bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathologic Alterations in Congestive Cardiomyopathy of Dogs
Authors: Van Vleet John F. , Ferrans Victor J. , Weirich Walter E.
Published: February 2025

Eleven large-breed dogs with congestive cardiomyopathy were studied at necropsy. Seven of 11 dogs were Great Dane and 9 of 11 were male. The most common clinical signs in affected dogs were dyspnea, abdominal distention by ascites, and weight loss. Three dogs had severe congestive cardiac failure. At necropsy, gross alterations in the hearts were cardiomegaly, dilation of all chambers, opacity of the endocardium, atrial thrombosis, and disseminated foci of myocardial necrosis. Extracardiac changes included hepatic congestion, pulmonary congestion and edema, ascites, and infarction of kidney, liver, lung, and spleen. Microscopically, the affected hearts had disseminated foci of subendocardial myocardial necrosis, scattered areas of myocardial fibrosis, and medial hyperplasia of intramyocardial arteries. Ultrastructurally, degenerated cardiac muscle cells had myocytolysis, proliferated elements of sarcoplasmic reticulum, numerous myelin figures and autophagic vacuoles, large numbers of lipofuscin granules, and mitochondrial alterations. These ultrastructural alterations are similar to those described for cardiomyopathy in persons and cats.
Comparative Anthelmintic Efficacy of Two Schedules of Mebendazole Treatment in Dogs
Authors: Guerrero Jorge , Pancari Gregory , Michael Bruce
Published: February 2025

Two schedules of anthelmintic oral treatment, using mebendazole powder, were compared in 73 dogs naturally infected with common helminth intestinal parasites. Mebendazole powder was administered to 26 dogs at doses of 22 mg/kg once daily for 3 days and was compared with the same dose given once daily for 5 days into 23 dogs. The 24 other dogs were kept as controls and received a placebo treatment for 5 days.

Efficacy results for the 3-day treatment schedule of mebendazole were as follows: Toxocara canis, 100%; Uncinaria stenocephala, 100%; Ancylostoma caninum, 99.4%; Trichuris vulpis, 100%; and Taenia pisiformis, 93.9%. Mebendazole powder given on the 5-day treatment schedule was 100% efficacious against the foregoing parasites. Anthelmintic efficacy against Dipylidium caninum was not detected in either schedule of treatment.
Regional Histochemical and Thickness Variations of Adult Canine Articular Cartilage
Authors: Kincaid Steven A. , Van Sickle David C.
Published: February 2025

Regional thickness and histochemical variations of the matrix of adult canine articular cartilage were studied. In the caudal-central region of the humeral head, differential staining for the presence of keratan sulfate in the territorial matrix of the chondrocytes was closer to the articular surface than in the thinner articular cartilage of the dorsal plateau region. The relevance of these observations to the biomechanical and physiochemical properties of articular cartilage was discussed.
Experimental Infection of Bovine Mammary Glands with Streptococcus agalactiae During the Nonlactating Period
Authors: McDonald J. S. , Anderson A. J.
Published: February 2025

Two experiments were done to determine the rate of intramammary infection (imi) in dairy cows during the nonlactating period. In experiment 1, all glands were equally exposed to Klebsiella pneumoniae and Streptococcus agalactiae for the first 3 weeks after the start of the nonlactating period. Nearly all new imi was caused by S agalactiae.

In experiment 2, the susceptibility of nonlactating mammary glands to new imi by S agalactiae after direct inoculation into the lactiferous sinus was determined. During the 1st month of the nonlactating period, 30% of inoculated glands became infected. During the last month of the nonlactating period, 90% of inoculated glands became infected.
Boron Content of Plasma and Urine as Indicators of Boron Intake in Cattle
Authors: Weeth H. J. , Speth C. F. , Hanks D. R.
Published: February 2025

Yearling beef heifers were offered drinking water (0.8 mg of B/L of water) to which 0, 15, 30, 60, or 120 mg of B/L of water was added for 10-day periods. Feed and water consumption were unaffected by treatments. There were no overt signs of toxicosis. Increased B ingestion increased plasma and urine B concentrations. The percentage of renally filtered B that was excreted was increased with the 30, 60, and 120 mg of B/L of water treatments, and B clearance exceeded endogenous creatinine clearance with these treatments. Ingesting increased amounts of B was associated with decreased plasma PO4-3 concentration and increased renal clearance and urinary excretion of PO4-3.

The B status of cattle can be predicted from plasma or urine B concentrations. Results indicated that prediction can be made from the B/creatinine ratio of urine. With an induced urine sample, the equation for predicting B ingestion is Ŷ = -67.79 + 976.74X - 141.91X2 (r = 0.96; Syx = 121.57) where Ŷ is B in milligrams per 100 kg of body weight per day, and X is the ratio of urine B (mg/L of urine) to creatinine (mg/L of urine).
Isolation of Moraxella bovis Ribosomes and Their Subsequent Use in a Vaccine Against Infectious Bovine Keratoconjunctivitis
Authors: Pugh G. W. , Phillips M. , McDonald T. J. , Kopecky K. E.
Published: February 2025

A study was conducted to determine whether a Moraxella bovis ribosomal vaccine would protect calves from infectious bovine keratoconjunctivitis (ibk). Each of 16 calves were given 2 inoculations 21 days apart. Twenty-one days after the 2nd inoculation, 8 of the calves were challenge exposed with a homologous strain culture and 8 calves were challenge exposed to a heterologous strain culture of M bovis.

Sedimentation velocity analysis of the ribosomes used in the study indicated that they were mostly 30S and 50S subunits. Chemical assay indicated that the ribosomes were composed of 64% to 65% RNA and 35% to 36% protein. The cesium chloride buoyant density of the ribosomes was 1.62 g/ml. Ribosomes used as antigen gave 1 line of precipitation in a gel-diffusion precipitin test with hyperimmune serum against the whole-cell antigen of the homologous strain of M bovis.

