bluuebunny/crossref_metadata_2025 huggingface dataset:
Feline model for the study of frozen osteoarticular hemijoint transplantation: Qualitative and quantitative assessment of bone healing
Authors: Henry William B. , Sckachar Norman S. , Wadsworth Peter L. , Castronovo Frank P. , Mankin Henry J.
Published: February 2025

Twenty-four outbred cats underwent massive osteoarticular allograft and control autograft transplantation, using the right distal femur with its articular cartilage, capsule, and medial collateral ligament intact. The cats were monitored clinically and radiographically for 1 year. Groups of cats (4 allografts and 2 control autografts) were euthanatized at 3-, 6-, 9-, and 12-month intervals. At necropsy, the grafts were photographed and assessed for bone healing and replacement by standard radiography, quantitative 99mTc bone scans, microradiography, and histologic examination of decalcified and nondecalcified specimens.

The osteosynthesis site of the allografts usually healed by 5 months, compared with the autografts that healed by 3 months. As illustrated by quantitative bone scans, creeping appositional new bone slowly invaded and replaced the allograft bone.

Seemingly, the cat can be used as an acceptable and clinically comparable model for the massive osteoarticular allografts currently being used for the reconstruction of joints damaged or destroyed by neoplasm surgery in limb-sparing procedures in human beings. This model may also be used to assess the rate and method of bone healing.
Enzyme-linked immunosorbent assay for detection of milk immunoglobulins to leukocidin toxin of Staphylococcus aureus
Authors: Loeffler David A. , Norcross Neil L.
Published: February 2025

Leukocidin toxin from a bovine strain of Staphylococcus aureus was partially purified by ion exchange chromatography. An enzyme-linked immunosorbent assay was developed to quantitate antibodies specific for leukocidin in bovine milk. This was used to assay quarter samples from 88 cows in a S aureus-in-fected herd for antibody levels to the toxin. Milk samples from 65 cows with S aureus infections in at least one quarter produced a mean optical density of 1.054, whereas milk samples from 23 cows that were free of bacteria on cultural examination had a mean optical density of 0.584. There was a significant difference (P < 0.001) in milk anti-leukocidin levels between these 2 groups. Evaluation of serum samples from 40 of these cows indicated that the milk anti-leukocidin concentrations were reflective of systemic anti-leukocidin values.

The capability of 57 milk samples to neutralize the cytolytic effect of minimal amounts of leukocidin on bovine peripheral blood neutrophils was examined. Good correlation existed between the enzyme-linked immunosorbent assay antibody concentration and toxin-neutralizing capability of individual milk samples.
Endotoxic shock in the awake young pig: Absence of beneficial effect of prednisolone sodium succinate treatment
Authors: Schrauwen Eric M. , Houvenaghel André M.
Published: February 2025

In nonanesthetized young pigs, the influence of prednisolone sodium succinate therapy on a 65% lethal dose of Escherichia coli endotoxin was studied by evaluating clinical signs, several hemodynamic variables, survival rate, and changes seen at necropsy. Endotoxin infusion induced reproducible clinical signs characterized by nausea, vomiting, dyspnea, cyanosis, and moderate excitement followed by severe cns depression. Among the hemodynamic variables, there were decreases in arterial blood pressure and cardiac output and increases in pulmonary arterial pressure, heart rate, and total peripheral and pulmonary vascular resistances. Core temperature and arterial pH did not change significantly. Survival rate at 30 hours after the start of the endotoxin infusion was 35%. According to the necropsy, marked edema and hemorrhages were in several organs.

Treating the experimental animals with prednisolone sodium succinate (3 injections of 10 mg/kg of body weight after the start of the endotoxin infusion) did not influence any of the monitored hemodynamic variables, except for arterial blood pressure, which was higher at the end of the hemodynamic recording period (270 minutes after the start of the endotoxin infusion). Clinical signs, survival rate, and changes at necropsy were similar in both treated and nontreated pigs. This lack of effect can be due to an inappropriate dosage of the steroid or failure of steroid treatment to alleviate endotoxin-mediated effects.
Development and clinical application of methods for detection of antineutrophil antibody in serum of the cat
Authors: Chickering William R. , Prasse Keith W. , Dawe Donald L.
Published: February 2025

Two techniques, leukoagglutination and indirect immunofluorescence, were adapted to test for the presence of antineutrophil antibody in cat serum. The leukoagglutination test was analogous to an indirect Coombs' test. The test was performed on freshly isolated cat blood neutrophils, with the test results read from stained smears (Wright's stain) made from sedimented antiserum-treated neutrophils. A positive test response was indicated by agglutinated neutrophils on the stained smear. The indirect immunofluorescence test was performed by incubating paraformaldehyde-fixed cat blood neutrophils with test serum, after which the neutrophils were stained with fluorescein isothiocyanate-tagged antiglobulin. A positive test response was a ring of fluorescence surrounding the cells, as viewed through a uv microscope.

