Histologic and histochemical techniques provided valuable information about muscle fiber composition, morphology, and enzyme activity and may serve as a standard for comparison with data obtained from skeletal muscles with suspected neuromuscular lesions.
Immunologic response and resistance to experimentally induced pneumonic pasteurellosis in cattle vaccinated with various dosages of lyophilized Pasteurella haemolytica
Authors: Confer A. W. , Panciera R. J. , Gentry M. J. , Fulton R. W.
Published: February 2025

Pasteurella haemolytica was lyophilized in an enriched soybean polypeptone broth. Lyophilization in this medium resulted in a mean 10-fold loss in P haemolytica viability, as opposed to up to a 10-fold loss in viability when other media were used. Lyophilized P haemolytica was reconstituted and used as a live vaccine in 3 experiments. Calves were challenge exposed by transthoracic injection with virulent P haemolytica. In experiment 1, 2 subcutaneous injections (7-day interval between injections) with 5 ml of recently harvested (1 × 109 colonyforming units [cfu]/ml) or lyophilized (1 × 108 cfu/ml) P haemolytica significantly (P < 0.001) enhanced resistance against challenge exposure, compared with resistance in calves given saline solution or sterile medium (control calves) or calves vaccinated with lyophilized organisms at a concentration of 1 × 108 cfu/ml. In experiment two, 1, 2, or 5 ml of lyophilized P haemolytica (1 × 108 cfu/ml) significantly (P < 0.05) enhanced resistance, compared with resistance in calves given saline solution (control calves). In experiment three, 1 or 2 injections of lyophilized P haemolytica significantly (P < 0.01) enhanced resistance against challenge exposure, compared with that of calves given saline solution. The mean lesion score for calves given 1 injection was not significantly higher than the mean lesion score for the group given 2 injections. Vaccination with lyophilized P haemolytica vaccine caused significant (P < 0.05) increases in serum antibody to P haemolytica somatic antigens, to a carbohydrate-protein subunit of the organism, and to leukotoxin.
Behavior and viability of the premature neonatal foal after induced parturitio
Authors: Leadon Desmond P. , Jeffcott Leo B. , Rossdale Peter D.
Published: February 2025

Parturition was induced in 2 groups of mares, < 300 (n = 49) and 300 to 320 days gestation (n = 31), by the administration of prostaglandin F2α or fluprostenol and oxytocin. Foals were categorized into 4 groups according to their ability to adapt in, and survive, the neonatal period. Group A had no demonstrable coordinating reflexes, were weak from birth, and all died within 90 minutes. Group B had some righting reflexes, but had poor coordination and a weak suck reflex. They showed some improvement for about 2 hours, but all died within 9 hours. Group C foals had a good suck reflex and made attempts to stand. After 24 hours, there was a steady deterioration and death occurred within 48 hours. Group D were initially weak, but showed rapid clinical improvement with good adaptation to the environment and survived for at least 7 days.

The overall survival rate for the 80 foals born was only 5%. Most group A foals had gestational ages of < 300 days, but a few (n = 9) were delivered after 300 days and 2 up to 319 days. The youngest survivor was delivered at 318 days and the 3 other survivors were delivered at 320 days. Aspects of the hazards of prematurely induced parturition were considered to be immaturity and stress of parturition.
Protein A in Staphylococcus intermedius isolates from dogs and cats
Authors: Cox Hollis Utah , Schmeer Norbert , Newman Susan S.
Published: February 2025

The presence and quantity of extracellular and cellbound protein A of Staphylococcus intermedius isolates from dogs and cats were determined, using an enzyme-linked immunoglobulin-binding assay. Horseradish per-dase-conjugated rabbit anti-bovine immunoglobulin G purified by affinity chromatography was reacted with whole cell and supernatant fractions of S intermedius (n = 139), a protein A-producing strain of S aureus, and a protein A-deficient strain of S epidermidis. Extracellular protein A was found in 118 (84.9%) of 139 isolates of S intermedius. Most (69/118; 58.5%) of these isolates produced > 0.2 μg of extracellular protein A/ml. Cell-bound protein A was found in 6 (4.3%) of 139 isolates. Only 1 of these isolates contained cell-bound protein A exclusively. The other 5 isolates produced significantly greater amounts of extracellular protein A than cell-bound protein A. Additionally, > 96% of extracellular protein A could be removed from supernatants by adsorption with agarose gel containing immunoglobulin G.
Transmission of bovine leukosis virus by blood inoculation
Authors: Evermann James F. , DiGiacomo Ronald F. , Ferrer Jorge F. , Parish Steven M.
Published: February 2025

The experimental transmission of bovine leukosis virus (blv)-infected whole blood was studied in 2 groups of Holstein calves. The 1st group of 4 blv-seronegative calves was given 10 μ1 of whole blood by either the im, iv, subcutaneous, or intradermal routes. All 4 calves seroconverted to blv within 8 weeks after they were inoculated. The 2nd group, also comprising 4 calves, was given the equivalent of 1 μl of whole blood by the described routes. These calves seroconverted to blv by 14 weeks after they were inoculated. The results indicated that small volumes of whole blood administered by 4 different routes were effective in the spread of blv.
Surface proteins of Breda virus
Authors: Koopmans M. , Ederveen J. , Woode G. N. , Horzinek M. C.
Published: February 2025

