bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimentally Induced Chronic Aflatoxicosis in Rabbits
Authors: Clark J. Derrell , Jain Anant V. , Hatch Roger C. , Mahaffey Edward A.
Published: February 2025

Male New Zealand White rabbits were given (orally) 4 dosage levels of aflatoxin B1 (afb1): 0.025, 0.0375, 0.05, and 0.0625 mg/kg of body weight daily for 24 days. Feed was available ad libitum. Other rabbits were ration-fed without added afb1, with the following amounts: 10, 20, 40, 80, and 160 g/day. Clinical condition, feed consumption, selected blood values, and gross and microscopic pathologic changes were determined.

The 2 smaller doses of afb1 did not produce clinical toxicosis or blood changes. The 2 larger doses produced anorexia, decreased weight gains, lethargy, emaciation, dehydration, icterus, and death. Clinicopathologic changes included decreased plasma total protein (tp) and increases in blood clotting time, serum bilirubin concentration, and alanine aminotransferase (alt) and aspartate aminotransferase (ast) activities. There were no consistent dose-related changes in serum alkaline phosphatase (alp) activity and little change in pcv and hemoglobin concentration.

Reduced feeding did not affect clotting time and serum bilirubin and ast values. Mean values for pcv, hemoglobin, and tp were within usual limits, but gradually decreased with time in animals given 10, 20, and 40 g of feed/day. In the latter rabbits, mean serum alp activity gradually decreased to less than that of control rabbits. Mean serum alt activity was normal except on day 23 when the values were moderately increased in rabbits given 10 and 40 g of feed/day.

Gross pathologic changes were observed in most rabbits given 0.05 and 0.0625 mg of afb1/kg each day. Icterus of body tissues was apparent, and liver of the icteric animals was yellow to orange. Traces of fresh blood were found within the jejunal lumen.

Microscopic changes were observed only in the liver and were more consistent and severe in animals given the daily dosages of 0.05 and 0.0625 mg of afb1/kg. Histopathologic changes in liver sections from rabbits given the 0.025 and 0.0375 mg of afb1/kg dosage included increased cytoplasmic eosinophilia and loss of cytoplasmic granularity of hepatocytes. In livers of some rabbits, a mild increase in the proportion of binucleate hepatocytes and mild karyomegaly was noted. Bile duct hyperplasia was not evident. Liver sections from rabbits given the 2 larger dose concentrations of afb1 had similar but more severe changes in hepatocytes. In addition, bile stasis was found within biliary canaliculi of several rabbits. Portal triads in some liver sections contained many cells with fusiform nuclei and little visible cytoplasm. Hepatic necrosis was not detected in any of the rabbits. Hyperplasia of biliary ductular epithelium was seen in 1 rabbit.
Acute Oral Median Lethal Dose of Haloxon and Coumaphos in Sheep as Influenced by Plasma A Esterase
Authors: Baker Norman F. , Fisk Robert A. , Stormont Clyde
Published: February 2025

Determination of the acute oral median lethal dose (ld50) of haloxon for lambs classified as to the presence or absence of plasma esterases (A esterase; EsA) rapidly hydrolyzing haloxon revealed markedly different values for the 2 phenotypes of sheep. The ld50 for EsA— lambs was 763 mg/kg of body weight with 95% confidence limits of 543 to 1,072 mg/kg. The acute oral ld50 for EsA+ lambs remains undetermined but was demonstrated to be in excess of 11,392 mg/kg.

The acute oral ld50 for a closely related organophosphate (coumaphos) was not different in the 2 phenotypes of sheep.
Demonstration of Canine Distemper Viral Antigen in Paraffin Sections, Using an Unlabeled Antibody-Enzyme Method
Authors: Ducatelle R. , Coassement W. , Hoorens J.
Published: February 2025

A peroxidase technique was used for the inununohistochemic demonstration of canine distemper viral antigen in formalin-fixed and paraffin-embedded tissues. The antigen was detected in epithelial cells and nerve cells of young dogs.

The application of a combined peroxidase and hematoxylin and eosin stain as a diagnostic technique is discussed.
Effects of Copper Pretreatment Upon the Toxicity of Selenium in Ponies
Authors: Stowe H. D.
Published: February 2025

Thirty-four adult ponies were used to determine the effects of single oral doses of copper (Cu) supplements (0, 20, and 40 mg of Cu/kg of body weight) on the toxicity of oral doses of selenium (Se) supplements (0, 2, 4, 6, and 8 mg of Se/kg of body weight) administered 24 hours after the copper was given. Signs of Se toxicosis—sweating, diarrhea, tachycardia, tachypnea, mild pyrexia, lethargy, and colic—developed in ponies given 6 and 8 mg of Se/kg of body weight without Cu pretreatment. Two of 4 ponies given 6 mg of Se/kg and both ponies given 8 mg of Se/kg without Cu pretreatment died within 36 hours after being given the Se. All ponies given either 20 or 40 mg of Cu/kg were unaffected by the subsequent Se supplement, regardless of dosage. The Cu pretreatment did not seem to inhibit absorption of Se, based on serum Se concentrations, but hastened the disappearance of the Se from the serum.
Lesions in Clinically Healthy Cattle Persistently Infected with the Virus of Bovine Viral Diarrhea—Glomerulonephritis and Encephalitis
Authors: Cutlip R. C. , McClurkin A. W. , Coria M. F.
Published: February 2025