The eyes of all the experimentally exposed calves became infected and all calves developed clinical signs of either unilateral or bilateral ibk. None of the sera of the vaccinated calves had detectable precipitins against the ribosomal antigen at the time they were challenge exposed, but most of the sera had precipitins against whole-cell and pilus antigens.

The results indicate that M bovis ribosomes, although similar to other bacterial ribosomes, did not protect cattle against ibk.
Anemia of Inflammatory Disease in the Dog: Availability of Storage Iron in Inflammatory Disease
Authors: Feldman B. F. , Kaneko J. J. , Farver T. B.
Published: February 2025

The iron-chelating agent deferoxamine (df) was administered as a single dose and also daily over a prolonged period to evaluate availability of storage iron in dogs with induced anemia of inflammatory disease. In a 6-hour period, total urinary ferrioxamine (measured as urinary iron) excretion in controls was 251.22 ± 119.68 μg (mean ± 1 sd), a 5.32 ± 2.64-fold increase over prechelation values. In anemia of inflammatory disease-affected dogs, excretion was diminished to 115.67 ± 34.86 μg, a 2.87 ± 1.10-fold increase, indicating a restricted iron excretion and sequestration of iron in a less soluble, less chelatable form. During prolonged df administration, a pattern of increasing total urinary iron excretion was observed. This pattern is consistent with iron being stored as an insoluble polynuclear hydroxide in protein of ferritin and hemosiderin.

The increase in hemoglobin and serum iron concentrations during prolonged df administration indicates that increased iron stores are present, but in a less labile form. During the process of chelation, iron is converted to a more readily utilized state, and the increased availability of iron promotes hemoglobin synthesis. Thus, storage iron in the form of hemosiderin and ferritin is released to the metabolizable pool.
Intravascular Neutrophilic Granulocyte Kinetics in Horses
Authors: Carakostas M. C. , Moore W. E. , Smith J. E.
Published: February 2025

Intravascular granulocyte kinetics in 4 healthy horses were determined with chromium-51 as the cell label. The disappearance rate of labeled granulocytes was an exponential function. Mean total blood granulocyte pool (± 1 sd) was 5.65 ± 1.514 × 108 granulocytes/kg of body weight, of which 2.71 ± 0.715 × 108 granulocytes/kg were circulating and 2.94 ± 0.876 × 108 granulocytes/kg were marginated along blood vessel walls. The mean disappearance half-life (T1/2) was 10.5 ± 1.33 hours and the mean granulocyte turnover rate was 8.84 ± 1.495 × 108 granulocytes/kg/day. A granulokinetic trial performed on a horse recovering from a recent infection revealed increases in all granulokinetic measurements.
Effects of Etiocholanolone and Prednisolone on Intravascular Granulocyte Kinetics in Horses
Authors: Carakostas M. C. , Moore W. E. , Smith J. E. , Johnson D.
Published: February 2025

The functional capacity of the marrow granulocyte reserve (mgr) in 4 adult horses was studied, using 51Cr-labeled leukocytes. The mean increase in the peripheral granulocyte count following injections of etiocholanolone (0.3 mg/kg) was 870 granulocytes/mm3, and the mean increase following prednisolone administration (200 mg) was 5,880 granulocytes/mm3. Etiocholanolone failed to mobilize the mgr and decreased the rate of granulocyte egress from the blood. Prednisolone rapidly mobilized the mgr and markedly decreased the granulocyte specific activity during the first 3 hours after injection.
Efficacy of Ethylenediamine Dihydrochloride in Dogs and Cats
Authors: Finco Delmar R.
Published: February 2025

Ethylenediamine dihydrochloride was administered to dogs and cats with induced Escherichia coli urinary tract infections and to clinically normal dogs and cats to determine if the drug had diuretic, antibacterial, or urinary acidification properties.

In dogs, the drug had no diuretic or antibacterial properties and did not modify the postprandial production of alkaline urine.

In cats, the drug had no diuretic or antibacterial properties, but caused a slight reduction in urine pH when multiple doses were administered.

Ethylenediamine dihydrochloride appeared to have no value in the treatment of E coli urinary infection under the conditions of the present study.
Hemagglutination Inhibition of Haemophilus paragallinarum Type 1 Hemagglutinin by Lipopolysaccharide
Authors: Iritani Y. , Yamaguchi T. , Katagiri K. , Arita H.
Published: February 2025

Action of Haemophilus paragallinarum type 1 hemagglutinin was not inhibited by mannose, methyl-α-d-mannoside, sialic acid, and cholesterol. Hemagglutination was inhibited by lipopolysaccharide from H paragallinarum and from Escherichia coli. Treatment of chicken rbc with trypsin or formalin increased the sensitivity of these cells to H paragallinarum type 1 hemagglutinin.
Acid-Base and Electrolyte Alterations Associated with Salivary Loss in the Pony
Authors: Stick John A. , Robinson N. Edward , Krehbiel Janver D.
Published: February 2025

Esophageal fistulas were made in 6 ponies to evaluate whole blood acid-base values and serum and salivary electrolyte alterations associated with salivary depletion. Acid-base and electrolyte values remained within normal ranges for 15 days in 3 control ponies fed a pelleted diet through nasogastric tubes. In 6 ponies with esophageal fistulas that were fed the same diet through esophagostomy tubes, hypochloremia and hyponatremia developed during the same period. Serum K concentrations were only marginally depleted, probably because of dietary replacement.

Salivary depletion resulted in transient metabolic acidosis from bicarbonate lost in saliva followed by progressive metabolic alkalosis. The alkalosis probably resulted from renal compensation of electrolyte imbalances.

