bluuebunny/crossref_metadata_2025 huggingface dataset:
Vaccination of cattle against pseudorabies (Aujeszky's disease) with homologous virus (herpes suis) and heterologous virus (herpes bovis 1)
Authors: Biront P. , Vandeputte J. , Pensaert M. B. , Leunen J.
Published: February 2025

Study was made to determine whether vaccination of cattle against pseudorabies (pr; Aujeszky's disease) affords protection upon subsequent intranasal challenge exposure with virulent virus. Vaccinations were performed with a commercially available oil-adjuvant pr virus vaccine, in some cases supplemented with Al(OH)3 (given subcutaneously), with the attenuated NIA4 strain of pr virus (given intranasally), and with a commercially available temperature-sensitive mutant of bovine herpesvirus-1 (infectious bovine rhinotracheitis [ibr] virus) given intranasally. Challenge exposure was performed intranasally with 103 median lethal doses (ld50) of the virulent pr virus. In earlier experiments, it was found that 104.6 median tissue culture infective doses of this virulent pr virus in primary pig kidney cells represented about 1 ld50 for cattle. This ld50 was practically no different for cattle whether or not they had antibodies against pr virus before exposure to virulent pr virus. In the seropositive animals, antibodies were present presumably as a consequence of a previous ibr infection in the field.

Vaccination intranasally with NIA4 or ibr virus did not result in serologic response or protection against challenge exposure. The inactivated-virus vaccine induced a good serologic reaction, but there was poor protection against challenge exposure. Consequently, vaccination of cattle at risk of exposure to virulent pr virus cannot be advised.

In the present experiments, initiation of infection with virulent pr virus in cattle always resulted in disease and death.
Delayed-type hypersensitivity, contact sensitivity, and phytohemagglutinin skin-test responses of heat- and cold-stressed calves
Authors: Kelley Keith W. , Greenfield Randall E. , Evermann James F. , Parish Steven M. , Perryman Lance E.
Published: February 2025

Three-week-old Holstein bull calves were used to investigate the effect of a 2-week chronic heat (35 C) or cold (-5 C) exposure on delayed-type hypersensitivity (dth) reactions to purified protein derivative after sensitization with heat-killed Mycobacterium tuberculosis, contact sensitivity (cs) reactions to l-fluoro-2,4-dinitrobenzene, and phytohemagglutinin (pha) skin tests. Heat exposure reduced expression of dth reactions by 42% and cs reactions by 38% at 24 hours after elicitation of the responses. The pha-induced skin tests were not affected after 1 week of heat exposure, but this reaction was reduced by 20% after 2 weeks of heat exposure. The immune response of calves exposed to cold air temperatures was more complex. Cold exposure suppressed cs reactions by 39% at the end of both the 1st and 2nd weeks. The pha response was reduced by 39% after 2 weeks of cold exposure. The dth response depended on duration of cold exposure. The dth reaction was increased by 42% after 1 week, but was reduced by 14% after 2 weeks.

These data are consistent with the hypothesis that environmental stressors alter host resistance by affecting the immune system. Furthermore, these stress-induced changes in immune events depend on the type of immune response, the nature of the environmental stressor, and the length of time that calves are exposed to the stressor.
Light microscopic and ultrastructural evidence of epithelial phagocytosis of sperm in the rete testis and ductuli efferentes in the bull
Authors: Goyal H. O.
Published: February 2025

Light microscopic and ultrastructural observations were made in the bull rete testis and the ductuli efferentes with emphasis on the presence of sperm in the epithelium. Phagocytosed sperm in various stages of degeneration were found in the epithelial cells lining the rete testis and in the nonciliated cells of the ductuli efferentes. Phagocytosis was more prevalent in the rete testis than in the ductuli efferentes. Besides the epithelial cells, degenerating sperm components and residual bodies were in the luminal macrophages of the rete testis. The degeneration of sperm heads presumably progressed in the following order: (i) disruption of the cell membrane, (ii) aggregation of small vesicles, probably of Golgi origin, between the disrupted cell membrane and an outer acrosomal membrane, (iii) loss of the acrosomal matrix, and finally (iv) disintegration of the nuclear chromatin. These degenerative changes probably resulted from increased lysosomal activity of phagocytosing cells. The possible importance and causes of spermiophagy are discussed.
Spinal nerve root origins of the cutaneous nerves arising from the canine brachial plexus
Authors: Bailey Cleta Sue , Kitchell Ralph L. , Johnson Richard D.
Published: February 2025

The spinal erve root origins of the cutaneous nerves arising from the brachial plexus were investigated in 10 babiturate-anesthetized dogs by stimulating dorsal roots C5 to T2 and recording from each cutaneous nerve. Upon completion of the experiment, the contributions of the spinal nerve ventral branches to the brachial plexus were verified by anatomic dissection. The brachial plexus was formed by the ventral branches of C6 to T2 in 8 dogs, C6 to T1 in 1 dog, and C5 to T1 in 1 dog. The cutaneous branch of brachiocephalicus nerve was formed primarily by contributions from the C6 dorsal root. The cranial lateral cutaneous brachial nerve, a branch of the axillary nerve, was formed predominately from C6 and C7. The median nerve received contributions primarily from C7, C8, and Tl, and the communicating branch from the musculocutaneous to the median nerve contained fibers primarily from C7 and C8. The medial and lateral branches of the superficial branch of the radial nerve arose from C6, C7, C8, and Tl, with the medial branch generally arising 1 segment craniad to the lateral. The palmar and dorsal branches of the ulnar nerve arose predominately from C8 and Tl, and the caudal cutaneous antebrachial nerve of the ulnar arose predominately from Tl and T2.
Amounts of twelve elements required to induce selenium vitamin E deficiency in ducklings
Authors: Van Vleet John F.
Published: February 2025