Four clinically healthy cattle persistently infected with the virus of bovine viral diarrhea were examined for viral antigen and lesions. Antigen was seen by direct immunofluorescence in cytoplasm of the neurons of the brain and cervical part of the spinal cord, cells and basement membrane of renal glomeruli, reticular cells of lymph nodes and spleen, epithelial cells of small intestinal crypts and renal and testicular tubules, and endothelial cells of blood vessels. Infected neurons were pyknotic and surrounded by astrocytes and macrophages. A few blood vessels in the brains were cuffed with mononuclear cells. Basement membranes of renal glomeruli were irregularly thick with eosinophilic material, and mesangial cells in the glomeruli were plentiful. The virus had a direct effect on some tissues, but was restricted in its cytopathogenicity and was not eliminated by defense mechanisms of the host. Renal glomerular lesions were believed to have an immunologic basis.
Passive Protection of Calves Against Experimentally Induced and Naturally Occurring Enteric Colibacillosis
Authors: Myers L. L.
Published: February 2025

Pregnant beef cows were vaccinated twice before calving with a 4-strain Escherichia coli bacterin, a K99 E coli bacterin, or a placebo. The 4-strain bacterin contained formalin-killed whole cells of 3 serogroups (O9:K35:K99, O101:K30:K99, and O8:K85:K99) of enterotoxigenic E coli (etec) prevalent in nature and strain B41 (O101:K–:K99), the source strain for the K99-pilus antigen. The K99 bacterin contained whole cells of etec strain B41. The degree of protection elicited in calves against experimentally induced (experiment 1) find naturally occurring (experiment 2) enteric colibacillosis was determined. In experiment 1, newborn colostrum-fed calves were orally challenge inoculated with 5 × 1010 viable cells of 1 of 2 serogroups (O9:K35:K99 or O8:K85:K99) of etec. None of the 21 calves whose dams were vaccinated with the 4-strain bacterin developed enteric disease. This compares with the development of enteric disease in 7 of 21 calves whose dams were given the K99 bacterin and 14 of 20 calves from dams given the placebo.

In experiment 2, involving 2,039 pregnant beef cows in 12 privately owned herds, 5 of 676 calves whose dams were vaccinated with the 4-strain bacterin died of naturally occurring enteric disease, compared with 16 of 699 calves whose dams were given the placebo. Significantly fewer calves whose dams were vaccinated with the 4-strain bacterin developed severe enteric disease in experiment 1 (P < 0.005), or died of enteric disease in experiment 2 (P < 0.025), as compared with the number of calves whose dams were given the placebo. In experiment 2, there was considerable interherd variation in efficacy of the 4-strain bacterin. In both experiments, severe enteric colibacillosis occurred in fewer (but not significantly fewer) calves from dams vaccinated with the K99 bacterin as compared with the colibacillosis that occurred in calves from dams given the placebo. Lack of efficacy of the K99 bacterin was probably due to an insufficient amount of K99 antigen in the bacterin.

Using the reverse radial immunodiffusion test, precipitating antibodies against E coli-capsular K antigens 30, 35, and 85 were detected in colostral whey from 21 of 27 dams vaccinated with the 4-strain bacterin. Colostral antibodies against K antigens 30, 35, and 85 were not detected in dams injected with the K99 bacterin or the placebo. The geometric means of the K99-agglutinating antibody titers were higher in cows vaccinated with the 4-strain bacterin than in cows vaccinated with the K99 bacterin. In experiment 1, there was a good correlation between K99 antibody titer and the development of enteric disease in calves from dams vaccinated with the K99 bacterin.
Vaccination of Dogs Against Pseudorabies (Aujeszky's Disease), Using an Inactivated-Virus Vaccine
Authors: Pensaert M. B. , Commeyne Sophie , Andries K.
Published: February 2025

Serologic and virus isolation studies were performed on dogs vaccinated against pseudorabies (Aujeszky's disease). A commercially available inactivated-virus vaccine was used in 29 dogs. The dogs were vaccinated once subcutaneously (sc; group A, n = 7), with 2 doses sc (group B, n = 9), with 1 dose sc followed by 1 im (group C, n = 8), and with 2 doses im (group D, n = 5). Twelve vaccinated dogs were challenge-exposed oronasally and 5 dogs were challenge-exposed im, using 5 × 106.0 tcid50 of virulent virus. The oronasal challenge exposure caused typical disease in nonvaccinated control dogs (group E, n = 4). Healthy dogs (group F, n = 2) exposed to infected dogs remained seronegative and did not become clinically ill. Disease in the challenge-exposed control group E dogs and in the vaccinated dogs (groups A, B, C, and D) was characterized by the progressive development of anorexia, cns depression, difficulties in swallowing, hypersalivation, dyspnea, ataxia or circling, and unconsciousness; then death. Head scratching was frequent, particularly around the eyes. Death occurred between 12 and 48 hours after clinical signs appeared.

Serum-neutralizing antibodies were detected in 15 of 23 dogs (groups A, B, and C) after the initial or the 1st sc vaccination. All dogs were seropositive after 2 vaccinations, regardless of route. The highest titers were obtained in the group D dogs (2 im administrations). Only 2 of the 12 oronasally and 1 of the 5 im challenge-exposed dogs survived. Virus isolation was attempted in 11 dogs that died after oronasal challenge exposure. Virus was isolated from the brain and cervical part of the spinal cord from these 11 dogs; it was regularly obtained from tonsils and parotid salivary gland, but rarely from the thoracic part of the spinal cord, lungs, and heart. Conjunctival tissue was positive in 5 of the 6 dogs examined. The present results indicate that protection of dogs against pseudorabies may be difficult to achieve with an inactivated-virus vaccine.
Therapeutic and Toxic Plasma Concentrations of Digoxin in the Cat
Authors: Erichsen Deborah F. , Harris Stanley G. , Upson Dan W.
Published: February 2025

Nonanesthetized cats of both sexes were given oral digoxin (0.011 mg/kg of body weight) in 3 forms: elixir, tablet, and crushed tablet mixed with food. Mean peak plasma concentrations of digoxin were highest with the elixir (1.89 ± 1.02 ng/ml) and lowest with the crushed tablet mixed with food (0.66 ± 0.35 ng/ml). Male cats had significantly higher (P < 0.10) mean plasma digoxin concentrations than did female cats.