Salivary electrolytes were in high concentrations, probably because of increased salivary flow rates. Initial saliva was rich in Na, Cl, and K, but progressive reduction in salivary Na and Cl concentrations occurred during the 5-day collection period. These electrolyte savings could be explained by dietary influences and hormonal control of electrolyte transport in salivary ducts.

Therapy for correction of acid-base and electrolyte alterations was also discussed.
Total and Differential Cell Counts in Secretions of the Nonlactating Bovine Mammary Gland
Authors: Jensen D. L. , Eberhart R. J.
Published: February 2025

Total cell counts and differential patterns in secretion of 52 mammary quarters of 23 Holstein-Friesian cows were determined at intervals in the early dry and the pre-and postpartum periods. Each sample was cultured to determine infection status of the gland.

Twelve quarters remained noninfected, and 10 quarters were infected throughout the test period. Patterns of bacterial isolation from the remaining 30 quarters indicated that transient or intermittent infections had occurred.

In secretions of noninfected quarters, geometric mean cell counts increased from 3.6 × 105 cells/ml on the last day of lactation to 1.8 × 107 cells/ml by the 7th day of the dry period. Total cell concentration remained high through most of the dry period; counts decreased in the prepartum period and reached a level of 2.8 × 105/ml by the 6th day after parturition. Macrophages were the predominant cell type through most of the dry period. The proportion of neutrophils was high initially, decreased as the dry period progressed, and tended to increase as parturition approached, whereas that of lymphocytes increased during involution and then decreased near parturition.

In secretions from persistently infected quarters, concentrations of total cells, neutrophils, macrophages, and lymphocytes were higher at all sampling times than in secretions from noninfected quarters. Neutrophils were the predominant cell type in infected secretions at all sampling times. Peak cell concentrations of 8.5 × 107/ml in infected quarters were reached in the immediate prepartum period.
Effect of Haemophilus somnus on Bovine Endothelial Cells in Organ Culture
Authors: Thompson Keith G. , Little Peter B.
Published: February 2025

The effect of 2 strains of Haemophilus somnus on bovine endothelial cells in cultured arterial segments was investigated and compared with the effects of Escherichia coli and Salmonella typhimurium.

In cultures inoculated with either strain of H somnus, there was widespread contraction and desquamation of endothelial cells, exposing large areas of subendothelial collagen. Many bacteria were adherent to endothelial cells and some were in phagosomes within cells. Endothelial changes were milder in arterial cultures inoculated with E coli or S typhimurium than in those inoculated with either strain of H somnus.

Adhesion of H somnus to vascular endothelial cells followed by exposure of subendothelial collagen may initiate the thrombosis, vasculitis, and ischemic necrosis characteristic of infectious thromboembolic meningoencephalitis in cattle

Arterial cultures might be useful in assaying the virulences of different strains of H somnus, and could be used to investigate the mechanism of their action on endothelial cells.
Localization of Foot-and-Mouth Disease Viral Antigens in Mammary Gland of Infected Cows
Authors: Blackwell J. H. , Yilma T.
Published: February 2025

Virolactias as a result of foot-and-mouth disease infection in dairy cattle would indicate active virus replication in the bovine mammary gland. In the present study, virus was readily detected throughout the mammary gland by infectivity assay after cows were exposed to the virus either by aerosol or by a combination of intramammary-iv inoculation. Furthermore, immunofluorescent and hematoxylin and eosin staining of alternate frozen sections showed viral antigens in rounded alveolar cells with pyknotic nuclei.
Development of Immunity to Sarcocystosis in Dairy Goats
Authors: Dubey J. P.
Published: February 2025

To determine the virulence of a microscopic species of Sarcocystis, forty-six 39- to 57-day-old goats were inoculated with 101 to 106 sporocysts; 7 age-matched goats served as noninoculated controls. Four of 4 goats fed 106 sporocysts, 4 of 4 goats fed 105 sporocysts, 2 of 4 goats fed 5 × 104 sporocysts, and 1 of 4 goats fed 104 sporocysts died of sarcocystosis, whereas 30 goats fed 101 to 103 sporocysts and the 7 noninoculated controls generally remained asymptomatic.

In 3 immunization trials, groups of 7 to 9 goats were challenge exposed with 105 or 106 (2 or 20 median lethal dose) sporocysts at 14, 30, and 60 days after vaccination. In the 1st trial (14 days after vaccination), 2 of 2 goats vaccinated with 103 sporocysts and 1 of 2 goats vaccinated with 102 sporocysts survived a challenge exposure with 105 sporocysts, whereas 2 of 2 goats fed 101 sporocysts and the control goat died of acute sarcocystosis. In the 2nd trial (30 days after vaccination), 2 of 2 goats vaccinated with 103 sporocysts and the 2 goats vaccinated with 102 sporocysts survived a challenge exposure with 105 sporocysts, whereas 2 goats vaccinated with 101 sporocysts and the control goat died of acute sarcocystosis. In the 3rd trial (60 days after vaccination), 2 goats vaccinated with 5 × 104 sporocysts, 2 goats vaccinated with 103 sporocysts, 2 goats vaccinated with 104 sporocysts, and the 2 goats vaccinated with 102 sporocysts survived after challenge exposure with 106 sporocysts, whereas 2 goats vaccinated with 101 sporocysts and the control goat died of acute sarcocystosis.