Mortality and myopathy of selenium-vitamin E (Se-E) deficiency was produced, in a concentration-dependent pattern, during a 4-week study of 750 ducklings fed a commercial duck starter mash that contained adequate amounts of Se and E, and supplemented with multiple amounts of Ag (50 to 3,000 mg/kg of feed, as acetate), Zn (3,000 to 6,000 mg/kg, as sulfate), Cd (10 to 500 mg/kg, as sulfate), Te (25-500 mg/kg, as tetrachloride), Co (100 to 1,000 mg/kg, as chloride), Cu (500 to 1,500 mg/kg, as sulfate), Hg (200 to 400 mg/kg, as chloride), and Sn (1,000 mg/kg, as chloride). Also, feeding supplements of Pb (500 mg/kg, as acetate), As (600 mg/kg, as sodium arsenilate), Fe (5,000 mg/kg, as sulfate), and S (5,000 mg/kg, as sodium sulfite) produced a low-to-medium frequency of lesions of Se-E deficiency.

In ducklings with muscle lesions, the gizzard was most often affected (84.2%), followed in decreasing order by skeletal muscles (69.7%), intestine (34.9%), and heart (23.0%). The frequency of skeletal muscle lesions was high in birds fed Ag, and myocardial necrosis was frequent in ducklings fed Te and Hg.

Ducklings affected with myopathy were reluctant to stand. Subcutaneous edema, with or without hemorrhages, and pale areas of myonecrosis in gizzard, skeletal muscles, intestine, and heart were seen at necropsy. Birds fed Te and Hg often had hydropericardium and hemorrhagic myocardial necrosis.

Seemingly, addition of many elements to a Se-E adequate commercial diet will increase the requirement for Se-E. In our duckling model, minimal amounts shown to induce Se-E deficiency were 50 mg of Ag/kg, 3,000 mg of Zn/kg, 10 mg of Cd/kg, 25 mg of Te/kg, 100 mg of Co/kg, 500 mg of Cu/kg, 200 mg of Hg/kg, 1,000 mg of Sn/kg, 500 mg of Pb/kg, 600 mg of As/kg, 5,000 mg of Fe/kg, and 5,000 mg of S/kg.
Anesthetic and hemodynamic effects of ketamine hydrochloride in buffalo calves (Bubalus bubalis)
Authors: Pathak S. C. , Nigam J. M. , Peshin P. K. , Singh A. P.
Published: February 2025

Ketamine HCl was evaluated as a general anesthetic alone and in combination with chlorpromazine HCl on the basis of sedative and cardiovascular effects in 40 buffalo calves (Bubalus bubalis). Calves were rapidly immobilized after iv administration of ketamine HCl (2 mg/kg of body weight). Preanesthetic treatment of calves with chlorpromazine increased the duration of analgesia, standing and recovery times, and the degree of muscle relaxation. The duration and degree of analgesia obtained were adequate for short-term surgical procedures.

All animals survived the anesthetic trials, and recovery was smooth and rapid. Hemodynamic studies revealed increases in heart rate, mean blood pressure, cardiac output, and peripheral vascular resistance during maximal depth of anesthesia. The venous pressure decreased initially and then increased progressively. Increases and decreases in these measurements were transient, and the measurements returned to base-line values within 30 minutes after ketamine administration. Definite trends were not seen on ecg tracings, except for elevations and depressions of ST segment, T-wave changes, and wandering pacemaker in a few animals, and sinus tachycardia in all animals.
Efficacy of albendazole for treatment of naturally acquired Fasciola hepatica in calves
Authors: Malone J. B. , Smith P. H. , Loyacano A. F. , Hembry F. G. , Brock L. T.
Published: February 2025

In calves given various doses of albendazole as a 4.55% (w/v) drench suspension, removal efficacies against mature Fasciola hepatica were 77.5% with the dose of 7.5 mg/kg; 92.3%, with 10 mg/kg; and 85.9%, with 15 mg/kg. Against immature F hepatica, drug efficacies with these doses were 32.7%, 20.0%, and 36.7%, respectively. Reductions in length and width measurements of mature and immature flukes recovered from the bile ducts correlated with the larger doses reflected a greater efficacy against mature flukes or a possible inhibiting effect of the drug on fluke size or growth. Numbers of eggs recovered in bile at necropsy were reduced by 87.8% with the dose of 7.5 mg/kg; 91.8%, with 10 mg/kg; and 95.6%, with 15 mg/kg.
Anthelmintic efficacy of oxibendazole in ponies: Comparison of methods
Authors: Theodorides V. J. , Nawalinski Ted , Chimes Nicholas , Weideman C. , Free S. M.
Published: February 2025

Oxibendazole paste at a dosage level of 10 mg/kg of body weight removed 94% to 100% of Craterostomum acuticaudatum, Cyathostomum spp, Cylicostephanus spp, Cylicocyclus spp, Cylicodontophorus spp, Gyalocephalus capitatus, Habronema spp, larval and adult Oxyuris equi, Poteriostomum spp, Strongylus edentatus, Strongylus equinus, Strongylus vulgaris, and Triodontophorus spp; it also removed 92% of immature small strongylids (as determined by a critical test) and 93% of Parascaris equorum (as determined by a control test). A detailed comparison of the 1-group critical test with the 2-group control test showed the 2-group test to be about 58% more efficient than the critical test, due to reduced labor cost, because posttreatment feces were not sieved for expelled worms. The 2- group test is also more statistically sound because, unlike the critical test, it develops data that permit an unbiased comparison.
Carotid artery exteriorization for percutaneous catheterization in sheep and dogs
Authors: Dueck R. , Schroeder J. P. , Parker H. R. , Rathbun M. , Smolen K.
Published: February 2025

