bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathogenesis of Rotaviral Enteritis in Gnotobiotic Pigs: A Microscopic Study
Authors: McAdaragh J. P. , Bergeland Μ. E. , Meyer R. C. , Johnshoy Μ. W. , Stotz I. J. , Benfield D. A. , Hammer R.
Published: February 2025

The pathogenesis of rotavirus (rv) infection was studied in gnotobiotic pigs orally inoculated with a field isolate of porcine rotavirus. Virus-intestinal cell interactions were examined by fluorescent antibody technique, light microscopy, and scanning and transmission electron microscopy. Clinical signs of diarrhea were observed in inoculated pigs at postinoculation hours (pih) 12 through 96. Examination of negative-stained fecal preparations revealed large numbers of coreless rotaviral particles in fecal material collected at pih 24 to 72, whereas nearly 100% of the virus particles were complete in fecal samples collected at pih 96. Specific fluorescence was observed in the cytoplasm of a few villous absorptive cells in the duodenum and upper portion of the jejunum (uj) at pih 12 with the most intense fluorescence at pih 24 to 96 in the absorptive cells of villi in the uj through the midportion of the small intestine. Virus replication resulted in desquamation of villous absorptive cells in the lower portion of the jejunum (lj) through the upper portion of the ileum (ui) beginning at pih 24. In the uj through the ui, the loss of villous absorptive cells resulted in a progressively shortened villi beginning at pih 24 and was most severe in inoculated pigs killed at pih 72 to 84. Crypt hyperplasia was observed in the uj through the ui at pih 60 to 96, resulting in replacement of villous absorptive cells, as evidenced by an increase in cuboidal villous epithelial cells present at pih 72 to 96 and an apparent increase in the length of villi at pih 96.

Segments of the small intestine examined by scanning electron microscopy revealed villous fusion, rounded absorptive cells, villous atrophy, and exposure of the lamina propria especially in the lj through the ui. Thin sections of the small intestine examined by transmission electron microscopy revealed rv particles in the absorptive cells of the midportion of the small intestine and duodenum through the ui at pih 12 and 24, respectively. Cytoplasmic lysis of absorptive epithelial cells was evident at pih 36, and viral particles were observed in the lumen near microvilli. Rotavirus-induced changes in the small intestine of gnotobiotic pigs were characteristic of those described for natural rv infection.
Effect of Cholecystokinin, Secretin, Glucagon, and Insulin on Gastric Emptying and Acid Secretion in the Calf
Authors: McLeay L. Μ. , Bell F. R.
Published: February 2025

The effect of iv infusion of secretin, cholecystokinin (cck), glucagon, and insulin on the gastric electromyogram (emg), gastric emptying, and gastric acid secretion during a saline test meal was studied in milk-fed calves. Secretin (1 U/kg of body weight/hr) and glucagon (5 μg/kg/hr) reduced the incidence of antral action potentials, slowed gastric emptying, and reduced gastric acid secretion. The cck (0.5 to 4 U/kg/hr) reduced the incidence of (at lower doses) and abolished (at higher doses) antral action potentials, inhibited gastric emptying, but increased gastric acid secretion. Insulin (1 U/kg/hr) at first reduced gastric emg activity in abomasal body and antrum, and diminished gastric emptying and acid secretion; however, greater secondary excitatory effects on the emg and marked emptying developed 30 to 35 minutes later and were attributed to hypoglycemic vagal excitation. In the calf, secretin and glucagon are inhibitory to gastric function, but cck, although it is inhibitory to gastric emptying, is an agonist to gastric acid secretion.
Bovine Mammary Gland Macrophage: Isolation, Morphologic Features, and Cytophilic Immunoglobulins
Authors: Desiderio J. V. , Campbell S. G.
Published: February 2025

Macrophages can be obtained easily and in large numbers from the involuted mammary gland of the cow without the use of stimulating agents. Daily injection of sterile isotonic saline solution into 1 quarter of the udder resulted in a gradual change of the resident cell population. After approximately 1 week, the macrophage was the predominant cell type present.

Upon initial harvesting, macrophages were round with a cell diameter of 30 to 40 μm. Through adherence to glass and subsequent washings, monolayers were obtained consisting of 95% to 99% macrophages. By 24 hours of culture in vitro, macrophages underwent a substantial change in general morphologic features, involving the reorganization of intercellular structures and the development of cytoplasmic processes.

Bovine immunoglobulins (Ig) of the IgG1 and IgG2 subclasses were both shown to be cytophilic for bovine mammary gland macrophages in vitro, although IgG2 was considerably more so.
Bovine Mammary Gland Macrophage: Effects of Colostral Components on Phagocytosis
Authors: Desiderio J. V. , Campbell S. G.
Published: February 2025

The interaction of bovine mammary gland macrophages with components of bovine colostrum was shown to have considerable influence on phagocytosis of Escherichia coli 078K80. Colostrum appeared to contain specific and nonspecific factors which affect the macrophage, as well as the target bacteria.
Neutrophil Leukocyte as a Source of Lactoferrin in Bovine Milk
Authors: Harmon R. J. , Newbould F. H. S.
Published: February 2025

The lactoferrin (lf) concentration of bovine blood and milk neutrophilic polymorphonuclear leukocytes (pmn) was determined and an estimate made of the pmn contribution to the elevated lf concentrations in milk during inflammation of the mammary gland. The mean blood and milk pmn concentrations of lf were 8.63 and 2.98 μg/106 pmn, respectively. It was suggested that this difference may be due to the phagocytosis of fat and degranulation by milk pmn, causing lf release. The results of immunoperoxidase staining of blood leukocytes indicated that lf was found only in pmn as no lf was detectable in bovine eosinophils, lymphocytes, or monocytes. Staining for lf appeared to be limited to the cytoplasm.