The results indicate that goats vaccinated with 102 to 103 sporocysts develop protective immunity against lethal doses of Sarcocystis, whereas goats vaccinated with 101 sporocysts were not protected against a later infection with a lethal dose.
Adrenocortical Suppression in the Dog After a Single Dose of Methylprednisolone Acetate
Authors: Kemppainen R. J. , Lorenz M. D. , Thompson F. N.
Published: February 2025

Adrenal function was assessed in dogs after intramuscular administration of a single dose of methylprednisolone acetate (mpa). Twelve dogs were test challenged with adrenocorticotropic hormone (acth) and then assigned randomly to 1 of 3 groups and given mpa. Individual groups were test challenged with acth 2, 3, or 4 weeks later. All dogs were rechallenged 5 weeks after mpa administration. Plasma cortisol concentration was determined by radioimmunoassay. Basal plasma cortisol (time 0) was depressed on weeks 2 and 3, but not on weeks 4 and 5. Adrenal response to acth (increment of cortisol change) was suppressed on weeks 2, 4, and 5, but not on week 3. It was concluded that a single dose of mpa is capable of altering adrenal cortical function in dogs for at least 5 weeks.
Evaluation of Chemical Disinfectants for Aleutian Disease Virus of Mink
Authors: Shen D. T. , Leendertsen L. W. , Gorham J. R.
Published: February 2025

Nine chemicals and commercial disinfectants were tested for inactivation of Aleutian disease virus of mink. In the presence of distilled water, a commercial disinfectant (O-Syl), halogen derivatives (iodophor and sodium hypochlorite), and glutaraldehyde (2.0%) inactivated 4 log10 (based on 0.25 ml) of the virus within 10 minutes at 23 C. Formalin (2.0%) and O-Syl were slower to inactivate the virus, but achieved a 4 log10 reduction in titer by 30 minutes’ contact time. In the presence of 10% bovine serum, formalin (1.0%), O-Syl, and sodium hydroxide (0.5%) achieved a 4 log10 reduction within 10 minutes. All agents tested had some virucidal effect.
Blastogenic Response of Swine Lymphocytes in Whole Blood, Purified Blood, Spleen Cell, and Lymph Node Cell Cultures with Concanavalin A and Phytohemagglutinin
Authors: Hussain A. , Tripathy R. N. , Mohanty S. B. , Rockemann D. D.
Published: February 2025

Microcultures of swine whole blood, purified blood lymphocytes (pbl), spleen cells, and lymph node (ln) cells were tested for stimulation by concanavalin A (conA) and phytohemagglutinin (pha). A cell concentration of 2 × 106/ml and a 1:20 dilution of whole blood were needed for optimal stimulation of conA and pha. Optimal stimulation of whole blood lymphocytes (wbl) and ln cells was obtained by 20 μg of conA/ml, but 10 μg/ml of this mitogen was adequate for spleen cells. The pbl and ln cells were optimally stimulated by 20 μl of pha/ml, but 80 μl/ml and 40 μl/ml of this mitogen were required for stimulating the whole blood and spleen cells, respectively. Four days’ incubation was needed for maximal blastogenesis of wbl with conA. This could be achieved after 3 days’ incubation with pbl and spleen and ln cells. Whole blood and spleen cells were stimulated by pha after 3 days’ incubation, but pbl and ln cells required 4 days’ incubation. Reproducibility, sensitivity, and comparison of various cultures were discussed.
Epizootiologic Study of Bluetongue: Virologic and Serologic Results
Authors: Osburn B. I. , McGowan B. , Heron B. , Loomis E. , Bushnell R. , Stott J. , Utterback W.
Published: February 2025

Heparinized blood and serum samples were obtained from 1,295 ruminants in herds or flocks with bluetongue virus (btv) infection in 4 western states. Submissions were from herds or flocks with clinical bluetongue (bt), as well as from animals on premises with no history of bt disease. Insects, including Culicoides variipennis, were collected in areas enzootic for bt disease. Viral isolations were in 10-day-old embryonating chicken eggs that were then adapted to Vero cells for serotyping. Sera were tested for group-specific antibody to btv by the micro agar gel precipitin (agp) test. Viral isolations were from cattle (81), sheep (122), goats (9), antelope (2), and C variipennis (5). There were 7 isolates of serotype 10, 114 of serotype 11, 42 of serotype 13, and 56 of serotype 17. In herds or flocks from which btv was isolated, 51% of cattle, 56% of sheep, 21% of goats, and 52% of antelope had agp antibodies. Virus was isolated from 43% of the cattle and 23% of the sheep that had no demonstrable evidence of agp antibodies. Viral isolations were seasonal, occurring from August until December. Approximately 30% of the herds or flocks from which virus was isolated had more than one serotype of virus causing infection.
Surgical Technique and Considerations for Implantation of Electromagnetic Blood Flow Transducer and Occluder Onto the Coronary Arteries
Authors: Tranquilli W. J. , Manohar M. , Thurmon J. C. , Benson G. J. , Shawley R. V. , Feller D. L.
Published: February 2025

A technique was developed for the implantation of an electromagnetic flow probe and vascular occluder onto the right and left coronary arteries in the calf and pony. Surgical manipulation was well tolerated in the animals. The subcutaneous housing on the peripheral ends of these devices of the lateral thoracic wall served as a maintenance-free technique for chronic exteriorization of these devices. Implantation onto the coronary arteries required a surgical technique which accomplished the prerequisites for proper flow probe function. A reactive hyperemic response was elicited in each animal by implanting an inflatable vascular occluder distal to the flow probe. The correct function of these devices post-operatively established the feasibility of this surgical technique for implanting these devices on the coronary arteries for chronic studies of coronary circulation.
Pharmacokinetics of Cephalothin and Cephalexin in Selected Avian Species
Authors: Bush Mitchell , Locke Diana , Neal Lawrence A. , Carpenter James W.
Published: February 2025

Plasma concentrations and the biological half-lives of cephalothin and cephalexin in avian species of a variety of body sizes and metabolic rates were studied. The species chosen were eastern bobwhite quail (Colinus v virginianus), pigeons (Columba livia), hybrid rosybill ducks (Netta sp), greater sandhill cranes (Grus canadensis tabida), and emus (Dromiceius novaehollandiae). In the 1st phase of the study, cephalothin sodium was given im in a dose of 100 mg/kg of body weight. Plasma concentrations reached peak (av 18 μg/ml) at 0.5 hour and were measurable 2.5 to 5.5 hours after drug administration. The biological half-life of cephalothin was 16 to 54 minutes; the half-life varied directly with increased species body weight, with the exception of the ducks studied.