Summary and reliable physiologic or pharmacologic investigation in animal models often requires arterial catheterization in awake animal subjects. This can be facilitated by surgical exteriorization of the carotid artery for subsequent percutaneous catheterization. A simplified surgical procedure is described that has been demonstrated to have limited morbidity and excellent applicability for multiple use, as well as to ensure high blood flow rates when needed. The surgical technique involves transfer of the carotid artery from a deep paratracheal position to a ventrolateral neck subcutaneous position, protected from the underlying mattress sutures by the sternomastoid muscle.
Persistent truncus arteriosus in a lamb
Authors: Milstein J. M. , deVries P. A. , Goetzman B. W.
Published: February 2025

A major great vessel abnormality was observed while performing a cardiovascular study on a newborn lamb. Persistent truncus arteriosus was present, with the right and left pulmonary arteries arising separately from either side of the truncus. In addition, a small ventricular septal defect was present. The embryology and classification of persistent truncus arteriosus are described.
Measurements of bone mineral content by photon absorptiometry of the Beagle
Authors: Jorch U. M. , Anderson C. , Delaquerriere-Richardson L. F. O. , Cook M.
Published: February 2025

Bone mineralization is an aspect of bone metabolism which may be studied with little difficulty in research animals. Changes in bone mineralization have been determined reliably in persons by measuring the bone mineral content of the antebrachium (forearm) by photon absorptiometry. The laboratory-raised Beagle dog has been used extensively in bone metabolism research. In this study, 8 Beagle dogs were killed and the bone mineral content of left and right femurs were determined by the photon absorptiometry technique. By obtaining data from healthy dogs, bone metabolism in disease states may be studied more effectively.
Ultrastructural alterations in the fibrous sheath, endocardium, and myocardium of dogs shocked with chronically implanted automatic defibrillator leads
Authors: Van Vleet John F. , Ferrans Victor J. , Barker Margaret A. , Tacker Willis , Bourland Joe D. , Schollmeyer Michael P.
Published: February 2025

Catheter-mounted automatic implantable defibrillator leads were implanted in 10 dogs for 11 to 21 months (mean 15.0 months). Single shocks of 10 A, 20 A, or 30 A (peak current) were then delivered through the chronically implanted leads. Two days after the shock, the dogs were euthanatized and necropsied. The intracardiac segment of the lead was covered by a fibrous sheath, the endocardium in contact with the lead was thickened by fibrous tissue, and shock-induced myocardial necrosis was present surrounding the distal pair of electrodes, with the largest amount of damage found in the dogs given the large shocks. Ultrastructurally, the fibrous sheath was covered by endothelium and contained numerous spindle cells and identified as smooth muscle cells by their prominent cytoplasmic filaments and external laminae or myofibroblasts with prominent endoplasmic reticulum. The spindle cells were surrounded by abundant collagen fibrils but not by elastic fibers. The thickened endocardium contained numerous fibroblasts, abundant collagen fibrils, and a few small elastic fibers. The shock-induced myocardial alterations included necrosis of cardiac muscle cells with prominent mitochondrial mineralization, interstitial edema, and infiltration of macrophages.
Removal of total organic carbon from marine mammal pool water by polymeric resins
Authors: Adams Gary , Spotte Stephen
Published: February 2025

Chlorinated organic compounds comprise a portion of the total organic carbon (toc) of marine mammal pool water. The long-term effects of these substances on the health of captive marine mammals are unknown, but good husbandry practices should include maintaining toc at low concentrations. Two polymeric resins (trade names XAD-2 and XAD-4) were tested for their capacity to adsorb toc from the water of a saline, closed-system marine mammal pool. At a concentration of 588 mg of XAD-2/L, toc was reduced by approximately ~9% after 96 hours; 630 mg of XAD-4/L reduced toc concentrations by ~9% after 77 hours. Equilibrium was not approached in any of the experiments. The 2 materials tested are ineffective in this particular application, but ion exchange resins may perform better.
Pharmacokinetic and anti-tumor studies with the radiosensitizer misonidazole in dogs with spontaneous fibrosarcomas
Authors: Creasey William A. , Thrall Donald E.
Published: February 2025

Nine dogs with spontaneous oral fibrosarcomas were given the radiosensitizer misonidazole (Ro-07-0582) in combination with orthovoltage radiotherapy. Although there appeared to be a trend toward greater disease-free survival of these animals as compared with a group of 13 dogs with similar tumors treated by orthovoltage x-rays alone, on analysis there was no significant difference. The plasma half-life and the volume of distribution of misonidazole were determined as 4.95 hours and 15.1 L/m2, respectively. In 3 dogs with evidence of misonidazole toxicosis, plasma concentrations at 4 hours after the dose exceeded 85 μg/ml, and the areas under the concentration vs time curve for this first 10 hours were greater than 850 μg·hr/ml.
Effect of dietary phosphorus restriction on the kidneys of cats with reduced renal mass
Authors: Ross Linda A. , Finco Delmar R. , Crowell Wayne A.
Published: February 2025