The serotypes 1 and 2 of Breda virus from feces of experimentally infected gnotobiotic calves were studied with respect to their sedimentation and density properties in sucrose gradients and their structural polypeptides; Berne virus, the proposed prototype of the new family Toroviridae, was included for comparison. After Breda-1 virus had been stored at 4 C for a prolonged period, it showed a heterogeneous sedimentation behavior (480 to 520 Svedberg units [S]) and density (1.18 to 1.21 g/ml) indicative of its poor state of preservation. In contrast, freshly prepared Breda-2 virus sedimented at 350 S and showed a buoyant density of 1.18 g/ml; these values compare well with those of Berne virus (400 S and 1.16 g/ml, respectively). Efficient purification of the Breda viruses could be achieved by a 2-step method, involving pelleting by ultracentrifugation followed by isokinetic and isopyknic sucrose gradient centrifugation. Radioiodinated purified virus showed polypeptides with apparent molecular weights of 105,000, 85,000 37,000, and 20,000; another labeled protein of 65,000 D is of doubtful virus specificity. Mouse immune serum raised against Breda-2 virus recognized the polypeptides of the homologous virus and the 2 highest molecular weight proteins of Breda 1 virus in radioimmune precipitation. The same serum inhibited hemagglutination of the heterologous serotype to a low, but significant, degree and efficiently neutralized the infectivity of Berne virus. These observations are taken as indications that the 105,000- and 85,000-D polypeptides represent surface structures of torovirions, probably peplomeric proteins.
Cytotoxin (leukotoxin) production by Pasteurella haemolytica: Requirement for an iron-containing compound
Authors: Gentry Martha J. , Confer Anthony W. , Weinberg Eugene D. , Homer John T.
Published: February 2025

In studies of Pasteurella haemolytica type 1 cytotoxin, filter-sterilized culture supernatants from organisms grown in RPMI-1640 tissue culture medium generally have been used. Supplementation of the medium with 7% bovine fetal serum was shown to be necessary for maximal cytotoxin production, as measured by percentage of bovine peripheral blood leukocytes that were killed. The serum-induced increase in cytotoxicity could not be explained simply by a greater percentage of increase in the number of viable organisms produced in the enriched medium. There also was no correlation between encapsulation of the organisms and cytotoxin production. Several natural iron-containing proteins including transferrin, lactoferrin, conalbumin, and hemoglobin stimulated cytotoxin production in lieu of bovine fetal serum, leading to the conclusion that one function of serum supplementation may be to increase the medium's iron concentration. A number of additional iron-containing and iron-chelating compounds were tested, with the conclusion that the iron concentration of the growth medium, as well as the presence of a suitable carrier molecule, may be critical for efficient cytotoxin production by P haemolytica.
Resistance of preimplantation bovine embryos to infection with Brucella abortus
Authors: Stringfellow D. A. , Wolfe D. F. , Lauerman L. H. , Sparling P. H.
Published: February 2025

Preimplantation bovine embryos were exposed in vitro to Brucella abortus to determine if the bacteria would adhere to zona pellucida (zp)-intact embryos or adhere to or infect zp-free embryos. Brucella abortus was not isolated from zp-intact or zp-free groups of embryos after 10 sequential antibiotic-free washings. Brucella abortus was isolated from all groups containing zp-defective embryos after the exposure period and washing. Detrimental effects on healthy in vitro development of embryos were not observed.
Inhibition of lacteal leukocyte phagocytosis by colostrum, nonlactating secretion, and mastitic milk
Authors: Targowski Stanislaw P. , Niemialtowski Marek
Published: February 2025

The Fc receptors on leukocytes obtained from normal milk, colostrum, nonlactating gland secretion, and mastitic milk were detected by rosette formation, using sensitized erythrocytes. The percentage of leukocytes bearing Fc receptors from normal milk was significantly (P < 0.01) greater than that from other secretions. Fc receptors were found primarily on polymorphonuclear leukocytes from normal milk, mastitic milk, and colostrum. However, in nonlactating gland secretion obtained 6 weeks after milking was completed, Fc receptors were predominantly on macrophages. The low percentage of leukocytes bearing Fc receptors obtained from colostrum, nonlactating gland secretion obtained 7 days after milking was completed, and mastitic milk was associated with the presence of a blocking factor in these secretions, which specifically attached to Fc receptors. These secretions significantly (P < 0.01) blocked the Fc receptors on leukocytes from normal milk and on other cells bearing Fc receptors. The presence of Fc receptors on leukocytes obtained from normal milk was related to a high percentage of phagocytizing leukocytes through Fc receptors and a large number of phagocytized bacteria (phagocytic activities). In contrast, the low percentage of leukocytes bearing Fc receptors from colostrum, from nonlactating gland secretion (7 days after milking), and from mastitic milk was associated with depressed phagocytic activities. Preincubation of leukocytes from normal milk with whey from colostrum, nonlactating gland secretion (7 days after milking), and mastitic milk significantly (P < 0.01) inhibited phagocytosis. This effect was associated with the blocking of Fc receptors by these secretions. Possible mechanisms for and implications of these findings are discussed.
Hemolytic and bactericidal activities of bovine complement in mammary secretions of cows during the early nonlactating (dry) period
Authors: Poutrel B. , Rainard P.
Published: February 2025