Increases in lf values in milk during endotoxin-induced mammary gland inflammation were preceded by increased somatic cell counts (94% pmn). It was estimated that an average of 4.9% of the peak lf levels in whey could have come from the pmn, suggesting this cell is not the major source of lf in milk during mastitis.
Experimental Infectious Bovine Keratoconjunctivitis: Effects of Feeding Colostrum from Vaccinated Cows on Development of Pinkeye in Calves
Authors: Pugh G. W. , McDonald T. J. , Kopecky K. E. , Beall C. W.
Published: February 2025

A study of infectious bovine keratoconjunctivitis (ibk) was done to determine whether calves fed colostrum from vaccinated (prepartum) cows would have increased resistance to ibk after challenge exposure with a virulent homologous culture of Moraxella bovis. Neonatal calves were allotted to 4 groups: group I—nonvaccinated and fed colostrom from nonvaccinated cows; group II—vaccinated and fed colostrum from nonvaccinated cows; group III—not vaccinated and fed colostrum from vaccinated cows; and group IV—vaccinated and fed colostrum from cows vaccinated with a pilus vaccine of Μ bovis. All calves were given challenge-exposure inoculum when calves in group I had a mean age of 67.75 days, calves in group II had a mean age of 67.60 days, calves in group III had a mean age of 71.86 days, and calves in group IV had a mean age of 73.70 days.

After challenge exposure, the percentage (46.43%) of the eyes resistant to ibk was greater in calves (groups III and IV) fed colostrum from vaccinated cows than was that of the eyes (19.44%) in calves (groups I and II) fed colostrum from nonvaccinated cows (P = 0.021). The larger percentage (38.24%) of the eyes resistant to ibk was larger but not highly significant (P = 0.156) in vaccinated calves (groups II and IV) than was that of the eyes (23.33%) in nonvaccinated calves (groups I and III). The severity of signs of ibk in the eyes of calves (groups III and IV) fed colostrum from vaccinated cows was significantly less (P = 0.032) than was the severity of signs in eyes of calves (groups I and II) fed colostrum from nonvaccinated cows. The lesions in the eyes of vaccinated calves (groups II and IV) were not significantly (P = 0.157) less severe than were the lesions in the eyes of nonvaccinated calves (groups I and III).

The overall results indicate that neonatal calves given colostrum from vaccinated cows would have some protection against ibk.
Recovery from Clinical Rabies of 2 Dogs Inoculated with a Rabies Virus Strain from Ethiopia
Authors: Fekadu Makonnen , Baer George Μ.
Published: February 2025

Two dogs, inoculated with a strain of rabies virus from Ethiopia, showed typical signs of rabies 8 days after inoculation. After 3 or 4 days with a deterioration in the physical condition, both animals began to recover, as shown by increased muscular movements, reaction to stimuli, awareness of surroundings, and attempts to rise. Both animals recovered completely, although 1 then died of Pseudomonas bacterial pneumonia. An increase in serum-neutralizing antibody and in csf or brain-neutralizing antibody was noted in both animals. Such concentrations have been noted only in animals or persons that recovered from rabies.
Nitrogen Requirement of the Kitten
Authors: Anderson P. A. , Baker D. H. , Sherry P. A. , Corbin J. E.
Published: February 2025

Three experiments were conducted to determine the nitrogen (N) requirement of the young kitten. The feline basal diet contained minimal requirement levels of each indispensable amino acid (iaa) to comprise a total dietary N concentration of 2.52% and an iaa N to dispensable amino acid (daa) N ratio (I/D) of 0.70. In experiments 1 and 2, both the dietary N concentration and I/D ratio were varied through changes in either the daa level (experiment 1) or iaa level (experiment 2). The resutts revealed that a reduction in either dietary N or in I/D ratio from basal levels (ie, 2.52% N and I/D ratio of 0.70) depressed (P < 0.05) kitten weight gain, feed efficiency, and N retention, whereas simultaneous increases in each resulted in no further improvement in these responses. Comparison of this feline basal diet with a commercial ration (experiment 3) revealed no differences (P < 0.10) in gain, gain/feed, or N retention, although the purified diet showed superiority (P < 0.01) when gain/N intake was determined (13.3 vs 5.7). Therefore, the feline dietary N requirement has been estimated to be 2.52% (15.75% protein equivalent) or 16% of the calories as protein.

In the process of these experiments, creatinine and orotic acid excretion from kittens fed the purified diet were constant, averaging (± sem) 24.7 ± 0.7 mg/kg of body weight and 9.95 ± 2.3 μg/mg of creatinine, respectively. Urea-N and ammonia-N comprised approximately 83.0% and 3.8% of the total urinary nitrogen.
Canine Leptospirosis in Detroit
Authors: Thiermann A. B.
Published: February 2025

Among 433 stray dogs in Detroit, Michigan, surveyed for leptospiral agglutinins, 164 (37.8%) had significant titers to 1 or more leptospiral serotypes; from 123 suburban stray dogs tested, 23 (18.7%) had significant titers. The use of 2-mercaptoethanol on positive serum samples was helpful in identifying acute from chronic phase titers. Cross-reaction patterns also were clarified by the use of 2-mercaptoethanol.

Cultural isolation of leptospires from dog urine was unsuccessful unless the urine had a pH from 6.6 to 8.0. Oral administration of sodium bicarbonate to alkalinize dog's urine resulted in the isolation of leptospires from dogs usually voiding acidic urine.

