bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrophysiologic characteristics of tibial and sciatic nerves in the hen
Authors: Robertson D. G. , Anderson R. J.
Published: February 2025

The peripheral nerve of the hen has become an increasingly important animal model in studies of peripheral neuropathy, especially that induced by organophosphorus agent exposure. However, few electrophysiologic studies have been performed, and few data on normal peripheral nerve function exist. The purpose in the present study was to measure the characteristics of the compound action potential of peripheral nerves of the healthy hen. The results showed that conduction velocities of the tibial and the sciatic nerves were 41 m/s and 60 m/s, respectively. The relative refractory period was slightly shorter in the sciatic nerve. The tibial nerve exhibited a lower threshold for stimulation and a significantly shorter chronaxie (19 μs) than did the sciatic nerve (25 μs). Variability between animals was relatively small. These data should provide useful reference points on studies in which peripheral neuropathy is induced or suspected.
Toxicologic studies of a conjugate of asparaginase and polyethylene glycol in mice, rats, and dogs
Authors: Viau Anna T. , Abuchowski Abraham , McCoy John R. , Kazo Glenn M. , Davis Frank F.
Published: February 2025

A conjugate of asparaginase and monomethoxypolyethylene glycol was evaluated in acute, subacute, and subchronic toxicologic studies in mice, rats, and dogs. The drug induced low-grade toxicosis. The appearance and behavior of rats and dogs were not affected by the treatment. Only large doses produced inactivity, loss of appetite, and loss of weight. The ld50 could not be established. The drug retarded slightly body weight gains in dogs and female rats and produced mild anemia in 30% of the female rats. Urinalysis and blood chemical determinations in rats and dogs were generally not affected by the treatment. Monomethoxypolyethylene glycol-asparaginase was detectable in the plasma of mice 13 days after iv, intraperitoneal, or im administration, and in dogs for 3 to 4 weeks.
Evaluation of intestinal carbohydrate malabsorption in the dog by pulmonary hydrogen gas excretion
Authors: Washabau Robert J. , Strombeck Donald R. , Buffington Charles A. , Harrold Doris
Published: February 2025

Breath H2 was measured for the assessment of intestinal carbohydrate absorption in healthy, fasted dogs before and after the ingestion of carbohydrate test meals. The dogs were fed lactulose, xylose, glucose, a hypoallergenic diet, or the hypoallergenic diet supplemented with rice, corn, or wheat flour. Breath samples for H2 analysis were collected by an interval-sampling technique during tidal breathing and were analyzed by thermal conductivity gas chromatography. Pulmonary H2 excretion in fasted dogs never exceeded 1 part per million (molecules of H2 per 106 molecules of air). Breath H2 excretion after the ingestion of 12.5 g of glucose, a completely absorbed monosaccharide, was not significantly different (P > 0.05) from that during fasting; however, ingestion of 12.5 g of xylose, an incompletely absorbed pentose, significantly increased (P < 0.001) breath H2 excretion. After ingestion of 12.5, 25, or 50 g of lactulose, a nonabsorbable disaccharide, pulmonary H2 excretion increased significantly (P < 0.001) over fasting amounts and the increases were different (P < 0.001) from one another. Increases in breath H2 excretion correlated (r = 0.97) with increases in lactulose dose. Breath H2 excretion after the ingestion of the hypoallergenic diet did not significantly (P > 0.05) differ from that after fasting. The addition of rice flour to this diet did not significantly (P > 0.05) increase H2 production. However, the addition of wheat or corn flour to this diet significantly (P < 0.001) increased breath H2 excretion. Seemingly, pulmonary H2 gas excretion reflects carbohydrate malabsorption, there is a quantitative relationship between unabsorbed carbohydrate and pulmonary H2 excretion, and dietary carbohydrate malabsorption can be a normal phenomenon in the healthy dog.
Bulk growth procedures and a button agglutination test for Campylobacter
Authors: Firehammer B. D. , Border Maryon M.
Published: February 2025

Bulk-cell yields were obtained from 4 Campylobacter spp incubated aerobically without the use of a special atmosphere. A button agglutination test was developed for quantitation of blood serum antibodies against C fetus subsp venerealis, C fetus subsp fetus, C jejuni, and “C hyointestinalis.” The test was sensitive, and different individuals reading it usually attained the same titers. Cells of C fetus subsp venerealis, C fetus subsp fetus, and “C hyointestinalis” grown aerobically in broth made satisfactory antigens for the button test, but some cell pools of C jejuni had a tendency to autoagglutinate. Cells of C jejuni grown on blood agar had less tendency to autoagglutinate.
Experimentally induced coronavirus infections in calves: Viral replication in the respiratory and intestinal tracts
Authors: Saif Linda J. , Redman Donald R. , Moorhead Philip D. , Theil Kenneth W.
Published: February 2025

Eleven 3- to 50-day-old colostrum-deprived gnotobiotic calves and seven 25- to 63-day-old colostrum-deprived conventional calves were allotted into 3 groups. Each group was inoculated with a fecal isolate of bovine coronavirus via different routes: orally/intranasally or/in, No. 1 through 8, group 1 calves; or, No. 9 through 13, group 2 calves; in, No. 14 through 18, group 3 calves. Nasal swab specimens and fecal specimens were collected daily and were examined for coronavirus antigen by use of direct immunofluorescent staining (nasal epithelial cells) or by use of immune electron microscopy (fecal specimens). All but 4 calves (No. 11, 13, 17, and 18) were euthanatized on postinoculation days (pid) 3 to 7. Calves 11 and 17 became severely dehydrated and died at pid 5. Calves 13 and 18 were evaluated for nasal and fecal shedding of coronavirus through pid 14. Distribution of coronavirus antigen in the respiratory and intestinal tracts of the 14 euthanatized calves was evaluated by use of direct immunofluorescent staining.