Hemolytic and bactericidal complement-dependent activities were measured in quarter mammary secretions obtained during the first 21 days of the nonlactating (dry) period from 8 Holstein-Friesian cows. We demonstrated an inhibition of hemolytic activity and bactericidal activity against a serum-sensitive Escherichia coli strain. Both hemolytic and inhibitory titers increased markedly during active involution. The bactericidal activity of dry secretions required a minimal threshold of complement and an inhibitory titer lower than the hemolytic titer.
Regulation of phytohemagglutinin-induced bovine lymphocyte blastogenesis by leukotrienes
Authors: Atluru D. , Goodwin J. S.
Published: February 2025

Leukotriene (lt) B4, a 5-lipoxygenase metabolite of arachidonic acid, is a potent inducer of suppressor cells in phytohemagglutinin-stimulated cultures of bovine peripheral blood mononuclear cells. In contrast, ltc4 and ltd4 have little activity. Incubation of T lymphocytes with ltb4 at concentrations as low as 1 × 10−l2M rendered these lymphocytes suppressive of [3H]thymidine incorporation in subsequent phytohemagglutinin-stimulated cultures of fresh autologous lymphocytes. This ltb4-induced cell was radiosensitive to irradiation at 2,000 rads. Leukotriene B4 may have an important part in immunoregulation during hypersensitivity reactions.
Channel catfish virus: Use of nucleic acids in studying viral relationships
Authors: Colyer Tracey E. , Bowser Paul R. , Doyle James , Boyle John A.
Published: February 2025

Restriction digestion patterns were used to determine differences in the DNA of various isolates of channel catfish virus (ccv). All viruses were different from each other and from the type strain of ccv. The differences in the digestion patterns were used to relate the viruses quantitatively as to sequence divergence between all pairs of viruses. A range of values from 104 nucleotide changes to 1,690 nucleotide changes/total DNA of ccv was found for the various pairs.

A cladistic analysis produced a phylogenetic network relating the viruses by possible ancestory. This network indicated that some viruses were relatively more separated from other viruses that were clustered in the network. A phenetic analysis indicated that the viruses that were clustered in the network were also reasonably similar to one another.
Comparison of four test procedures to identify Staphylococcus aureus isolated from bovine intramammary infections
Authors: Hogan Joseph S. , Cornetta Angelyn , Pankey J. Woodrow
Published: February 2025

A comparison was made between conventional tube coagulase, macrocupsular coagulase, latex agglutination, and miniaturized biochemical test systems for identification of Staphylococcus aureus of bovine origin. A total of 303 gram-positive, catalase-positive cocci of bovine origin were tested. Agreement between each pair of 4-hour tube coagulase, macrocupsular coagulase, latex agglutination, and miniaturized biochemical test results within isolates was > 95.0.

Seventeen (5.6%) isolates were test negative for 4-hour tube coagulase, but test positive for 24-hour tube coagulase. Thirteen (76.5%) of these isolates were identified as S hyicus, 3 were S aureus, and 1 was not identified.
Detection of mink enteritis virus in mink feces, using enzyme-linked immunosorbent assay, hemagglutination, and electron microscopy
Authors: Shen David T. , Ward Alton C. S. , Gorham John R.
Published: February 2025

Twenty-five mink were inoculated with mink enteritis virus (mev). Fecal specimens were collected daily and were simultaneously evaluated for mev antigen by use of a direct enzyme-linked immunosorbent assay (elisa), hemagglutination (ha), and electron microscopy. Results of the evaluations indicated that mev was shed in the feces on postinoculation days 5 and 6. The virus was not detectable by elisa or ha after postinoculation day 6, although viruses were found in reduced numbers by use of electron microscopy. The elisa was specific for mev, and the sensitivity of the elisa for mev was comparable with that of ha.
Anthelmintic treatment of pastured dairy cattle in California
Authors: Miller James E. , Baker Norman F. , Farver Thomas B.
Published: February 2025

The relationship of anthelmintic treatment for subclinical gastrointestinal nematode parasitism with resultant milk production was studied on 3 California dairies where animals were maintained on a pasture-based nutritional program. All of the animals that started lactating (freshened) during a 12-month period participated in trials in which coumaphos was given as a feed top dressing to animals averaging 30 days into lactation. All of the animals that freshened during the subsequent 12-month period from 2 of the same 3 dairies participated in trials in which thiabendazole was administered at or within 2 weeks before freshening.

