bluuebunny/crossref_metadata_2025 huggingface dataset:
Anatomy of the Beagle in Cross-Section: Head and Neck
Authors: Zook B. C. , Hitzelberg R. A. , Fike J. R. , Bradley E. W.
Published: February 2025

The transverse anatomy of the head and neck of the Beagle was studied. Cross-sectional preparations were photographed and compared with computerized tomographic scans, freshly prepared dissection specimens, and with skeletal preparations. Anatomic structures were identified by these means with the aid of anatomy texts. A series of labeled photographs were provided as a basis for interpretation of computerized tomography scans.
Relative Efficacies of Pyrantel Tartrate and Pyrantel Citrate Against Oesophagostomum sp in Swine
Authors: Pratt S. E. , Brauer M. A. , Corwin R. M.
Published: February 2025

The relative efficacies of pyrantel tartrate and of pyrantel citrate against Oesophagostomum sp in swine were evaluated in a controlled-critical study and the efficacy of pyrantel citrate in a field trial. In the controlled-critical study, pigs naturally infected with Oesophagostomum dentatum were either not treated or were treated with pyrantel citrate or pyrantel tartrate at a dosage of 510 mg of free pyrantel base/kg of feed. Six days later, the pigs were necropsied, adult O dentatum was recovered and counted, and fecal samples were examined for helminth eggs. The efficacies of pyrantel citrate and pyrantel tartrate were each 100% based on fecal egg counts and numbers of adults at necropsy.

The field trial was conducted in a similar manner except that pyrantel citrate only was tested against a control group on the basis of fecal egg counts made both at the beginning and at the termination of the trial. In this study pyrantel citrate was found to reduce Oesophagostomum sp egg counts by 89.4%.
Origin and Importance of Increased Alkaline Phosphatase Activity in Peritoneal Fluids of Horses with Colic
Authors: Froscher B. G. , Nagode L. A.
Published: February 2025

The origin of increased alkaline phosphatase (alp) activity in peritoneal fluid (pf) of horses with clinical signs of abdominal pain was investigated to determine the usefulness of measuring alp in pf in the diagnosis of small intestinal injury. The alp isoenzymes in pf from 10 clinically normal horses and from 50 horses with clinical signs of acute abdominal pain were analyzed for their sensitivities to inhibition by l-phenylalanine, l-homoarginine, and levamisole and to inactivation by heat (56 C, 15 minutes). The enzymes also were discriminated by their patterns of migration during polyacrylamide gel disc electrophoresis.

Of 50 horses with colic, 20 had alp activity in pf at least 3 times the upper limit of normal. Of these 20 horses, 10 had marked increases of alp activity in pf ranging from 10 to 150 times the mean value of activity as determined in the 10 normal horses. In the 50 horses with colic, alp values in serum were within the normal range. In 19 of the 20 sick horses, the alp in pf had properties different from small intestinal alp. Of the 10 pf samples with markedly increased alp activity, 9 had a group of properties that were unique tor granulocytic alp. The clinical diagnoses for the 10 horses with markedly increased alp activity in pf included thromboembolic colic (4 horses), colonic torsion (2 horses), small intestinal volvulus (2 horses), peritonitis (1 horse), and salmonellosis (1 horse). Properties of the enzyme in the 10 pf samples with moderately increased alp activity were compatible with a granulocytic origin, but insufficient enzyme concentration precluded electrophoretic confirmation of the source. The pf from 1 horse had a mixture of alp isoenzymes derived from granulocytes and small intestinal mucosa. Of the 50 horses with colic, 6 had severe small intestinal disease without increased alp activity in pf.

Apparently, increased alp activity in pf cannot be used as a reliable indicator of small intestinal injury in horses, because the alp is predominantly granulocytic in origin.
Characterization of Toxoplasma gondii Isolates from an Outbreak of Toxoplasmosis m Atlanta, Georgia
Authors: Dubey J. P. , Sharma S. P. , Juranek D. D. , Sulzer A. J. , Teutsch S. M.
Published: February 2025

Toxoplasma gondii was isolated from tissues of 5 of 7 cats and of 4 of 4 field mice trapped in a riding stable in Atlanta where an outbreak of toxoplasmosis had occurred in persons. Dye-test antibodies were not found in serum of 4 cats and 4 field mice shown to be infected with T gondii by mouse inoculation. The pathogenicity and infectivity of the 9 isolates of T gondii from cats and mice were compared in mice with the same characteristics of an isolate from a person who acquired toxoplasmosis in association with the stable. Oocysts of all 10 isolates were more pathogenic than cysts of the same isolates. Epidemiologic implications of isolates from cats and mice are discussed.
Separation and Identification of Equine Leukocyte Populations and Subpopulations
Authors: Dutta S. K. , Bumgardner M. K. , Scott J. C. , Myrup A. C.
Published: February 2025

Various methods of separation and identification of major equine leukocyte populations and subpopulations were used. The purity of T and B lymphocytes separated in Sephadex anti-equine F(ab')2 columns was 87% to 99% and 83% to 97%, respectively. The purity of T lymphocytes separated in nylon-wool columns was 89% to 98%. Preparations of B lymphocytes separated in glass-bead columns were 68% to 79% pure. The presence (or absence) of surface immunoglobulin by immunofluorescence was the most consistent and reliable method for the identification of B or T lymphocytes, respectively. However, the erythrocyte-antibody-complement-rosette method for the identification of B cells and the erythrocyte-rosette method for the identification of T cells were not suitable. Monocytes were separated by the adherence method, and the purity, as identified by the latex particle ingestion procedure, was 70% to 78%. Electron microscopy of monocytes stained by peroxidase activity did not identify these cells. The purity of neutrophils obtained by the Ficoll-Hypaque separation method was 95% to 97%. The merits and usefulness of these methods were discussed.
Effects of Naturally Acquired Mixed Helminth Parasitism in Yearling Dairy Calves
Authors: Smith S. B. , Gibbs H. C.
Published: February 2025