Leptospira icterohaemorrhagiae was the most common serotype in this dog population by serologic techniques and was the only one isolated in culture.
Determination of Incidence Rates for Chronic Mastitis Using Heifer Prevalence Data
Authors: Thurmond Mark C.
Published: February 2025

Two methods for calculating the incidence rate for staphylococcal mastitis were investigated, using prevalence data among heifers. A method utilizing bacteriologic culture results from prevalence surveys, clinical cases, and fresh heifers was more sensitive in determining incidence rates than was a method utilizing results from serial prevalence surveys only.
Lactic Acidosis and Arterial Hypoxemia During Sublethal Endotoxemia in Conscious Ponies
Authors: Moore J. N. , Garner H. E. , Shapland J. E. , Hatfield D. G.
Published: February 2025

Effects of a sublethal iv dose (10 μg/kg of body weight) of Escherichia coli endotoxin were studied in 7 conscious ponies. Arterial blood gases and plasma lactic acid were determined periodically throughout the 180 minutes of the study. Arterial hypoxemia occurred within 5 minutes despite intense hyperventilation. Colic and diarrhea occurred in all ponies within 30 minutes after endotoxin administration. Metabolic acidosis developed within 30 minutes and persisted throughout the study, indicating widespread reduced tissue perfusion.
Serologic Responses of Pregnant Thoroughbred Mares to Vaccination with an Inactivated Equine Herpesvirus 1 Vaccine
Authors: Bryans John T.
Published: February 2025

The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under experimentally controlled conditions. The safety of the vaccine was demonstrated by the occurrence of only 2 local untoward reactions to the administration of 941 im injections.
Plasma Progesterone Concentration in the Bovine Before Abortion or Parturition in Pregnant Animals Exposed to Sarcocystis cruzi, Campylobacter fetus, or Aspergillus fumigatus
Authors: Baetz Albert L. , Barnett Dean , Bryner John H. , Cysewski Sigmund J.
Published: February 2025

Pregnant cows in the 4th to 5th month of the gestation were exposed to Sarcocystis cruzi, Campylobacter fetus, or Aspergillus fumigatus. Plasma progesterone concentrations were determined at intervals from before the cows were exposed until they had aborted or calved. The plasma progesterone concentration of the exposed pregnant cattle remained at 3.95 ± 2.0 ng/ml until 24 to 48 hours before abortion or parturition, when it decreased to below 1.00 ng/ml. This pattern was similar for cattle exposed to each of the infective agents. Thus, changes in progesterone concentrations in bovine plasma cannot be used as a diagnostic tool for fetal distress or fetal death.
Evaluation of an Enzyme-Labeled Antiglobulin Test for Anti-Brucella Immunoglobulin G Among 3 Cattle Populations
Authors: Stemshorn B W. , Nielsen K. H. , Samagh B. S. , Forbes L. B. , Ingram D. G.
Published: February 2025

Antibody to smooth Brucella abortus lipopolysaccharide antigen on the surface of polystyrene tubes was detected with peroxidase-labeled antibody against bovine immunoglobulin G. The enzyme-labeled antiglobulin test (elat) activity of samples was expressed in arbitrary units/0.01 ml by reference to a standard curve based on tests of dilutions of a positive serum pool. Reactions > 3.0 U/0.01 ml were classified positive because specificity at this level was 99.8% (417/418 samples correctly classified negative) with agglutination test-negative sera from 33 Brucella-free herds. Results of the elat were compared with results of agglutination tests and the complement-fixation test (cft), using 430 sera from cattle in 7 infected herds. Activity of > 5.0 elat U/0.01 ml was detected in all 54 sera classified as positive (titer > 1:10) by the cft, including 5 sera classified as negative by the tube agglutination test. Sera from 8 nonvaccinated cows in the infected herds reacted only by the elat, whereas reactions were obtained with 25 and 5 sera by only agglutination tests and the cft, respectively. The elat and cft results were in agreement for 25 of 26 sera from agglutination test-reactor cattle in herds of unknown status. Comparisons of milk ring and whey agglutination tests with the whey elat on 146 quarter samples from cows in an infected herd revealed no elat activity ≥1.0 U/0.01 ml in the 73 samples considered negative by the 2 other tests. Samples (n = 47) that contained ≥ 1.0 elat U/0.01 ml included all (n = 40) samples with milk ring or whey agglutination titers ≥ 1:16 and ≥ 32, respectively, and 7 samples that gave weaker reactions to the latter tests.
Canine Anatomy as Assessed by Computerized Tomography
Authors: Fike John R. , Druy Edward M. , Zook Bernard C. , Davis David O. , Thompson Josephine E. , Chaney Elizabeth , Bradley Eileen W.
Published: February 2025

Computerized tomographic studies of normal canine anatomy were obtained, using a whole body scanner. The regions of interest were head and neck, thorax, and abdomen and pelvis. Scans were compared with gross transverse sections from one euthanatized dog. Identification and labeling of anatomic structures were aided by reference to recognized texts of canine anatomy.
Karyotype Analysis of Leukocytes of Gray Collie (Cyclic Neutropenia)-Normal Bone Marrow Transplant Chimeras Six Years After Transplantation
Authors: Matsas D. J. , Yang T. J.
Published: February 2025

Karyotype analysis was made on the leukocytes of 2 gray Collie (cyclic neutropenia)-normal bone marrow transplant chimeras transplanted 6 years previously to correct cyclic neutropenia of the gray Collie syndrome. In a male-to-female transplant chimera, all of the 50 metaphase spreads showed the karyotype of male donor origin. In this and the male-to-male chimera, the morphology of all chromosomes examined showed no gross anomalies or breaks which might be of recipient origin.
Inheritance of Copper Toxicosis in Bedlington Terriers
Authors: Johnson G. F. , Sternlieb I. , Twedt D. C. , Grushoff P. S. , Scheinberg I. H.
Published: February 2025