Serum samples (n = 55) from clinically neutropenic cats were tested for the presence of antineutrophil antibody by the indirect immunofluorescence technique. Ten positive-control sera (rabbit anti-cat neutrophil serum) and 10 negative-control sera (normal cat serum) were included. Only the positive control sera exhibited neutrophil fluorescence, indicative of antineutrophil antibody. None of the 55 samples of clinical origin showed any appreciable fluorescence.
Effects of aspirin and propranolol on feline platelet aggregation
Authors: Greene Craig E.
Published: February 2025

Three groups of cats were given aspirin in single dosages of 5, 10, and 25 mg/kg. A 4th group was given 2 dosages of 25 mg/kg, 3 days between doses. The degree of inhibition of platelet function and the duration of antagonism to platelet aggregation were studied. The dosage of 25 mg/kg (single and repeated) consistently inhibited platelet function, and the effects lasted 3 to 5 days. Additive drug effect was not noted in group 4, since the 2nd dosage antagonized platelet function to a degree and duration similar to the effects of the 1st. The dosage of aspirin recommended for antiplatelet activity in the average-sized cat (3 kg) equals approximately 1 pediatric aspirin (90 mg) given twice a week. Propranolol, given to cats at dosages of 2.5 to 15 mg had no effect on platelet aggregation.
Cardiopulmonary effects of an intravenous infusion of guaifenesin, ketamine, and xylazine in dogs
Authors: Benson G. J. , Thurmon J. C. , Tranquilli W. J. , Smith C. W.
Published: February 2025

A 5% solution of dextrose in water containing 50 mg of guaifenesin, 0.25 mg of xylazine, and 1 mg of ketamine/ml was infused iv at the rate of 2.2 ml·kg−1·hour−1 in dogs. Heart rate, systemic vascular resistance, mean arterial blood pressure, rate-pressure product, and arterial oxygen tension were not altered significantly from baseline values during 2 hours of anesthesia. Cardiac index was significantly (P < 0.05) decreased from base-line values. Hypoventilation resulted in increased arterial carbon dioxide tension and decreased arterial pH. After the dogs were given glycopyrrolate, cardiac index returned to base line, and heart rate, mean arterial pressure, and rate-pressure product were significantly greater (P < 0.05) than base-line values.
Prevention of coccidiosis in domestic dogs and captive coyotes (Canis latrans) with sulfadimethoxine-ormetoprim combination
Authors: Dunbar Mike R. , Foreyt William J.
Published: February 2025

Sulfadimethoxine-ormetoprim combination was evaluated as a coccidiostat against experimentally induced coccidiosis in young dogs and coyotes (Canis latrans). The animals were experimentally inoculated with 50,000 or 100,000 sporulated oocysts of Isospora ohiohensis (98%) and Isospora canis (2%). In experiment 1, daily treatment for 13 to 23 days with a combination of 27.5 mg of sulfadimethoxine/kg of body weight (bw) and 5.5 mg of ormetoprim/kg of bw admixed to the feed resulted in no significant (P > 0.05) difference in fecal oocyst counts between treated and nontreated groups of dogs or coyotes. In experiment 2, treatment with a combination of 55 mg of sulfadimethoxine/kg of bw and 11 mg of ormetoprim/kg of bw for 23 days was 99.8% effective against Isospora spp infections in dogs. Significantly (P < 0.05) fewer oocysts were present in feces of treated dogs than were present in feces of nontreated dogs from first passage of oocysts at day 4 to the end of the patent period at days 19 to 21. After the 2nd week of treatment, bw of treated dogs were significantly greater (P < 0.05) than bw of nontreated dogs. Evidence of drug toxicity was not observed clinically or by serum chemical analyses.
Immunologie reactions of pigs regrouped at or near weaning
Authors: Blecha Frank , Pollmann D. Steven , Nichols David A.
Published: February 2025

Using 64 pigs, 2 experiments (32 pigs each) were conducted to evaluate the effects of regrouping nonlittermate pigs at weaning or 2 weeks after weaning on mitogen-induced lymphocyte blastogenesis, intradermal reactions to phytohemagglutinin, and primary antibody responses to sheep erythrocytes. Plasma cortisol concentrations were determined in all pigs and behavior of regrouped pigs was monitored. Compared with control values, plasma cortisol concentrations were higher in nonlittermate pigs regrouped at weaning (P < 0.001) or 2 weeks after weaning (P < 0.01). However, negrouping pigs at weaning or 2 weeks after weaning did not influence lymphocyte blastogenesis, phytohemagglutinin skin-test responses, or antibody titers to sheep erythrocytes. Plasma cortisol concentrations were not related to agonistic behavior in regrouped pigs or to lymphocyte blastogenic or phytohemagglutinin skin-test responses; however, higher plasma cortisol concentrations were related (P < 0.05) to lower sheep erythrocyte antibody titers. These data indicate that regrouping nonlittermate pigs at weaning or 2 weeks after weaning is an acute stressor that does not detrimentally affect mitogen-induced lymphocyte blastogenesis, intradermal reactions to phytohemagglutinin, or primary antibody responses to sheep erythrocytes.
Field-trial evaluation of a Pasteurella vaccine in preconditioned and nonpreconditioned lightweight calves
Authors: Kadel Wade L. , Chengappa M. M. , Herren Charles E.
Published: February 2025

A field-trial evaluation confirmed the efficacy of a pasteurella vaccine as a means of preventing bovine pneumonia. The vaccine was comprised of streptomycin-dependent Pasteurella multocida (type A:3) and Pasteurella haemolytica (type 1). Vaccinal efficacy was defined in terms of greater body weight gains, less severe clinical signs of pneumonia, and smaller death rates as compared with the same factors in nonvaccinated calves. During the 50-day trial, vaccinated calves gained weight faster than did nonvaccinated calves (P = 0.05). Economic advantage was not found for administering a booster dose of the vaccine (P = 0.25). Nonpreconditioned nonvaccinated calves made greater dollar profits than did preconditioned nonvaccinated calves (P = 0.16). A comparison of all preconditioned calves with all nonpreconditioned calves revealed that illness and death losses were less in the preconditioned calves (P = 0.07).