Cats with reduced renal mass were fed a phosphorus-restricted diet (0.42% P, dry weight) or a normal phosphorus diet (1.56% P, dry weight) for 65 to 343 days. Renal function was determined biweekly by blood urea nitrogen and plasma creatinine measurements and by initial and terminal inulin clearance procedures. Neither diet caused a significant change in renal function during the study. However, histologic examination of kidneys obtained at necropsy clearly separated the cats on the basis of dietary phosphorus. The kidneys from cats fed the normal phosphorus diet had mineralization, fibrosis, and mononuclear cell infiltration, whereas the kidneys from cats fed the phosphorus-restricted diet had little or no changes.
Interaction of amphipathic drugs with erythrocytes from various species
Authors: Smith Joseph E. , Mohandas Narla , Shohet Stephen B.
Published: February 2025

Changes in morphology of human erythrocytes exposed to certain amphipathic drugs can be predicted by the bilayer couple hypothesis as proposed by Sheetz and Singer (Proc Natl Acad Sci USA 71:4456-4461, 1975). When we tested that hypothesis, using erythrocytes from other mammals, we found that most, but not all, underwent the predicted changes. Both camel and llama erythrocytes showed minimal morphologic changes when exposed to anionic and cationic phenothiazines. The spicules formed by anionic drug in different species were numerically related to cell sizes. We conclude that structural rigidity of the erythrocyte membrane can alter the response predicted by the bilayer couple hypothesis.
Amounts of eight combined elements required to induce selenium-vitamin E deficiency in ducklings and protection by supplements of selenium and vitamin E
Authors: Van Vleet John F.
Published: February 2025

In 2 experiments, 330 newly hatched ducklings were fed, for 4 weeks, a commercial ration with 8 combined elements added. In the 1st experiment, graded amounts of the 8 combined elements were fed, and mortality and the frequency of myopathy from induced selenium-vitamin E (Se-E) deficiency were determined. The potential of the 8 combined elements to induce Se-E deficiency was additive because approximately one-tenth of the amount of each of the elements, as fed alone, was effective when fed in combination. The minimum amounts of the added elements that were needed to induce Se-E deficiency when fed together were 10 mg of Ag (as acetate)/kg of feed, 300 mg of Zn (as sulfate)/kg 1 mg of Cd (as sulfate)/kg, 2.5 mg of Te (as tetrachloride)/kg, 10 mg of Co (as chloride)/kg, 50 mg of Cu (as sulfate)/kg, 40 mg of Hg (as chloride)/kg, and 100 mg of Sn (as chloride)/kg.

In the 2nd experiment, ducklings were fed the 8 combined elements in amounts 6-fold greater than the minimum amount needed to induce Se-E deficiency, and the ability of supplements of various amounts of Se and/or vitamin E to prevent induction of Se-E deficiency was determined. Protection was not given by adding 0.1 mg of Se/kg or 10 IU of vitamin E/kg; slight protection was provided by supplements of 0.5 mg of Se/kg, 50 IU of vitamin E/kg, or 0.1 mg of Se/kg and 10 IU of vitamin E/kg combined; marked protection was given by feeding 2.5 mg of Se/kg, 250 IU of vitamin E/kg, or 0.5 mg of Se/kg and 50 IU of vitamin E/ kg combined; and complete protection was provided by feeding 2.5 mg of Se/kg and 250 IU of vitamin E/kg combined.

Initial hepatic Se and a-tocopherol concentrations were high and terminal values were moderate for Se and low for α-tocopherol in ducklings fed the commercial ration for 4 weeks, with or without the 8 combined elements.

These studies demonstrated that feeding small amounts of combined Se antagonistic elements will induce Se-E deficiency in ducklings and that feeding large supplements of Se and vitamin E concurrently can prevent the condition.
Quantitative parasitemia in calves fed Sarcocystis cruzi sporocysts from coyotes
Authors: Dubey J. P.
Published: February 2025

For the quantitation of parasitemia, seven 7- to 10-day-old calves were orally inoculated with 2 virulent isolates of Sarcocystis cruzi from coyotes. Three calves were each given 2.5 million sporocysts of the 1st isolate; these calves died 31, 35, and 33 days later. The other 4 calves were given 2, 1, 0.76, and 0.38 million sporocysts of the 2nd isolate; these calves died or were euthanatized at 34, 44, 43, and 55 days after inoculation. Buffy coat smears from 7 ml of jugular blood of each calf were examined daily from day 14 after inoculation to time of necropsy. Merozoites were found in peripheral blood of all calves between days 25 and 46. The numbers of merozoites in 3 calves given identical inocula of the 1st isolate were 62, 48, and 17. The numbers of merozoites in the 4 calves given the 2nd isolate were 185, 11, 70, and 61, with decreasing dosages, respectively. The number of merozoites ranged from 0.14 to 9.8/ml of blood. More than 97% of merozoites were intracellular in mononuclear cells and 2.8% were extracellular in blood. Of 454 merozoites, 18 had 2 nuclei and 5 contained 2 dividing zoites; all dividing organisms were intracellular.
Effectiveness of ivermectin in the treatment of equine Parascaris equorum and Oxyuris equi infections
Authors: Yazwinski T. A. , Hamm D. , Williams M. , Greenway T. , Tilley W.
Published: February 2025

Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 μg/kg of body weight; and (3) injectable ivermectin at the rate of 300 μg/ kg. All treatments were given im in the neck.

All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decreased by 98.5% in both ivermectin-treated groups. Oxyuris equi 4th-stage larval infections were decreased by 95.7% and 99.9% by the 200 and 300 μg/kg ivermectin treatments, respectively. Adverse reactions to the injections of drug were not seen.
Parafilaria bovicola (Tubangui 1934) in cattle: Epizootiology—Vector studies and experimental transmission of Parafilaria bovicola to cattle
Authors: Bech-Nielsen Steen , Bornstein Set , Christensson Dan , Wallgren Tor-Bjorn , Zakrisson Goran , Chirico Jan
Published: February 2025

Parafilaria bovicola (Tubangui 1934), a filarial nematode, causes cutaneous bleedings of live cattle and bruiselike lesions in the subcutaneous and im surfaces of affected carcasses.