The mode of transmission of copper toxicosis, previously reported to be associated with progressive hepatic disease in certain Bedlington Terriers, has been studied by means of 5 matings involving affected and unaffected Bedlington Terriers and dogs of different breeds. The abnormally large concentration of hepatic copper underlying the disorder was found to follow an autosomal recessive pattern of inheritance.
Western Hemisphere Isolates of African Swine Fever Virus: Asymptomatic Carriers and Resistance to Challenge Inoculation
Authors: Mebus C. A. , Dardiri A. H.
Published: February 2025

Convalescent clinically normal pigs were tested for the persistence of African swine fever (asf) infection. One group of pigs was examined 135 days after inoculation with a Brazilian isolate and a 2nd group was examined 110 days after inoculation with a Dominican Republic isolate. Susceptible pigs exposed by contact to these groups remained clinically normal. These contact pigs plus 2 more pigs added to each group developed asf after being fed and inoculated with tissues collected from recovered pigs. African swine fever virus was not isolated in swine buffy coat cultures inoculated with supernatant fluid from the collected tissues.

The remaining convalescent Brazilian and Dominican Republic asf pigs were challenge inoculated with homologous virus and then with Lisbon 60 asf virus. Pigs in both groups remained clinically normal after homologous virus challenge inoculation. Pigs in the Brazilian group remained clinically normal after inoculation of the Lisbon 60 asf viral isolate. Of 5 pigs in the Dominican Republic group, 3 developed a transient viremia after inoculation of the Lisbon 60 asf viral isolate.
Sensitivities of Escherichia coli Isolated from Bovine and Porcine Enteric Infections to Antimicrobial Antibiotics
Authors: Coates S. R. , Hoopes K. H.
Published: February 2025

The antibiotic sensitivities of Escherichia coli isolated from 91 diarrheal pigs and 98 diarrheal calves were determined to 19 different microbials by the Kirby-Bauer method. Virtually all E coli isolated from pigs and calves were sensitive to amikacin, colistin, gentamicin, and polymyxin B. In vitro minimum inhibitory concentrations for these 4 antibiotics were determined for isolates from both pigs and calves.
Increased Weight Gains of Wisconsin Dairy Heifers Following Systematic Deworming with Fenbendazole
Authors: Myers G. H. , Todd A. C.
Published: February 2025

Average daily weight gains (adg) were compared among 206 dairy heifers on 11 farms. Half of the heifers were treated with fenbendazole (5 mg/kg) at 30- or 60-day intervals. Treatment every 60 days did not effectively control subclinical nematode parasitism, but did increase adg by 0.05 kg, P < 0.05. Treatment every 30 days effectively controlled the parasitisms and significantly improved adg by 0.09 kg, P < 0.01. Repeated treatment increased rate of gain on 10 of 11 farms. Cooperia, Ostertagia, and Nematodirus were the predominant genera found parasitizing the heifers. On several farms, the pattern of infection indicated that overwintering larvae were a source of infection.
Effect of Pyrrolizidine Alkaloid-Induced Hepatic Disease on Plasma Amino Acid Patterns in the Horse
Authors: Gulick Bonnie A. , Liu Irwin K. M. , Qualls Charles W. , Gribble David H. , Rogers Quinton R.
Published: February 2025

Plasma amino acid patterns were studied in 6 clinically normal adult horses during the course of hepatic disease induced by feeding them plants containing pyrrolizidine alkaloids.

At death, there were significant (P < 0.01) increases in glutamine, proline, tyrosine, asparagine, lysine, histidine, alanine, phenylalanine, methionine, aspartic acid, and ornithine values. There were no significant changes in glycine, valine, isoleucine, tryptophan, and arginine values. There were significant (P < 0.01) decreases in citrulline. Ammonia increased 4-fold. α-Aminoadipic acid and α-aminobutyric acid were not detectable in the plasma of clinically normal horses, but were in the plasma of horses with severe hepatic disease. The ratio of branched chain amino acids (isoleucine + leucine + valine) to phenylalanine plus tyrosine progressively decreased from a normal of 4.0 ± 0.5 to 1.3 ± 0.3 (mean ± 1 SD) just prior to death. The relative changes in plasma amino acid pattern in horses with hepatic diseases seem similar to those changes occurring in man and other animals with hepatic disease.
Host Metabolic Alterations During Inflammatory Stress as Related to Nutritional Status
Authors: Powanda Michael C.
Published: February 2025

Malnutrition predisposes to infection, whereas infection can exacerbate malnutrition, resulting in hindered growth and development. This intereplay between infection and nutrition suggests that host metabolism has a role in host defense during infection, Infection occasions profound alterations in host trace metal, nitrogen, and hormone metabolism and redisi tribution as a result of factors [leukocyte endogenous mediator (endogenous pyrogen)] released from stimulated phagocytes. Many of these alterations occur even in malnourished, protein-restricted, and zinc-deficient animals and persons, bespeaking the essential nature of these changes. Although these metabolic sequelae of infection appear to be of value to the host during acute illness, a metabolic deficit is often incurred which may persist long after resolution of clinical illness. Understanding host-parasite relationships and their metabolic consequences will allow formulation of an integrated approach to the care of infected patients, combining the appropriate elements of nutrition with the best features of antimicrobial therapy.
Equine Postanesthetic Forelimb Lameness Intracompartmental Muscle Pressure Changes and Biochemical Patterns
Authors: Lindsay W. A. , McDonell W. , Bignell W.
Published: February 2025

Intracompartmental muscle pressures were recorded from the right and left forelimbs (extensor carpi radialis, triceps brachii) of healthy horses maintained in left lateral recumbency while under deep halothane anesthesia for 180 to 240 minutes. Cardiac output, blood pressure, blood gases, and acid-base status were monitored throughout the anesthesia, and electrolyte levels (Ca2+, P+, K+, Cl−, Na+) and enzyme activities (aspartate aminotransferase (ast), creatine phosphokinase (cpk), and blood lactate) were monitored for 7 days.