Anthelmintic administration during 2 consecutive lactation cycles under the conditions of the present study resulted in no consistent reproducible significant changes in milk production.
Xenobiotic metabolism in suspensions and primary cultures of isolated hepatocytes prepared from the caudate process of bovine liver
Authors: Shull Lee R. , Kirsch Donald G. , Lohse Carleton L. , Carlson Gary P. , Doody Linda A. , Wisniewski Joy A.
Published: February 2025

Isolated hepatocytes were prepared from 100- to 125-kg Holstein male calves (n = 10) by perfusion of the caudate process of the caudate lobe of the liver. The 11th or 12th rib on the right side was resected to provide exposure of the caudate process. Complete postsurgical recovery of the donor from partial lobectomy was confirmed by growth data and serum chemical and hematologic criteria. Hepatocytes were isolated under aseptic conditions, using a 2-step collagenase vascular perfusion procedure. Hepatocyte preparations averaged 85% viability, and the yield averaged 1.2 × 107 viable hepatocytes/g of (wet weight) liver.

Morphologic characteristics of hepatocytes examined under light and scanning electron microscopy were considered normal, except for occasional surface blebs. Freshly isolated hepatocytes in suspension rapidly decreased in viability and xenobiotic metabolizing capacity (aldrin epoxidation and ethoxycoumarin 0-deethylation and 7-hydroxycoumarin glucuronidation and sulfation), and hepatocytes surviving the initial 2 to 3 hours appeared to undergo repair.

As an alternative, primary monolayer cultures on collagen-coated plates were evaluated. Hepatocytes attached to the collagen surface within 4 hours and appeared flattened by 12 hours. Although metabolic activity decreased about 30% over 8 hours in culture, the pattern of ethoxycoumarin metabolites was relatively constant. It was not determined to what extent the apparent loss of metabolic capacity was caused by hepatocyte detachment from the collagen surface. Although complicated by the requirement for asepsis, primary cultures were superior to suspensions for xenobiotic metabolism studies in cattle.
Pharmacodynamics and pharmacokinetics of orally administered bishydroxycoumarin in the goat
Authors: Gross David R. , Kramer William G. , McCord Fiona , Wagner-Mann Colette
Published: February 2025

Eight goats, 2 nontreated controls and 6 treated, were used to study the pharmacodynamics and pharmacokinetics of bishydroxycoumarin. In 5 of the 6 treated goats, there was a significant relationship between prothrombin times and drug concentrations. Activated clotting times did not change with time in either the controls or the treated goats. Five of 6 treated goats reached a plateau of drug concentration after 24 to 36 hours. Lag times for onset of pharmacologic effect ranged from 12 to 24 hours. The one goat (No. 3) that did not respond in concert with the other 5 was extremely nervous and became anorectic during the period of indoor confinement.
Pharmacokinetic evaluation of a slow-release cefotaxime suspension in the dog and in sheep
Authors: Guerrini V. H. , English P B. , Filippich L. J. , Schneider J. , Bourne D. W. A.
Published: February 2025

Three Merino ewes were given cefotaxime im, and 3 were given cefotaxime subcutaneously (50 mg/kg of body weight each); each dose was suspended in 6 ml of oil. Five dogs were also given an oily suspension of cefotaxime subcutaneously (sc) (50 mg/kg of body weight). The plasma concentrations (Cp) and pharmacokinetic data obtained after cefotaxime in the oily suspension was injected im and sc were compared with data from the same animals after they were given an aqueous solution of cefotaxime by the same routes. Key pharmacokinetic values obtained after cefotaxime was administered iv to sheep and to dogs are discussed.

Mean peak Cp (Cpeak) in sheep when given the oily suspension im was approximately 53 μg/ml at 0.18 to 0.40 hour, and that value in sheep given the aqueous preparation was 62 μg/ml 0.08 to 0.18 hour. Mean Cpeak values after the oily suspension and the aqueous preparation were injected sc were 11.0 μg/ml (between 0.8 and 1 hour) and 51 μg/ml (between 0.25 and 1 hour), respectively. Bioavailabilities were approximately 70% after im injection was done and 90% after sc injection was done. The P-plasma half-lives were 0.7 hour after im injection was done and 2.9 hours after sc injection was done.

Mean Cpeak in dogs when given the oily suspension sc was 30 μg/ml at 1.0 hour, and when dogs were given the aqueous preparation sc, Cpeak was 27 μg/ml at 0.6 hour. Absorption was virtually complete after the oily suspension and aqueous preparations were given. The (β-plasma half-lives were 0.9 hour and 1.1 hour after the oily and aqueous preparations were injected, respectively.

The sc administration of cefotaxime in an oil suspension in dogs and sheep provided satisfactory and more prolonged Cp than did aqueous preparation given im (sheep only) or given sc (sheep and dogs).
Barbiturate anesthesia in Greyhound and mixed-breed dogs: Comparative cardiopulmonary effects, anesthetic effects, and recovery rates
Authors: Robinson E. P. , Sams R. A. , Muir W. W.
Published: February 2025

The cardiovascular effects, anesthetic effects, and recovery rates were evaluated in racing Greyhounds under barbiturate anesthesia. Greyhounds and mixed-breed dogs of similar body weights were given (by iv route) thiopental (15 mg/kg), thiamylal (15 mg/kg), methohexital (10 mg/kg), and pentobarbital (20 mg/kg).