To determine the vector(s) of this nematode under Swedish conditions, a field survey was conducted during the pasture season, May-September 1980. A total of 9,931 insects were collected from cattle and subsequently examined for infective 3rd stage Parafilaria larvae. From the fly species collected, Musca autumnalis (De Geer), Hydrotaea irritans (Fall), and Haematobia stimulans (Meig) were those most frequently identified. The 3rd-stage larvae were only found in M autumnalis, face fly. Overall infection rate in these flies was 3.5%, with peak prevalence of 30% in June. Most of the nematode larvae were recovered from heads of female flies.

In experiments in insect-free stables, 5 calves were experimentally inoculated with infective 3rd-stage P bovicola larvae. Two calves inoculated by the intraconjunctival route (larvae were instilled inside the eyelid) became infected, whereas 3 calves injected subcutaneously did not. Signs of infection were not seen in 4 control calves.

The median development period of P bovicola from infective 3rd-stage larvae to the development of bleeding points was 43 weeks (301 days) in 26 cattle with spontaneous parafilariasis.
Temporary protection of calves against adenovirus infection by nasal secretion interferon induced by infectious bovine rhinotracheitis virus
Authors: Cummins Joseph M. , Rosenquist Bruce D.
Published: February 2025

Six calves were inoculated intranasally with a vaccinal strain of infectious bovine rhinotracheitis virus (ibrv). Three calves each were given 106.3 or 107.3 plaque-forming units (pfu) of ibrv, and 4 calves were given a placebo. All calves were challenge exposed with 105.3 tcid50 of bovine adenovirus (bav) type 3 by aerosol on postinoculation day (pid) 4. Nasal excretion of ibrv and bav, interferon concentrations and antibody against bav in the nasal secretions, and serum antibody were measured before and at intervals after calves were inoculated.

All calves given ibrv had detectable interferon in their nasal secretions, and 3 calves had interferon in their nasal secretions at pid 1. All calves given 107.3 pfu of ibrv had interferon from pid 2 to 6, and 2 of the 3 still had interferon in their nasal secretions at pid 7. All calves given 106.3 pfu of ibrv had interferon at pid 4 and 6, 2 had interferon at pid 1, 2, 7, and 8, and 1 calf had interferon in the nasal secretions at pid 10. Interferon was detected in the nasal secretions of only 1 control calf after challenge exposure to bav. Serum interferon was detected in only 1 calf after viral inoculation.

Those calves with interferon in nasal secretions at postchallenge exposure day (pcd) 2 and 3 had bav excretion reduced over 97%, on the average, compared with control calves without interferon. Near the end of the interferon response to ibrv, as interferon titers decreased, nasal excretion of bav increased until all calves were excreting comparable amounts of bav. Adenovirus excretion was detected on pcd 10 in 2 of 4 control calves, in all calves given 106.3 pfu, but not in calves given on 107.3 pfu of ibrv.

Titers of interferon in the nasal secretions at various times ranged from 16 to 10,000. Bovine interferon was active in swine testicular cells, but not in cultures of chicken embryo fibroblasts, chicken kidney cells, quail embryo fibroblasts, Crandell feline kidney cells, rat embryo fibroblasts, and guinea pig kidney cells. Bovine nasal secretion interferon was stable at pH 2.0, was usually stable at 56 C for 30 minutes, was destroyed at 70 C for 30 minutes, and inhibited pseudorabies virus.

All calves developed bav infection despite the presence of serum-neutralizing antibody in 9 calves and antibody in the nasal secretions of 3 calves at the time of bav challenge exposure. At pcd 10, when all calves had ceased or decreased excretion of bav, only 3 calves had an increase in nasal secretion antibody titers and none had an increase in their serum antibody titers. In the present studies, interferon in the nasal secretions induced by ibrv provided temporary protection against a challenge exposure of bav, but protection against challenge exposure was not provided by bav antibody in the nasal secretions or serum.
Decay of colostral antibodies to bovine leukemia virus with application to detection of calfhood infection
Authors: Thurmond M. C. , Carter R. L. , Puhr D. M. , Burridge M. J.
Published: February 2025

An estimated weighted-regression method was used to describe the decay of colostral bovine leukemia virus (blv) antibodies in the calf, as measured by agar-gel immunodiffusion with glycoprotein antigen. The prediction equation, based on 473 observations from 130 animals, was log10 inverse titer = 1.29 − 0.012 age (days). The half-life of blv antibodies was estimated to be 25.8 days. Ages at which colostral antibodies were last detected were between 51 and 187 days. Normal limits of antibody decay were estimated and used to identify virus-induced active antibodies in calves during the colostral antibody period. Calves known to be infected were identified between 2 and 180 days of age, using 95% limits. Application of this procedure for the early serologic detection of blv-infected calves in eradication or control programs is discussed.
Detection of cell-surface antigens of bovine ocular squamous cell carcinoma
Authors: Atluru D. , Kleinschuster S. J. , Zupancic M. L. , Muscoplat C. C.
Published: February 2025