Postanesthetic forelimb lameness was produced in 5 of the 6 horses with this prolonged anesthetic regime. This lameness was associated with muscle plaque formation and clinical signs which were similar to the forelimb lameness sometimes seen in horses after surgical anesthesia. Plasma protein, serum calcium, plasma sodium, and blood urea nitrogen concentrations did not change, whereas significantly increased hematocrit, plasma potassium, and serum inorganic phosphate values were seen at the end of anesthesia, along with a decrease in plasma chloride values. Blood lactate, serum ast, and serum cpk activities were significantly high in the postanesthetic period, although the sequence of the changes differed. Intracompartmental muscle pressures were higher in the left forelimb adjacent to the floor (contact limb), and in the instance of the triceps of the contact limb, the pressures were sufficiently high (> 30 mm of Hg) that they may have compromised capillary blood flow. However, these high intracompartmental muscle pressures did not persist when positional changes of the horses were introduced at the end of the anesthetic period. There was no correlation between the severity of postanesthetic lameness and any of the measured values.

The results demonstrate an experimentally induced postanesthetic lameness which was primarily related to the development of a myositis. Although the causative factors of this myositis may be multiple, the present study implicates local hypoxia in that increased blood lactate and inorganic phosphate values preceded the increased cpk activity. Intracompartmental muscle pressures in the contact limb were possibly high enough to have restricted local capillary blood flow.
Ultrastructure of Anaplasma marginale Theiler in Dermacentor andersoni Stiles and Dermacentor variabilis (Say)
Authors: Kocan Katherine M. , Hair Jakie A. , Ewing S. A.
Published: February 2025

Cattle were inoculated with a Virginìa isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor andersoni Stiles and D variabilis (Say) nymphs. Anaplasma marginale was demonstrated by electron microscopy in gut tissues of replete nymphal ticks and in unfed, incubated, and feeding adult ticks that were exposed to the organism as nymphs when they fed on an infected cow. The A marginale organisms in replete nymphs and adult feeding ticks were morphologically similar to A marginale described previously from infected bovine erythrocytes. Colonies of A marginale were demonstrated by light and electron microscopy in midgut epithelial cells of unfed adult D andersoni and D variabilis that had been incubated at 37 C for 3 days. Anaplasma marginale organisms in colonies were very pleomorphic. Small electron-dense particles were demonstrated in all infected tick stages studied, but were most evident in colonies from incubated, unfed ticks. They may represent a reproductive form of A marginale.
Demonstration of Anaplasma marginale Theiler in Dermacentor variabilis (Say) by Ferritin-Conjugated Antibody Technique
Authors: Kocan Katherine M. , Hsu Konrad C. , Hair Jakie A. , Ewing S. A.
Published: February 2025

Cattle were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source for laboratory-reared Dermacentor variabilis (Say) nymphs. Transstadial transmission of A marginale was demonstrated by feeding the newly molted adult ticks on susceptible cattle and by inoculation of gut homogenates collected from adult ticks at postattachment day 6. A similar gut homogenate from the same group of ticks was caused to react with A marginale-bovine antisera that had been conjugated with ferritin. The homogenate contained organisms similar to those observed in the gut of adult feeding ticks that were infected as nymphs and the labeling of the outer membrane confirmed that organisms observed were A marginale. A gut homogenate prepared from control ticks did not cause infection when inoculated into a susceptible cow and no organisms were demonstrated.
In Vitro Antimycotic Sensitivity of Yeasts Isolated from Infected Bovine Mammary Glands
Authors: McDonald J. S. , Richard J. L. , Anderson A. J. , Fichtner R. E.
Published: February 2025

A total of 91 yeast cultures isolated from infected bovine mammary glands in several herds were studied in vitro to determine their sensitivity to 7 antimycotic agents.

Yeast cultures were most sensitive to clotrimazole followed by ketoconazole, nystatin, myxin, miconazole, and amphotericin B and least sensitive to 5-fluorocytosine. The isolants represented 18 species. Candida lusitaniae was most sensitive (85.7%) and C rugosa was least sensitive (31.9%) to the 7 antimycotic agents.
Identification of Yeasts from Infected Bovine Mammary Glands and Their Experimental Infectivity in Cattle
Authors: Richard J. L. , McDonald J. S. , Fichtner R. E. , Anderson A. J.
Published: February 2025

Cultures of yeasts (n = 91) were obtained from infected mammary glands of cows in New York and Iowa. Of the isolants, 78% belonged to the genus Candida. Eleven Candida species were found, with C tropicalis being the most frequently isolated species and C rugosa being the 2nd most frequently isolated species.