The anesthesia lasted longer in Greyhound than in non-Greyhound mixed-breed dogs given thiopental, thiamylal, and methohexital. The mean times from recumbency to standing were 3 to 4 times longer for Greyhounds anesthetized with thiobarbiturates than for non-Greyhound mixed-breed dogs anesthetized with the same drugs, with recovery times for some Greyhounds lasting more than 8 hours. With thiobarbiturate anesthesia, Greyhounds had long periods of respiratory depression, struggled, and relapsed into sleep, whereas in the other dogs, the recovery was quiet.

Respiratory depression related to the stage of anesthesia was produced by all barbiturates, but did not result in significant changes in blood gas values. Rectal temperature decreased in all dogs, but did not result in significant hypothermia. Cardiovascular variables and acid-base estimations in Greyhounds were not significantly different from those in mixed-breed dogs before and during barbiturate anesthesia. Packed cell volumes in Greyhounds were significantly higher than those in non-Greyhound mixed-breed dogs after the thiobarbiturates and methohexital were administered. Total plasma protein concentrations were significantly lower in Greyhounds, compared with those in the other dogs before and during barbiturate anesthesia.

Methohexital is a useful alternative to thiobarbiturates for short-duration barbiturate anesthesia in Greyhounds.
Effect of acepromazine on the anesthetic requirement of halothane in the dog
Authors: Heard Darryl J. , Webb A. I. , Daniels R. T.
Published: February 2025

Five adult dogs were used to determine whether acepromazine maleate (acp) administered im, decreases the maintenance requirement of halothane and to measure any decrease for the acp dosages of 0.02, 0.04, 0.06, 0.08, 0.10, and 0.20 mg/kg. The value minimal alveolar concentration, a measure of anesthetic potency, was used as the measure of anesthetic requirement of halothane before and after acp was administered.

All dogs were randomly exposed to each dosage of acp, as well as to the control of 0.2 ml of sterile water. At all dosages of acp, the decrease in the minimal alveolar concentration of halothane was significant (P ≤ 0.05) when compared with that of the control. The decreases at the 0.04 and 0.20 mg/kg dosages were significantly (P ≤ 0.05) greater than those at the 0.02 and 0.00 mg/kg dosages. Halothane requirements at all other acp dosages (0.08 and 0.10 mg/kg) were not significantly different from each other or from those at any of the other dosages. The percentage of decrease in anesthetic requirement after acp was administered varied from 34% to 46%, with a mean decrease of 40%. The largest decrease was recorded at the dosage of 0.04 mg/kg.
Pharmacokinetics of sodium amoxicillin in foals after intramuscular administration
Authors: Carter G. Kent , Martens Ronald J. , Brown Scott A. , Martin Michael T.
Published: February 2025

Pharmacokinetic values of sodium amoxicillin (22 mg/kg of body weight) in foals were determined after a single im injection in 6 Quarter Horse foals at 3, 10, and 30 days of age. Serum amoxicillin concentrations were measured serially over a 24-hour period. The absorption of amoxicillin was rapid and followed a 1st-order elimination. Mean peak serum concentrations occurred 30 minutes after the injection in foals at all ages and were 17.31 ± 9.59 μg/ml when the foals were 3 days old, 23.28 ± 9.86 μg/ml when the foals were 10 days old, and 21.35 ± 6.39 μg/ml when the foals were 30 days old. Serum samples collected beyond 8 hours after administration contained amoxicillin concentrations < 0.05 μg/ml.

The elimination rate constant increased with increasing age (0.5265 ± 0.0891 hour−1 when the foals were 3 days old, 0.6494 ± 0.1114 hour−1 when the foals were 10 days old, and 0.7112 ± 0.1016 hour−1 when the foals were 30 days old). Serum clearance increased with increasing age (498.4 ± 82.6 ml/hr/kg at 3 days, 631.6 ± 170.5 ml/hr/kg at 10 days, and 691.2 ± 127.3 ml/hr/kg at 30 days). Serum half-life decreased with increasing age (1.34 ± 0.243 hour at 3 days, 1.10 ± 0.239 hour at 10 days, and 0.991 ± 0.139 hour at 30 days), whereas the extrapolated concentration at time zero and apparent volume of distribution did not change during the first 30 days of age.
Detection of transmissible gastroenteritis virus in feces from pigs by reversed passive hemagglutination
Authors: Asagi Masayoshi , Ogawa Tetsuo , Minetoma Toshimi , Sato Kunihiko , Inaba Yuji
Published: February 2025

A reversed passive hemagglutination (rpha) method was developed for the detection of transmissible gastroenteritis (tge) virus in the fecal specimens from pigs. Ovine erythrocytes fixed with glutaraldehyde and treated with tannic acid were coated with anti-tge virus swine antibodies, which were purified by affinity chromatographic technique linked with purified tge virus. The rpha test was done by the Microtiter method. Erythrocytes coated with purified specific antibodies were agglutinated by tge virus, but not by porcine rotavirus or porcine enterovirus. The reaction was specifically inhibited by antiserum against tge virus, confirming the specificity of the reaction.

A litter of seven 3-day-old pigs was orally inoculated with tge virus, and fecal specimens were obtained once a day and serum was obtained every 4th day. With the rpha test, tge virus was detected in the diarrheal feces; all of the inoculated pigs developed virus-neutralization antibody for the tge virus.