An evaluation of the cost vs benefit factors revealed significant advantages for administering 1 dose of vaccine of $19.08 for a preconditioned calf (P = 0.006) and of $11.39 for a nonpreconditioned calf (P = 0.05). The data indicated that there was no economic advantage for preconditioning and that the greatest economic gain was made by the vaccinated nonpreconditioned calves.
Early phase components of the kallikrein kinin system in hemorrhagic ascitic fluid and plasma in the rat with induced acute pancreatitis
Authors: Seung Won P. , Feldman Bernard F.
Published: February 2025

Acute hemorrhagic pancreatitis (ahp) was induced in 43 anesthetized rats by retrograde injection of sodium taurodeoxycholic acid into the common pancreatic biliary duct. At postinjection hours 1, 3, 6, 12, and 18, samples of plasma and hemorrhagic ascitic fluid (haf) were obtained from rats in which ahp was induced and from rats that were sham operated.

Early phase components of the kallikrein kinin system, including kallikrein-like (kk) activity and prekallikrein pkk) and kallikrein inhibitor (kki) concentrations, were measured in plasma and haf samples. In the rats with induced ahp, pkk concentrations were decreased significantly in 18-hour plasma samples (P < 0.05) and in all haf samples (P < 0.001) from 1 to 18 hours after induction of ahp. The kk activity was significantly increased (P < 0.001) in the 6- and 12-hour plasma samples. In the 1-hour haf samples, kk activity was increased > 10 times over that in the plasma pool of rats and remained increased for 18 hours. The kki concentrations were markedly decreased in all haf samples. In the sham-operated group, no significant change was observed.

Histopathologic changes included edema, extensive hemorrhage, focal necrosis of many acinar cells around the head of the pancreas, slight inflammatory cell infiltration, vascular thrombosis, and partial lysis of pancreatic ducts.

The extent of the changes of pkk, kk, and kki values haf was greater than the extent of those in plasma. Increasing kk activity in plasma and haf is indicative of bradykinin generation and the participation of this system in local and systemic pathologic change. In addition, the simple measurement of plasma pkk, kk activity, and kki concentrations in haf may prove useful in the diagnosis and treatment of ahp.
Angles of inclination and anteversion in hip dysplasia in the dog
Authors: Hauptman Joe , Cardinet G. H. , Morgan J. P. , Guffy M. M. , Wallace L. J.
Published: February 2025

The angles of inclination and anteversion of the femoral head and neck were measured on 150 limbs of 75 dogs. These hip angles were compared with pathoanatomic and radiographic scores of hip dysplasia. There was a minimal difference between dysplastic and healthy dogs in the angles of inclination and anteversion. It was concluded that in this series of dogs, hip angles did not have a part in the development of hip dysplasia.
Enhancement of resistance of lambs to Haemonchus contortus by previous infection with Ostertagia circumcincta
Authors: Blanchard J. L. , Wescott R. B.
Published: February 2025

Two experiments were performed to determine whether previous infection of young lambs with Ostertagia circumcincta increased their resistance to the development of Haemonchus contortus and to explore alterations in the microenvironment of the abomasum related to the interaction. The parasitic infections were monitored with periodic fecal egg counts and by recovery and enumeration of parasites at necropsy of the lambs. Alteration of the microenvironment was examined by measurement of serum gastrin concentrations at critical times during both experiments.

The results indicated that the numbers of H contortus were significantly (P < 0.05) less in lambs which had O circumcincta infections before their exposure to H contortus. There was less reduction in lambs from which O circumcincta was removed (anthelmintic therapy) before their exposure to H contortus. Fecal egg counts also were significantly (P < 0.05) less in the former group of lambs (exposed to both parasites) than those in lambs exposed only to H contortus. Serum gastrin values were significantly (P < 0.05) increased in lambs infected with O circumcincta and indicated that the interaction observed could be due, in part, to alteration of abomasal pH.
Oral lactose tolerance test in foals: Technique and normal values
Authors: Martens Ronald J. , Malone Polly S. , Brust David M.
Published: February 2025

Oral lactose tolerance tests were evaluated in 25 healthy foals (principals) assigned to 4 groups of approximately 1 week, 4 weeks, 8 weeks, and 12 weeks of age. Lactose monohydrate (1 g/kg of body weight [in a 20% water solution]) was administered via nasogastric tube after a 4-hour fast. Plasma glucose concentrations were monitored before dosing (0 minutes) and sequentially for 300 minutes. Six control foals were given a volume of water equivalent to the volume of lactose mono-hydrate administered to principal foals.

After oral lactose loading, mean plasma glucose concentrations of all principal foals increased from 99.76 mg/dl at 0 minutes to 176.80 mg/dl by 90 minutes. Peak increases in plasma glucose concentrations were attained by 8% of the foals (2 foals) at 30 minutes, 76% (19 foals) at 60 minutes, and 16% (4 foals) at 90 minutes. The mean plasma glucose concentration increase of principal foals, regardless of age or time of peaking, was 77.04 mg/dl.

There was no significant (P > 0.05) difference in fasting plasma glucose concentrations (0 minutes) among the 4 groups of principal foals or between principal and control foals; however, there was a significant (P < 0.05) difference in peak glucose concentrations between 1-week-old and 12-week-old principal foals, with the older foals having the higher concentrations.

Mean plasma glucose concentrations of control foals decreased from 79.67 mg/dl at 0 minutes to 55.17 mg/dl by 180 minutes. The mean peak decrease in plasma glucose concentrations of control foals, regardless of time of peaking, was 24.50 mg/dl.