In the 2nd phase, cephalexin monohydrate was given orally in doses of 25, 35, and 50 mg/kg of body weight. Plasma concentrations reached peak (av 20 μg/ml) at 0.5 to 1 hour and were measurable 2.5 to 5.5 hours after drug administration. The biological half-life of cephalexin was 36 to 126 minutes.

In the 3rd phase, differences in plasma concentrations and the half-lives of cephalexin between fed quail and fasted quail were insignificant.

Dosage regimens for cephalothin of 100 mg/kg 4 times a day and for cephalexin of 35 to 50 mg/kg 4 times a day would be expected to establish and maintain therapeutic plasma concentrations in large birds (pigeons, cranes, and emus). These same doses, administered every 2 to 3 hours, would be expected to establish and maintain therapeutic plasma concentrations in smaller birds (quail, ducks).
Effect of Excessive Exposure to Sodium Fluoride on Composition and Crystallinity of Equine Bone Tumors
Authors: Shupe J. L. , Eanes E. D. , Leone N. C.
Published: February 2025

Sodium fluoride (5 mg/kg of body weight) was fed for 20 months to horses with hereditary multiple exostoses (hme), a skeletal disorder that primarily affects endochondral bones during skeletal development. Rib biopsies were performed on both hme horses not fed fluoride (control) and hme horses that were fed fluoride to obtain comparable specimens for chemical analyses and x-ray diffraction.

Fluoride content of the rib from a horse fed fluoride for 20 months was approximately 20 to 30 times higher than that from a control horse. Fluoride content of the bone tumors was higher than those of normal bones in both control and fluoride-fed horses. The effect of fluoride uptake on the Ca/P ratio was slight. The Ca/P ratios did not differ significantly between tumorous and normal ribs.

X-ray diffraction studies showed that the crystallinity (ie, crystal size/perfection) of the mineral apatite in the tumor of the rib from the control horse was lower than that of normal bone from the same rib. Fluoride, however, induced a marked change in the crystallinity at both the tumorous and the normal bone sites. The crystallinity of the tumor apatite in the fluoride-fed horse exceeded that of normal bone in the control horse. Otherwise, there were no demonstrable fluoride-induced gross or radiographic changes in the bone tumors.
Apparent Inactivity of Several Antiparasitic Compounds Against the Eyeworm Thelazia lacrymalis in Equids
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

Activity of 15 compounds, given alone or in mixtures [butamisole, cambendazole, caviphos, febantel (alone or with trichlorfon), fenbendazole, ivermectin, levamisole-piperazine, oxfendazole, oxibendazole, pyrantel pamoate (alone or with piperazine-carbon disulfide complex), thiabendazole (alone or with piperazine or with trichlorfon), tioxidazole, and trichlorfon], against Thelazia lacrymalis was evaluated in 102 equids. Determination of activity was based on comparison of infection rate in treated animals examined at necropsy with infection rate of dead equids in our contemporary surveys. None of the compounds appeared to be active against T lacrymalis.
In Utero Transmission of Bovine Leukemia Virus
Authors: Van Der Maaten M. J. , Miller J. M. , Schmerr M. J. F.
Published: February 2025

In an initial study, 18 calves born to cows persistently infected with bovine leukemia virus (blv) were tested for infective virus and antibodies at birth, and no infected or seropositive animals were found. Four of these calves were maintained in quarters where infected animals were housed, and 3 of the 4 subsequently became infected. These were probably contact infections acquired during, or at some time after, birth. The remaining 14 calves were kept in isolation pens in a building housing no infected cattle. None of this group was found to be blv infected during 1 year of observation. In further studies, 15 pregnant cows inoculated with blv became infected. One abortion, considered to be unrelated to the blv inoculation, occurred 38 days later. The remaining 14 cows gave birth to 1 dead and 14 live calves. The dead calf and its live twin were seropositive for blv at birth, indicating that they had been infected in utero. The remaining 13 calves were negative for blv antibodies at birth and remained so during 1 year of observation.
Anthelmintic Efficacy of Albendazole in Calves with Naturally Acquired Fasciola hepatica Infections
Authors: Bradley Richard E. , Randell Wallace F. , Armstrong Douglas A.
Published: February 2025

The anthelmintic efficacy of albendazole was evaluated as an oral drench at dosages of 15.0, 10.0, and 7.5 mg/kg of body weight in 3 groups crossbred Brahman calves (n = 12 group) infected with Fasciola hepatica. Although posttreatment fluke ova counts for the 3 albendazole treatment groups were significantly (P < 0.01) lower (av 82%) than were counts in nontreated calves, there were no significant differences in the responses to the different albendazole treatments. At necropsy, adult fluke counts in treated calves were lower (P < 0.05) than were counts in nontreated calves, but as with ova counts, a dose-related trend was not noticed. Efficacy against adult flukes was 63.4%, 50.0%, and 56.6% for 15.0, 10.0, and 7.5 mg/kg, respectively. Activity against immature flukes was not observed in calves given the 10.0 and 7.5 mg/kg, but there was a 36% decrease of flukes in those calves given 15.0 mg/kg. Significant decreases (P < 0.05) in fluke ova viability were observed for the 3 treatment groups in which 12.9% of ova collected at necropsy failed to embryonate (control group av 6.7%).

