bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum chemical profile of feeder pigs, as influenced by market stress and feeding regimen
Authors: Clemens E. T. , Schultz B. D. , Brumm M. C. , Jesse G. W. , Mayes H. F.
Published: February 2025

Two hundred eighty-eight crossbred feeder pigs were used in 2 trials to determine the effects of feed and/or water deprivation at an auction market, and the effects of restricting the intake of the receiving diet on their serum chemical profile. The study also was designed to assess the value of the serum chemical profile as a diagnostic data base for stress disorders in feeder pigs. Performance data indicated that feeder pigs provided water only at the auction facilities lost significantly more weight than did those provided feed and water. Feeder pigs deprived of both feed and water were not significantly different in body weight from either group. Several serum chemical values (creatinine, triglycerides, cholesterol, blood urea nitrogen, and lactate dehydrogenase) were significantly influenced by feed deprivation, but not by feed and water deprivation. However, only the serum creatinine values were significantly different after the 24-hour posttransport period. There were no significant differences in pig weight or serum chemical values 84 days after pigs had arrived at the finishing unit. The serum chemical profile, widely used in human medicine, appears not to provide a reliable marker for identification of short-term nutritional deprivation, nor for transport stress in feeder pigs.
Spectrophotometric method for differentiation of cardiac and hepatic lactate dehydrogenase activities in dogs
Authors: Aguilera-Tejero E. , Mayer-Valor R. , Gómez-Cárdenas G.
Published: February 2025

To differentiate the origin of high total lactate dehydrogenase (ld) activity in canine sera, a spectrophotometric method based on the preferential inhibition of cardiac ld isoenzymes by pyruvate was performed.

Comparison with the electrophoretic separation of ld isoenzyme activities and determination of the hydroxybutyrate dehydrogenase-to-ld ratio indicated that the method proposed gave a better discrimination between cardiac and hepatic ld activities than did the other tests.
Light and electron microscopy of keratinization in the laminar epidermis of the equine hoof with reference to laminitis
Authors: Budras K.-D. , Hullinger R. L. , Sack W. O.
Published: February 2025

The laminar epidermis (epidermis parietis) of hooves from 14 clinically normal horses, 6 months to 15 years old, was examined by light and electron microscopy and immunofluorescence to measure the contributions of this region to the formation of the hoof wall. By their progressive keratinization to form primary epidermal laminae, the secondary epidermal laminae ultimately contributed about 20% of the thickness of the hoof wall (as revealed in the white line [zona alba]). The keratinized, primary epidermal laminae were developed to a height of 4 mm during their proximodistal course, much of this obscured because of their basal portion being embedded in the cap horn epidermis. From evaluation of structural changes accompanying keratinogenesis in the cell and determination of the contribution of the laminar epidermis to the formation of laminar horn, cap horn, connecting horn, terminal horn, and the white line, we concluded that the sterile bed concept of a nongerminative role for the secondary epidermal laminae is no longer tenable.
Release of immunoreactive arachidonate metabolites by equine endometrium in vitro
Authors: Watson Elaine D.
Published: February 2025

The ability of equine endometrium to release prostaglandin (pg) f, pge2, and leukotriene (lt) b4 was studied in vitro, using endometrial tissue from diestrous mares. Because of the high cross-reactivity of the pgf antiserum with pgf1α and with pgf2α, results were quoted as total immunoreactive pgf. Significant concentrations of these arachidonate metabolites were released into tissue culture medium between 1 and 24 hours of incubation. Significantly higher concentrations of pgf, but not of pge2 or ltb4, were released from endometria of mares with chronic endometritis than from genitally normal mares. Prostaglandin F was released only in low concentrations from the endometrium of a mare with pyometra, but concentrations of pge2 and ltb4 were similar to those of genitally normal mares.
Evaluation of normal triiodothyronine and tetraiodothyronine concentrations in llamas (Lama glama)
Authors: Smith Bradford B. , Pearson Erwin G. , Leon Juan
Published: February 2025

Basal serum triiodothyronine (T3) and tetraiodothyronine (T4) concentrations have not been established for the llama (Lama glama). In addition, changes in T3 and T4 concentrations in response to thyroid-stimulating hormone (tsh) administration have not been determined, making clinical evaluation of problems referable to thyroid dysfunction difficult. In study 1, basal T3 and T4 concentrations were determined in serum samples collected 132 clinically healthy llamas. The llamas were allotted to 3 groups: mature intact or neutered males (group I, n = 25), nonpregnant sexually mature females (group II, n = 21), and pregnant females (group III, n = 86). A mean concentration and a 95% confidence interval were computed for each group. An analysis of variance (anova) indicated that a single confidence interval range (0.45 to 4.18, mean = 1.37 ng T3/ml) adequately defined the normal T3 concentrations for all groups. An anova indicated that the T4 concentrations for the female populations (groups II and III) could be combined with a normal confidence interval range of 39 to 204 ng/ml (mean = 88 ng/ml), whereas a separate range (70 to 220 ng/ml, mean = 124 ng/ml) was determined for the male population. An anova indicated that a single confidence interval range (0.0066 to 0.0321, mean = 0.0146) adequately defined the normal T3/T4 ratio for all groups.