Oral lactose tolerance tests in healthy foals between 1 and 12 weeks of age should increase the plasma glucose concentration by at least 34.96 mg/dl (mean increase ± 2 sd) within 90 minutes.
Enhanced biliary bilirubin excretion after heparin-induced erythrocyte mass depletion
Authors: Engelking Larry R. , Mariner Jeffrey C.
Published: February 2025

The effect of large-dose heparin therapy on erythrocyte mass depletion in ponies was investigated to determine whether stimulation of reticuloendothelial cell activity and catabolic function would be evidenced by enhanced catabolism of heme to bilirubin. Ponies with chronic external biliary fistula were used to examine biliary excretion of bilirubin both before and after heparin loading (107 U/kg, iv, plus 320 U/kg, subcutaneously) and at maintenance dosages of 320 U/kg given (subcutaneously) at 12 and 24 hours after initial loading with heparin. Results indicated that by 48 hours after ponies were first treated with heparin, catabolism of heme increased, resulting in a 35% increase in plasma bilirubin concentration and a 65% enhancement in biliary bilirubin excretion. During this period, both hematocrit and blood hemoglobin concentrations decreased by 35%. After the last heparin treatment at 24 hours after initial heparin loading, all measured variables returned toward base line within 48 hours. These studies indicated that heparin augments phagocytosis of erythrocytes, resulting in enhanced plasma bilirubin concentration and biliary bilirubin excretion.
Importance of neutrophils in the pathogenesis of acute pneumonic pasteurellosis in calves
Authors: Slocombe R. F. , Malark J. , Ingersoll R. , Derksen F. J. , Robinson N. E.
Published: February 2025

Acute lung injury was induced in 24 calves by intratracheal inoculation with Pasteurella haemolytica. Calves in groups 1 and 2 were neutrophil depleted, using hydroxyurea given iv. Group 1 calves (n = 7) were inoculated intratracheally with saline solution, and group 2 calves (n = 7) were inoculated with P haemolytica. Group 3 calves (n = 7) had normal numbers of neutrophils and were inoculated with P haemolytica. Group 4 calves (n = 3) were treated acutely with hydroxyurea iv, had normal numbers of neutrophils, and were inoculated with P haemolytica. After inoculation, calves with normal numbers of neutrophils (groups 3 and 4) became hypoxemic 2 hours after inoculation, and hypoxemia persisted until necropsy (6 hours after inoculation). These calves also developed tachypnea, bradycardia, neutropenia, and lymphopenia. Lung lesions consisted of necrosis of the alveolar walls, intra-alveolar hemorrhage, and a severe exudative and necrotizing bronchopneumonia, with accumulation of proteinaceous fluid in alveoli and lymphatics. In neutrophil-depleted calves (groups 1 and 2), blood gas values, heart and respiratory rates, and numbers of circulating leukocytes did not change after inoculation with saline solution or with P haemolytica. At necropsy, the lungs of neutrophil-depleted calves were grossly normal. Therefore, neutrophils were required for the acute lung injury induced by P haemolytica. The protective effect of neutrophil depletion was a specific effect of hydroxyurea because calves with high circulating concentrations of hydroxyurea and calves with normal numbers of neutrophils (group 4) developed lung injury.
Lymphocyte blastogenesis, complement fixation, and fecal culture as diagnostic tests for paratuberculosis in North American wild ruminants and domestic sheep
Authors: Williams Elizabeth S. , DeMartini James C. , Snyder Stanley P.
Published: February 2025

The efficacy of the lymphocyte blastogenesis and complement-fixation tests and fecal culture for detection of Mycobacterium paratuberculosis infection was assessed in bighorn sheep (Ovis canadensis), elk (Cervus elaphus nelsoni), mule deer (Odocoileus hemionus), white-tailed deer (O virginianus), bighorn × mouflon (O musimon) hybrid sheep, and domestic sheep. Spontaneously infected bighorns were tested at the time of capture; experimentally infected animals were tested monthly for 12 months or periodically for 36 months.

Lymphocyte blastogenesis tests were conducted with peripheral blood mononuclear cells and protein antigens of M avium, M bovis, and M paratuberculosis. Best diagnostic results were obtained when M avium purified-protein derivative was used as antigen and 20% bovine fetal serum was incorporated in the culture medium; a positive test was defined as a stimulation index ≥ 3.5. Test sensitivity and specificity, respectively, were 82% and 94% in hybrid sheep and were 72% and 100% in domestic sheep. Sensitivity and specificity, respectively, were 39% and 94% in elk and 53% and 92% in deer. When infection was determined in spontaneously infected bighorns by culture of M paratuberculosis and/or the presence of acid-fast bacilli in characteristic microscopic lesions, sensitivity was 75% and specificity was 87%.

Fecal cultures and the complement-fixation tests seldom correctly identified infected animals.
Preliminary characterization of a serum viral inhibitor in goats
Authors: Yilma Tilahun , Owens Sally , Adams D. Scott
Published: February 2025

A serum viral inhibitor (svi) was isolated from goats and partially characterized. The inhibitor prevented the cytopathic effects of vesicular stomatitis virus, encephalomyocarditis virus, and a caprine herpesvirus, indicating broad antiviral activity. The svi was distinct from interferon because svi did not induce an antiviral state in cells (ie, lack of protection of svi-treated cells from virus challenge). The svi had activity on heterologous cells, including human, bovine, and ovine cells. The lack of antiviral activity in mouse cells indicated that svi was not an antibody. Like fibroblast interferon, however, svi was sensitive to trypsin, was acid stable at pH 2 and 4 C for 4 days, was heat stable at 56 C for 1 hour, and could not be sedimented by centrifugation at 100,000 × g for 4 hours.
Serum concentrations of thyroxine and 3,5,3’-triiodothyronine before and after intravenous or intramuscular thyrotropin administration in dogs
Authors: Wheeler S. L. , Husted P. W. , Rosychuk R.A.W. , Allen T. A. , Nett T. M. , Olson P. N.
Published: February 2025

Response to thyrotropin (tsh) was evaluated in 2 groups of mixed-breed dogs. Thyrotropin (5 IU) was administered iv to dogs in group 1 (n = 15) and im to dogs in group 2 (n = 15). Venous blood samples were collected immediately before administration of tsh and at 2-hour intervals for 12 hours thereafter. In group 1, the maximum mean concentration (± sd) of thyroxine (T4; 7.76 ± 2.60 μg/dl) and 3,5,3’-triiodothyroxine (T3;1.56 ± 0.51 ng/ml) was attained at postinjection hours (pih) 8 and 6, respectively. However, the mean concentration of T4 at pih 6 (7.21 ± 2.39 μg/dl) was not different (P > 0.05) from the mean concentration at pih 8. The maximum mean concentration of T4 (10.10 ± 3.50 μg/dl) and T3 (2.22 ± 1.24 ng/ml) in group 2 was attained at pih 12 and 10, respectively.