A 2nd group of nonanesthetized cats of both sexes was given digoxin elixir orally at therapeutic amounts (0.011 mg/kg) once a day for 4 consecutive days. The cumulative effect of digoxin resulted in 62% increase in the mean peak plasma concentration and 231% increase in the 24-hour plasma concentration of digoxin over the 4-day period. Male cats had a significantly (P < 0.05) higher mean plasma digoxin concentration than did female cats. Significant changes in the ecg were not recorded.

A 3rd group of nonanesthetized cats of both sexes was given a single toxic dose (0.11 mg/kg) of digoxin elixir orally. All cats showed clinical signs of digitalis toxicosis (depression, vomiting, salivation, and anorexia) before ecg changes appeared. Alterations in the ecg were minimal; the most important changes were a slight increase in the PQ interval, an elevated ST segment, and decreased heart rate. Plasma concentrations of digoxin at the time of vomition ranged from 4.45 to 12.12 ng/ml with a mean peak plasma value of 7.37 ± 3.61 ng/ml. The cats were clinically ill for 48 to 96 hours. A plasma digoxin concentration of 2.3 ng/ml was not toxic.
Comparisons of Serotests with Calf Inoculations for Detection of Carriers in Anaplasmosis-Vaccinated Cattle
Authors: Luther D. Gene , Cox Hollis Utah , Nelson Walter O.
Published: February 2025

Fifteen months after discontinuing vaccination for anaplasmosis in a herd of 131 cattle, 126 of the animals were reactive to the complement-fixation or card-agglutination tests. Inoculation of splenectomized calves proved that 9 animals were carriers and 117 animals were free of anaplasmosis. Anaplasmosis vaccination induced titers detectable by the standard serotests that persisted for at least 15 months.
Canine Babesiosis: Indirect Fluorescent Antibody Test for a North American Isolate of Babesia gibsoni
Authors: Anderson John F. , Magnarelli Louis A. , Sulzer Alexander J.
Published: February 2025

A sensitive and reproducible indirect fluorescent antibody test for a North American isolate of Babesia gibsoni was described. In blind tests (coded samples), titer reproducibility was within two 4-fold dilutions and the appropriate positive and negative sera were identified as such. Babesia gibsoni antisera reacted with homologous antigen at one to three 4-fold dilutions greater than with the following heterologous species: B bigemina, B argentina, B equi, Plasmodium falciparum, and P brasilianum. The titer of B canis antiserum to B gibsoni antigen was 1:1,024.

Low parasitemia (< 0.01%) of B gibsoni preceded development of minimum significant titer (1:64) by 10 days in a splenectomized dog. Maximum titer was detected 25 days later. In a nonsplenectomized dog, low parasitemia (< 0.01%) was noted 6 days after injection; it reached 8% at 5 weeks and decreased to and remained below 1% at 7 weeks. A titer of 1:256 occurred at 25 days and increased to 1:65,536 at 18 weeks. Thereafter, it fluctuated to 1:4,096 until the experiment was ended at 24 weeks.

Organismic antigen retained its reactivity for 5 days at 5 C.

This indirect fluorescent antibody test should be useful in the diagnosis of dogs infected with B gibsoni.
Silicon in Plasma of Sheep
Authors: Hidiroglou M. , Ivan M. , Ihnat M.
Published: February 2025

Plasma silicon (Si) concentrations were determined (i) in lambs at 49 days of age reared artificially in confinement (system A), or fed a postweaning diet, or suckled and reared conventionally (system B), (ii) in 2-year-old ewes reared under systems A and B, (iii) in lambs at 49, 70, and 100 days of age reared under system A, and (iv) in lambs (reared under system A) injected with a vitamin D3 preparation. The lambs reared under system A had a significantly lower (P < 0.01) plasma Si concentration than did lambs reared under system B, but in ewes there was no significant difference (P > 0.05) between the 2 rearing systems. Plasma Si concentration of lambs increased (P < 0.01) as the lambs aged.

The vitamin D3 injection had no significant effect (P > 0.05) on the plasma Si value.
Transfer of Tritium-Labeled Vitamin D3 and 25-Hydroxyvitamin D3 in Ovine Placenta
Authors: Hidiroglou M. , Williams C. J.
Published: February 2025

Placental transmission of iv-administered label from vitamin D3 and 25-hydroxycholecalciferol was studied in gestating ewes. Radioactivity concentrations were higher in the tissues of ewes dosed with vitamin D3 than in those dosed with 25-hydroxycholecalciferol. Concentrations were higher in maternal tissues than in fetal tissues. The highest radioactivity concentrations were found in the kidneys, followed by concentrations in the adrenal glands.
Glucose Uptake and Insulin Secretory Responses to Intravenous Glucose Loads in the Dog
Authors: Rottiers R. , Mattheeuws D. , Kaneko J. J. , Vermeulen A.
Published: February 2025

Twenty-one healthy young nonanesthetized Dalmatian dogs (10 male, 11 female) were given iv glucose loads between 300 and 1,500 mg/kg of body weight in a standard time period of 30 s. The fractional glucose turnover rates and the insulin peak responses gradually increased with glucose loads up to 1,000 mg/kg, and the total insulin secretion with loads to 1,250 mg/kg and remained constant. The insulinogenic index (ΔI/ΔG) varied inversely with the size of the glucose loads. The pattern of responses indicates that the optimum glucose load is near 600 mg/kg for evaluating normal glucose metabolism in dogs by the iv glucose loading technique.
Cardiopulmonary Effects of Butorphanol Tartrate in Horses
Authors: Robertson J. T. , Muir W. W. , Sams R.
Published: February 2025