The rpha test detected tge virus in feces from pigs with naturally occurring diarrhea. The rpha test detected tge virus in 5 of 6 fecal specimens (80%), whereas the positive rate was only 50% (3/6) for the imrnunofluorescent staining of primary cultures of porcine kidney cells inoculated with the specimens. The advantages of the rpha method are simplicity, high sensitivity, and rapid to do.
Cervical spine motion: Radiographic study
Authors: Morgan Joe P. , Miyabayashi Takayoshi , Choy Susan
Published: February 2025

Knowledge of the acceptable range of motion of the cervical spine of the dog is used in the radiographic diagnosis of both developmental and degenerative diseases. A series of radiographs of mature Beagle dogs was used to identify motion within sagittal and transverse planes. Positioning of the dog's head and neck was standardized, using a restraining board, and mimicked those thought to be of value in diagnostic radiology. The range of motion was greatest between C2 and C5. Reports of severe disk degeneration in the cervical spine of the Beagle describe the most severely involved disks to be C4 through C7. Thus, a high range of motion between vertebral segments does not seem to be the cause for the severe degenerative disk disease. Dorsoventral slippage between vertebral segments was seen, but was not accurately measured. Wedging of disks was clearly identified. At the atlantoaxio-occipital region, there was a high degree of motion within the sagittal plane at the atlantoaxial and atlanto-occipital joints; the measurement can be a guideline in the radiographic diagnosis of instability due to developmental anomalies in this region. Lateral motion within the transverse plane was detected at the 2 joints; however, motion was minimal, and the measurements seemed to be less accurate because of rotation of the cervical spine. Height of the vertebral canal was consistently noted to be greater at the caudal orifice, giving some warning to the possibility of overdiagnosis in suspected instances of cervical spondylopathy. The possible error in radiographic measurements was recognized; however, it was felt that this study showed a reproducibility of most measurements and could serve as a guideline for further studies in other breeds.
Gastric emptying of a radionuclide-labeled test meal in healthy dogs: A new mathematical analysis and reference values
Authors: van den Brom W. E. , Happé R. P.
Published: February 2025

The gastric retention of a semisolid meal, labeled with 99mTc, was measured in 27 clinically healthy dogs, using a gamma camera coupled to a data acquisition and analysis system. A new mathematical analysis was introduced describing the retention (Q [t]) of a unit meal as a function of time (t), as follows:

Where α and p are fitting variables. The rate of gastric emptying depends strongly on the variable α. The shape of the retention pattern is influenced by the variable p, particularly by the value of 1-1/p (median, 0.51). The description includes the exponential and the linear model.

Initial half-time (median, 87 minutes), real half-time (median, 66 minutes), and 95% emptying time (median, 148 minutes) were determined from α and p, the latter being obtained from computer fitting Q (t) to the data. A wide variation of the values between the dogs was observed. Initial half-time and the value of 1-1/p varied strongly in the individual dogs, but the real half-time was reproducible (r = 0.85, P < 0.01, 10 dogs).
High-sensitivity radioimmunoassay screening method for fentanyl
Authors: Woods W. E. , Tai H. H. , Tai C. , Weckman T. , Wood T. , Barios H. , Blake J. W. , Tobin T.
Published: February 2025

A radioiodinated analog of fentanyl was synthesized for use with a commercially available radioimmunoassay for fentanyl. The sensitivity of the modified assay was at least 100 times greater than that of the original assay. Using this modified assay, concentrations of fentanyl as low as 1 pg/ml of fentanyl or fentanyl equivalents in equine urine were detected.

Doses of fentanyl 100 times smaller than the minimum dose for a pharmacologic effect were detectable and a pharmacologically effective dose of fentanyl was detectable for up to 96 hours or more. The high sensitivity of the assay indicated that large numbers of urine samples (ie, 10 to 20) probably could be pooled and screened simultaneously, which would result in an economical analysis for fentanyl in the urine of horses after a race. Sufentanil and its metabolites also were detectable, using this assay, but at only about 1% of the efficiency at which fentanyl was detectable.
Changes in equine metabolic characteristics due to exercise fatigue
Authors: Miller P. A. , Lawrence L. M.
Published: February 2025

Eight horses exercised to fatigue were used to characterize the resulting changes in blood pH, in blood lactate, free fatty acid, bicarbonate, and ammonia concentrations, and in muscle glycogen concentrations. The exercise test was conducted at a speed of 4.5 m/s on a motorized equine treadmill set at a 9% grade. At fatigue, all variables differed significantly (P < 0.05) from base-line values. Heart rate averaged 191.1 ± 6.5 beats/min at fatigue, and the plasma lactate concentrations increased from 7.8 ± 0.95 mg/dl to 94.3 ± 19.2 mg/dl. Ammonia concentrations increased from 66.7 ± 6.9 μmol/L before exercise to 136.9 ± 18.6 μmol/L at fatigue. Bicarbonate concentrations decreased from 31.3 ± 0.4 mM to 21.1 ± 1.8 mM, and pH decreased from 7.37 ± 0.01 to 7.28 ± 0.04. Free fatty acid concentrations were higher at fatigue and increased throughout the recovery period. Exercise resulted in a 25% decrease of muscle glycogen concentration in gluteus medius specimens.
Coagulation assays and platelet aggregation patterns in human, baboon, and canine blood
Authors: Feingold Hollace M. , Pivacek Linda E. , Melaragno Anthony J. , Valeri C. Robert
Published: February 2025