Because dogs given tsh by the im route manifested pain during injection, had variable serum concentrations of T3 after tsh administration, and may require 5 IU to achieve maximal increases in serum T4 concentrations, iv administration of tsh is recommended. The optimal sampling time to observe maximal increases in T3 and T4 after iv administration of tsh was 6 hours. Repeat iv administration of tsh may cause anaphylaxis and, therefore, is not recommended.
Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs
Authors: Dubey J. P. , Brake R. J. , Murrell K. D. , Fayer R.
Published: February 2025

Muscles from tongue, heart, and limbs of 14 pigs inoculated orally with Toxoplasma gondii oocysts were irradiated with 10, 20, 25, and 30 krad of γ (cesium-137 and cobalt-60) irradiation. Viability of T gondii cysts was assayed by feeding porcine muscles to T gondii-free cats and/or by inoculation of sediment from acid-pepsin digested porcine muscle into mice. Cats fed 500-g samples of muscles irradiated with up to 20 krad shed T gondii oocysts. Cats fed muscles irradiated with 25 or 30 krad did not shed oocysts. Mice were inoculated with 8 isolates of T gondii, and tissue cysts in their brains irradiated with up to 40 krad were infective to mice; however, there was a 10,000-fold reduction in the viability of organisms in tissue cysts irradiated with 40 krad, compared with that in nonirradiated cysts. At 50 krad of γ irradiation, there were no detectable infective organisms in infected mouse brains.
Concentration of ivermectin in bovine serum and its effect on the fecundity of psoroptic mange mites
Authors: Guillot Frank S. , Wright Fred C. , Oehler Delbert
Published: February 2025

The concentration-time profile of ivermectin in serum was determined for 3 Hereford heifers. The mean maximum serum concentration, 29 ng of ivermectin/ml, was obtained 48 hours after single subcutaneous injection of 200 μg/kg of body weight.

The fecundity of mites placed on 9 treated animals at 5, 9, 12, 15, 18, and 21 days after injection was reduced by 96% to 99%. At 24 days after treatment, when serum concentration had decreased to about 2 ng/ml, the capability of mites to produce eggs increased to 50% of mites from nontreated calves. At 27 and 30 days after the drug was injected, egg production by mites on treated calves was equivalent to that of mites on nontreated calves. The reduced fecundity resulted from an almost complete cessation of oviposition by females after only a 1-day exposure to ivermectin-treated calves.
Endotoxemia in horses: Protection provided by antiserum to core lipopolysaccharide
Authors: Morris Debra Deem , Whitlock Robert H. , Corbeil Lynette B.
Published: February 2025

An equine antiserum to core lipopolysaccharide was produced by inoculation of 6 horses with a boiled cell bacterin made from the J-5 mutant of Escherichia coli O111:B4. The antiserum immunoglobulin G titer to J-5 mutant E coli, as determined by enzyme-linked immunosorbent assay, was 1:15,006. Pooled serum prepared before inoculation (preimmune serum) had a J-5 immunoglobulin G titer of 1:350.

The J-5 antiserum was tested for its protective efficacy in sublethal endotoxemia in 14 horses. Four horses served as nontreated controls and were given nothing before endotoxin challenge exposure (10 μg/kg of body weight, iv). Pooled preimmune serum (3 ml/kg, iv) was administered to 5 horses and J-5 antiserum (3 ml/kg, iv) was administered to 5 other horses 2 to 15 hours before endotoxin challenge exposure. During the 24 hours postendotoxin challenge exposure, endotoxemia was accompanied by significant (P < 0.05) time-related changes in temperature, heart rate, pulse character, respiratory rate and character, capillary refill time, mucous membrane color, fecal composition, attitude, pcv, total plasma protein, wbc count, platelet count, plasma fibrinogen, prothrombin time, activated partial thromboplastin time, fibrinolytic degradation products, plasma glucose, and plasma lactate in all horses. There were no apparent treatment vs time interactions (P > 0.05). Two horses (1 control and 1 given J-5 antiserum) died suddenly from unknown causes immediately after endotoxin challenge exposure. Seemingly, equine antiserum to core lipopolysaccharide did not provide protection from the adverse effects of experimental endotoxemia produced by bolus iv infusion of 10 μg of endotoxin/kg.
Equine intravenous glucose tolerance test: Glucose and insulin responses of healthy horses fed grain or hay and of horses with pituitary adenoma
Authors: Garcia Marolo C. , Beech Jill
Published: February 2025