SUMMARY AND CONCLUSIONS

The cardiopulmonary and behavioral effects of butorphanol were evaluated in pain-free adult horses. Butorphanol tartrate was administered iv in doses of 0.1, 0.2, and 0.4 mg/kg to the same horses on 3 separate occasions. There were no significant (P < 0.05) changes in heart rate, mean and diastolic arterial blood pressure, mean and diastolic pulmonary arterial blood pressure, or cardiac output recorded in the horses given these doses. Systolic arterial blood pressure was significantly (P < 0.05) increased in only the horses given the 0.2 mg/kg dose. Significant (P > 0.05) changes in electrocardiographic intervals, respiratory rate, arterial blood gas values, or pH were not recorded. Increasing iv doses of butorphanol resulted in varied behavioral changes, but were predominantly excitatory.
A Swine Dysentery Model for Evaluation of Drug Prophylaxis: Efficacy of Various Drugs in the Control of Swine Dysentery
Authors: Raynaud J. P. , Brunault G. , Patterson E. B.
Published: February 2025

A swine dysentery (sd) model that produces consistent, homogeneous, and severe sd was used in 2 experiments to compare the prophylactic effectiveness of 5 commercially available swine feed additive products. Under the conditions of these studies, carbadox and carbadox + sulfamethazine proved to be the most effective agents in preventing sd during the infection + medication and postmedication periods. Olaquindox was effective in preventing sd in the infection + medication period; however, sd recurrence was high during the postmedication period. Nithiamide and chlortetracycline + sulfamethazine + penicillin were least effective in preventing sd during the infection + medication and postmedication periods.
Enzyme-Linked Immunosorbent Assay for Measurement of Antibody Responses to Dirofilaria immitis in Experimentally Infected Dogs
Authors: Grieve Robert B. , Mika-Johnson Marcia , Jacobson Richard H. , Cypess Raymond H.
Published: February 2025

The chronology of the antibody response to Dirofilaria immitis was measured in 2 groups of experimentally infected Beagle dogs. An enzyme-linked immunosorbent assay (elisa), using a semipurified, adult D immitis-derived antigen was used to quantitate antibody levels. Group A consisted of 4 dogs inoculated once with D immitis infective larvae, 4 dogs inoculated twice with D immitis infective larvae, and 4 noninoculated dogs. Group B consisted of 26 dogs which were all infected with D immitis; however, 16 of these were given daily prophylactic concentrations of diethylcarbamazine (dec) beginning 5 days before inoculation.

Significant levels of antibody were demonstrable 16 weeks after inoculation of group A dogs and remained significantly increased throughout the study. There were no significant differences in antibody levels in dogs inoculated once or twice. Nontreated and diethylcarbamazine-treated dogs in group B developed significant antibody titers 11 weeks after inoculation. Significant differences in antibody titers between treated and nontreated dogs were first observed 13 weeks after inoculation; these differences remained for the duration of the investigation. There was no apparent correlation between antibody levels and either adult worm numbers or microfilaria counts.
Survival of Viruses in Fermented Edible Waste Material
Authors: Wooley R. E. , Gilbert J. P. , Whitehead W. K. , Shotts E. B. , Dobbins C. N.
Published: February 2025

The survival of selected viruses in fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Seven viruses, including pseudorabies, Newcastle disease, infectious canine hepatitis, avian infectious bronchitis, measles, vesicular stomatitis, and a porcine picornavirus were inoculated into a mixture of ground food waste (collected from a school lunch program) containing Lactobacillus acidophilus. Mixtures were incubated at 5 C, 10 C, 20 C, and 30 C for 96 hours. Temperature, pH, and redox potential were monitored. Samples for virus isolation were obtained daily. Newcastle disease virus and infectious canine hepatitis virus survived the entire test period. The porcine picornavirus was inactivated at 30 C after 72 hours, but survived for the entire test period at the other temperatures. Pseudorabies virus was inactivated at 20 C and 30 C within 24 hours, but survived for 48 hours at 10 C and 96 hours at 5 C. Avian infectious bronchitis virus was inactivated at 20 C and 30 C within 24 hours, but survived 72 hours at 5 C and 10 C. Measles and vesicular stomatitis viruses were rapidly inactivated at all 4 temperatures.
Monitoring the Estrous Cycle of the Asian Elephant (Elephas maximus), Using Urinary Estrogens
Authors: Ramsay E. C. , Lasley B. L. , Stabenfeldt G. H.
Published: February 2025

The estrous cycle of the Asian elephant (Elephas maximus) was monitored by analysis of urinary estrogens. Daily morning urine samples were analyzed for estrone (E1), estradiol (E2), and total immunoreactive estrogen (ET). The ET values were shown to correlate poorly with E1 and E2 values and failed to reveal any patterns of reproductive cycling. Daily E1 and E2 values, indexed by creatinine concentrations, demonstrated cyclic profiles in those samples of sufficient concentration. The technique offered a simple, noninvasive method of documenting ovarian function in the elephant.
Morphologic Characteristics of the Parathyroid and Thyroid Glands and Serum Immunoreactive Parathyroid Hormone in Dogs with Pseudohyperparathyroidism
Authors: Yarrington John T. , Hoffman Walter E. , Macy Dennis , Hawker Charles
Published: February 2025

Hypercalcemia, normo- or hypophosphatemia, and increased urinary calcium clearance were observed in 8 dogs with malignant disease consisting of lymphosarcoma (n = 4), lymphogenous leukemia with bone involvement (n = 2), or carcinoma arising in the perianal region (n = 2). Parathyroid glands from these dogs had a normal or atrophic microscopic appearance. Ultrastructurally, the chief cells of the parathyroid glands had small cytoplasmic areas devoid of secretory granules and containing few organelles associated with hormonal synthesis, which is indicative of an inactive phase of the secretory cycle. In relationship to total serum calcium, serum canine immunoreactive parathyroid hormone was moderately increased in 3 dogs whose parathyroid glands had morphologic characteristics of inactivity.