A serologic study was conducted to identify surface antigens on cultured cells of bovine ocular squamous cell carcinoma. Sera from cattle with various stages of disease were tested for reactivity with surface antigens of cultured autologous and allogeneic cells. Radioiodine-labeled protein A assays were conducted to determine the presence of antibodies for tumor cells. It was found that all sera tested had antibodies at a high level to autologous cells, whereas the reactivity of allogeneic serum to cultured cells varied. Furthermore, surface reactivity was not observed in these sera in tests for reactivity with normal epithelial cells. Reactive sera were analyzed by absorption tests with autologous and allogeneic cells. Absorbed sera showed no reactivity to surface antigens on autologous or allogeneic cells. Also, results of quantitative absorption studies indicated that absorption with precarcinoma cells eliminated the reactivity of sera from carcinoma- (cancer-) bearing animals toward cultured tumor cells. This indicates that there might be a shared antigen among the cells from precarcinoma and carcinoma lesions.
Host humoral factors in natural resistance to Haemophilus somnus
Authors: Simonson Randy R. , Maheswaran Samuel K.
Published: February 2025

Natural serum bactericidal activity against Haemophilus somnus in various age groups of cattle was investigated. The level of antibacterial reactivity correlated with the agglutinating titer and age of the given animal. This activity was complement dependent, but the concentration of bactericidal antibody appeared to be the limiting factor in sera which had reduced killing capacity. Immunized animals developed high serum concentrations of bactericidal activity. The results of this study indicated that bactericidal antibodies may be important in host defense from H somnus infection and that immunization can enhance this resistance by stimulating high serum concentrations of bactericidal activity.
Effects of dietary milk fat (whole milk) and propionic acid on intestinal coliforms and lactobacilli in calves
Authors: Ward G. E. , Nelson D. I.
Published: February 2025

Calves fed whole milk had 1,000-fold fewer (P < 0.001) coliforms in the cranial part of the small intestine than did calves fed skim milk (fat removed). Calves fed milk with 32 mM added propionic acid had nearly 1,000-fold lower (P < 0.001) counts of lactobacilli in the entire gastrointestinal tract than did calves fed milk without added propionic acid.
Effect of venereal transmission of ovine ureaplasma on reproductive efficiency of ewes
Authors: Livingston C. W. , Gauer Betty B.
Published: February 2025

Rambouillet yearling ewes (n = 20) selected from a flock culturally negative for Ureaplasma sp were assigned randomly and equally to 2 groups. One group (principal) was bred to a ram experimentally infected with a specific serotype of an ovine ureaplasma. The other group (control) was bred to a ram culturally negative for Ureaplasma sp. All the ewes in the control group conceived during the first estrous cycle, remained free of infection with ureaplasma, and lambed on schedule with only 1 lamb failing to survive. The ewes in the principal group became infected with ureaplasma immediately after coitus. Ureaplasmas were routinely isolated for all ewes in this group for 50 days after the first coitus. Only 3 ewes were culturally negative for ureaplasma shortly after lambing. Two ewes failed to conceive on the first estrous cycle and 4 lambs failed to survive. Several lambs, from the ewes in the principal group were small and weak, and their birth weight was 0.64 kg less than that of lambs from the control ewes. One lamb in the principal group was mummified, whereas its twin appeared to be clinically normal. In sheep, ureaplasmosis appears to be a venereal disease possibly capable of causing infertility and low birth weights.
Origin of the early digestive disturbances induced by Haemonchus contortus infection in lambs
Authors: Buéno Lionel , Hondé Chantal , Luffau Gérard , Fioramonti Jean
Published: February 2025

Gastrointestinal motility (reticulum, abomasum, duodenum) and ionic contents (Na+, Cl−, HCO3−, pH) of the abomasum were determined in 4 lambs fitted with permanent abomasal cannulae.

During the 1st series of experiments, the animals were given 3 preparations (3 days between each): an extract of 25,000 crushed L3 larvae of Haemonchus contortus, a porous nylon bag containing 25,000 sheathed larvae, and a porous nylon bag containing 25,000 exsheathed larvae. The preparations were deposited directly into the fundic part of the abomasum. In the 2nd series of experiments, an extract of 25,000 crushed larvae was administered iv before and at 10 to 15 days after inoculation of 25,000 L3 larvae of H contortus.

Reticular and abomaso-duodenal motility were unaffected by the intra-abomasal administration of the extract of crushed L3 larvae or placement of either of the bags containing sheathed or exsheathed larvae. The Na+, Cl−, HCO3−, and pH of the abomasal contents were unaffected by the intra-abomasal administration of the crushed larvae extract and placement of the nylon bag with the sheathed larvae. In contrast, Na+, HCO3−, and pH were significantly increased by 51%, 850%, and 63% when the bag contained exsheathed larvae, the effects being maximal in 90 to 120 minutes.

The iv administration of crushed larvae extract at once produced a 40- to 60-minute inhibition of reticular contractions followed by a significant reduction of abomaso-duodenal motility for 3 to 4 hours. By the 4th hour, Na+ and HCO3−, as well as Cl− concentrations and pH, of the abomasal contents were increased by 79%, 340%, 43%, and 101%, respectively, these effects lasting more than 6 hours. Motor and secretory disturbances were nearly halved with the iv administration of the crushed larvae extract at 15 days after the lambs had been given 25,000 L3 infective larvae.