The effects of Strongyle parasitism were studied in yearling calves. One group (4 calves) was a noninfected control, and 2 groups (4 calves each) were infected by exposure on pasture to the same type and degree of parasitism. One of the 2 infected groups were given coumafos at 4-week intervals and the other was not treated. Few significant differences were found between the control and infected groups in hematologic and serum glucose and urea nitrogen values. The control group gained an average of 2.2 kg/week, as compared with 1.0 kg/week for the treated group. The parasitized-untreated group lost 0.2 kg/week. Overall, the control group gained 26.8 kg for the 12-week period, which was significantly different (P < 0.05) from an 11.4-kg gain by the parasitized-treated group and a 2.3 kg loss for the parasitized-untreated group. In the face of constant pasture challenge exposure, most adult worms were eliminated from the drug-treated animals, but the adverse effects of parasitism were not reversed.
Allogeneic Antibody Response in Cattle
Authors: Newman M.J. , Brandon M.R.
Published: February 2025

Antibody responses following immunization with allogeneic bovine lymphocytes, goose red blood cells (grbc), and ovalbumin (given iv) were studied in 20 heifers. Antibody to grbc was detectable by 4 to 9 days in all heifers and followed the characteristic pattern of a low-titer primary response which was predominantly immunoglobulin (Ig) M, whereas a high titer IgG secondary response was observed. The dose of ovalbumin used failed to elicit a detectable antibody response.

An immune response to allogeneic lymphocytes was observed, but it differed from the grbc response. Cytotoxic antibody directed against lymphocytes was detectable by day 14 in 5 of the heifers. Five others responded by days 17 to 24 after secondary immunization. The responses were of low titer and predominantly IgM, after both primary and secondary immunizations. The time of antibody appearance and titers varied between heifers and was not dependent on differences at the major histocompatibility complex (BoLA) between heifers and immunizing lymphocytes. Cytotoxic antibody reacted with both B and T lymphocytes and appeared to recognize the serologically defined BoLA antigens. Noncytotoxic alloantibody was detected in the serum of 1 heifer and appeared to be directed against a subpopulation of lymphocytes, possibly those bearing Ia-like antigens
Pharmacokinetic Analysis of Intravenously and Orally Administered Quinidine in Horses
Authors: McGuirk S. M. , Muir W. W. , Sams R. A.
Published: February 2025

SUMMARY AND CONCLUSIONS

A pharmacokinetic study was made, using 7 healthy adult horses (weighing between 400 and 560 kg) given quinidine gluconate iv and quinidine sulfate orally. The apparent volume of distribution of quinidine base was 3.10 ± 0.79 L/kg, total body clearance was 5.49 ± 2.40 ml/minute/kg, and plasma half-life was 6.65 ± 3.00 hours. The systemic availability of quinidine sulfate after oral administration of a 10 mg/kg dose was 48.5 ± 20.4%. Oral administrations of quinidine sulfate in doses of 10 mg/kg and 10 g produced peak plasma concentrations of 0.79 μg/ml at 146 minutes and 1.47/μg/ml at 131 minutes, respectively. In 4 horses given 4 oral doses of 10 mg of quinidine sulfate/kg, each dose separated by 2 hours, maximal plasma concentrations of quinidine averaged 13% higher than the preceding minimal plasma concentration. The application of these pharmacokinetic determinations to the clinical use of quinidine in the horse is discussed.
Effects of Atmospheric Ammonia on Young Pigs Experimentally Infected with Bordetella bronchiseptica
Authors: Drummond J. G. , Curtis S. E. , Meyer R. C. , Simon J. , Norton H. W.
Published: February 2025

Effects of atmospheric ammonia on performance and respiratory tract health of young pigs experimentally infected with Bordetella bronchiseptica were studied. Treatments were: (1) control, (2) Bordetella inoculation (approx 109 bacteria/naris) alone, (3) Bordetella inoculation plus exposure to atmospheric ammonia at 34.7 mg/m3 (50 ppm), and (4) Bordetella inoculation plus exposure to atmospheric ammonia at 69.4 mg/m3 (100 ppm). Pigs weighted 8.01 kg (av) at start of treatment. Body weight and feed disappearance were measured weekly. After 4 weeks, all pigs were killed and examined grossly, and appropriate specimens were obtained for histopathologic examination. Regression models were fitted to growth, feed disappearance, and gain-to-feed data.

The growth model indicated that Bordetella-inoculated pigs gained 26% less body weight than did controls, regardless of atmospheric ammonia concentration. Bordetella inoculation, regardless of ammonia exposure, reduced feed disappearance 12% below the control rate. Treatment difference was not noted in gain/feed data. Shrunken turbinates were observed in Bordetella-inoculated pigs. Shrinkage also appeared to be related directly to ammonia concentration. Rhinitis was confirmed histopathologically, and its severity was related with atmospheric ammonia concentration, but no difference was seen in the osseous core of the turbinates.
Experimentally Induced Thiamine Deficiency in Beagle Dogs: Clinical Observations
Authors: Read Deryck H. , Harrington Daniel D.
Published: February 2025