Posttreatment weight changes were not significantly different, although gains were greater within albendazole treatment groups. Decreases in gastrointestinal parasite ova counts after treatment were 98%, 93%, and 93% for groups given 15.0, 10.0, and 7.5 mg/kg, respectively. Ova counts in nontreated calves increased 26.2% during the same period.
Effects of Dietary Aflatoxin on Existing Bacterial Intramammary Infections of Dairy Cows
Authors: Brown R. W. , Pier A. C. , Richard J. L. , Krogstad R. E.
Published: February 2025

Aflatoxin, a naturally occurring mycotoxin with immunosuppressive properties, was given to 4 lactating dairy cows that had experimentally induced or naturally occurring mammary infections in 2 of their 4 mammary quarters. Aflatoxin was given orally in daily doses approximating 0.3 mg of B1 activity/kg of body weight for periods of 12 to 14 days. Infecting organisms were Streptococcus agalactiae, Staphylococcus aureus, and Staphylococcus hyicus. The 4 cows were monitored for clinical signs of disease and signs of mastitis for periods before, during, and after aflatoxin consumption. The cows developed inappetence, lost body weight, and had variable reductions in daily milk yield. Serum ornithine-carbamoyl transferase and sorbitol dehydrogenase activities were elevated during and 1 to 3 weeks after aflatoxin consumption. Exacerbations of acute clinical mastitis did not occur in any of the infected quarters; however, bacterial populations in the milk increased in 3 of the 4 cows during aflatoxin consumption. Mean California mastitis test scores were generally highest in the infected quarters in the period after the last dose of aflatoxin was given. Aflatoxin M1 appeared in milk 3 to 6 hours after aflatoxin consumption began, and persisted for 72 hours or longer after the last dose of aflatoxin was given. Aflatoxin B1 and M1 were present in urine samples taken at 6 hours after aflatoxin consumption began and persisted for 72 through 120 hours after the last dose of aflatoxin was given.
Pharmacokinetics of Fenbendazole in Sheep
Authors: Marriner Susan E. , Bogan James A.
Published: February 2025

Concentrations of fenbendazole and its sulfoxide, oxfendazole, and sulfone metabolites were determined in 6 sheep after oral administration of fenbendazole (10 mg/kg of body weight). Mean peak concentrations in plasma of fenbendazole, oxfendazole, and sulfone of 0.15, 0.29, and 0.17 μg/ml occurred 24, 30, and 36 hours after administration, respectively. Mean peak concentrations in abomasal fluid were 1.82, 0.66, and 0.07 μg/ml occurring at 30, 48, and 72 hours, respectively. Fenbendazole and oxfendazole were detectable in plasma and abomasal fluids for 5 days after administration. Much of the anthelmintic activity of fenbendazole may be due to the oxfendazole metabolite. Plasma concentrations of fenbendazole were less and persisted for a shorter period after intra-abomasal administration than after oral administration.
Experimental Induction of Proteus mirabilis Cystitis in the Pony and Evaluation of Therapy with Trimethoprim-Sulfadiazine
Authors: Divers T. J. , Byars T. D. , Murch O. , Sigel C. W.
Published: February 2025

Proteus mirabilis cystitis was induced in 9 ponies by chemically eroding the bladder mucosa before the organism was inoculated. Comparisons were made in the treatment of P mirabilis cystitis between ponies treated daily for 13 days with a trimethoprim-sulfadiazine (tmp-sdz) paste and both positive and negative controls. Urine cultures from ponies treated with tmp-sdz became negative for P mirabilis between days 3 and 9 after the start of the treatment, whereas positive controls remained infected until day 13. Urine cultures from all ponies were negative for P mirabilis on day 28. Urine concentrations of tmp and sdz were relatively high after day 1 of therapy.
Experimental Evidence of a Reciprocal Temperature Relationship Between the Parietofrontal Region and the Orbital Emissary Vein in the Pony
Authors: Magilton J. H. , Swift C. S. , Ghoshal N. G.
Published: February 2025

The heads of 5 ponies were embalmed and the vessels were double injected with latex. Dissection of these specimens revealed venous pathways (1) from the nasal area to the cavernous sinus and (2) from the parietofrontal region to the ventral petrosal sinus. Thermistors were chronically implanted near the orbital emissary veins of 3 additional ponies. Hot and cold packs were applied alternately to the parietofrontal regions. The temperature near the orbital emissary veins increased during the 5 trials with cold application and decreased during the 5 trials with hot application. The authors were able to influence physiologic adjustments in the heat loss in the nasal area (evidenced by temperature changes near the orbital emissary veins) by imposing nonphysiologic changes in the temperature of the venous blood draining the parietofrontal region.
Nicotiana glauca-induced congenital deformities in calves: clinical and pathologic aspects
Authors: Keeler Richard F. , Shupe James L. , Crowe M. Ward , Olson Arland , Balls Lew Dell
Published: February 2025

Seven calves born to 7 cows fed Nicotiana glauca during portions of the 1st trimester of gestation were deformed at birth. Deformities increased in severity as the calves aged. At birth, calves typically had arthrogryposis of the forelimbs or curvature of the spine; severity varied among calves. In 4 calves necropsied at about 15 months of age, there was general malpositioning and misalignment of the distal ends of the radius and ulna and the proximal ends of the metacarpal bones. Carpal joints were severely affected, fetlock joints were moderately affected, and pastern joints were slightly affected, with lateral rotation of forelimbs common; severity varied among calves. In 1 of the 4 calves, there was moderate torticollis and scoliosis resulting from wedging of some of the cervical and thoracic vertebrae and abnormal cranial curvature of the left thoracic ribs. Histologic changes were not noticed in muscle, brain, spinal cord, or endocrine organs of the 4 calves.
Effect of Acetate or Chloride Anions on Intestinal Absorption of Water and Solutes in the Calf
Authors: Demigé C. , Rémésy C. , Chartier F. , LeFaivre J.
Published: February 2025