It is concluded that the abomasal permeability alterations occurring rapidly after H contortus infection in lambs were due to a substance(s) released by the exsheathed larvae reaching the abomasum and that these early changes were followed by antigenic reactions mainly responsible for the gastrointestinal motor disturbances.
Comparison of the steroid-induced, intestinal, and hepatic isoenzymes of alkaline phosphatase in the dog
Authors: Wellman Maxey L. , Hoffmann Walter E. , Dorner Joseph L. , Mock Richard E.
Published: February 2025

The steroid-induced, intestinal, and hepatic isoenzymes of canine alkaline phosphatase (alp) were compared, usmg antibodies against the steroid-induced alp isoenzyme, heat inactivation, phenylalanine inhibition, prednisolone inhibition, and Michaelis constant determinations. The results indicate that the steroid-induced and intestinal alp isoenzymes are similar and indicate that the steroid-induced isoenzyme might be a product of the same gene that controls the intestinal isoenzyme.
Plasma concentrations of chloramphenicol in birds
Authors: Clark Carl H. , Thomas J. E. , Milton J. L. , Goolsby W. D.
Published: February 2025

The plasma concentrations of chloramphenicol after oral, im, and iv administrations were studied in 15 species of birds. The biological half-lives of chloramphenicol ranged from 26 minutes in the pigeon, Columbia livia, to 288.3 minutes in the bald eagle, Haliaeetus leucocephalus. In those birds studied, the oral route gave low and inconsistent plasma chloramphenicol concentrations. The im route was the most satisfactory. Based on the data presented, an im dose of 50 mg/kg would produce plasma concentrations above 1 μg/ml for 8 to 12 hours, except in the pigeon, macaw, and conure.
Predicting the probability of quarter infection (by major pathogens) from somatic cell concentration
Authors: Poutrel B. , Rainard P.
Published: February 2025

The herd factor did not significantly affect distributions of somatic cell counts of 6,560 milk samples (collected in 3 herds) within an infection status. Minor-infections distribution for a herd was closer to that of healthy quarters than that of major infections. About 35% of the quarters infected by major pathogens had counts less than 400,000 cells/ml.

Statistical analysis by conditional probability indicated that herd major-infection level should be taken into account to predict the probability of quarter infection by major pathogens. Discrimination with a good reliability between presence and absence of pathogens, as estimated by a single somatic cell count, is possible only in herds with high major-infection level.
Morphologic and clinicopathologic changes following Strongylus vulgaris infections of immune and nonimmune ponies
Authors: Klei Thomas R. , Torbert Betty J. , Ochoa Ricardo , Bello Thomas R.
Published: February 2025

Ten 2-year-old ponies that were Strongylus vulgaris naive were randomly assigned to 2 groups. One group was given a single inoculation of 5,000 S vulgaris infective larvae (L3)/pony and each pony in the 2nd group was given 50 L3/week for 20 weeks. All ponies surviving these initial infections were each challenge exposed with 5,000 L3 236 days after the initial infections. Clinical reactions to initial and challenge-exposure infections were monitored by daily rectal temperatures, weekly weights, and twice daily observations of behavior. Quantitative measurements on blood and peritoneal fluid components were made at weekly or semiweekly intervals for 55 days after the initial infection and for 35 days after the challenge-exposure infections.

Observations on clinical responses of ponies after initial and challenge-exposure infection indicated that a single inoculation of 5,000 L3 was more immunogenic than were 20 weekly inoculations of 50 L3. Protective immunity was judged by the severity of the clinical responses that followed a challenge-exposure inoculation of 5,000 L3. Necropsy observations demonstrated that after inoculations of 5,000 L3, larvae migrated to sites other than the cranial mesenteric artery. In many ponies, these involve migrations through the liver. Blood glucose, blood urea nitrogen, and HCO3− concentrations did not change after any infections. Blood and peritoneal lactate values increased after challenge-exposure infections of 5,000 L3 in all ponies. The peritoneal fluid lactate values showed more marked increases than did the blood values. Lactate values of ponies that died did not differ from those that survived the verminous colic. Serum values of γ-glutamyltranspeptidase and alkaline phosphatase increased to significant (P < 0.05) amounts 21 to 28 days after inoculations with 5,000 L3. Peritoneal fluids obtained 7 to 21 days after inoculations of 5,000 L3 were (i) more difficult to collect, (ii) turbid, (iii) straw-to-amber colored, and (iv) contained high concentrations of protein, erythrocytes, and leukocytes. Differential cell counts of peritoneal fluids of all ponies given 5,000 L3 showed increased numbers of neutrophils and monocytes. Ponies with clinical signs of colic also had increased numbers of eosinophils in peritoneal fluids.
Lymphocytes from ponies experimentally infected with equine herpesvirus 1: Subpopulation dynamics and their response to mitogens
Authors: Bumgardner M. K. , Dutta S. K. , Campbell D. L. , Myrup A. C.
Published: February 2025

Six pony foals, free of detectable serum neutralization (sn) antibody against equine herpesvirus type 1 by the standard virus-neutralization (vn) test, were inoculated with equine herpesvirus type 1. The ponies showed typical clinical signs of respiratory tract disease and developed a transient leukopenia, involving lymphocytes as well as neutrophils. The leukopenia reached its lowest point on postinoculation days (pid) 3 to 5 and then returned to base-line values by pid 8 to 10. On quantitation of lymphocyte subpopulations, T and B lymphocytes were decreased during the onset of leukopenia and then recouped during the recovery from leukopenia. However, the proportions of the T and B lymphocytes remained constant during the lymphopenia, ranging from 70% to 80% and 20% to 30%, respectively. The lymphocyte blastogenic response to mitogens increased to a peak by pid 2 to 5 and then decreased to base line values or below by pid 7. Mitogen responses of T lymphocyte and mixed lymphocyte preparations were nearly similar. However, the responses of 2 ponies were somewhat different from the responses of others in that there was an increase in the B lymphocytes in the range of 40% to 50% during the recovery phase of lymphopenia. Also, the 2 ponies’ mixed lymphocyte response to mitogens was considerably higher and the T lymphocyte response to mitogen was lower as compared with that of mixed lymphocyte preparation. The importance of these 2 types of responses is discussed.
Comparative in vitro leukotoxin production of three bovine strains of Fusobacterium necrophorum
Authors: Scanlan C. M. , Berg J. N. , Fales W. H.
Published: February 2025