Twenty-three 2- to 5-month-old Beagle dogs were fed a purified thiamine-deficient ration (2 to 3 μg of thiamine/100 g of ration) at a rate of 40 to 70 g/kg of body weight/day depending on age. Eleven dogs were used as principals, 6 as pair-fed controls, and 6 as ad libitum-fed controls. Controls were treated once a week with an im dose of 300 μg of thiamine hydrochloride/kg of body weight. Three stages of clinical disease occurred in the principals: (i) an initial short (18.0 ± 7.9 days) stage of induction, during which the dogs usually grew suboptimally, but were otherwise healthy, (ii) an intermediate stage of preliminary clinical signs of deficiency, characterized by a variable period (58.6 ± 37.0 days) of progressive inappetance, failure to grow, loss of body weight, and coprophagia, and (iii) a terminal stage, which, in most dogs, was abrupt in onset and short (7.6 ± 6.0 days) and consisted of either a neurologic syndrome or sudden unexpected death syndrome. Eight of the principals developed the neurologic syndrome characterized by anorexia, emesis, cns depression, paraparesis, sensory ataxia, torticollis, circling, exophthalmos, tonic-clonic convulsions, profound muscular weakness, recumbency, and then died. Common reflex abnormalities included exaggerated patella reflex, proprioceptive and supporting reflex deficits, induced torticollis and ventroflexion of head, and absent eye menace (blink) reflex. Three other principals developed the sudden unexpected death syndrome. Common signs of deficiency were inappetance and paresis. Two were found dead and 1, with severe ecg abnormalities (including elevation of ST segment and tall or deeply inverted T waves), was killed.
Combined Pharmacologic and Surgical Treatments for Acute Spinal Cord Trauma
Authors: Rucker Nolan C. , Lumb William V. , Scott Robert J.
Published: February 2025

Acute spinal cord trauma was induced by the Allen method at T12 in 48 dogs. Six groups of 7 dogs each were treated with combinations of pharmacologic and surgical treatments; a 7th group of 6 dogs remained as traumatized nontreated controls. Results indicate an additive therapeutic effect in those patients treated with myelotomy and dimethyl sulfoxide. Dexamethasone, reserpine, and perfusion with hypertonic dextrose solution were of no benefit.
Efficacy of Fenbendazole Against Five Genera of Swine Parasites
Authors: Stewart T. B. , Marti O. G. , Hale O. M.
Published: February 2025

Thirty-three pigs were sequentially infected with Oesophagostomum spp, Metastrongylus spp, and Trichuris suis while being maintained in lots contaminated with Ascaris suum, Strongyloides ransomi, and other parasites. Pigs were assigned to 1 of 3 groups on the basis of weight (6.8 to 25.9 kg), sex, and litter. Pigs in the 1st group were used as nontreated controls; pigs in the 2nd and 3rd groups were given fenbendazole in the feed at doses of 3 and 5 mg/kg of body weight, respectively, on 3 successive days. Pigs were necropsied either on the 4th or 5th day after completion of treatment, and worms were recovered and counted. Based on the mean numbers of worms in the control group, drug efficacies at 3 and 5 mg/kg were, respectively, 100% against A suum; 59% and 81% against S ransomi; 97% and 99.9% against Metastrongylus spp; 94% and 99.7% against T suis; and 99.9% against Oesophagostomum spp.
Effects of Aflatoxin Consumption on the Clinical Course of Swine Dysentery
Authors: Joens L. A. , Pier A. C. , Cutlip R. C.
Published: February 2025

Specific-pathogen-free pigs were examined for susceptibility to swine dysentery after daily treatment with aflatoxin B1 (0.07 to 0.14 mg/kg). In the pigs (group II) given both aflatoxin and Treponema hyodysenteriae, the incubation period before the onset of swine dysentery was shorter than that in pigs (group III) given T hyodysenteriae alone. Also, the number of days in which infected pigs showed signs of diarrhea and dysentery was greater in the group given aflatoxin and T hyodysenteriae than in the group given T hyodysenteriae alone. Four of 8 pigs given aflatoxin and T hyodysenteriae died during the experiment, whereas only 1 of 8 infected pigs in the other group died.

Pigs in both groups, convalescent from swine dysentery, were immune to rechallenge exposure. Subclinical effects of aflatoxin consumption were evident at necropsy, but clinical signs and lesions of swine dysentery were not observed in group III pigs (given aflatoxin only).
Spontaneous Cardiomyopathy: Histopathologic and Ultrastructural Alterations of Turkey Heart Tissue
Authors: Gough Alec W. , Pinn Stephen , Hulland Thomas J. , Thomson Reginald G. , de la Iglesia Felix
Published: February 2025

Twelve turkey poults, 4 to 5 weeks of age, were selected from a farm chosen for the study of spontaneous cardiomyopathy (sc) because of repeated outbreaks in successive flocks. An augmented myocardial mass accompanied the characteristic gross features of cardiomegaly and biventricular dilatation in sc-affected birds. Histologic alterations in myocardium were attributed to artifacts, resulting from unopposed cardiac muscle contraction prior to formalin fixation; specific pathologic lesions were not detected. Ultrastructural artifacts were minimized by perfusion fixation. Salient ultrastructural changes were mild when compared with the changes in the myocardium of nonaffected poults and consisted mainly of Z-band abnormalities. Virus-like particles were identified within sarcoplasmic reticulum of 2 sc-affected birds. The pathogenesis of sc, including acquired and inherited etiologic factors, is discussed.
Sequential Morphologic and Clinicopathologic Alterations in Dogs with Experimentally Induced Glucocorticoid Hepatopathy
Authors: Badylak Stephen F. , Van Vleet John F.
Published: February 2025

Glucocorticoid hepatopathy was induced in 6 Beagle dogs by daily im injections of prednisone (4.4 mg/kg) for 14 consecutive days. Sequential blood samples and percutaneous hepatic biopsy tissues were obtained during this 14 day period and for an additional 42 days. Serum alkaline phosphatase activity was significantly increased by day 2, reached maximum (64-fold increase) by day 20, and decreased gradually to 8-fold above the base-line value by day 56; alanine aminotransferase activity was significantly increased by day 3, reached maximum (10-fold increase) by day 12, and gradually decreased to 3-fold above the base-line value on day 56; and γ-glutamyl transpeptidase activity was significantly increased by day 6, reached maximum (23-fold increase) by day 29, and slowly decreased to 7-fold above the base-line value by the end of the study. Serum leucine aminopeptidase activity and sulfobromophthalein retention remained within the reference interval (for 30 healthy dogs) throughout the study. Serum glucocorticoid concentration reached maximum by day 2 in the treated dogs and slowly decreased throughout the study.