Intravenous glucose tolerance testing (0.5 g/kg of body weight) was done on 2 groups of healthy horses maintained with hay (group 1, n = 5) and with hay plus grain supplementation (group 2, n = 5) and on a group of horses with clinically diagnosed pituitary adenoma (group 3, n = 10). Healthy horses showed an immediate increase of plasma glucose concentration after the iv glucose injection, with return of values to base line in 1 hour. Group 3 horses showed resting hyperglycemia and a delayed return of glucose values to base line (3 hours). Group 3 horses showed resting hyperinsulinemia and a feeble (nonsignificant) response to the glycemic stimulus, with gradual decrease of insulin values to base line. In addition to the apparently reduced tissue sensitivity to insulin in group 3 horses, as evidenced by hyperglycemia, hyperinsulinemia, and protracted glucose and insulin curves, the initial decrease in the insulin/glucose ratio indicates that there was secretory deficiency in response to acute iv glucose loading.
Histologie findings in the gastrointestinal tract of horses with colic
Authors: Meschter Carol L. , Tyler David E. , White Nathaniel A. , Moore James
Published: February 2025

Thirty horses were admitted to the University of Georgia Veterinary Medical Teaching Hospital with colic severe enough to warrant surgery and/or euthanasia. Gastrointestinal tracts of these 30 horses were histologically examined for morphologic changes. The horses were grouped according to cause of the colic (ie, simple obstruction, strangulation obstruction, thromboemboli, and inflammation). Lesions were graded as to severity, and grade scores were correlated with survival or nonsurvival. Mucosal changes developed distal and proximal to the primary lesion site and, although there were some differences between groups, changes characteristic of ischemia were common to all groups. The predictability of lesion grades of 2 or higher for nonsurvivability (90%) indicates that intestinal biopsy may have prognostic value in the postsurgical evaluation and management of equine colic.
Plasmid DNA of virulent Alcaligenes faecalis
Authors: Luginbuhl G. H. , Cutter D. , Campodonico G. , Peace J. , Simmons D. G.
Published: February 2025

Alcaligenes faecalis strains originating from chickens and from epizootics of coryza in turkeys were screened for antibiotic susceptibility and for the presence of plasmid DNA. Seven of 35 strains contained plasmid DNA ranging in size from 10.5 to approximately 32 megadaltons. All of the strains isolated from turkeys were virulent in turkey poults, but only the plasmid-containing strains were resistant to sulfonamides and streptomycin. Four of the plasmid-containing strains were also resistant to tetracycline. Five different plasmids representing at least 2 different incompatibility groups were identified in the 7 plasmid-bearing A faecalis strain.
Cardiopulmonary effects of acepromazine and of the subsequent administration of ketamine in the dog
Authors: Farver Tom B. , Haskins Steve C. , Patz John D.
Published: February 2025

Cardiopulmonary consequences of acepromazine (0.2 mg/kg of body weight, iv) followed by iv administration of ketamine (10 mg/kg) were evaluated in 13 dogs. Acepromazine caused significant decreases in arterial blood pressure, stroke volume, left ventricular work, left ventricular stroke work, breathing rate, minute ventilation, and oxygen consumption. Subsequent administration of ketamine caused significant increases in heart rate, effective alveolar volume, alveolar-arterial PO2 gradient (transient increase), venous admixture (transient increase), and PaCO2 and
(transient increases), and caused significant decreases in stroke volume, minute ventilation, physiologic dead space, and arterial and venous PO2 (transient decreases).
In vitro study of polymorphonuclear leukocyte damage to mammary tissues of lactating cows
Authors: Capuco A. V. , Paape M. J. , Nickerson S. C.
Published: February 2025

Effects of polymorphonuclear neutrophil leukocytes (pmn) on mammary tissue of lactating cows were studied in vitro. The pmn were isolated from mammary glands of nulliparous heifers given an injection of 5 μg of Escherichia coli endotoxin. Mammary tissue was obtained from noninfected quarters of 5 lactating Holstein cows and was cultured in supplemented medium 199. Mammary explants were treated by addition of intact or lysed pmn (105, 106, 107/ml) or pmn (105, 107/ml) which were allowed to phagocytose opsonized zymosan. Controls included cultures of mammary tissue alone, pmn alone, and mammary tissue plus zymosan. Cultures were incubated at 37 C for 3, 8, or 24 hours. Tissue from 1 randomly selected culture/treatment was weighed and processed for microscopy. Tissue from remaining cultures was incubated with [3H]amino acids or [14C]acetate to determine rates of protein and fatty acid synthesis. Media from all cultures were assayed for activity of the lysosomal enzyme, N-acetyl-β-d-glucosaminidase.

An increase (P < 0.02) in the activity of this enzyme was detected in the medium of explant cultures treated with 107 phagocytosing pmn/ml at 3 and 8 hours and with 107 intact or lysed pmn/ml at 8 hours. Treatment did not inhibit (P > 0.05) rates of protein or fatty acid synthesis. Microscopic examination indicated that epithelial cell damage resulted from treatment with 106 and 107 intact, lysed, or phagocytosing pmn/ml. Greatest morphologic damage resulted from treatment with phagocytosing pmn.
Electroacupuncture-induced analgesia in sheep: Measurement of cutaneous pain thresholds and plasma concentrations of prolactin and β-endorphin immunoreactivity
Authors: Bossut D. F. B. , Stromberg M. W. , Malven P. V.
Published: February 2025

Eleven male and 15 female sheep were subjected to electroacupuncture (ea) treatment, using 2 needle loci described in the Chinese veterinary literature as Yao Pang (lumbar region) and San Yang Lu (1 thoracic limb). Non-injurious cutaneous stimuli were applied, using a calibrated pin-prick probe, a clamp, and a contact heat (75 to 95 C) probe. Cutaneous pain thresholds (pt) were quantified in 7 body areas during control (no acupuncture needles and no electrostimulation) and ea experiments, before and after iv injection of naloxone. Using each animal as its own control, each ea experiment was classified as inducing either good or poor anagelsia on the basis of whole-body pt values. Plasma concentrations of immunoreactive β-endorphin (βE) and prolactin were quantified in sequential plasma samples collected at 9-minute intervals throughout all experiments.