Five species of Candida and an isolant of Cryptococcus lactativorus were used for experimental inoculation of mammary glands of healthy cows. Of glands inoculated with C tropicalis, C rugosa, C parapsilosis, and Crypt lactativorus, 100% became infected. Only 3 of 8 glands inoculated with C krusei and 1 of 5 glands inoculated with C albicans became infected. Recovery of organisms from infected glands occurred on an average of 7.4 days after inoculation, and infections were eliminated spontaneously from 10 to 30 days after inoculation. Clinical differences were not noticed in the cows or glands regardless of the species of yeast used for establishing infection.
Serum Inorganic Fluoride and Renal Function in Dogs After Methoxyflurane Anesthesia, Tetracycline Treatment, and Surgical Manipulation
Authors: Fleming John T. , Pedersoli W. M.
Published: February 2025

Effects of 2 hours of methoxyflurane-induced anesthesia in 25 dogs were determined by serum inorganic fluoride, serum urea nitrogen, serum creatinine, water intake, urine excretion, and urine specific gravity measurements; arterial concentrations of the anesthetic were also determined.

The dogs were allotted to 5 groups (ptm, ctm, ptml, ctml, ml) of 5 dogs in each group and were anesthetized (m, in group designations) for 2 hours. The dogs were injected with chemically pure tetracycline or commercial tetracycline (pt and ct, in group designations) before, on the day of, and after anesthesia. In 3 groups, laparotomy (l, in group designations) was done; group ml did not receive tetracycline but a laparotomy was performed.

Serum inorganic fluoride increased (P < 0.05) in all groups 24 hours after anesthesia when compared with the base-line values; the highest mean serum concentration was 81.1 ± 7.91 μmol/L (group ptm) and the lowest was 32.7 ± 4.53 μmol/L (group ptml).

There was no difference (P > 0.05) seen in serum urea nitrogen concentrations between groups. Methoxyflurane and tetracycline treatment caused no difference (P > 0.05) on serum concentrations of inorganic fluoride and urea nitrogen. Serum creatinine concentrations differed (P < 0.05) only for groups ptm, ctm, ptml, and ctml vs group ml. Water intake reached peak at 48 hours after anesthesia.

Arterial concentrations of methoxyflurane determined at 60 and 120 minutes of anesthesia indicated no difference (P > 0.05) among groups.

Neither clinical nor laboratory signs of severe kidney dysfunction were detected in any of the experimental dogs during a 5-day observation period after anesthesia.
Sarcocystis Species in Moose (Alces alces), Bison (Bison bison), and Pronghorn (Antilocapra americana) in Montana
Authors: Dubey J. P.
Published: February 2025

The transmission of Sarcocystis spp from naturally infected moose, bison, and pronghorn was attempted in laboratory-raised coyotes and dogs. Infected musculature from a moose was fed to a dog and a coyote, and 12 days later, both animals shed sporocysts. Sporocysts were 14 to 17 × 8.5 to 10.5 μm (av 14.5 × 8.8). A coyote was fed muscle from a bison, and 11 days later, it shed sporocysts. The sporocysts were 14 to 16 × 9 to 11 μm (14.0 × 9.0). Infected tissues from a pronghorn were fed to a dog; the dog did not shed sporocysts. Two morphologically distinct sarcocysts (thick walled and thin walled) were found in musculature of a moose. The name, Sarcocystis alceslatrans, sp n, is proposed for the thin-walled sarcocysts in the moose.
Lymphocyte Responses to Virus and Mitogen in Ponies During Experimental Infection with Equine Herpesvirus 1
Authors: Dutta S. K. , Myrup A. , Bumgardner M. K.
Published: February 2025

Six pony foals, experimentally infected with equine herpesvirus 1 (ehv-1), were studied for their lymphocyte responses to ehv-1 and phytohemagglutinin (pha) stimulations. Lymphocyte blastic transformation in the presence of ehv-1 appeared as early as 2 days after the foals were inoculated, reached a peak in 7 to 10 days, and subsequently decreased. In contrast, the lymphocyte blastic transformation in the presence of pha increased sharply, reaching a peak in 2 to 3 days, and then decreased to its lowest level in 10 days after which it returned to its near preinoculation level. As for the mechanism of the transient hyporesponsiveness to mitogen, sera from the ponies after inoculation did not cause lessened stimulatory response of normal lymphocytes to pha. The possible mechanism of this transient hyporesponsiveness to mitogen is discussed.
Prophylactic Medication with Pyrantel to Prevent liver Condemnation in Pigs Naturally Exposed to Ascaris Infections
Authors: Kennedy T. J. , Conway D. P. , Bliss D. H.
Published: February 2025

The use of pyrantel tartrate (106 mg/kg of feed) as a continuous feed medication was evaluated in 848 finishing hogs for efficacy in preventing Ascaris suum infections, and in reducing liver fibrosis and liver condemnation at slaughter, associated with A suum infections. Liver condemnations due to Ascaris damage were reduced 100% in all pigs given pyrantel, when compared with condemnation in nonmedicated controls. None of the livers from any of the medicated animals was condemned, whereas livers from 101 (21%) of 479 nonmedicated pigs were condemned due to extensive hepatic scarring. Pyrantel medication administered for 62, 45, or 28 to 31 days resulted in reductions of total number of liver lesions at slaughter by 93.4%, 80.5%, and 68.6%, respectively. In nearly all cases, hepatic lesions remaining at slaughter of pigs given pyrantel in the feed were less distinct than were lesions found on livers from nonmedicated pigs.
Distribution of T and B Lymphocytes in Blood and Lymphoid Tissues of Fetal and Adult Sheep
Authors: Chandra P. , Chanana A. D. , Joel D. D.
Published: February 2025

Distributions of B and T lymphocytes in blood and various lymphoid tissues of clinically normal adult and fetal sheep were studied. The B and T lymphocytes were identified in enriched preparations of blood lymphocytes and cell suspensions of solid tissues. The T lymphocytes were quantitated by indirect immunofluorescence, using rabbit antisera to sheep thymus cells. The B lymphocytes were identified by direct immunofluorescence, using rabbit antisera to sheep immunoglobulin.
Evaluation of the Agar-Gel Immunodiffusion Test in the Diagnosis of Canine Blastomycosis
Authors: Legendre Alfred M. , Becker Penny U.
Published: February 2025

The agar-gel immunodiffusion test was used to evaluate 35 dogs with nistopathologically confirmed blastomycosis and 98 dogs without blastomycosis. The test had a sensitivity of 91% and a specificity of 96%.