Histopathologic evaluation revealed that vacuolar change in hepatocytes was present by day 2, progressed to maximum severity between days 5 and 14, and gradually decreased in severity, but remained present throughout the study. The hepatocellular vacuolation changed from a diffuse distribution to centrilobular as the study progressed. Glycogen content of hepatocytes steadily increased during the period of prednisone administration, reached maximum amount on day 15, and slowly decreased, but was still increased at the end of the study. The distribution of glycogen accumulation progressed from diffuse to periportal during the study.

Clinical signs of Cushing's syndrome developed by day 7 and included decreased hair growth, polyphagia, polydipsia, polyuria, mild lethargy, and semisolid feces. Necropsies on day 56 revealed slightly swollen, pale, and friable liver in 2 of 5 treated dogs (1 dog had died on day 14) and catarrhal enteritis in the 6 treated dogs. Atrophy of the adrenal gland zona fasciculata was observed microscopically in treated dogs. Gross and microscopic alterations were absent in other organs.

This study demonstrates the rapid appearance and prolonged persistence of clinical, morphologic, and clinicopathologic alterations in dogs with experimentally induced glucocorticoid hepatopathy. The findings will be useful in the diagnosis and prognosis of naturally occurring glucocorticoid hepatopathy and chemotherapeutic hepatopathy.
Development and Characterization of Feline Ovarian Antiserum
Authors: Chan S. Y. W. , Wildt D. E. , Chakraborty P. K.
Published: February 2025

Studies were conducted to determine the feasibility of producing feline ovarian antiserum (foa) in the rabbit and to characterize the antigenic composition of the feline ovary. Adult male rabbits were immunized by injecting an ovarian homogenate prepared from feline ovaries that had corpora lutea (cl) macroscopically removed. Using the agar-gel double diffusion (agdd) and the immunoelectrophoretic (ie) techniques, 5 feline ovarian antigens were detected when feline ovarian extract was reacted with purified foa (γ-globulin fraction solution; protein content 24 mg/ml). The foa reacted with 4 other feline reproductive organs tested, including the follicle, cl, oviduct, and uterus, to form 5 precipitin bands. The purified foa also cross-reacted with feline serum and plasma and 10 other feline nonreproductive organ extracts tested to give 2 to 5 precipitin bands. Species cross-reactivity was also observed with foa reacting with the rat ovary and the canine ovary, cl, and uterus, to form 1 to 2 precipitin bands. Immunoabsorption of the purified foa by feline liver, kidney, or small intestine extract removed antibodies reacting with feline ovarian antigens. Precipitin bands failed to develop when such absorbed foa were tested against the feline ovarian extract. Within the sensitivity limits of the agdd and ie tests, organ-specific antigens of the feline ovary could not be detected. Feline ovarian antigens were located in isolated feline ovarian cells by the immunofluorescence technique.

Fertility-regulating effects of the developed foa were studied. One female cat given foa during late gestation [gestation day (gd) 49 to 51] aborted 1 dead premature fetus on day 52 and delivered 3 live offspring on gd 64. Another queen was given foa during midgestation (gd 36 to 40) and apparently resorbed 1 of 2 conceptuses. The foa produced in the rabbit was not organ and species specific and may cause abortion or influence fetal development in the pregnant cats.
Brain Cholinesterase Activity in Healthy Cattle, Swine, and Sheep and in Cattle and Sheep Exposed to Cholinesterase-Inhibiting Insecticides
Authors: Mount Michael E. , Oehme Frederick W.
Published: February 2025

Cholinesterase activity of the cerebrum, brain stem, and cerebellum was measured in cattle, swine, and sheep. Mean activities of the individual brain parts were expressed as micromoles of acetylthiocholine iodide hydrolyzed per minute per gram of brain. Cerebrum values were 3.01, 3.88, and 3.32; brain stem values were 3.42, 4.48, and 3.93; and cerebellum values were 2.36, 2.89, and 6.77 for cattle, swine, and sheep, respectively. The average activity of the 3 brain portions from cattle, swine, and sheep was 2.93, 3.75, and 4.67, respectively. Cholinesterase activity was stable for several days at 25 C and under refrigeration or freezing conditions for longer periods. Cattle and sheep poisoned with organophosphate or carbamate insecticides had cholinesterase depression ranging from near 50% to 80%,
Total and Differential Somatic Cell Counts in Secretions from Noninfected Bovine Mammary Glands: The Early Nonlactating Period
Authors: McDonald J. S. , Anderson A. J.
Published: February 2025

Total somatic cells in secretions of nonlactating bovine mammary glands remained < 5 × 105 cells/ml for the first 3 days after the last milking. Macrophages predominated the 1st day, and polymorphonuclear neutrophils were most common during the 2nd and 3rd day.