All calves developed profuse diarrhea by pid 2 to 4; however, calves did not develop clinical signs of respiratory tract disease before euthanasia or death. Inoculated calves shed coronavirus in their feces as detected by use of immune electron microscopy. Infected nasal epithelial cells were detected in all but 2 orally inoculated calves (No. 9 and 10). Route of inoculation influenced the sequence of initial detection of coronavirus antigen from fecal specimens or nasal swab specimens. Shedding of coronavirus in the feces and nasal passages was concurrent for all but 1 calf inoculated or/in, whereas detection of fecal shedding preceded nasal shedding in all but 1 or inoculated calf (No. 12). The converse was true for most in inoculated calves. Nasal and fecal shedding of coronavirus persisted through at least pid 6 in the 1 calf eu-thanatized at pid 7 (No. 8) and in the 2 calves examined through pid 14 (No. 13 and 18).

Of the 14 euthanatized calves examined, all had coronavirus antigen in the intestine, with most infected cells in the ileum and colon. Villous atrophy was evident in the ileum of all but 2 calves (No. 9 and 14). Corona-virus-infected cells were detected in upper respiratory tract tissue, including the nasal turbinates or trachea of all but 2 or inoculated calves (No. 9 and 10). Four of 18 calves (2 or/in inoculated, 1 or inoculated, and 1 in inoculated) had coronavirus antigen in their lung tissue: 2 of these 4 calves (No. 1 and 12) had focal interstitial emphysema in the lung tissue and had higher than normal rectal temperatures. Results of the present study indicated that oral or intranasal inoculation of calves with bovine coronavirus can induce respiratory tract and enteric infections in calves.
Biochemical characteristics of various strains of Mycobacterium paratuberculosis
Authors: Chiodini Rodrick J.
Published: February 2025

Biochemical activities of 20 wild-type strains and of 2 laboratory strains of Mycobacterium paratuberculosis were evaluated. Biochemical activities evaluated were growth at 30 C, 37 C, and 42 C; production of urease, niacin, pyrazinamidase, arylsulfatase, and catalase; hydrolyzation of Tween 80; reduction of nitrate and tellurite; and growth in 5% NaCl. Antimicrobial susceptibility to thiophene-2-carboxylic acid hydrazide (10 μg/ml), neotetrazolium chloride (1:40,000), streptomycin (2 μg/ml), rifampin (0.25 μg/ml), and isoniazid (10 μg/ml) also was determined. Generally, M paratuberculosis was biochemically inactive, with only a few strains producing pyrazinamidase and maintaining catalase activity after heating. All strains grew optimally at 37 C, grew slightly at 30 C, and did not grow at 42 C. Wild-type strains did not grow in the presence of neotetrazolium chloride, streptomycin, and rifampin, and grew in the presence of thiophene-2-carboxylic acid hydrazide and isoniazid. Although biochemical evaluation can be used as an aid in the identification of M paratuberculosis, growth rate, and mycobactin dependency remain major criteria for positive identification.
Use of monoclonal antibodies to identify outer membrane antigens of Actinobacillus species
Authors: Healey Mark C. , Gharpure Hemant M. , Kleinschuster Stephen J. , Hwang Hank H. , Johnston Alice V.
Published: February 2025

Three monoclonal antibodies (LG17, LG30, and LG33) were used to identify outer membrane antigens of Actinobacillus sp (As8C isolate) cultured from the epididymides of an infected ram lamb. Specificity of the 3 antibodies to As8C antigens was determined by use of bacterial agglutination, the enzyme-linked immunosorbent assay, and the indirect fluorescent antibody test. Results of immunoelectron microscopy confirmed that each antibody was specific for epitopes on As8C outer membrane antigens. Evaluation by use of enzyme-linked immunoelectrotransfer blot indicated that target antigens for LG17 and LG33 antibodies had molecular weights of 10 kilodaltons and 43 kilodaltons, respectively. Multiple-band staining was observed with the LG33 antibody. The target antigen for the LG30 antibody could not be discerned by use of enzyme-linked immunoelectrotransfer blot.

For each of the 3 monoclonal antibodies, enzyme-linked immunosorbent assay titers were obtained for Actinobacillus seminis, A actinomycetemcomitans, and 10 field isolates of Actinobacillus spp. Target antigens for LG17 and LG30 antibodies occurred infrequently or were absent on these bacteria. However, the target antigen for the LG33 antibody was shared by Actinobacillus seminis, A actinomycetemcomitans, and the 10 field isolates of Actinobacillus spp, indicating some diversity of outer membrane antigens between isolates.
Desferoxamine and iron dextran in acute Salmonella cholerae-suis infection in pigs
Authors: Kramer Theodore T. , Saucke Lois , Griffith Ronald W. , Kunesh Jerry P.
Published: February 2025

Serum iron (si)-related and hematologic changes were evaluated in a herd of weaned pigs inoculated with a strain of Salmonella choleraesuis, causing 83% mortality within 22 days after inoculation was done. Serum iron concentrations decreased to 35% of base-line values 2 days after inoculation was done, but recovered to near base line subsequently. Total si-binding capacity (tibc) decreased gradually for 14 days after inoculation was done. Transferrin (tf) concentrations decreased to near half the base line throughout the postinoculation observation period. The calculated si saturation coefficient decreased to half the base line, but recovered to or above the base-line value subsequently. Combined observations of si, tibc, tf, and si saturation coefficient concentrations indicated that there was higher saturation of host iron-binding proteins and recruitment of additional iron-binding systems subsequent to 2 days after inoculation was done. Day 2 after inoculation seemed to be a critical period for host iron metabolism.