As a result of prolonged hypercalcemia, the thyroid glands contained prominent areas of parafollicular cell hyperplasia. The ultrastructure of a typical hyperplastic parafollicular cell was characterized by a large cytoplasmic area filled with numerous secretory granules and moderate numbers of organelles associated with hormonal synthesis.

The results of this study indicate that some nonendocrine malignant neoplasms of dogs may be capable of secreting a hypercalcemic substance immunologically indistinguishable from parathyroid hormone. In the absence of neoplastic involvement of bone, the canine disease has many similarities to pseudohyperparathyroidism.
Lyophilized Hyperimmune Equine Serum as a Source of Antibodies for Neonatal Foals
Authors: Burton S. C. , Hintz H. F. , Kemen M. J. , Holmes D. F.
Published: February 2025

In a study with 15 neonatal foals (5 per treatment group), foals were fed within 4 hours of birth as follows: 250 ml of colostrum, 250 ml of lyophilized serum reconstituted at 5 times the original concentration, or 250 ml of a mixture (1:1) of colostrum and lyophilized serum. Foal serum samples were tested for immunoglobulin (Ig)G concentration and titrated for anti-equine rhinovirus 1 and antiequine influenza A1 and A2 antibodies at 0 and 24 hours after foals were born. Except in a foal which had suckled the dam before treatment, there was no evidence of IgG or specific viral antibodies in the samples taken at birth.

There were no significant differences found in the serum IgG concentrations and antibody titers among the 3 treatment groups. Seemingly, IgG was absorbed efficiently from both serum and colostrum, so that the use of reconstituted lyophilized serum as a prophylactic measure of conferring passive immunity to a newborn foal deserves serious consideration.
Serum Immunoglobulin A Antibody Response in Swine Infected with Transmissible Gastroenteritis Virus, as Determined by Indirect Immunoperoxidase Antibody Test
Authors: Kodama Y. , Ogata M. , Shimizu Y.
Published: February 2025

Using an immunoperoxidase antibody test, the serum immunoglobulin (Ig) A antibody titer was determined in swine naturally infected with transmissible gastroenteritis (tge; group A), swine inoculated orally with high-virulent tge virus (group B), and swine inoculated im (group C) or orally (group D) with low-virulent tge virus. Studies were then made on the relationship between active immunity to tge and the serum IgA antibody titer.

In group A swine, serum IgA antibody and virus-neutralizing (vn) antibody were absent in the serum collected in the acute stage, but were detected from the serum collected in the convalescent stage. In group B swine, serum IgA antibody and vn antibody began to be detected on postinoculation day (pid) 7 and were still detectable on pid 100. In group C and D swine, vn antibody was detected, but serum IgA antibody was not.

Swine were inoculated orally with high-virulent tge virus and were challenge exposed orally with the same strain of virus on pid 18, 21, 80, and 120 (group E). None of group E swine manifested clinical signs of infection. Their serum IgA antibody titers ranged from 2 to 512 at the time of inoculation. Swine were inoculated im with low-virulent tge virus and intranasally with the same virus on pid 60 (group F). They were challenge exposed with the high-virulent strain of tge virus on pid 140, 200, and 260 (80, 140, and 200 days after the 2nd inoculation). At the time of challenge exposure, IgA antibody was undetected in serum at a 1:2 dilution. All group F swine had severe diarrhea 3 to 4 days after inoculation. Many of them vomited at the same time. In these swine, villous atrophy was observed in the jejunal portion of the small intestine. The vn antibody titer of porcine serum obtained at the time of challenge exposure was higher than was that determined in the group E swine.

Seemingly, serum IgA antibody titer determined by the immunoperoxidase antibody test may be an indicator of active immunity to tge.
Shedding of Treponema hyodysenteriae, Transmission of Disease, and Agglutinin Response of Pigs Convalescent from Swine Dysentery
Authors: Fisher Lawrence F. , Olander Harvey J.
Published: February 2025

Fecal shedding of Treponema hyodysenteriae, transmission of disease, and humoral antibody production against the large spirochete were evaluated in pigs convalescent from experimentally induced swine dysentery. Untreated pigs (n = 21) and 5 pigs that had been treated with virginiamycin were included in the study. Treponema organisms were culturally detected in the feces of 2 untreated pigs as long as 70 and 71 days, and in the feces of 1 treated pig as long as 83 days after the last clinical evidence of disease. Of 8 convalescent pigs that intermittently discharged T hyodysenteriae in their feces, 4 transmitted clinical disease to exposed susceptible pigs. One of the convalescent animals had been free of clinical signs of disease for 57 days before introduction of the susceptible pigs. Treated and untreated convalescent pigs developed similarly elevated agglutinin titers that were maintained as long as 150 days after infection. There was no apparent correlation between the frequency or duration of fecal shedding of the spirochetes and the magnitude of the agglutinin titers of the convalescent pigs.
Experimental Infection of Bovine Mammary Glands with Streptococcus uberis During the Nonlactating Period
Authors: McDonald J. S. , Anderson A. J.
Published: February 2025

A study was done to determine the susceptibility of nonlactating mammary glands to experimental infection with Streptococcus uberis ATCC 27958.