The influence of acetate, compared with chloride, included in glucose-glycine-sodium formulation was investigated in anesthetized calves, using isolated segments of jejunum or ileum filled with one of the formulations. Maximal absorption of water was observed in the jejunum; this absorption was markedly higher with acetate formulations. The absorption of sodium was highest in the jejunum with the acetate formulation. With the acetate formulation, sodium absorption was still substantial in the ileum, but sodium absorption was maximal with the chloride formulation. Acetate was readily absorbed in the small intestine, particularly in the jejunum, whereas chloride was essentially absorbed in the ileum. With acetate formulations, there was a concomitant secretion of chloride and bicarbonate. These results indicate that acetate favors very efficiently the absorption of water and sodium in the jejunum. In addition, acetate has other interesting properties, such as alkalinizing effects after metabolization.
Anthelmintic Efficacy of 22,23-Dihydroavermectin B1 Against Gastrointestinal Nematodes in Calves
Authors: Benz G. W. , Ernst J. V.
Published: February 2025

Anthelmintic activities of 22,23-dihydroavermectin B1 (comprised to ≥ 95% 22,23-dihydroavermectin B1a and ≤ 5% 22,23-dihydroavermectin B1b) against gastrointestinal nematodes in calves were evaluated in 2 controlled experiments. Infective larvae of Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, Cooperia oncophora, and C punctata were given to 11-week-old calves and Oesophagostomum radiatum had been given 21 days earlier to allow all larvae to attain adulthood at the same time.

Each experiment had 4 groups of 5 calves each. Treatment was given to the calves at 14 weeks of age, and 7 to 8 days after treatment, the calves were necropsied. In experiment 1, group 1 control calves had a geometric mean of 11,054 nematodes; groups 2, 3, and 4 calves (at 14 weeks of age) given 22,23-dihydroavermectin B1 orally at doses of 50, 100, or 200 μg/kg had reductions of 73.5%, 97.3%, and 99.7%, respectively. In experiment 2, group 5 control calves had a geometric mean of 18,897 nematodes; groups 6, 7, and 8 calves given 22,23-dihydroavermectin B1 subcutaneously at doses of 50, 100, or 200 μg/kg had reductions of 74.6%, 95.3%, and 98.8%, respectively.
Controlled Evaluation of Ivermectin in Shetland Ponies
Authors: Craig T. M. , Kunde J. M.
Published: February 2025

Ivermectin was injected im into 12 yearling Shetland ponies. The following reductions in percentages of parasites recovered from ponies given 200 μg/kg or 300 μg/kg, as compared with the parasitic population in those given the vehicle at 1 week after injection, were as follows: Otobius megnini nymphs—no reduction; Gasterophilus intestinalis—100% and 99.9%; G nasalis—100% and 99.9%; Parascaris equorum adults—100% and 96%; Strongylus vulgaris adults—100% and 100%; S edentatus adults—100% and 100%; cyathostome adults of the genera Gyalocephalus, Cylicocyclus, Cyathostomum, Cylicostephanus, and Poteriostomum—99.9% and 100%; 4th-stage larvae—97.3% and 96.8%; Oesophagodontus robustus adults—100% and 100%; Triodontophorus spp—adults—100% and 100%, 4th-stage larvae—95.1% and 100%; and Oxyuris equi adult males—66.7% and 77.7%, adult females—96.5% and 100%, and 4th-stage larvae—94.1% and 96.9%. Other parasites encountered were too few in number to estimate drug efficacy.
Electrocardiographic Values for Anesthetized Cats in Lateral and Sternal Recumbencies
Authors: Calvert Clay A. , Coulter Dwight B.
Published: February 2025

The values from ecg leads I, II, III, aVF, rV2, V2, V4, and V10 were recorded from cats given ketamine and acepromazine. The recordings were made with the cats in right lateral and sternal recumbent positions. Position had minimal effects. The data were compared with published values and included new data on leads rV2, V2, and V4.
Bovine Leukemia Virus Infection in a Large Holstein Herd: Cohort Analysis of the Prevalence of Antibody-Positive Cows
Authors: Huber N. L. , DiGiacomo R. F. , Evermann J. F. , Studer E.
Published: February 2025

Serum samples were obtained annually (from 1977 to 1980) from cows in a large Holstein herd and were tested for antibodies to bovine leukemia virus (blv), using the agar-gel immunodiffusion test. The prevalence of reactors in the herd decreased from 23.0% to 11.8%. Analysis by 12-month cohorts revealed that the decrease in herd prevalence was due to successive cohorts entering the herd with significantly lower blv antibody prevalences. This was accompanied by a low annual incidence of blv seroconversion, which ranged from 0.9% to 2.1%.
Effect of Hypocalcemia on Motility of the Ruminant Stomach
Authors: Huber T. L. , Wilson R. C. , Stattelman A. J. , Goetsch D. D.
Published: February 2025

The sensitivity of ruminal and abomasal contractions to hypocalcemia was evaluated in sheep. Serum diffusible calcium concentrations were determined during induction of hypocalcemia (iv infusion of Na2EDTA) and recovery from hypocalcemia (no infusion). Contractile strength of the rumen gradually decreased as serum diffusible calcium concentrations decreased; significant correlation (r = 0.75; P < 0.001) was observed. Ruminal contractions disappeared before clinical signs of hypocalcemia were seen. Abomasal contractions were slightly reduced when serum diffusible calcium concentrations were equal to those producing ruminal stasis and clinical signs of hypocalcemia. These observations indicated that ruminal dysfunction may occur considerably before the onset of clinical signs of hypocalcemia.
Pharmacology of Narcotic Analgesics in the Horse: Quantitative Detection of Morphine in Equine Blood and Urine and Logit-Log Transformations of This Data
Authors: Combie Joan , Blake J. W. , Ramey B. E. , Tobin Thomas
Published: February 2025