The total somatic cell count was highest about 10 days after lactation ceased, and counts of 2 to 3 × 106 cells/ml were common. Equal numbers of macrophages and polymorphonuclear neutrophils were observed. Total cell populations gradually decreased during the period from 10 to 25 days of the nonlactating period.
Evidence for Suppression or Incomplete Maturation of Cell-Mediated Immunity in Neonatal Calves as Determined by Delayed-Type Hypersensitivity Responses
Authors: Rossi C. R. , Kiesel G. K. , Hudson R. S. , Powe T. A. , Fisher L. F.
Published: February 2025

Fifteen bovine fetuses were inoculated in utero 20 to 123 days before birth with a mixture of killed Mycobacterium bovis, tetanus toxoid, and ferritin in Freund's complete adjuvant. On the day of birth (day 0) and when the calves were 21 days of age, the calves were skin-tested to each of the antigens for delayed-type hypersensitivity. Nine delayed-type hypersensitivity responses to the various antigens were obtained at the 0-day test, whereas 28 responses were obtained at the 21-day test. Of those responses that were positive, the mean differences in the double skin-fold thickness before testing and 48 hours later were 5.4 mm for the 0-day and 21-day test and 9.4 mm for the 21-day test. Six control calves that were not inoculated in utero were skin tested on days 0 and 21 and did not exhibit any positive reactions. There was no indication that the interval between immunization and birth had any effect on the immune response. Cellular characteristics of the reactions at 0 and 21 days were the same.
Effects of (DTrp6-Des Gly10-ProNH29)-Luteinizing Hormone-Releasing Hormone Ethylamide on the Estrous Cycle, Weight Gain, and Feed Efficiency in Feedlot Heifers
Authors: Herschler R. C. , Vickery B. H.
Published: February 2025

Subcutaneous implantation of pelleted (DTrp6-Des Gly10-ProNH29)-luteinizing hormone-releasing hormonea in 3 heifers (at a total dose of approx 5 μg/0.45 kg of body weight) shortly after ovulation did not affect the ongoing luteal phase, but prevented the next expected estrus and ovulation. The effect was reversible and estrus was reestablished 16 and 19 days after pellet removal. The subsequent luteal phase concentrations of plasma progesterone appeared to be below normal concentrations. In a 2nd study, 25 heifers were implanted subcutaneously twice, 56 days apart, at random stages of the cycle. The mean number of estrous episodes over the 112 days of observation was decreased from 5.56 in controls (n = 25) to 1.12 in treated (n = 25) heifers. This suppression of estrus was not associated with change in live weight gain or food intake.
Diagnosis of Eastern Equine Encephalomyelitis by Immunofluorescent Staining of Brain Tissue
Authors: Monath T. P. , McLean R. G. , Cropp C. B. , Parham G. L. , Lazuick J. S. , Calisher C. H.
Published: February 2025

Brain tissues were obtained from 5 horses with clinical encephalomyelitis during an epizootic in southwestern Michigan in August-September 1980. These tissues were tested for virus by intracerebral inoculation of suckling mice and by examination of frozen sections and impression smears by the indirect fluorescent antibody (fa) technique. Eastern equine encephalomyelitis virus was isolated and detected by fa technique in brains of 3 horses which died or were euthanatized within approximately 24 hours of onset of the disease but not from 2 horses at 2 and 3 days after onset. The latter 2 animals had serum-neutralizing antibodies at the time of death. Seven areas of the brain of 1 horse were tested. The proportion of fluorescing cells in frozen sections correlated with infectivity titers. Impression smears were negative. Viral titers ranged from 105.7 to 1010.0 suckling mouse intracerebral median lethal doses/g; highest titers and most intense fluorescence were present in the thalamus and pons, emphasizing the need to obtain selective samples of central brain structures for diagnostic examination. The fa technique appears useful for the rapid diagnosis of fatal eastern equine encephalomyelitis and may be applicable in laboratories not equipped for isolation of viruses.
Gross and Microscopic Lesions of Middle and Inner Ear Infections in Swine
Authors: Olson L. D.
Published: February 2025

In all infected middle ears from 36 swine, there was purulent material in the tympanic cavity and tympanic bulla. Frequently, there were lysis of the tympanic membrane and ossicles and purulent material in the external ear canal. Sometimes, there were desquamation of the stratified squamous epithelium lining the tympanic cavity, and osteolysis of the underlying osseous wall with subsequent fibrosis. In those swine with inner ear infections, there were infiltration of neutrophils and fibrin in the cochlea and vestibule. The predominant isolation from the infected middle ears was non-groupable β-hemolytic streptococci, although isolations of streptococcic groups C, E, and G, Pasteurella multocida, and Corynebacterium pyogenes were made.
Computer-Based Animal Record System in a Nonhuman Primate Colony
Authors: Beland M. F. , Bronson R. T. , Peacock W. C.
Published: February 2025

A relatively inexpensive microcomputer system was developed to store and manipulate clinical and pathologic data from a large colony of nonhuman primates. The programming for the system was designed so that the computer instructs users, who may have no knowledge of programming, how to enter data of all kinds and how to command it to answer any ad hoc queries about the data. Minimum input from a professional programmer is required. As many as 4 investigators may use the system simultaneously by means of satellite terminals located in several areas throughout the facility. Most alphabetic data are coded, using 2- or 3-digit codes. More complex diagnostic data are coded, using the numeric codes of the Systematized Nomenclature of Medicine. Presently, 17 record types encompass all data entered into the computer. The system is functionally designed and about 50% operational at this time. This is the first description of an animal medical data system designed to exploit the lower costs and increased power of commercially available microcomputer packages.
Effect of Colostral Antibody on Bovine Leukemia Virus Infection of Neonatal Calves
Authors: Van Der Maaten M. J. , Miller J. M. , Schmerr M. J. F.
Published: February 2025