Injection of supplemental iron dextran simultaneously with Salmonella infection resulted in lower mortality of iron-injected pigs (P < 0.005). A highly significant negative correlation was observed between si concentration and rectal temperatures after pigs were inoculated with Salmonella (r = −0.54; P < 0.0001). Hemoglobin concentrations, mean corpuscular volume, and mean corpuscular hemoglobin were not significantly affected by Salmonella infection or iron injection concurrent with Salmonella infection. Erythrocyte counts and erythrocyte sedimentation rates were decreased after Salmonella infection (P < 0.0001).

The iron-binding compound desferoxamine had no effect on si, tibc, and tf concentrations before or after Salmonella inoculation was done. Desferoxamine had no effect on hematologic and si-related changes in pigs not inoculated with Salmonella and did not influence the effects of iron dextran injection.
Canine parvovirus: Environmental effects on infectivity
Authors: Gordon John C. , Angrick Elisabeth J.
Published: February 2025

Effects of various environments on the infectivity of canine parvovirus-2 (cpv-2) were studied. When cpv-2 was subjected to several controlled indoor environments, the virus remained infective at approximate initial inoculation amount (median tissue culture infective dose [tcid50] = 105.5/ml) for 12 months at temperatures < −20 C, decreased to tcid50 of 102.3/ml by 12 months at 4 C, and had a tcid50 of < 101ml at room temperature (20 C) or higher in < 2 months. The cpv-2 subjected to outdoor environments was not infective beyond 5 months, except that kept in areas protected from sunlight and drying conditions. The virus surviving in the outdoor environments was not infective for study dogs, whereas the virus maintained at < 20 C was.
Blood vitamin and choline concentrations in healthy domestic cats, dogs, and horses
Authors: Baker Herman , Schor Sanford M. , Murphy Brian D. , DeAngelis Barbara , Feingold Susan , Frank Oscar
Published: February 2025

Blood concentrations of thiamin, biotin, nicotinates, pantothenates, folates, riboflavin, vitamins A, B6, B12, C, E, β-carotene and choline were analyzed in healthy animals (23 horses, 25 dogs, and 29 cats). B-Complex vitamins and choline also were analyzed in the liver of the dogs and cats. Vitamin concentrations in the blood and livers of dogs were similar; however, blood vitamin A and β-carotene concentrations were lower in the cat than in the dog. Horses had a higher B12 blood concentration than did the dogs and cats. These data can be useful for detecting overt and hidden vitamin deficits in these species due to various conditions.
Bovine chlamydial abortion: Serodiagnosis by modified complement-fixation and indirect inclusion fluorescence tests and enzyme-linked immunosorbent assay
Authors: Perez-Martinez J. A. , Schmeer N. , Storz J.
Published: February 2025

Sequential serum samples from 11 cows experimentally inoculated with different abortigenic strains of Chlamydia psittaci were tested by a modified complement-fixation (MoCF) test, an indirect inclusion fluorescence antibody (iifa) test, and an enzyme-linked immunosorbent assay (elisa). One of these cows was not pregnant, another gave birth at term to c healthy calf, and all the others prematurely delivered infected dead calves or weak live calves. The results achieved with these tests on sera of 3 of the cows were compared with those from the previously used standard complement-fixation (cf) test. Six of 11 cows had detectable preinoculation titers between 1:8 and 1:16 when tested by the MoCF test, yet preinoculation titers were not detected by cf. In contrast, 9 of 11 and 10 of 11 preinoculation samples had detectable chlamydia-specific antibodies when examined by the iifa test and the elisa, respectively. The preinoculation iifa titers ranged from 1:8 to 1:64, and the elisa optical density values varied from 0.150 to 0.450.

All cows responded with significant increases in antibody levels detected by the MoCF test, the hfa test, and elisa after they were experimentally inoculated and after they aborted or delivered infected calves. Overall, the dynamics of the antibody responses were found to be similar with the 3 different serologic techniques. When cows aborted later than 36 days after they were inoculated, the antibody response was biphasic, whereby the more pronounced responses occurred after the abortion occurred. The nonpregnant cow and the cow that delivered a healthy calf at term had only one phase of increasing and decreasing titers directly after they were inoculated. The correlation between the iifa test and the elisa was highly significant (r = 0.65, P < 0.001).

The detection level of the standard cf test was improved by the addition of bovine complement. However, the iifa test and the elisa detected a larger number of seropositive cows than did the MoCF test and were easy to perform and to interpret. The elisa was the most objective, and simultaneous testing of large numbers of sera was possible by evaluating single-serum dilutions of 1:100 under strictly quantitative conditions.
An enzyme-linked immunosorbent assay for the detection of bovine antibodies to vesicular stomatitis virus
Authors: Workman Theresa , Shen David , Woodard Lynn , Yilma Tilahun
Published: February 2025

An indirect enzyme-linked immunosorbent assay (elisa) was developed to detect bovine antibody to vesicular stomatitis virus (vsv). Serum samples from cows experimentally infected with the New Jersey serotype of vsv (vsv-nj) were assayed by the elisa and serum-neutralization (sn) assay. The elisa was as sensitive as the sn assay in detecting bovine antibody to vsv. The correlation between sn titers and elisa values at absorbance at 405 nm was statistically significant. The elisa was not specific for vsv-nj, however, and could detect serum samples positive to the Indiana serotype of vsv that had sn titers of > 480. Nonspecific reactions were due to cross-reactive group-specific viral proteins that are shared by both serotypes. The cross-reactivity allows the use of a single rapid test in identifying both serotypes of vsv from the other exotic vesicular diseases, especially foot-and-mouth disease. The elisa titers of serum samples positive for vsv-nj were comparable with the corresponding sn titers of each sample. The sensitivity, rapidity, and ease of the elisa system and the use of a single test in identifying both serotypes of vsv from the other exotic vesicular diseases make this elisa suitable as a rapid diagnostic assay for vs.
Turbinate atrophy in gnotobiotic pigs intranasally inoculated with protein toxin isolated from type D Pasteurella multocida
Authors: Dominick M. A. , Rimler R. B.
Published: February 2025