Morphine was detected in equine biological fluids by a combination of liquid-liquid extraction and column chromatography, followed by derivatization and gas-liquid chromatographic assay, using electron capture detector. Recovery of morphine from the equine biological samples was poor. However, despite an overall recovery of less than 20%, this method had a detection limit of 0.2 ng/ml. Addition of 5,000 U of bovine liver β-glucuronidase/ml of urine enabled detection of the drug in urine for up to 144 hours after horses were given 0.1 mg of morphine/kg of body weight. Morphine was found for at least 24 hours in serum samples. An adaptation of logit-log transformation of gas-liquid chromatographic data for linearization over 3 log units suggested a simple adaptation to existing semiautomated data handling systems.
Ultrastructural Evidence of a Functional Heterogeneity Among Physeal Chondrocytes in Growing Swine
Authors: Wilsman N. J. , Farnum C. E. , Hilley H. D. , Carlson C. S.
Published: February 2025

Chondrocytes from the distal ulnar physis of 1- and 5-month-old boars were studied by transmission electron microscopy. Among reserve, proliferating, and early hypertrophic chondrocytes, 2 distinct cell types (dark cells and light cells) were recognized, and in the distal proliferative and early hypertrophic regions, dark cells seemed to be involved in matrix vesicle production. Late hypertrophic light cells seemed to follow 2 lines of maturation. One pathway resulted in cells with a stellate shape, typical of hypertrophic cells in several species other than swine. A 2nd pathway resulted in large oval cells with water-clear cytoplasm. These cells appeared to become encased in a lamina of fine fibrils interspersed with irregularly shaped electron-dense material. The functional significance of these 2 pathways remains unclear.
Arterial and Venous Blood Gas Tensions in Clinically Healthy Cats
Authors: Middleton Deborah J. , Ilkiw Jan E. , Watson A. D. J.
Published: February 2025

Reference values for arterial and jugular venous blood gas tensions and acid-base equilibrium were determined in clinically healthy cats fitted with aortic catheters. Comparison of arterial and jugular venous blood within individual cats indicated that venous specimens were of limited use in the prediction of arterial blood gas tensions.
Toxoplasmosis Associated with Abortion in Goats and Sheep in Connecticut
Authors: Dubey J. P. , Sundberg J. P. , Matiuck S. W.
Published: February 2025

Toxoplasmosis was diagnosed in a caprine fetus from a farm in Stonington, Conn. Placenta had multiple areas of focal necrosis and calcification. Toxoplasma was found in the placenta and in the fetal liver and heart. The doe had an indirect hemagglutination (iha) titer of 1:2,048 to T gondii 2 days after abortion. There was no other abortifacient agent isolated.

Serologic survey on the farm showed that the remaining 4 adult goats, the 8 sheep, the 4 cats, and the 4 persons on the farm had antibody to T gondii. One of the goats had an iha titer of 1:2,048 at about 3 months after abortion, and 1 of the ewes had an iha titer of 1:2,048 at about 5 months after abortion.
Antigenicity of Bacillary Hemoglobinuria Toxoids in Cattle
Authors: Lozano E. A.
Published: February 2025

Antihemolytic titers were obtained from cattle given experimental Clostridium haemolyticum toxoids. Fifty-six yearlings of mixed breed were used for the experiments. Sixteen of these animals were used for preliminary studies, 10 were used as negative controls, and 30 were used for verification and other studies.

The 16 yearlings used in the preliminary studies were allotted to 4 groups of 4 animals each—1 group being used to determine the reactions of a commercial bacterin (positive control), and the other groups being given 3 different doses of experimental toxoid. The animals given the experimental toxoid also were used to determine the safety of the product. It was observed that toxoids prepared from fluids containing 6,670, 33,330, and 66,700 hemolytic units induced averages of 4.0, 65.0 and > 30.0 antihemolytic units, respectively. Only one of the yearlings given the commercial bacterin produced measurable antihemolysin. Strong anamnestic responses were observed in animals given toxoids containing 33,330 and 66,700 hemolytic units. Weaker responses were seen in the animals given the commercial bacterin and toxoid containing 6,670 hemolytic units.

The antihemolytic reactions induced by inoculations of experimental toxoids prepared with fluids containing 33,370 hemolytic units were studied further, using 30 animals. An additional 10 yearlings were given a placebo. Twenty of the 30 animals were given toxoids prepared with added glycine (immunogens similar to those used in the preliminary experiment) and the animals responded with an average of 54.7 antihemolytic units. A toxoid prepared without the added glycine was given to the remaining 10 yearlings which responded with an average of 8.0 antihemolytic units. Rapid losses of antihemolytic titers were observed in all animals that developed this antibody.
Clinical Toxicosis and Erythrocyte Cholinesterase Inhibition of Trichlorfon Combined with Mebendazole in Horses
Authors: Gingerich Daniel A. , Mia A. Salam
Published: February 2025

Thirty adult horses were used to compare the toxicity and cholinesterase (ChE) inhibition of various dosages of a combination anthelmintic, trichlorfon + mebendazole. Single oral doses of up to 5 times the effective dosage (39.7 mg of trichlorfon and 8.8 mg of mebendazole/kg of body weight) did not result in deaths. Horses given a placebo and horses treated at the recommended dosage rate showed few or no side effects, whereas horses given higher dosages showed dosage-related increases in the severity of clinical signs of organophosphate toxicosis. Dosage-related inhibition of erythrocyte ChE activity was also detected.

A 2nd treatment of some of the horses at the recommended dosage 35 days after the initial treatment resulted in minimal or no side effects, despite the fact that erythrocyte ChE activity was still depressed before the repeat treatment. Changes indicating organ toxicosis were not detected in any of the clinical pathologic determinations in any of the dosage groups.