Thirteen of the dogs treated for blastomycosis were tested at 6 to 33 months after treatment with amphotericin B. Ten of 13 dogs became seronegative and 3, though clinically normal, remained seropositive at 19, 20, and 20 months, respectively, after amphotericin treatment.
Treatment of Psoroptic Mange with Avermectins
Authors: Wilkins C. A. , Conroy J. A. , Ho P. , O'Shanny W. J. , Malatesta P. F. , Egerton J. R.
Published: February 2025

Good control of Psoroptes cuniculi was achieved in rabbits treated with various avermectin analogues by topical application or by subcutaneous injection of the 22,23-dihydro-avermectin B1.
Determination of Plasma Fibrinogen Concentration in the Horse
Authors: Campbell Mervyn D. , Bellamy James E. C. , Searcy Gene P.
Published: February 2025

The microhematocrit heat-precipitation methods of Millar et al (1971) and Schalm et al (1975) were compared with the reference clottable protein method of Ratnoff and Menzie (1951) in the measurement of plasma fibrinogen concentration in horses. The Millar et al method was more precise and accurate and showed better positive correlation with the reference method than did the Schalm et al method. There was no significant difference in the plasma fibrinogen concentration between healthy Thoroughbreds and healthy horses of other breeds. Horses with bacterial pneumonia and abscesses had significantly greater plasma fibrinogen values than did those with colic, fractures, and nonsuppurative wounds. The Millar et al method was recommended as a simple, relatively accurate procedure for the determination of plasma fibrinogen that might be used as an additional diagnostic and prognostic indicator in the laboratory investigation of diseases in the horse.
Use of the Portable Infrared Thermometer as a Means of Measuring Limb Surface Temperature in the Horse
Authors: Palmer Scott E.
Published: February 2025

Evaluation was made of the portable infrared thermometer to measure limb surface temperature in 3 horses—first standing in a stall and then placed in lateral recumbency under general anesthesia. To determine the effect of pigment, black and white targets were examined with the instrument under various clinical conditions.

In each horse, thermal gradient measurements were consistent along the extremities. Mean limb surface temperatures were less than rectal temperature and greater than ambient temperature. Limb surface temperatures measured in lateral recumbency under general anesthesia were uniformly higher than those obtained in the standing position in the stall.

The average sd of absolute temperature measurements made under general anesthesia was ± 0.1 C, whereas the average sd of those made in standing horses was ± 0.2 C. For practical use, the latter deviation of ± 0.2 C was considered more appropriate as the limit of significance for clinical measurements made with the instrument. When used indoors in the absence of direct sunlight, the influence of pigment on measurements made with the instrument was not significant.

Optimal conditions for the clinical use of the portable infrared thermometer are defined and factors which affect limb surface temperature are discussed.
Lack of Intracellular Degradation of Mycobacterium paratuberculosis by Bovine Macrophages Infected in Vitro and in Vivo: Light Microscopic and Electron Microscopic Observations
Authors: Bendixen P. H. , Bloch B. , Jorgensen J. Berg
Published: February 2025

Blood-derived macrophages from clinically healthy cows and cows infected with Mycobacterium paratuberculosis were cultured in vitro and inoculated with heat-killed M paratuberculosis. Five weeks after infection, acid-fast bacteria continued to be demonstrated in the macrophages.

Macrophage cultures also were infected with living M paratuberculosis and were examined by electron microscopy. Four weeks after infection, intact bacteria were found in all cultures.

Electron microscopic examinations of intestinal macrophages from infected cows also demonstrated intracellular intact bacteria.
Isolation of Encysted Toxoplasma gondii from Musculature of Moose and Pronghorn in Montana
Authors: Dubey J. P.
Published: February 2025

Pieces of skeletal muscle from 43 mule deer, 34 elk, 4 white-tailed deer, 21 pronghorn, 7 moose, and 2 bison were examined for Toxoplasma infection, by the acid-pepsin digestion technique. Toxoplasma gondii was isolated from 1 moose and 1 pronghorn. The isolated strains of T gondii were of low virulence to mice.
Quantitative Survival of Toxoplasma gondii Tachyzoites and Bradyzoites in Pepsin and in Trypsin Solutions
Authors: Sharma S. P. , Dubey J. P.
Published: February 2025

Bradyzoites of Toxoplasma gondii survived in pepsin solution and in trypsin solution. After 120 minutes in trypsin solution at 37 C, infectivity of bradyzoites for mice was reduced 100-fold, whereas in pepsin solution there was no reduction in infectivity. Tachyzoites survived in trypsin, but after 15 and 60 minutes’ incubation at 37 C, there was a 100,000-fold reduction in infectivity titer.