Three doses (75 μg, 25 μg, and 25 μg) of purified toxin isolated from a toxigenic strain of type D Pasteurella multocida were given (by atomizer) into the right nasal cavities of each of 10 gnotobiotic pigs on the 21st, 24th, and 27th days of age, respectively. Inoculated pigs (usually 2) and 1 noninoculated control pig each were necropsied on 3, 6, 9, 12, and 15 days after inoculations were given. Severe bilateral atrophy of turbinates occurred in all toxin challenge-exposed pigs. Atrophy was more severe in the inoculated nasal cavity than that in the noninoculated side in 2 of the 10 pigs. Microscopic changes in turbinates of toxin challenge-exposed pigs were more severe in pigs killed at later dates. Dominant changes included degeneration and necrosis of osteoblasts, markedly accelerated osteoclastic osteolysis, replacement of the osseous core by a highly cellular mesenchymal stroma, and multifocal atrophy of submucosal glands. Seemingly, a protein toxin isolated from toxigenic type D strains of P multocida produced rapid atrophy of turbinates and may be a contributing factor in development of clinical progressive atrophic rhinitis in swine.
Age-related changes in carbohydrate tolerance in healthy neonatal calves
Authors: Rollin Ruth E. , Fettman Martin J. , Phillips Robert W.
Published: February 2025

Calves at 3 to 4 days of age had higher plasma glucose concentrations during glucose and lactose tolerance tests (orally administered glucose and lactose) than when the calves were 8 to 9 days old. These observations may be accounted for by decreased insulin secretion and/or insulin sensitivity of the target tissues. Lower hepatic glucokinase activity in neonates also may allow increased passage of splanchnic glucose to the system circulation.
Serum salicylate concentrations and endoscopic evaluation of the gastric mucosa in dogs after oral administration of aspirin-containing products
Authors: Lipowitz Alan J. , Boulay James P. , Klausner Jeffrey S.
Published: February 2025

The serum salicylate concentration produced by oral administration of plain aspirin and several aspirin-containing products given at 8-hour intervals for 7 treatments was measured in 36 laboratory-conditioned adult dogs. The dogs were randomly allotted to 6 groups of 6 dogs each: group 1 was given plain aspirin at a dosage of 25 mg/kg of body weight; group 2 was given plain aspirin at a dosage of 10 mg/kg; group 3 was given buffered aspirin at a dosage of 25 mg/kg; group 4 was given enteric-coated aspirin at a dosage of 25 mg/kg; group 5 was given buffered aspirin at a dosage of 25 mg/kg; and, group 6 was given a placebo. Serum salicylate concentration was measured at 2-hour intervals for the first 8 hours, and then at 8-hour intervals for the next 40 hours. Following the last dosing, serum salicylate concentration was measured at 2-hour intervals until 56 hours; the final 2 samples were measured at 64 and 72 hours. The effect of aspirin on the gastric mucosa was studied in 12 dogs, 3 each randomly selected from groups 1, 3, 4, and 5. The gastric mucosa of each dog was examined with a fiberoptic gastroscope 3 days before the beginning of treatment; lesions were not seen. The drugs were administered as described and the gastric mucosa of each dog was reexamined at 72 hours.

Administration of the aspirin-containing products at 8- hour intervals resulted in sustained therapeutic serum salicylate concentrations (> 5 mg/dl) in all dogs, except those of group 2. The greatest fluctuation in serum salicylate concentration was found in dogs of group 4. Gastric lesions were seen only in the 3 dogs of group 1. The lesions varied from mild petechiation to linear hemorrhages, and were confined to the distal fundic and pyloric antral regions.

It appears from the results of this study that the plain, buffered, and enteric-coated aspirin products administered at a dosage of 25 mg/kg of body weight every 8 hours will produce and maintain therapeutic serum salicylate concentrations. It also appears that, for the duration of this study, this dosage of plain aspirin was more irritating to the gastric mucosa, compared with the other products studied.
Prediction of pharmacokinetic profiles of ampicillin sodium, gentamicin sulfate, and combination ampicillin sodium-gentamicin sulfate in serum and synovia of healthy horses
Authors: Bowman K. F. , Dix Lynn P. , Riond J. -L. , Riviere J. E.
Published: February 2025

Pharmacokinetics of ampicillin sodium (11 mg/kg), gentamicin sulfate (2.2 mg/kg), and combination ampicillin sodium-gentamicin sulfate were determined for serum and synovia of healthy horses given single-dose iv injection and were not found to be different from those from other reports; however, a prolonged terminal γ-phase for gentamicin (8,498 ± 1,842 minutes) in serum of horses was found to exist. Pharmacokinetic interaction between combination ampicillin sodium-gentamicin sulfate was not observed in the serum or synovia. Prediction of ampicillin sodium or gentamicin sulfate concentrations in synovia, based on serum-based pharmacokinetics, cannot be accomplished solely upon analysis of peripheral-compartment pharmacokinetics. However, once equilibrium is achieved between synovia and extracellular fluid in the peripheral compartment, the decrease in drug concentrations in synovia parallels that in serum. Therefore, after 6 hours, synovial concentrations of gentamicin sulfate can be predicted based on peripheral-compartment pharmacokinetics, using an appropriate correction factor. The significance of these findings need to be correlated with clinical conditions so that a pharmacostatistical model for the prediction of synovial concentrations of drug(s) during treatment of horses with septic arthritis can be developed.
Transplantation of pancreatic islets in dogs
Authors: Williams Malcolm D. , Walshaw Richard , Bull Robert W. , Schall William D. , Padgett George A.
Published: February 2025