After inoculation on the day of dry off, none of the glands became infected. At 7 days after inoculation, 12% of the inoculated glands became infected; at 14 days, 50%; and at 21 days, 80%. During the last half of the nonlactating period, all inoculated glands became infected.
Anthelmintic Activities of Ivermectin Against Gastrointestinal Nematodes of Cattle
Authors: Yazwinski T. A. , Williams M. , Greenway T. , Tilley W.
Published: February 2025

The anthelmintic efficacy of ivermectin, a combined solution of the B1a and B1b fractions of avermectin, was assessed in a controlled trial. Twenty-four yearling calves experiencing naturally acquired, clinical gastrointestinal helminthiasis were evenly divided on the basis of weight into two 12-animal groups. The medicated group was given (subcutaneously) ivermectin at the dose rate of 200 μg/kg of body weight. The control animals were given the vehicle alone, at an equivalent rate. All animals were killed 14 days later. At necropsy of the calves, gastrointestinal helminth arithmetic means were 178,626 and 575 for the control and the treated groups, respectively, an overall reduction of 99.7%. Nematodes which were present at substantial levels were Ostertagia ostertagi, O lyrata, Trichostrongylus axei, Cooperia punctata, C oncophora, C mcmasteri, and Oesophagostomum radiatum. Anthelmintic activity of ivermectin was excellent regardless of nematode species, sex, or stage of development.
Further Studies with Polyglycolic Acid (Dexon) and Other Sutures in Infected Experimental Wounds
Authors: Varma S. , Lumb W. V. , Johnson L. W. , Ferguson H. L.
Published: February 2025

Seven suture materials (braided polyglycolic acid [bpga, Dexon], multifilament stainless steel, monofilament nylon, black braided silk, braided Dacron [bd, Mersilene], and plain and chromic catgut) were implanted in surgical wounds which were inoculated with 3 dilutions of Staphylococcus aureus. The degree of swelling was measured at 6, 10, 20, and 40 days. Monofilament nylon and multifilament steel produced the least amount of swelling; plain and chromic catgut produced the most. The bpga, bd, and silk caused swellings that were intermediate in degree.

In chronic implantations, inflammatory reactions to the various suture materials differed from those occurring soon after implantation. Response to steel and nylon remained minimal; that to silk was gradual, but overall became the most severe. There was slightly less response with bd. The catguts varied little from each other in their responses. Intense reaction was induced by bpga in the early stages, but the response was mild in chronic implantations.
Malignant Hyperthermia-Triggering Liability of Selected Inhalant Anesthetics in Swine
Authors: McGrath Charles J. , Rempel William E. , Jessen Carl R. , Addis Paul B. , Crimi Anthony J.
Published: February 2025

Twenty pigs, known to be malignant hyperthermia (mh)-susceptible by previous mh-positive [mh(+)] reactions to halothane testing, were given 5 inhalant anesthetics. The number of mh(+) responses evoked by the different anesthetics varied. In response to halothane, isoflurane, and enflurane, mh(+) reactions were exhibited by 12, 11, and 7 pigs, respectively. The number of mh(+) reactions to nitrous oxide (0) and methoxyflurane (1) was significantly (P = 0.02) less. In the present study, all 4 halogenated-hydrocarbon volatile liquid inhalant anesthetics were capable of evoking a mh(+) reaction in susceptible pigs.
Procedure for Granulokinetic Studies in the Horse with Chromium-51
Authors: Carakostas M. C. , Moore W. E. , Smith J. E.
Published: February 2025

A procedure with chromium-51 (51Cr) as the cell label that maintains high-cell viability for studying granulocyte kinetics in horses is described. The procedure combines and modifies several methods for isolating leukocytes and granulocytes for use in the horse when a large volume of labeled cells is required. Also described is an improved technique for measuring granulocyte specific activity in large serial blood samples, using a Ficoll-sedimentation method. The procedure should be useful for determining granulocyte kinetics in the horse, the only major domestic species for which such data are not available.
Segmental Thoracolumbar Subarachnoid Analgesia in Cows
Authors: Skarda R. T. , Muir W. W.
Published: February 2025

A new technique for producing segmental subarachnoid analgesia in adult cows without causing complete loss of locomotor control is described. Segmental subarachnoid analgesia was produced in 18 adult nonpregnant Holstein-Friesian cows. A 17-gauge Huber point directional needle was used to place a catheter with a stylet into the subarachnoid space at the lumbosacral intervertebral space and advance it craniad to the thoracolumbar intervertebral space. The position of the catheter was confirmed radiographically in 8 cows. A 5% solution of procaine hydrochloride was injected through the catheter. The volume injected varied between 1.5 ml (8 cows) and 2 ml (10 cows). The rate of injection was approximately 0.5 ml/30 s. In 5 cows, 1.5 or 2 ml of normal saline solution was injected intrathecally 1 hour before the injection of procaine hydrochloride. These cows served as the control group. Segmental analgesia was achieved 7 to 10 minutes after completing the procaine hydrochloride injection and extended between spinal cord segments T9 and L4 on one or both sides of the spinal cord. The average duration of analgesia, as determined by response to superficial and deep muscular pinprick stimulation at the L1 dermatome, was 43.7 ± 17.6 minutes, with a range of 22 to 80 minutes.

Significant decreases (P < 0.05) in respiratory rate and rectal temperature and increases in heart rate and subcutaneous temperature occurred in cows given procaine hydrochloride. The clinical application of the technique was demonstrated in one surgical procedure described. The advantages and disadvantages of segmental subarachnoid analgesia compared with segmental epidural analgesia are discussed.
Interaction of Blood-Borne Escherichia coli with Phagocytes of Spleen and Liver in Turkeys
Authors: Arp L. H. , Cheville N. F.
Published: February 2025