Pairs of newborn calves were exposed to bovine leukemia virus (blv) when they were given their 1st colostrum feeding. Calves that were given 106 blv-infected lymphocytes in colostrum free of blv-specific antibody became infected. Calves that were fed 107, 108, or 109 infected lymphocytes in colostrum that contained blv-specific antibody did not become infected. One of 2 calves inoculated intradermally with 250,000 infected lymphocytes was protected by colostral antibody, but the other was not. Colostral antibody titers in the unprotected calf decreased normally until the calf was 4 months old and then increased markedly; this pattern indicates that the presence of colostral antibody may have prolonged the latent period of the blv infection.
Regional Blood Flow to the Stomach and Small Intestine in Swine
Authors: Zamora C. S. , Reddy V. K.
Published: February 2025

The radioactive microsphere technique was used to measure regional blood flow to the stomach and small intestine of pigs weighing 20 to 37 kg. Mean regional blood flow (ml/min/100 g of tissue) was least in the nonglandular region, followed in an increasing order by the pyloric gland, cardiac gland, and proper gastric (fundic) gland regions. The region of the proper gastric glands accounted for 47.5% of the total gastric blood flow, with 24.9%, 23.8%, and 3.7% of the total flow going to the cardiac gland, pyloric gland, and nonglandular regions, respectively. Although there appeared to be a blood flow gradient in the small intestine, no significant difference in blood flow between the duodenum, jejunum, and ileum was observed. Mean blood flow to the small intestine was significantly greater than that to the stomach.
Rabies Virus Titer from Tissues of Naturally Infected Skunks (Mephitis mephitis)
Authors: Howard D. R.
Published: February 2025

Rabies virus was titrated from the hippocampus and salivary glands (mandibular, parotid, and sublingual) of 19 naturally infected skunks.

Selection of the skunks was based on a positive fluorescent antibody test (fat) on the hippocampus. One fat- and virus isolation-negative skunk served as a control.

The fat was positive on 19 mandibular salivary glands, 16 parotid glands, and 17 sublingual glands. Rabies virus was subsequently isolated in albino Swiss mice from all (ie, 19) hippocampi and mandibular salivary glands, 16 parotid glands, and 17 sublingual glands. Virus was not isolated from the fat-negative tissues.

Titers (mouse intracerebral ld50/0.03 ml) were calculated in all fat-positive tissues by the Reed-Muench method. Rabies titers from hippocampi ranged from 10−0.7 to 10−4.5; from mandibular salivary glands, 10−2.8 to 10−7.2; from parotid glands, 10−0.5 to 10−5.8; and from sublingual glands, 10−0.3 to 10−3.8.

Results indicate that “rabies-virus inhibiting substance” did not interfere with fat or virus isolation from tissues of naturally infected skunks.
Age at Death of Necropsied Intact and Neutered Cats
Authors: Bronson Roderick T.
Published: February 2025

Mean ages at death of 344 male and of 186 female cats necropsied in a veterinary hospital were 2.9 and 3 years, respectively. Exponential curves fit the histograms of age at death for male and female cats with great precision. For 252 castrated males and 245 spayed females, mean ages at death were 6.3 and 8.2 years, respectively. Chi-square analysis of the proportion of cats of each sex status dying in each of 4 age groups from each of 6 disease categories failed to show that natural diseases accounted for the great differences in age at death between intact and neutered cats.
Effect of Vitamin E Deficiency on the Proliferative Response of Canine Lymphocytes
Authors: Langweiler Marc , Schultz Ronald D. , Sheffy Ben E.
Published: February 2025

The effect of vitamin E deficiency on the proliferative response of canine lymphocytes was examined, using the lymphocyte blastogenesis assay, with phytohemagglutinin, concanavalin A, and pokeweed as mitogenic stimulants. A litter (4 pups; group 3) from a bitch fed a complete diet was given a complete diet from the time of weaning (6 weeks) until termination of the experiment, and served as a control group. A litter (4 pups; group 1) from a bitch fed a vitamin E-defident diet was given a vitamin E-deficient diet from the time of weaning (6 weeks) until termination of the experiment. A litter (6 pups; group 2) from a bitch fed a complete diet was weaned onto a complete diet and then changed to a deficient diet until termination of the experiment. Lymphocytes from group 1 and 2 pups (fed deficient diets) were poorly responsive to mitogen-induced blastogenesis, compared with the lymphocytic responses seen in the controls. Washing the lymphocytes from pups fed the vitamin E-defident diet resulted in enhanced responsiveness to mitogen stimulation. Lymphocytes from controls which had good responses when cultured in bovine fetal serum or normal canine serum were poorly responsive when cultured in serum from groups 1 and 2 pups (fed vitamin E-deficient diet). Reducing the concentration of group 1 and 2 pup sera in the culture medium restored the responsiveness of lymphocytes from control pups. Supplementation of group 1 and 2 pup sera with bovine fetal serum did not result in enhancement of the responses of lymphocytes from controls. The capability of sera from vitamin E-deficient pups (groups 1 and 2) to support blastogenesis of lymphocytes from control dogs was restored following dietary supplementation with vitamin E. It was concluded that the depressed lymphocyte responsiveness in pups fed the vitamin E-deficient diet was due to the presence of a suppressive factor in the serum.
Failure of Ribosomes from Nonencapsulated Pasteurella multocida To Protect CF-1 Mice
Authors: Phillips Marshall , Rimler Richard B. , Rebers Paul A.
Published: February 2025

Monomeric ribosomes (70S) were isolated from nonencapsulated Pasteurella multocida strain X-73 by mechanical disruption and by chemical lysis. Contamination of the initial preparations by lipopolysaccharide (lps) was evident by gel immunodiffusion. Gel filtration chromatography of the 70S ribosomes resulted in ribosomes with lps contamination below the concentration that was detected by gel immunodiffusion, but chickens vaccinated with these preparations responded serologically to lps by producing a detectable titer of passive hemagglutination antibody. Washing the 70S ribosomes through 0.5 M NH4Cl and 30% sucrose rendered them virtually free of contamination by lps as evidenced by lack of passive hemagglutination titer.