Toxoplasma gondii was demonstrated in mice inoculated with experimentally infected goat brain digested in pepsin and in trypsin solutions, but not in mice inoculated with undigested brain of the same goat. Seemingly, tissues should be digested in pepsin solution to isolate T gondii from chronically infected animals.
Effects of Killed Brucella abortus Strain 45/20 Vaccine on Reindeer Later Challenge Exposed with Brucella suis Type 4
Authors: Dieterich R. A. , Deyoe B. L. , Morton J. K.
Published: February 2025

Six seronegative pregnant reindeer (Rangifer tarandus L) were vaccinated with killed Brucella abortus strain 45/20 with added adjuvant. These were challenge exposed with B suis type 4 after 90 days; at the same time, 4 seronegative, nonvaccinated, pregnant reindeer (controls) were given the challenge inoculum.

Humoral antibodies were detected in the vaccinated reindeer by postvaccination day 14. A marked increase in antibody levels also occurred after they were challenge exposed, but did not reach the levels observed in control reindeer which seroconverted within 8 days after they were given the challenge inoculum. One control reindeer aborted at 45 days after challenge exposure (at 165 days of a normal 225-day gestation period), and the fawn of another lived only a few days after delivery. Brucella suis type 4 was isolated from tissues of 3 of 4 control reindeer and of 2 of their fawns. All vaccinated reindeer gave birth to live fawns which were culture negative, although 1 fawn lived only a few days. Brucella suis type 4 was isolated from tissues of 1 vaccinated reindeer. Under the conditions of this experiment, killed B abortus 45/20 vaccine provided increased resistance to brucellosis.
Characterization of Anaplasma marginale Infection in Splenectomized Domestic Goats
Authors: Maas J. , Buening G. M.
Published: February 2025

An inoculum of Anaplasma marginale was given (iv) to a splenectomized domestic goat and then was serially passed through 4 additional goats. The results indicated that goats can be latent carriers at 75 days after inoculation, but not at 208 days. There was no evidence of serial passage of A marginale in goats.
Electroretinographic Components of the Canine Visual Evoked Response
Authors: Malnati George A. , Marshall Arvle E. , Coulter Dwight B.
Published: February 2025

SUMMARY AND CONCLUSIONS

Electroretinograms (erg) and visual evoked responses (ver) were recorded from 2 anesthetized dogs before and after surgical manipulation. The erg was recorded from a corneal contact lens, and the ver, from 9 different scalp sites. The recordings were made on a signal averager as done in clinical situations. Surgical manipulation consisted of an alcohol block of the stimulated eye and enucleation of the nonstimulated eye. The results indicated that under the conditions of making the recordings, the major and consistent waves of the ver from all scalp sites were a far-field erg and were not of cortical origin.
Prepartum Changes of Plasma Concentrations of Prostaglandin F and 13,14-Dihydro-15-Ketoprostaglandin Metabolites in Pregnant Animals Exposed to Sarcocystis cruzi or Campylobacter fetus
Authors: Baetz Albert L. , Leiting Sally E. , Bryner John , Barnett Dean
Published: February 2025

Pregnant cows at 4- to 5-months’ of gestation were exposed to Sarcocystis cruzi or Campylobacter fetus. Plasma prostaglandin F (pgf) and 13,14-dihydro-15-keto-prostaglandin metabolite (pgm) concentrations were determined at intervals from before exposure until abortion or parturition. The plasma pgf concentration of pregnant infected cattle remained at 0.02 ± 0.04 ng/ml until 24 to 48 hours before abortion or parturition when it increased 5-fold to 0.11 ± 0.12 ng/ml. The plasma pgm concentration of these cattle remained at 0.10 ± 0.07 ng/ml until 24 to 48 hours before abortion or parturition when it increased over 10-fold to 1.36 ± 0.60 ng/ml. This change in pgf and pgm was similar to that of cattle exposed to each of the infective agents and to that of normal cows at parturition. Thus, changes in pgf or pgm concentrations in bovine plasma cannot be used as a diagnostic tool to determine fetal distress or fetal death for these infections.
Ultrastructural Observations in Ponies After Treatment with Monensin
Authors: Mollenhauer H. H. , Rowe L. D. , Cysewski S. J. , Witzel D. A.
Published: February 2025

Ultrastructural studies were made of myocardium, diaphragm, appendicular muscle, liver, and kidney of 3 ponies acutely poisoned with a single oral dose of monensin (4 mg/kg of body weight). These ponies developed severe signs of toxicosis and were killed 28 to 72 hours after treatment. Severe mitochondrial damage (swelling) and lipoidosis in myocardial tissues were observed in 2 of the 3 ponies; similar, but less severe, changes were observed in the 3rd pony. The hepatocytes of the 3 ponies were characterized by increased amounts of smooth endoplasmic reticulum, large numbers of lipid droplets, vacuoles bounded by fibrous material, and a 2-fold increase in the number of peroxisomes per cell. Some hepatocytes also contained a membrane-bounded protein-like body. The observations indicate that heart mitochondria are primary targets of monensin poisoning in ponies.
Contagious Equine Metritis: Effect of Vaccination on Control of the Disease
Authors: Sahu S. P.
Published: February 2025

Pony mares were vaccinated with killed contagious equine metritis (cem) bacteria by iv, subcutaneous, and intrauterine (iu) routes (or a combination of these routes). The serum agglutinating antibody titer varied from 1:64 to 1:1,024 after vaccination. In pony mares challenge exposed with 96-hour-old culture of cem bacteria given by iu route, there were clinical signs of cem, but these signs were less severe in vaccinated mares than in nonvaccinated mares. The bacterium was isolated for the exudate and from uterine samples collected from the mares after challenge exposure.

A low titer of iu antibodies to cem bacteria in infected mares was observed with agglutination tests (plate, tube, and antiglobulin), and enzyme-linked immunosorbent assay. However, a high antibody titer was obtained when passive hemagglutination test was used.