Electroacupuncture at each locus increased (P < 0.01) pt (ie, caused cutaneous analgesia) in 6 of 7 body areas, and increased (P < 0.05) plasma concentrations of immunoreactive βE and prolactin. In ea experiments in which good analgesia was induced, plasma βE was increased more (P < 0.05) than in ea experiments in which poor analgesia was induced. This difference was more evident for the Yao Pang locus. Generally, plasma prolactin concentrations were increased more with good analgesia than with poor analgesia for the Yao Pang locus. Electroacupuncture stimulation of the San Yang Lu locus was associated with higher plasma βE concentrations than that associated with the Yao Pang locus. Increases in plasma prolactin concentrations were comparable between loci. Intravenous injection of naloxone (1.1 mg/kg of body weight) generally decreased the increased pt that had resulted from ea of the Yao Pang locus, whereas naloxone did not have a consistent effect on the increased pt resulting from ea of the San Yang Lu locus. In control experiments, naloxone briefly increased plasma βE concentrations. In ea experiments in which good analgesia was induced, naloxone decreased plasma prolactin concentrations. Because ea-induced increases in plasma βE and prolactin concentration correlated with the amount of ea-induced analgesia, βE and prolactin in plasma can be considered indices of analgesia, but their putative function in the mechanisms of endogenous pain inhibition remains equivocal.
Familial nonspherocytic hemolytic anemia in Poodles
Authors: Randolph J. F. , Center S. A. , Kallfelz F. A. , Blue J. T. , Dodds W. J. , Harvey J. W. , Paglia D. E. , Walsh K. M. , Shelly S. M.
Published: February 2025

Nonspherocytic hemolytic anemia, characterized by marked reticulocytosis, hepatosplenomegaly, hemosiderosis of reticuloendothelial organs and bone marrow myelofibrosis, and osteosclerosis, was diagnosed in 5 related Poodles. The unremitting anemia was clinically evident by 1 year of age, and was fatal as early as 3 years of age. Despite intense diagnostic endeavors including rbc fragility studies, rbc enzyme assays, and hemoglobin electrophoresis, the cause of this nonspherocytic hemolytic anemia remains to be determined.
Serodiagnosis of inapparent caseous lymphadenitis in goats and sheep, using the synergistic hemolysis-inhibition test
Authors: Brown Corrie C. , Olander Harvey J. , Zometa Carlos , Alves Selmo F.
Published: February 2025

The synergistic hemolysis-inhibition (shi) test, a serologic test for the detection of infection with Corynebacterium pseudotuberculosis, was applied to serum samples from 196 goats and 76 sheep, including animals both with and without C pseudotuberculosis abscesses. Fifty-one of 52 (98%) goats and 27 of 28 (96%) sheep with abscesses caused by C pseudotuberculosis had seropositive titers. Seropositivity continued on subsequent samplings, even after superficial lesions were completely healed. The shi test may detect subclinically infected animals, as well as animals with clinically recognizable lesions. Of the animals without abscesses, 53 of 186 (28%) goats and 4 of 41 (10%) sheep were seropositive. Either the shi test is lacking in specificity or these titers are a reflection of a past or a current infection without any grossly visible abscesses.
Production and preliminary characterization of murine monoclonal antibodies to Ichthyophthirius multifiliis, a protozoan parasite of fish
Authors: Dickerson H. W. , Evans D. L. , Gratzek J. B.
Published: February 2025

An initial panel of 34 hybridomas, each secreting antibodies reactive with an infective theront stage of an Ichthyophthirius multifiliis isolate, was produced. Three of these cell lines, each producing immunoglobulin M class antibodies, were cloned by limiting dilution and were expanded as ascites-producing tumors in syngeneic mice. Three monoclonal antibodies (mab) reacted with intact whole theronts in an enzyme-linked immunosorbent assay to dilutions of 1:10,000 in ascitic fluids and had a similar pattern of surface and cytoplasmic staining in indirect immunofluorescent tests. Only antigen specified by mab E6 could be characterized by acrylamide gel electrophoresis and immunoblotting; initial data indicated a molecular weight of 200,000. Physicochemical properties of the determinants recognized by the 3 mab were tested by pronase digestion and periodate oxidation. Seemingly, a protein, glycoprotein, and carbohydrate were recognized by mab E6, FE10, and AC8, respectively.
Bovine leukocytes in mammary secretions during involution: Surface protein changes
Authors: Hurley Walter L. , Finkelstein Eve
Published: February 2025

Changes in surface proteins of leukocytes in bovine mammary secretions were examined during mammary involution. Leukocytes were collected from mammary secretions from involution days (id) 1 to 36 and were labeled with biotin. Labeled proteins were separated by polyacrylamide-gel electrophoresis, transferred to nitrocellulose by protein blotting, and detected with avidinperoxidase and color reagent. The population of leukocytes in mammary secretions changed during involution from predominantly polymorphonuclear leukocytes (pmn) at id 1 to predominantly mononuclear leukocytes by id 36. The gel profile of surface proteins also changed during involution, and some of those changes may have been caused by shifts in leukocyte populations. Profiles of surface proteins of leukocytes from mammary secretions containing predominantly pmn (id 1) were different from profiles of pmn from blood. A distinctive change in the pattern of surface proteins on the leukocytes occurred between id 1 and 3, even though the proportion of pmn did not change appreciably between those days.
Induced atrophic rhinitis in rats
Authors: Kimman T. G. , Kamp E. M.
Published: February 2025