Dispersed pancreatic islet tissue, prepared by collagenase digestion without separation of exocrine and endocrine components, was transplanted into the splenic pulp of 12 dogs made diabetic by total pancreatectomy. Four dogs (group 1) were given autotransplants, and all became euglycemic 4.5 ± 1.5 days (mean ± se) after the transplantation was done. Three of these dogs remained euglycemic until splenectomized 60 days after transplantation was done. Four dogs (group 2) given allogeneic transplants from histocompatible littermates within the same group were administered cyclosporine (40 mg/kg of body weight/day; starting 2 days before transplantation was done until dogs were splenectomized), and 3 of these dogs became euglycemic 8.0 ± 2.0 days after the transplant was done. Two of the 3 dogs that became euglycemic remained so until splenectomized 60 days after transplantation was done, and the 3rd was euglycemic until 31 days after transplantation. Four dogs (group 3) given allogeneic islet transplants from nonrelated histocompatible donors within the same group were given cyclosporine (40 mg/kg/day; as described for group 2), and none became euglycemic.
Osmolal and anion gaps in dogs with acute endotoxic shock
Authors: Hauptman J. G. , Tvedten Harold
Published: February 2025

Serum osmolalities, biochemical concentrations, osmolal and anion gaps, blood lactate concentrations, and acid base status were evaluated in anesthetized, healthy control dogs and in dogs with endotoxic shock. The osmolal gap was not affected by endotoxemia. Compared with control dogs, dogs with endotoxic shock had mildly, though insignificantly, increased anion gaps and significantly increased blood lactate concentrations. The anion gap in dogs with endotoxic shock was positively (r = 0.77) and significantly correlated with the blood lactate concentration. Therefore, the blood lactate concentration of a dog in endotoxic shock may be estimated by use of the equation: lactate = 0.27 (anion gap) - 1.46. Confidence limits for this estimation were calculated. Dogs with endotoxic shock developed a lactic acidosis and hyperchloremic metabolic acidosis, with hyperventilation.
Effect of internal hemorrhage on fibrin(ogen) degradation products in canine blood
Authors: McCaw Dudley L. , Jergens Albert E. , Turrentine Mark A. , Johnson Gary S.
Published: February 2025

To determine effects of internal hemorrhage on fibrin(ogen) degradation products, blood was pumped from catheters in the jugular veins of 7 anesthetized dogs into extravascular sites in the same dogs. Blood (25 ml/kg of body weight) was transported into their peritoneal cavi-ties (3 dogs) or into the muscle of the pelvic limbs (4 dogs). Blood samples were obtained periodically from these dogs for 4 days after the injections were given. Fibrin(ogen) degradation products (fdp) could not be detected in any of these samples by standard procedures with a commonly used clinical assay, based on the agglutination of antibody-coated latex beads. Even when the assay was modified to make it 2.5 times as sensitive, fdp was not detected. Seemingly, extravascular blood from internal hemorrhage is unlikely to supply enough fdp to the circulating blood to produce clinically important increases in fdp concentrations.
Effects of deoxynivalenol in a wheat ration fed to growing lambs
Authors: Harvey Roger B. , Kubena Leon F. , Corrier Donald E. , Witzel Donald A. , Phillips Timothy D. , Heidelbaugh Norman D.
Published: February 2025

A wheat diet containing deoxynivalenol (vomitoxin) at 15.6 mg/kg was fed to crossbred lambs for 28 days. Feed consumption, weight gain, and feed efficiency of deoxynivalenol-treated lambs did not differ (P < 0.05) from those values of controls. Group differences were not noted for hematologic or serum biochemical variables, and gross or microscopic lesions were not observed in treated lambs.
Food and water intake and urine composition in cats: Influence of continuous versus periodic feeding
Authors: Finco Delmar R. , Adams D. Daryl , Crowell Wayne A. , Stattelman Arthur J. , Brown Scott A. , Barsanti Jeanne A.
Published: February 2025

Twenty healthy, noncastrated, adult male cats had periodic (11 am to 12 am) or continuous (24 hours daily) access to food. With periodic feeding, cats ate less food, drank less water, and produced less urine than when food was available continuously. The composition of urine obtained by cystocentesis at 7:30 am, 3:30 pm, and 10 pm was influenced somewhat by feeding pattern. With periodic feeding, urine pH was lower at 7:30 am and higher at 3:30 pm than it was with continuous feeding. Most mineral concentrations and urine osmolality-specific gravity did not differ with the different feeding schedules. However, when periodic feeding was used, concentrations of magnesium and phosphorus in urine were as high or higher preprandially (7:30 am) than postprandially (3:30 pm).

Frequency of urination per 24 hours was not influenced by the feeding schedule, but the time that urination occurred during the 24-hour period was somewhat different.

An experimental, high magnesium diet fed to the cats for 200 days caused urethral obstruction in 7 of 10 cats fed periodically and in 7 of 10 cats fed continuously. Cats with obstruction had urinary mineral concentrations similar to concentrations in cats without obstruction, indicating that urinary mineral concentration may not be the only factor relevant to the process of obstruction.