The response of splenic and hepatic macrophages to blood-borne virulent and avirulent Escherichia coli was studied in 3-week-old turkeys. Bacterial titers in blood, spleen, and liver were determined for 20 minutes after iv injection of E coli. Spleen and liver were examined by light and electron microscopy. Blood titers of avirulent E coli were reduced to 1/3,000 of their original level in 20 minutes, whereas titers of virulent E coli were only slightly reduced. The E coli localized in macrophages of hepatic sinusoids and splenic reticular sheaths (ellipsoids). In liver, phagocytosis was more efficient for avirulent E coli than for virulent E coli. In splenic macrophages, phagosomal membranes were separated from ingested avirulent E coli by a prominent space, whereas phagosomal membranes surrounding virulent E coli were wavy and closely apposed to the bacterial surface. The appearance of phagosomes may reflect the capacity of splenic macrophages to kill intracellular E coli. Cultural and histopathologic results indicated that virulent E coli resisted trapping and killing by macrophages of spleen and liver.
Variations of Plasma Enzymes in the Pony and the Dog After Carbon Tetrachloride Administration
Authors: Noonan Norine E.
Published: February 2025

Adult female dogs or pony mares were subjected to a nonlethal dose of CC14 (0.5 ml/kg of body weight). Amounts of several plasma enzymes thought to be indicative of hepatic disease were monitored. Plasma enzymes alanine aminotransferase, aspartate aminotransferase (ast), alkaline phosphatase (alp), arginase, γ-glutamyltransferase (ggt), and iditol dehydrogenase (id), as well as total plasma bilirubin, were determined in these animals before and after the administration of the CCl4. In the dog, ggt was not significantly increased, whereas alp values were increased during days 1 to 6. In the pony, ggt was significantly increased during the entire course of the study, whereas alp exhibited only small, transient (though significant) increases. Responses of id, ast, and alp were unremarkable when compared between the pony and the dog. Total bilirubin was significantly (P ≤ 0.05) increased from days 1 to 4 (pony) or days 5 to 8 (dog) after the CCl4 dose, but subsequently returned to or decreased below base-line values. Animals did not have evidence of icterus at any time.

Seemingly, the dog and the pony are distinct clinical entities, and only the appropriate laboratory tests for each species should be used to provide information for the clinicopathologic evaluation of hepatic disease.
Isolation and Identification of Five New Serotypes of Calicivirus from Marine Mammals
Authors: Smith Alvin W. , Skilling Douglas E. , Latham Arthur B.
Published: February 2025

Five new serotypes of calicivirus have been isolated from marine mammals. San Miguel sea lion virus (smsv)-8 and smsv-10 were recovered from vesicular lesions on the flippers of northern fur seals in the Pribilof Islands of Alaska. Serotype smsv-9 was isolated from a sea lion in southern California, and smsv-11 was isolated from 2 northern fur seal pups in southern California. Serotype smsv-12 was also isolated in southern California from sea lion and fur seal pups.
Histamine H1, H2 Receptor Effects on Mechanics of Ventilation and Gas Exchange in Neonatal Calves
Authors: Slocombe R. F. , Robinson N. E.
Published: February 2025

The effect of histamine infusion (iv) on pulmonary mechanical and gas exchange properties of healthy neonatal Holstein-Friesian calves was determined. Histamine increased pulmonary resistance and static pressure-volume hysteresis and decreased dynamic compliance, but failed to change static compliance; changes were compatible with constriction of both large and small airways without a change in lung elasticity.

Histamine decreased arterial oxygen tension by increasing the alveolar-arterial oxygen difference, probably because ventilation-perfusion inequalities resulted from small airway constriction. The pulmonary mechanical and gas exchange effects of histamine were prevented by pretreatment with the H1 receptor antagonist, tripelennamine, but not with the H2 receptor antagonist, metiamide. The histamine-induced changes in static pressure-volume hysteresis and dynamic compliance were reversed by sighing, and histamine effects on the lung were eliminated by 15 minutes after cessation of histamine infusion.
Cell-Mediated and Humoral Immune Response in Swine After Vaccination and Natural Infection with Mycoplasma hyopneumoniae
Authors: Kristensen B. , Paroz Ph. , Nicolet J. , Wanner M. , de Weck A. L.
Published: February 2025

Litters of pigs were vaccinated with inactivated Mycoplasma hyopneumoniae organisms in Freund's complete adjuvant. The cell-mediated and humoral immune response following vaccination was investigated, and the protective effect of the induced immunity was assayed. The cell-mediated immune response to whole M hyopneumoniae organisms was determined as incorporation of tritiated thymidine, using a microculture system. After vaccination, detectable sensitization of peripheral blood lymphocytes was induced. The inoculations induced considerable antibody titers in the animals. The animals were challenge exposed by natural infection and protective effect of the cell-mediated or humoral immune response could not be detected.
Comparison of a Microtitration Complement-Fixation Test and a Tube Latex Agglutination Test for Diagnosis of Mycoplasma hyopneumoniae Swine Pneumonia
Authors: Slavik Michael F. , Switzer W. P.
Published: February 2025

Comparison of a tube latex agglutination (la) test and a microtitration complement-fixation (cf) test for the diagnosis of Mycoplasma hyopneumoniae swine pneumonia was done. In a group of 107 pigs from Iowa, Texas, and California (survey A), correlation of data on microscopic pulmonary changes with the la and cf titers indicated the la test might be a better indicator of microscopic lesions than the cf test. In another field study involving lungs from 50 pigs from various herds (survey B), both la and cf test results predicted gross lesions at a 0.01 significance level, using chi-square analysis. Data from 3 Nebraska swine herds (survey C) indicated good correlation of gross and microscopic pulmonic lesions with cf and la test results in 2 of the 3 herds. In the 3rd herd, results of the cf test failed to agree with either gross and microscopic pulmonic lesions or culture results, whereas la test results closely correlated with these variables. Chi-square analysis at 0.05 significance level of 106 pigs from 5 Iowa specific-pathogen-free herds (survey D) indicated a correlation of cf and la test results with the microscopic pulmonic changes of penmates.
Effects of Maternal Nutritional Restriction and Cold Stress on Young Calves: Absorption of Colostral Immunoglobulins
Authors: Olson D. P. , Bull R. C. , Woodard L. F. , Kelley K. W.
Published: February 2025