The in vitro leukotoxic activity of 3 bovine isolates of Fusobacterium necrophorum which varied in pathogenicity were compared. Monolayers of mouse peritoneal macrophages were exposed to culture filtrates from each F necrophorum strain, and cell viability was determined, using the trypan blue dye exclusion test. Two methods were used for production of the leukotoxin: (1) medium M-1 continuous dialysis sac cultures and (2) brain-heart infusion agar plate cultures. Supernatant cultural fluids containing the leukotoxin were subjected to membrane-partition chromatography, using ultrafilters with approximate molecular weight (mol wt) exclusion limits of 100,000, 10,000, 2,000, and 500. All ultrafiltrates had a cytotoxic effect on the monolayers. Cytotoxic activity was not found in the ultrafilter residues or in the control media ultrafiltrates. Comparative study of leukotoxin production indicated that F necrophorum 2101, type A, produced the most leukotoxin; F necrophorum 2030, type AB, produced slightly less leukotoxin; and F necrophorum 2035, type B, produced small amounts of leukotoxin. Endotoxin activity, as demonstrated by the mouse lethality test, was found in the residues of the XM-100A ultrafilter (100,000 mol wt), but not in the filtrates. Culture supernatant fluids and the XM-100A ultrafiltrates were positive for endotoxin, using the limulus amebocyte lysate assay; however, the other ultrafiltrates with lower mol wt exclusion limits were negative.
Vaccination of cattle against experimentally induced thromboembolic meningoencephalitis with a Haemophilus somnus bacterin
Authors: Stephens L. R. , Little P. B. , Humphrey J. D. , Wilkie B. N. , Barnum D. A.
Published: February 2025

The capability of a commercial Haemophilus somnus bacterin to protect cattle against experimentally induced thromboembolic meningoencephalitis was examined. Eighteen cattle were vaccinated twice, 8 were vaccinated once, and 14 were nonvaccinated controls. Serum antibody responses to vaccination were measured by gel immunodiffusion, bacterial agglutination test, and complement-fixation test.

Deaths occurred in 8 of the 14 controls, 3 of the cattle vaccinated once, and 3 of the cattle vaccinated twice. Two vaccinations were found to give significant protection against challenge exposure (P < 0.05). There were no cattle which gave positive reactions in the gel immunodiffusion test, and significant changes in bacterial agglutination test titers were not seen in the cattle after vaccination. There was a significant (P < 0.01) increase in the complement-fixation test titers of cattle vaccinated twice. Serum antibody titers were unrelated to the outcome of challenge infection, regardless of vaccination status, in any of the serotests.
Equine ocular onchocerciasis: Histopathologic study
Authors: Schmidt Gretchen M. , Krehbiel Janver D. , Coley S. Claire , Leid R. Wesley
Published: February 2025

Equine eyes (368) were examined clinically and histologically for abnormalities associated with the presence of ocular microfilariae of naturally occurring Onchocerca sp infection. Forty of the eyes had microfilariae in the conjunctiva, but distinguishing clinical abnormalities were not associated with their presence. In 1 horse with ocular microfilariae that was treated with diethylcarbamazine daily for 2 weeks, ocular tissue samples were obtained before, during, and after the horse was treated, and the samples were compared histologically. During treatment of the horse, microfilariae apparently moved from the conjunctival stroma into the perilimbal corneal stroma; inflammatory cells were more abundant in the perilimbal tissues. The tissue samples obtained before and after the treatment appeared similar.
Indirect imaging of the canine optic nerve, using metrizamide (optic thecography)
Authors: LeCouteur Richard A. , Scagliotti Randall H. , Beck Kathy A. , Holliday Terrell A.
Published: February 2025

Between the optic nerve and its sheath is a small, csf-filled space that communicates with the subarachnoid space of the brain. A technique for the radiographic opacification of the optic nerve subarachnoid space following the intrathecal injection of metrizamide was investigated in 8 dogs.

The technique enabled indirect visualization of the optic nerves from the optic chiasm to the eyeball and of structures within the subarachnoid basal cisterns of the brain, including the optic chiasm, hypophysis, and blood vessels of the cerebral arterial circle. Displacement and obstruction of the optic nerve subarachnoid space were demonstrated after surgically creating optic nerve lesions to simulate orbital tumors and trauma. The technique was found to be safe, effective, and advantageous over other techniques currently available for the visualization of these structures.
Efficacy of injectable and oral paste formulations of ivermectin against gastrointestinal parasites in ponies
Authors: Torbert Betty J. , Kramer Barbara S. , Klei Thomas R.
Published: February 2025

A controlled test was used in ponies to compare the antiparasitic efficacy of ivermectin (22,23-dihydroavermectin B1) in an injectable micelle solution administered im with the efficacy of the same drug in an oral paste formulation. Parasite infections were naturally acquired in southern Louisiana. The drug was tested in both formulations at a dosage level of 0.2 mg/kg of body weight.

Ivermectin in both formulations tested had an efficacy > 98% against Gasterophilus intestinalis and G nasalis larvae, Trichostrongylus axei, Habronema spp, Strongylus vulgaris, S edentatus, and species of small strongyles present. Efficacy of ivermectin against Oxyuris equi larvae was 100% in the paste formulation and 93% in the injectable formulation. The ponies were less uniformly infected with S equinus, Draschia megastoma, Parascaris equorum, O equi adults, Anoplocephala perfoliata, and A magna. However, observations indicated that the drug in either formulation was also effective against these parasites, except Anoplocephala spp.