Necropsy findings and histologic evaluation of tissues from the cats indicated incidental lesions or abnormalities caused by urethral obstruction, but did not indicate anatomic abnormalities that would have predisposed the cats to obstruction.

Compared with continuous feeding, periodic feeding had some favorable effects in cats, but food accessibility did not alter the incidence of urethral obstruction associated with the use of the experimental diet.
Urban cats: Characteristics and estimation of mortality due to motor vehicles
Authors: Childs James E. , Ross Lloyd
Published: February 2025

The present study was undertaken to characterize and estimate cat mortality caused by motor vehicles in Baltimore, Md. Analysis of Muncipal Animal Shelter records revealed that the number of dead cats annually removed from Baltimore streets averaged 2,721 over 3 years. The number of cats removed per year was notably constant (range 2,621 to 2,917), with a consistently greater number of animals being picked up during summer months. A map of the location of 634 dead cats removed from city streets showed that areas of highest cat mortality were associated with areas of highest human population density. This map was used to stratify Baltimore into areas of high, medium, and low cat mortality for subsequent stratified random placement of tagged dead cats for the mark-recapture study. One hundred fifteen tagged dead cats were placed on city streets during the course of 1 year, and 50.5% were retrieved by the Municipal Animal Shelter. We estimate over 5,000 free-ranging cats are killed by automobiles/year in Baltimore. Analysis of 212 dead cats removed from city streets showed that the majority were male (63%) and that most animals were sexually intact (90%). At least 20% of the dead animals was previously owned, and few kittens or juvenile cats were found in the sample.
Longevity of colonies of Anaplasma marginale in midgut epithelial cells of Dermacentor andersoni
Authors: Kocan Katherine M. , Holbert Donald , Edwards Wanda , Ewing S. A. , Barron Selwyn J. , Hair Jakie A.
Published: February 2025

Colonies of Anaplasma marginale in midgut epithelial cells of experimentally infected Dermacentor andersoni were studied in adult ticks 1, 3, and 6 months old. Longevity of the parasite in ticks was assessed by evaluating its infectivity for splenectomized calves; calves were exposed by feeding ticks and by inoculation of tick gut homogenates. Longevity was also evaluated by determining size, type, and density of colonies m male and female ticks. The effect of incubation (2.5 days at 37 C) on colony density was also examined for ticks at each age period. All methods used to assess longevity of A marginale in ticks (tick transmission, calf inoculation, and histologic studies) indicated a decrease of the numbers of organsms in 6-month-old ticks. Furthermore, when tick gut homogenates from 6-month-old nonincubated ticks were not infectious for susceptible calves, incubation of ticks before dissection restored infectivity of homogenates. Colonies of A marginale were detected in gut tissues of 6-month-old ticks that were not infective; therefore, infectivity of ticks could not be confirmed merely by presence of A marginale colonies.
Experimental Babesia equi infection in mature horses
Authors: Kuttler K. L. , Gipson C. A. , Goff W. L. , Johnson L. W.
Published: February 2025

Nine 4-year-old Arabian geldings were experimentally infected with Babesia equi of European origin. All horses developed detectable parasitemia an average of 30 days after they were inoculated, which was accompanied by a decrease in pcv. The infections were generally mild with no animal deaths. All horses became serologically positive by the indirect fluorescent antibody test within an average of 23 days after they were inoculated and by the complement-fixation test 30 days after they were inoculated.
Susceptibility of fourth-stage Ascaris suum larvae to fenbendazole and to host response in the pig
Authors: Stewart T. B. , Rowell T. J.
Published: February 2025

Fenbendazole given at the rate of 2.5 g/kg of feed for 3 days had 100% efficacy against 4th-stage Ascaris suum larvae in 8 pigs. Eight control pigs had a total of 108 A suum. In 6 pigs infected 3 times with 3rd-stage A suum larvae and treated with fenbendazole after the larvae molted to the 4th stage, the challenge exposure-derived population was decreased by 64%. Similar sequential infections in 6 pigs similarly infected, but not treated with fenbendazole, decreased the challenge exposure-derived population by 98%; however, developing and/or adult vmrms from the vaccinating infections were present.
Seasonal occurrence of infective nematode larvae in california sierra foothill pastures grazed by cattle
Authors: Baker Norman F. , Fisk Robert A.
Published: February 2025

Worm-free Holstein tracer calves were used to assess the seasonal variation in number and course of development of nematode parasites of cattle on an irrigated pasture located in the California Sierra foothills.

The most common genera of nematodes found in the abomasum and small intestine were Ostertagia and Cooperia, respectively. The infective Ostertagia larvae on herbage were most numerous in early spring and lowest in summer months. Arrested development of Ostertagia occurred in mid-to-late spring. The percentage of the population of Ostertagia found to be arrested larvae was constant (73% to 95%) over 4 years, even though the total number of nematodes in the genus was markedly different. Levels of infection with Ostertagia and Cooperia were found to correlate with pasture contamination occurring in the preceding fall and concurrent winter months.

In the cecum and large intestine, Oesophagostomum venulosum was found to be the most common nematode. It is suggested that this species may replace Os radiatum as the cattle nodular worm in regions where climate is similar to that of the southwestern coast of North America. Evidence of seasonal hypobiotic development of Oe venulosum was found.