Fifty-seven newborn calves delivered from heifers fed rations either adequate or restricted in protein or metabolizable energy were housed in cold (1 C) or normothermic (21 C) environmental chambers for 3 days to determine the effects of maternal nutritional stress and cold exposure on ability of the animals to absorb colostral immunoglobulins (Ig). In general, the serum Ig concentrations in the newborn calves from dams fed rations restricted in protein or metabolizable energy and the concentrations in sera of the respective calves from dams fed adequate protein or metabolizable energy were similar throughout the 3-day period of observation. Likewise, the serum Ig concentrations in the cold-exposed calves were similar to those in the calves kept at normothermic temperature. An exponential increase in mean serum concentrations of IgM, IgG1, and IgG2 occurred between 3 and 6 hours of age; the values continued to increase, but at a slower rate after 6 hours and reached a peak by 12 hours of age. Then, IgM and IgG2 decreased until 48 hours, after which time they increased, but IgGl varied only slightly from the peak at 12 hours and then increased. With one exception, data indicated that neither the maternal dietary restrictions nor the cold exposure imposed on the calves caused significant (P > 0.05) differences in absorption of colostral Ig when compared with that of the respective calves from dams fed adequate diet or the calves kept at normothermic temperature.
Diurnal Changes in Rectal and Body Surface Temperatures of Conscious, Chair-Restrained Rhesus Macaques
Authors: Liu C. T. , Sanders R. P. , Robbins V. W.
Published: February 2025

A system has been established for continuous recording of rectal and body surface temperatures in conscious, chair-restrained rhesus macaques. Diurnal changes in rectal temperature and body surface temperatures of head, back, abdomen, and inner thigh were recorded for 24 hours under conditions of intermittent or constant light. When lights were on for 8 hours (0800 to 1600 hours) and off for 16 hours, maximal rectal temperatures (37.6 ± 0.3 C) were observed at 0900 hours, whereas minimal rectal temperatures (36.7 ± 0.4 C) were demonstrated between 0200 and 0400 hours. Mean rectal temperatures varied 0.9 C during a 24-hour period. A trend of diurnal changes in body surface temperatures was also observed with low surface temperatures recorded between 0400 and 0800 hours. The surface temperatures (33.8 to 36.5 C) were markedly lower than rectal temperatures (36.7 to 37.6 C) under the same experimental conditions. When macaques were subjected to constant light, high rectal temperatures were recorded between 0900 and 1700 hours and low rectal temperatures were observed between 2400 and 0300 hours with a mean variation of 0.7 C (36.3 ± 0.15 to 37.0 ± 0.2). Diurnal body surface temperature changes during constant light were less pronounced than those of rectal temperatures. Furthermore, low surface temperatures of abdomen and inner thigh recorded between 0200 and 0800 hours were similar to those obtained with macaques exposed to the light-dark conditon.
Laboratory Evaluation of Selected Disinfectants as Virucidal Agents Against Porcine Parvovirus, Pseudorabies Virus, and Transmissible Gastroenteritis Virus
Authors: Brown T. T.
Published: February 2025

Of a variety of disinfectants evaluated, only sodium hypochlorite and sodium hydroxide inactivated porcine parvovirus (ppv) after a 5-minute incubation period. After the same incubation time, pseudorabies and transmissible gastroenteritis viruses were inactivated by all of the disinfectants tested. When the incubation time was increased to 20 minutes, 2% glutaraldehyde and a double-strength concentration of a commercial formaldehyde preparation also inactivated ppv. Formaldehyde vapor and ultraviolet radiations inactivated ppv also, but relatively long exposure times were required.
Tioxidazole: Evaluation of Antiparasitic Activity of a Micronized Formulation in Horses by the Critical Test Method
Authors: Lyons E. T. , Drudge J. H. , Tolliver S. C.
Published: February 2025

Antiparasitic activity of a micronized formulation of the benzothiazole compound, tioxidazole, at the dose rate of 11 mg/kg, was evaluated by the critical test method. Drug was given by stomach to 3 horses and on feed to 3 horses. Excellent removal activity was found for Strongylus vulgaris (100%) in 5 naturally infected horses, S edentatus (91% to 100%) in 5 horses, small strongyles (88% to 99%) in 6 horses, immature Oxyuris equi (100%) in 5 horses, and Parascaris equorum (100%) in 5 horses (a 6th horse had 10 small specimens present at necropsy).

There was no measurable activity against bots, tapeworms, or stomach worms. Tioxidazole, administered in the feed, was palatable. Signs of toxicosis were not observed.
Clonidine or Xylazine as Provocative Tests for Growth Hormone Secretion in the Dog
Authors: Hampshire J. , Altszuler N.
Published: February 2025

Base-line values of plasma growth hormone (gh) are low in most species, requiring provocative tests to assess gh deficiency. Clonidine, an antihypertensive drug, and its analogue, xylazine, a sedative hypnotic, were found to stimulate gh secretion. Administration (iv) of clonidine to conscious healthy, dogs at doses of 30, 16.5, and 3μg/kg produced significant increases in plasma gh by 15 minutes and the effects subsided by 120 minutes. Plasma glucose concentration increased slowly with all doses, but less so and for shorter duration in dogs given the 3 μg/kg dose. Xylazine increased plasma gh when injected at doses of 300 and 100 μg/kg, but not at 30 μg/kg. Plasma glucose increased only with the 300 μg/kg dose. The α-adrenergic blocker, phentolamine, markedly attenuated these responses. Thus, both clonidine and xylazine, when used at appropriate doses, can stimulate gh secretion, with minimal effect on plasma glucose and without causing significant sedation.