Coagulation assays in citrated plasma and platelet-aggregation patterns in citrated platelet-rich plasma were performed, using human, baboon, and canine blood. Similar fibrinogen concentrations, factor VIII antihemolytic factor (ahf) clotting protein concentrations, and thrombin times were seen in human and baboon plasma, whereas prothrombin times and activated partial thromboplastin times were significantly (P < 0.017) more prolonged in baboon plasma than in human plasma. Canine plasma had significantly lower prothrombin times, activated partial thromboplastin times and thrombin times, and significantly higher concentrations of fibrinogen and factor VIII (ahf) clotting protein than did human plasma. The baboon factor VIII antigen cross-reacted with an antibody against human factor VIII antigen, whereas the canine factor VIII antigen did not.

Human and canine platelets had similar aggregation patterns to adenosine diphosphate (adp), whereas baboon platelets were less responsive to adp than were human platelets. The response to collagen-induced aggregation in human and baboon blood was similar at concentrations of 0.190, 0.100, 0.050 and 0.025 mg/ml, whereas the response in human and canine blood was similar at concentrations of 0.190, 0.100, and 0.050 mg/ml. The lag time before aggregation with collagen was 2 to 3 times longer for canine platelets than for human platelets; human and baboon platelets had similar lag times. Baboon platelets were more responsive to arachidonic acid than were human platelets at concentrations of 0.25, 0.12, and 0.06 mg/ml, whereas canine platelets were less responsive than were human platelets at the highest concentration of 0.5 mg/ml. Human platelets were more responsive to epinephrine than were baboon or canine platelets. Human and baboon platelets aggregated to ristocetin, but canine platelets did not. Human and baboon platelet-aggregation patterns were comparable after treatment with 0.025 mM and 0.012 mM of adp, the 4 concentrations of collagen, 0.5 mg/ml of arachidonic acid, and 0.012 mg/ml of ristocetin. Human and canine platelet-aggregation patterns were similar after treatment with the 4 concentrations of adp, and with arachidonic acid at concentrations of 0.12 and 0.25 mg/ml.
In vitro responses of bronchial spirals and parenchymal strips from healthy and heartworm-infected dogs
Authors: O'Malley Nancy A. , Crawford M. Patrick , Venugopalan Changaram S.
Published: February 2025

Bronchial spirals and pulmonary parenchymal strips from control (noninfected) and Dirofilaria immitis-infected dogs were tested for isometric contractile response to histamine and carbamylcholine. Responses of bronchial spirals from control dogs and from D immitis-positive groups did not differ in responses to histamine or carbamylcholine. Parenchymal strips from D immitis-positive dogs showed greater response to histamine than did those from controls; responses to carbamylcholine did not differ.
Effect of flunixin meglumine on surgical wound strength and healing in the rat
Authors: Donner Gayle S. , Ellison Gary W , Peyton Llewellyn C. , Crowley Ann M. , Szempruch Ned , Williams Jerry W.
Published: February 2025

Forty male adolescent Sprague-Dawley rats were anesthetized and standardized ventral midline laparotomies and uniform-length gastrotomies and typhlotomies were performed. The visceral and abdominal surgically inflicted wounds were closed with 5-0 polypropylene and 4-0 nylon suture, respectively. The rats were allotted into 4 groups (10 rats/group); 2 groups were not given flunixin meglumine (controls) and 2 groups were given flunixin meglumine (1.1 mg/kg of body weight, im, every 12 hours). On day 5 and again on day 14 after surgery, 1 control and 1 flunixin meglumine-treated group were euthanatized. Tensile strength of the skin and linea alba incisions was determined, using a computerized tensiometer. Gastric and cecal incision bursting strengths were determined, using a pressure manometer.

Flunixin meglumine significantly (P < 0.05) decreased the tensile strength of wounds in the skin and linea alba, but did not affect visceral bursting strength at day 5 after surgery. At day 14 after surgery, a significant difference in wound strength was not found between the flunixin meglumine and control groups in any of the tissues evaluated. Flunixin meglumine had an adverse influence on the inflammatory stage of wound repair, but not on the proliferative stage, when fibroplasia is a major factor in wound strength. Major histologic differences were not found in the incision wounds of flunixin meglumine-treated and nontreated control rats.
Humaneness of an electroimmobilization unit for cattle
Authors: Pascoe Peter J.
Published: February 2025