Other genera of nematodes observed in tracer calves were Trichostrongylus, Haemonchus, Bunostomum, Trichuris, and Dictyocaulus.
Colonization of the nasal passages of calves with Pasteurella haemolytica serotype 1 and regeneration of colonization after experimentally induced viral infection of the respiratory tract
Authors: Frank Glynn H. , Briggs Robert E. , Gillette Kenneth G.
Published: February 2025

Healthy nonstressed calves were inoculated intranasally with or subjected to aerosol exposure to Pasteurella haemolytica serotype 1. Only 4 of 28 calves harbored the bacterium in enough numbers to be isolated from the nasal passages for more than 7 days. After apparent clearing from the nasal passages, 8 calves were inoculated intranasally with infectious bovine rhinotracheitis virus; 2 of these calves shed the P haemolytica during clinical illness due to the virus. The remaining 20 calves were aerosol-exposed to parainfluenza-3 virus; 6 of these calves shed P haemolytica during clinical illness due to the parain fluenza-3 virus.
Immunologic comparison of the proteins of pseudorabies (Aujeszky's disease) virus and bovine herpesvirus-1
Authors: Bush C. E. , Pritchett R. F.
Published: February 2025

The immunologic relationship between bovine herpesvirus-1 and pseudorabies virus was examined by 80% serum cross-neutralization test, enzyme-linked immunosorbent assays, and Western immunoblotting procedures. Immunogenic cross reactivity between the 2 viruses was observed with both the serum-neutralization test and the enzyme-linked immunosorbent assay. A probing of viral Western immunoblots with rabbit hyperimmune antiserum showed that there were a number of viral-specific cross-reactive proteins between bovine herpesvirus-1 and pseudorabies virus.
Molecular and genetic comparisons of two serotypes of epizootic hemorrhagic disease of deer virus
Authors: Kusari J. , Roy P.
Published: February 2025

The virus-specific double-stranded genome RNA of 2 serotypes of epizootic hemorrhagic disease of deer virus (ehdv) was evaluated by use of coelectrophoresis in polyacrylamide and agarose gel systems. The molecular weights of virion RNA segments were 0.32 to 2.57 × 106 for ehdv-1 and 0.33 to 2.54 × 106 for ehdv-2. Seven of 10 double-stranded RNA segments of the 2 serotypes had different electrophoretic mobilities in the polyacrylamide-gel electrophoresis system. Although the individual RNA segments of each serotype contained unique RNA sequences determined on the basis of 2-dimensional polyacrylamide-gel electrophoresis analysis of oligonucleotides, the corresponding segments of the 2 serotypes were found to be comparable and at least 1 pair of RNA segment was almost identical. Virus-specific polypeptides for the 2 serotypes were compared by use of gel electrophoresis. Eleven polypeptides were detected for ehdv-1 and 10 for ehdv-2. Six corresponding polypeptides of these 2 serotypes had different electrophoretic mobilities, indicating that these corresponding polypeptides differ in their molecular weights. A genetic relationship was not determined between the 2 ehdv serogroups and the bluetongue serogroup viruses, using oligonucleojtides mapping.
First isolation of calicivirus from reptiles and amphibians
Authors: Smith Alvin W. , Anderson Marilyn P. , Skilling Douglas E. , Barlough Jeffrey E. , Ensley Philip K.
Published: February 2025

Calicivirus isolations were made from 4 poikilothermic species in a zoologic collection. Viruses were recovered from 8 asymptomatic Aruba Island rattlesnakes (Crotalus unicolor, rectal swab samples) and from 8 symptomatic animals (4 Aruba Island rattlesnakes, 2 Bell's homed frogs [Ceratophrys orata], 1 rock rattlesnake [C lepidus], and 1 eyelash viper [Bothrops schlegeli] tissue samples obtained at necropsy). On the basis of cross-neutralization test results, the 16 isolates were antigenically indistinguishable and were considered to represent a unique calicivirus serotype, tentatively designated reptilian calicivirus Crotalus type 1. These isolations could not be associated causally with any specific disease entity either in naturally infected poikilotherms] or in experimentally infected snakes and pigs.
Susceptibility of colostrum-deprived swine of various ages to streptococcic lymphadenitis
Authors: Wood Richard L. , Wessman Garner E. , Cutlip Randall C. , Matthews Peter J.
Published: February 2025

The effect of age on susceptibility of young pigs to streptococcic lymphadenitis was investigated. Twenty-nine cesarean-derived, colostrum-deprived pigs were allotted to 7 groups exposed to type IV group E Streptococcus (ges) at 5, 14, 28, 35, 56, 70, and 84 days of age. Four cesarean-derived, colostrum-deprived pigs were maintained as nonexposed controls. Six naturally farrowed, susceptible controls were exposed to ges at 63 to 84 days of age. All exposed pigs were killed and necropsied 28 days after exposure. Lesions of streptococcic lymphadenitis were not observed in pigs exposed at 5 or 14 days of age, except for 1 microabscess in a mandibular lymph node in a pig exposed at 14 days, but ges was recovered from 11% of lymph nodes examined from pigs of those age groups. Lesions and ges-positive lymph nodes were frequent in cesarean-derived, colostrum-deprived pigs exposed at 28 days and older and in susceptible controls. Serologic response to exposure, as determined by microtitration agglutination test and bactericidal test, was observed only in pigs exposed at 14 days and older. The absence of abscess development in pigs exposed at 5 or 14 days of age was not caused by antibody or failure of infecting organisms to reach the target organs.
Pharmacokinetic disposition of dimethyl sulfoxide administered intravenously to horses
Authors: Blythe Linda L. , Craig A. Morrie , Christensen J. Mark , Appell Loren H. , Slizeski Marilyn L.
Published: February 2025

Dimethyl sulfoxide (dmso) was administered iv to 6 Thoroughbred horses at 2 dosages: 1.0 g/kg and 0.1 g/kg. The pharmacokinetics seemed linear, with biological half-lives of 8.6 ± 0.3 hours and 9.8 ± 2 2 hours for the 1.0 g/kg and 0.1 g/kg dosages, respectively. This was further substantiated by mean residence times of 9.8 ± 0.44 hours and 13.8 ± 4.25 hours, areas under the curve of 12.55 ± 1.42 mg/ml/hr and 1.63 ± 0.49 mg/ml/hr, and the clearances of 0.081 ± 0.009 L/kg/hr and 0.066 ±,0.022 L/kg/ hr for the large and small dosages, respectively. At 12 hours after 1.0 g/kg was administered, 26.6% of the dmso dose was excreted unchanged into the urine; at 12 hours after 0.1 g/kg was administered, 25.3% of the dmso dose was excreted unchanged into the urine. It was predicted that 29.4% and 40.6% of the total dmso dose would be excreted into the urine for the 1.0 g/kg and 0.1 g/kg dosages, respectively.