Ribosomes were evaluated as protective immunogens in CF-1 mice. Two inoculations (14 days apart) at each dosage level of 0.4, 4.0, 40.0, and 400 μg/mouse were given. At 21 days after vaccination, the mice were challenge exposed with encapsulated P multocida X-73 cells. None of the ribosomal preparations (crude or purified) protected against challenge exposure. Killed whole nonencapsulated cells did protect against challenge exposure. In contrast to numerous reports on the effectiveness of ribosomes as protective immunogens, ribosomes from nonencapsulated P multocida cells were not protective immunogens in mice challenge exposed with encapsulated cells under these conditions.
Kanamycin Sulfate in the Horse: Serum, Synovial Fluid, Peritoneal Fluid, and Urine Concentrations After Single-Dose Intramuscular Administration
Authors: Brown Murray P. , Stover Susan M. , Kelly Robin H. , Farver Thomas B.
Published: February 2025

Six healthy adult mares were given a single dose of kanamycin sulfate (200 mg/ml) im at a dosage rate of 5 mg/kg of body weight. Kanamycin concentrations in serum, synovial fluid, peritoneal fluid, and urine were measured serially over a 48-hour period. The mean peak serum kanamycin concentration was 12.55 μg/ml at 1 hour. Mean peak kanamycin concentrations in synovial fluid and peritoneal fluid were 7.25 μg/ml and 9.27 μg/ml at 2 hours and 3 hours, respectively. These concentrations decreased steadily in parallel with serum concentrations and were still measurable at 48 hours. Urine concentrations of kanamycin were relatively high, with a mean peak concentration of 80.51 μg/ml at 1 hour.
Immunogenicity of Capsular Antigens of Pasteurella multocida in Turkeys
Authors: Kodama H. , Matsumoto M. , Snow Laura M.
Published: February 2025

Capsular antigens were isolated from Pasteurella multocida, strain P-1059 and their immunogenicity was tested in turkeys. The crude capsular antigen (cca) was extracted from bacterial cells grown on membranes by heating at 56 C in a 2.5% NaCl solution. The purified polysaccharide antigen (ppa) was obtained by precipitation of cca by cetylpyridinium chloride. Young adult turkeys were inoculated at 0 and 14 days and were challenge exposed at 28 days by im inoculation of a live culture of P-1059. The turkeys were observed for 2 weeks and mortality was recorded; bacterial isolation was done at the time of necropsy.

In 3 trials, cca provided 80% to 100% protection; in 1 trial, ppa failed to provide protection. Freund’s incomplete adjuvant and aluminum hydroxide gel were effective as potentiating agents when higher than 280 μg of cca was used. The cca showed significant (P < 0.05) protection after treatment with heat (100 C, 5 min), chloroform, or trypsin, but lost its immunogenicity completely by acid hydrolysis. The cca was not toxic to mice at 2 mg. The Limulus lysate test showed that cca contained endotoxin in ≤ 5% of the total solids. These results indicate that the surface antigen isolated from P multocida by saline extraction was immunogenic in young adult turkeys.
Lymphocytic Thyroiditis in Dogs: Induction with a Local Graft-Versus-Host Reaction
Authors: Gosselin S. J. , Capen C. C. , Krakowka S. , Martin S. L.
Published: February 2025

Fifty million allogeneic canine lymphocytes were injected in the left lobe of the thyroid gland of 10 dogs. The left lobe of the gland was surgically removed at 1 and 4 weeks after injection. The intrathyroidal injection of immunocompetent cells resulted in local graft vs host reaction within the thyroid gland. Multifocal infiltration of lymphocytes, plasma cells, and macrophages associated with scattered, isolated, or small groups of degenerated follicular cells were present in the follicular wall and colloid on day 7. Thyroidal lesions at 1 month after injection were characterized by extensive destruction of follicular cells, disseminated foci of mononuclear cell infiltration, and electron-dense deposits between follicular cells and the basement membrane. The contralateral (noninjected) lobe of the thyroid gland at 4 weeks after injection was infiltrated by lymphocytes, macrophages, and many plasma cells. The inflammatory lesions were associated with multifocal areas of degeneration of follicular cells and focal electron-dense thickenings of the basement membrane. The noninjected lobe, following hemithyroidectomy at 1 week after injection of the thyroid gland undergoing graft-vs-host reaction, either had a focal infiltration of polymorphonuclear leukocytes, lymphocytes, macrophages, and mast cells or had no significant lesions.
Interaction of Pasteurella haemolytica with Bovine Neutrophils; Identification and Partial Characterization of a Cytotoxin
Authors: Baluyut C. S. , Simonson R. R. , Bemrick W. J. , Maheswaran S. K.
Published: February 2025

Timed cultures of Pasteurella haemolytica 12296 strain in RPMI 1640 medium (with l-glutamine, pH 7.4) were used to determine the correlation between cytotoxin production and the age of the culture. Cytotoxic activity was measured by a 51Cr-release assay and trypan blue exclusion test with bovine neutrophils as target cells. Results demonstrated that optimal cytotoxin production occurred during the logarithmic phase (peaked at 6 hours) and decreased during the stationary phase of bacterial growth. The cytotoxin was concentrated by sequential ultrafiltration on Diallo XM 50, XM 100, and XM 300 membranes. The cytotoxin was retained on an XM 300 membrane. These studies indicated that the molecular weight of cytotoxic substance was 300,000 or more. The cytotoxin was heat labile, oxygen stable, and susceptible to extremes of pH and killed bovine neutrophils and mononuclear leukocytes. It was not hemolytic to bovine or ovine rbc. The cytotoxic activity was inactivated by trypsin and did not contain any detectable endotoxin. Bovine fetal serum and serum collected before immunization from neonatal calves did not neutralize the cytotoxic effects of toxin on neutrophils. However, adult bovine serum from 6 cows and an antiserum (against the cytotoxin) neutralized the cytotoxin, as revealed by both the 5lCr-release assay and the trypan blue exclusion test. This was confirmed by transmission electron microscopy. These results indicated that the cytotoxin may be antigenic in cattle. The significance and implications of these findings to bovine pasteurellosis are discussed.
Oxygen Consumption Changes in the Septic Pony
Authors: Sembrat Roger , DiStazio John , Maley Warren , Stremple John
Published: February 2025