Application of an electroimmobilization unit was evaluated in adult Holstein cows. Twenty cows were acclimated to being led from their stanchion, down a corridor, and into a set of stocks. After the first 7 sessions when the cows were exposed to a conditioning stimulus, cows were assigned to 4 groups of 5. One group served as a control group, 2 groups were given a high or low stimulus with the electroimmobilizer immediately after the conditioning stimulus, and 1 group was given saline solution im. These stimulus treatments were repeated 10 times, followed by an extinction trial of 10 sessions when stimulus treatments were stopped. The time taken to enter the stocks, the heart rate before and after treatment was given, and an assessment of the physical reaction were used as measurements of the response of each cow. At the end of the stimulus treatment phase, cows in high- or low-stimulus groups had significantly greater (P < 0.05) reluctance to enter the stocks and had higher heart rates during the period before they were given the stimulus. These cows also had significantly greater (P < 0.05) physical reaction than did cows in the control group and the group given the im injection. Cows given the im injection demonstrated significantly (P < 0.05) greater physical reaction than did cows in the control group. Seemingly, electroimmobilization was a noxious event and was more noxious than a simple im injection.
Change in triceps muscle intracompartmental pressure with repositioning and padding of the lowermost thoracic limb of the horse
Authors: White N. A. , Suarez M.
Published: February 2025

Triceps intracompartmental pressure was measured in the lowermost limb of the recumbent horse during the initial period of recumbency during elective surgical procedures in 11 horses. Intramuscular pressure, using an im catheter, was measured with the thoracic limbs in 4 different positions, including (I) table-contact limb unadvanced-unsupported free limb, (II) table-contact limb unadvanced-supported free limb, (III) table-contact limb advanced cranially, unsupported free limb, and (IV) table-contact limb advanced cranially, supported free limb. Pressure was measured in the 4 positions with and without padding. The highest pressure was measured in position I without padding. The lowest pressure was measured with position IV with padding and was significantly lower than all pressures in other positions (P < 0.05). Foam mattress padding significantly decreased muscle pressure in each position.
Response of the canine corneal endothelium to intraocular irrigation with saline solution, balanced salt solution, and balanced salt solution with glutathione
Authors: Nasisse Mark P. , Cook Cynthia S. , Harling David E.
Published: February 2025

The right or left anterior chamber of 12 dogs (ie, 24 eyes) was irrigated with 100 ml of 0.9% saline solution, balanced salt solution, or balanced salt solution with glutathione (8 eyes/solution) for 22 minutes. Changes in endothelial cell density and corneal thickness from pretreatment values were evaluated immediately after, and at 2 and 7 days after irrigation. Using specular microscopy and scanning and transmission electron microscopy, corneas were examined immediately after and at 2, 7, and 14 days after irrigation. Changes were not seen in endothelial cell density after irrigation with any of the solutions evaluated. Corneal thickness increased 4% immediately after irrigation with 0.9% saline solution and returned to normal by 1 week after irrigation; treatment with 0.9% saline solution was not associated with visible corneal edema. Ultrastructural changes attributable to differences in irrigating solution composition were not observed. The difference between the endothelium's response to limited irrigation with saline solution, balanced salt solution, and balanced salt solution with glutathione was small and irrigation with these solutions was not associated with permanent endothelial damage.
Effect of drying on the infectivity of cryptosporidia-laden calf feces for 3- to 7-day-old mice
Authors: Anderson Bruce C.
Published: February 2025

Cryptosporidium-laden calf fecal specimens (n = 13) of various consistencies were infective for infant mice, but infectivity for infant mice ceased after 1 to 4 days of drying.
Digestion in horses after resection or ischemic insult of the large colon
Authors: Ralston Sarah L. , Sullins Kenneth E. , Stashak Ted S.
Published: February 2025

The effect of 60% resection of the large colon vs ischemic insult without resection on the ability of horses to digest grass hay was investigated. Digestion trials were performed on 9 horses before surgery (base line) and 3 weeks, 6 weeks, and 6 months after surgery. The percentage of apparent digestion of crude protein, crude fiber, nitrogen-free extract, calcium, phosphorus, magnesium, manganese, copper, and zinc was calculated. Horses that had resection (n = 5) had decreased apparent digestion of crude protein, crude fiber, and phosphorus 3 weeks after surgery, compared with those in horses with ischemic insults (n = 4) and with base-line values. Horses with ischemic insults also had a decrease in crude protein digestion 3 weeks after surgery, compared with base-line values. All horses returned to base-line values of digestion at the 6-month trials, although horses that had resection had higher fecal concentrations of phosphorus and nitrogen-free extract than did horses with ischemic insult. During the study, all horses had maintained good body condition.
Canine storage disease characterized by hereditary progressive neurogenic muscular atrophy: Breeding experiments and clinical manifestation
Authors: Inada Shichiro , Yamauchi Chuhei , Igata Akihiro , Osame Mitsuhiro , Izumo Shuji
Published: February 2025

Progressive neurogenic muscular atrophy due to storage of a compound lipid in the lower motor neurons was diagnosed in 3 English Pointers that were littermates. Using 2 clinically normal littermates of these 3 affected dogs and 2 clinically normal dogs of the 2nd litter from the parents of the original 3 affected dogs as the initial breeding stock, a breeding experiment was performed, resulting in a breeding line of 26 dogs, 4 of which had the disease and 6 of which died before 3 months of age. Results indicated that the disease may have an autosomal recessive mode of inheritance. The clinical manifestation and electrophysiologic findings indicated lower motor neuron involvement in the affected dogs produced by breeding consistent with findings in the original 3 affected dogs. Upper motor neurons or the sensory system was not involved. The disease appeared to be distinct from other canine storage diseases previously reported.