A 10% dmso concentration in normal saline solution was safe to give as rapid iv infusion. Slow administration is recommended for more concentrated solutions. Based on the half-life, dmso should be administered 2 times a day rv for the treatment of increased intracranial pressure and/or cerebral edema in horses.
Effects of naloxone in treating hemorrhagic shock in dogs with maintained baroreceptor responsiveness
Authors: Wagner-Mann Colette C. , Gross David R.
Published: February 2025

The efficacy of treating hemorrhagic shock with naloxone in conjunction with fluids, compared with fluid therapy alone, was studied. Previously instrumented dogs were anesthetized with 0.04 mg of fentanyl/kg + 2.2 mg of droperidol/kg and pentobarbital sodium (to effect). Blood was withdrawn from each animal to achieve and maintain a mean arterial blood pressure of 40 to 50 mm of Hg for the first 2 hours of the experiment (t = 0 to 120 minutes). At t = 120 minutes, iv fluid administration was begun (all dogs) and continued for 1 hour (lactated Ringer’s solution at a dosage of 70 ml/kg/hr). Hypothermia was corrected. Control dogs were given no other treatment. Dogs in the naloxone plus fluids group were given an iv bolus of naloxone (1 mg/kg) at t = 120 minutes and 1 mg of naloxone/kg/hr in the fluids from t = 120 to t = 180 minutes. Treatment (either naloxone plus fluids or fluids alone) was stopped at t = 180 minutes, and measuring of response was continued for an additional hour (posttherapeutic period). Significant differences were not seen in mean arterial pressures, left ventricular peak systolic pressures, dP/dt max, time constant T (a measure of left ventricular elasticity), and mean pulmonary arterial pressures between the dogs given naloxone and fluid therapy and those given fluid therapy alone. All dogs in both groups survived the procedure.
Lactate dehydrogenase isoenzymes in blood and cerebrospinal fluid from healthy beagles
Authors: Heavner James E. , Colaianne James , Roper Margaret
Published: February 2025

Serum and csf lactate dehydrogenase (ldh) activity and ldh isoenzyme profile, as well as total protein, were measured in samples obtained from 26 healthy Beagles. The ldh activity in serum was approximately 10 times that in the csf. The csf ldh isoenzyme profile was a mirror image of the serum ldh isoenzyme profile. Age was negatively correlated (ie, as age increased, the activity decreased) with ldh3 in csf and ldh5 in serum and was positively correlated with ldhX in serum. Seemingly, simultaneous measurement of serum and csf ldh activity and ldh isoenzyme profile can aid in establishing status of the blood-brain barrier, whether brain damage exists and whether other organ systems are involved.
Clinicopathologic study of horses surviving pyrrolizidine alkaloid (Senecio vulgaris) toxicosis
Authors: Lessard Pierre , Wilson W. David , Olander Harvey J. , Rogers Quinton R. , Mendel Vern E.
Published: February 2025

Twenty horses of various ages had inadvertently ingested alfalfa hay contaminated with Senecio vulgaris. Among them, 4 died of liver disease. Blood was collected from affected horses at monthly intervals for 7 months and at the 9th and 14th months. The following serum enzymes and chemical items were assayed: aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, γ-glutamyl transferase, sorbitol dehydrogenase, total bilirubin, bun, glucose, cholesterol, inorganic phosphate, calcium, total protein, and albumin. Amino acid profiles, conjugated bile acids, sulfobromophthalein clearance times, and liver histopathologic changes via serial biopsies were also monitored. Liver histopathologic changes revealed lesions progressively increasing in severity. Aspartate aminotransferase and plasma amino acid ratios indicated chronic liver degeneration (0.05 level of significance), γ-Glutamyl transferase and lactate dehydrogenase as well as bun values fluctuated, but returned to within reference values. Horses appeared clinically normal 14 months after intoxication, but were unable to tolerate stress of exercise.
Multiple bluetongue virus-cloned genetic probes: Application to diagnostics and bluetongue virus genetic relationships
Authors: Squire K. R. E. , Chuang R. Y. , Dunn S. J. , Dangler C. A. , Falbo M. T. , Chuang L. F. , Osburn B. I.
Published: February 2025

A shotgun-cloning method incorporating all 10 bluetongue virus genome segments can simultaneously produce complete and partial copies of any of the genome segments. We report here 4 different cloned probes derived from 3 genome segments and individually defined by different hybridization recognition capabilities. One probe hybridized strongly with all 5 United States prototype strains of the 5 different bluetongue virus (btv) serotypes existing in the United States and, as such, is a strong candidate for a broad btv diagnostic probe in the United States. Another probe derived from genome segment 2 of btv-17 hybridized only with the btv-17 prototypic serotype, thereby demonstrating serospecific hybridization diagnostic potential. The implications for diagnostic and genetic relationship studies on btv, using various genetic probes, are discussed.