Oxygen consumption was studied in 5 awake septic ponies after iv injection of live Escherichia coli. Cardiac output, rectal temperature, pcv, heart rate, arterial and pulmonary arterial blood gas, pH, and hemoglobin (Hb) determinations were performed before (base line) and after injection of E coli.

After injection of E coli, the cardiac index decreased from a base line mean of 4.45 ± 0.15 L/min/m2 to 2.83 ± 0.21 L/min/m2 (P < 0.05). Mean arterial oxygen content increased from a base line mean of 15.19 ± 0.67 ml of O2/dl of blood to 20.73 ± 0.07 ml of O2/dl (P < 0.05). Mean mixed venous content increased from a mean base-line value of 10.65 ± 0.74 ml of O2/dl to 16.65 ± 1.14 ml of O2/dl at postinfusion hour (pih) 1 (P < 0.05). There were no significant changes in the difference between mean arterial and mean mixed venous oxygen content.

Arterial pcv increased from a mean base line of 28.91 ± 0.31% to 39.44 ± 0.54% (P < 0.05). Although pcv was increased, there were no significant changes in total protein until pih 5. Arterial Hb increased from a base-line mean of 11.18 ± 1.71 g/dl to 14.73 ± 1.0 g/dl (P < 0.05).

Oxygen delivery index was maintained near a base-line mean of 587.2 ± 29.0 ml of O2/min/m2. Significant decreases in oxygen delivery were seen only at pih 5.

Oxygen consumption index decreased from a mean base-line value of 181.7 ± 2.8 ml of O2/min/m2 to mean value of 122.8 ± 7.8 ml of O2/min/m2 at pih 2 (P < 0.05). Significant decreases were also seen in the oxygen diffusion capacity to 2.42 ± 0.49 ml of O2/min/m2/mm of Hg from a base-line mean of 5.05 ± 0.49 ml of O2/min/m2/mm of Hg.

The septic pony develops pronounced changes in total body oxygen consumption. Although cardiac depression was severe, oxygen delivery was maintained due to an increased arterial Hb concentration. The oxygen consumption decreased as oxygen diffusion capacity decreased. Early decreases in oxygen consumption may have been due to the decreased area for oxygen diffusion that resulted from an increased peripheral resistance, whereas later decreases in oxygen consumption may have been due to increased amounts of interstitial fluid.
Efficacy of Ivermectin Against Cutaneous Draschia and Habronema Infection (Summer Sores) in Horses
Authors: Herd R. P. , Donham J. C.
Published: February 2025

Thirty-one horses with naturally occurring summer sores were given a single im injection of 0.2 mg of ivermectin (22,23-dihydroavermectin B1)/kg during the summer of 1980. Larvae of Draschia and/or Habronema spp were recovered from biopsy samples taken from 21 of 25 horses (84%) on the day of anthelmintic treatment.

There was a marked clinical improvement in 26 horses (84%) 7 days after ivermectin was given. The typical summer sore was replaced by healthy pink granulation tissue at 7 days and this healed after 1 to 5 weeks. Biopsy samples were taken from 21 of these horses 1 to 6 weeks after treatment, and the samples in 18 horses (86%) were negative for larvae. Five of the 31 infected horses did not respond to a single dose and appeared to have become reinfected. Biopsy samples taken from 3 of these horses were positive for larvae 2 to 4 weeks after the 1st dose, but became negative and healed 1 to 2 weeks after a 2nd dose with ivermectin.

Histopathologic examination of sections from lesions before anthelmintic treatment showed granulation tissue with marked eosinophilic infiltration, multiple eosinophilic abscesses, and transverse sections of nematodes. In sections examined after anthelmintic treatment, there were marked reduction in the number of eosinophils and absence of eosinophilic abscesses or nematodes, and the granulation tissue was more mature, as indicated by the appearance of dense fibrous connective tissue.
Glutaraldehyde-Treated Carrier Erythrocytes for Organ Targeting of Methotrexate in Dogs
Authors: DeLoach John R. , Barton Claudia
Published: February 2025

Chemotherapeutic doses of methotrexate (mtx) were encapsulated in as little as 1 ml of canine carrier erythrocytes. Carrier erythrocytes prepared by a dialysis technique contained more than 3.0 mg of mtx/ml of cells. In vivo pharmacokinetic studies indicated that most of the drug leaked from the circulating mtx-loaded erythrocytes. In dogs, glutaraldehyde treatment of mtx-loaded erythrocytes prevented drug leakage and targeted more than 50% of the drug to the liver.
Quantitative Determination of Serum Origin Cerebrospinal Fluid Proteins in the Dog
Authors: Krakowka Steven , Fenner William , Miele James A.
Published: February 2025

Concentrations (in mg/dl) of serum proteins (albumin, immunoglobulin (Ig) G, IgM, IgA, and 3rd component of complement) were determined by rocket immunoelectrophoresis in csf of 41 dogs (37 healthy; 4 with disease). Albumin (9.3 to 15 mg/ dl) and IgG (1.16 to 1.77 mg/dl) were present in all samples tested. The IgM, IgA, and 3rd component of complement were detected in several dogs with clinically inapparent inflammatory disease of the brain.