Infections with Bordetella bronchiseptica and Pasteurella multocida were inducted in newborn specific-pathogen-free rats. Turbinate atrophy was quantified by measuring the length of the osseous core of the ventral turbinates. Bordetella bronchiseptica readily colonized the nasal cavity. Inoculated rats developed serum agglutinating antibodies to B bronchiseptica. Turbinate atrophy, correlating with a severe inflammatory reaction, was observed after dual inoculation with B bronchiseptica or after a single inoculation when the inoculum contained relatively large numbers of B bronchiseptica. Pasteurella multocida only rarely colonized the nasal cavity, even after prior instillation of weak acetic acid solution or B bronchiseptica.
Prevalence of K88, K99, and 987P pili of Escherichia coli in neonatal pigs with enteric colibacillosis
Authors: Evans M. G. , Waxler G. L. , Newman J. P.
Published: February 2025

One hundred nineteen live neonatal pigs with diarrhea ≤ 2 weeks old were euthanatized, and frozen sections of their ilea were submitted to an indirect fluorescent antibody technique to identify K88, K99, and 987P pili (also referred to as F-4, F-5, and F-6 pili, respectively) in Escherichia coli. Ten-centimeter ileal sections were used to determine numbers of lactose-fermenting bacteria.

Of 52 pigs in which E coli pili were found, 14 had K88 (27%), 23 had K99 (44%), 13 had 987P (25%), and 2 had K88 and K99 simultaneously (4%). Numbers of lactose-fermenting bacteria were significantly (P ≤ 0.05) higher in pigs with piliated E coli than in pigs without piliated E coli.

Results of this study indicated that piliated E coli are a major cause of enteric disease in neonatal swine in Michigan, and that in pigs ≤ 2 weeks of age, K99 was the most frequently encountered pilus antigen.
Trigeminal nerve-evoked potentials in the dog
Authors: Whalen L. R. , Spurgeon T. L.
Published: February 2025

Brain stem and cerebrocortical potentials were evoked by electrical stimulation of the infraorbital nerve of dogs and recorded through needle electrodes placed adjacent to the contralateral parietal bone. Five individual, short latency peaks were recorded in each averaged trigeminal nerve-evoked potential and were identified as I, II (A and B), III (A and B), pi (a, b, and c), and ni. Mean peak latencies ± 1 sd were as follows: I = 0.9 ± 0.1 ms, IIA = 1.7 ± 0.1 ms, IIB = 2.5 ± 0.1 ms, IIIA = 3.6 ± 0.15 ms, IIIB = 4.1 ± 0.2 ms, pia = 5.2 ± 0.15 ms, pib = 6.4 ± 0.2 ms, pic = 7.3 ± 0.3 ms, and ni = 11.0 ± 0.6 ms.

Trigeminal nerve-evoked potentials recorded through needle electrodes were essentially the same as potentials evoked by direct stimulation of the infraorbital nerve and recorded directly from the dura mater overlying the contralateral rostral suprasylvian gyrus. The specificity of the stimulating site was verified by recording before and after the infraorbital nerve was cut proximal to the stimulating site.
Response to isoantigens and mitogens in the cat: Effects of cyclosporin A
Authors: Gregory C. R. , Taylor N. J. , Willits N. H. , Theilen G. H.
Published: February 2025

Growing interest in the use of domesticated cats to study immune-mediated disease and in the research and clinical application of organ and tissue transplantation provided the need for in vitro assays estimating histocompatibility and cell-mediated immunity. In the present study, a whole-blood lymphocyte-stimulation microassay and mixed lymphocyte-response assay were adapted and used to measure significant responses from feline lymphocytes to mitogen and lymphocyte-defined histocompatibility antigens. The addition of cyclosporin A to whole-blood lymphocyte-stimulation microassay and mixed lymphocyte-response assay produced similar non-cytotoxic decrease in lymphocyte responses seen in other species.
Pharmacokinetics and tissue residues of Gentamicin in lactating cows after multiple intramuscular doses are administered
Authors: Haddad Nadim S. , Ravis W. R. , Pedersoli W. M. , Carson R. L.
Published: February 2025

Gentamicin was administered im to 6 healthy, mature, lactating cows at a dosage of 3.5 or 5 mg/kg of body weight every 8 hours for 10 consecutive days (total, 30 doses). Endometrial biopsies were done at 72, 136 or 144, and 216 hours after the first dose was administered. On the 10th day, just before the last dose of gentamicin was administered, blood samples (designated 10th-day base-line samples) were obtained, and serial blood samples were obtained for 144 hours after the last injection was given. The cows were catheterized on the 10th day, and urine was obtained for 10 to 18 consecutive hours. Milk samples were also obtained. The cows were slaughtered at different times after the last dose was given, and samples were taken from 22 tissues and organs. Serum, milk, urine, and tissue gentamicin concentrations were determined by radioimmunoassay.

Serum gentamicin concentrations were best fitted to a 2-compartment open model. The mean half-lives for absorption, distribution, and elimination were 0.16 ± 0.14, 2.59 ± 0.53, and 44.91 ± 9.38 hours, respectively. Total body clearance and renal clearance were 1.65 ± 0.69 and 1.32 ± 0.25 ml/min/kg, respectively. The percentage of the dose excreted unchanged in the urine at 8 hours after the last dose was given was 98 ± 15. As expected, of the tissues examined, the gentamicin concentrations in the kidney cortex and medulla were 1,500 times greater than those in serum. Renal function remained within the baseline range during the 10 days of gentamicin treatment. In order to achieve average serum gentamicin concentrations of 5.95 μg/ml, maximal steady-state concentrations of 12.34 μg/ml, and minimal steady-state concentrations of 2.19 μg/ml, a dosage regimen of 5 mg/kg of body weight every 8 hours is recommended.