In study 2, T3 and T4 concentrations were evaluated in 10 healthy llamas immediately preceding and at 2, 4, 6, 8, and 24 hours after the iv administration of 3 IU of tsh/ 44 kg of body weight. The T3 and T4 concentrations were significantly higher by 2 hours after tsh administration of both groups. Peak T3 and T4 concentrations were observed at 4 and 8 hours, respectively, after tsh administration. When normalized with respect to serum T3 concentrations in samples collected immediately prior to tsh administration, the maximal increase in predicted T3 concentration was 4.06-fold (80% confidence interval range = 2.99- to 5.50-fold) at 4 hours after tsh administration. The maximal increase in predicted normalized T4 concentration was 2.32-fold (80% confidence interval range = 1.76- to 3.05-fold) at 8 hours after tsh administration. The tsh-stimulated increases in T3 and T4 concentrations st 4 hours were clearly distinguishable from values in samples obtained before tsh administration.
Effect of zearalenone on early pregnancy in guinea pigs
Authors: Long Gerald G. , Diekman Mark A.
Published: February 2025

Female guinea pigs were tested to determine whether they could serve as a model of zearalenone (zen) toxicosis during early pregnancy, as observed in domestic swine. Only 1 of 4 female guinea pigs that were given 21 mg of zen/kg of body weight orally during the first 8 days after mating was pregnant when examined 22 days after mating. Guinea pigs that were given 7 or 14 mg of zen/kg had normal fetal development. Serum concentrations of progesterone were < 12 ng/ml in all guinea pigs 8 and 15 days after mating. Serum concentrations of progesterone were > 100 ng/ml in pregnant guinea pigs on day 22, but remained < 12 ng/ml in nonpregnant guinea pigs.

Three of 5 guinea pigs treated with 20 mg of zen/kg and only 1 of 4 guinea pigs given 30 mg of zen/kg on days 1 to 3 after mating were pregnant 22 days after mating. Female guinea pigs treated with 20 or 30 mg of zen/kg on days 4 to 5 or 6 to 8 after mating and female guinea pigs treated with 60 or 90 mg of zen/kg on days 4 and 5 after mating had normal pregnancies. Serum concentrations of progesterone were < 10 ng/ml in all guinea pigs on day 15 and remained low on day 22 only in nonpregnant guinea pigs.

Pregnancy in domestic swine is disrupted by zen treatment on days 7 to 10 after mating, when embryos are migrating within the uterus, analagous to days 4 to 5 after mating in guinea pigs. Guinea pigs responded to the estrogenic effects of zen on early pregnancy in a manner similar to that seen in other rodents and dissimilar to that demonstrated by swine. Hence, despite its prolonged estrous cycle in comparison with other rodents, the guinea pig does not serve as a model for zen toxicosis in swine.
Relationship of plasma gastrin immunoreactivity and gastroesophageal sphincter pressure in clinically normal dogs and in dogs with previous gastric dilatation-volvulus
Authors: Hall Jean A. , Twedt David C. , Curtis Charles R.
Published: February 2025

Fasting and postprandial gastroesophageal sphincter pressure (gesp) and plasma gastrin immunoreactivity were measured in 6 dogs from 9 through 60 months after treatment for and recovery from gastric dilatation-volvulus (gdv). The gesp was not significantly increased in these dogs, compared with that in clinically normal dogs in either the fasting or postprandial state. Corresponding plasma gastrin immunoreactivity was not significantly increased in dogs of the gdv-recovered group, compared with that in clinically normal dogs (fasting or postprandial). An exaggerated increase in gesp in response to food-induced gastrin release was not observed in dogs of the gdv-recovered group.

Exogenously administered pentagastrin (3-μg/kg bolus, iv) increased fasting gesp in clinically normal dogs over a 4-minute test period (P = 0.01). Gastric distention in response to oral administration of isosmolar saline solution (500 ml) did not significantly increase gesp or plasma gastrin immunoreactivity in clinically normal dogs. In anesthetized clinically normal dogs, gastric distention in response to use of balloons filled to exert intragastric pressure of 30 mm of Hg also did not cause significant increase in plasma gastrin immunoreactivity. Increased gesp, secondary to hypergastrinemia or gastric distention, is an unlikely cause of eructation failure in dogs with gdv.
Effect of exocrine pancreatic insufficiency on cobalamin absorption in dogs
Authors: Simpson Kenneth W. , Morton David B. , Batt Roger M.
Published: February 2025

The possibility that the canine pancreas might have an important role in the physiologic absorption of cobalamin (vitamin B12) has been explored by determining the effect of exocrine pancreatic insufficiency on cobalamin absorption and by examining the subsequent influence of bovine pancreatic enzymes and canine pancreatic juice. Exocrine pancreatic insufficiency was induced by ligation of pancreatic ducts and confirmed by indirect assessment of exocrine pancreatic function. Cobalamin absorption was determined by oral administration of cyano[58Co]cobalamin and quantitation of radioactivity in blood, urine, and feces during 48 hours. Pancreatic duct ligation resulted in a significant (P < 0.001) decerease in cobalamin absorption, which was not restored by oral administration of bovine pancreatic enzymes, despite considerable improvements in steatorrhea and in vivo proteolytic activities. In marked contrast, malabsorption of cobalamin was significantly (P < 0.05) reversed by oral administration of canine pancreatic juice. These results indicate that pancreatic secretions have an important role in the normal absorption of cobalamin in the dog, a role that does not appear to be attributable to pancreatic enzymes, but is consistent with the existence of a pancreatic intrinsic factor in this species.
Alteration of neutrophil function associated with coccidiosis in cattle: Influence of decoquinate and dexamethasone
Authors: Roth James A. , Jarvinen Julie A. , Frank Dagmar E. , Fox James E.
Published: February 2025

Twenty Holstein steers subclinically infected with coccidia were allotted to 2 groups of 10 steers each. One group received a diet containing 0.5 mg of decoquinate/kg of body weight. After 25 days on the diet, there was no difference between the groups in lymphocyte blastogenic responsiveness to mitogens; However, there were differences in neutrophil function. Neutrophils from steers of the decoquinate-fed group had decreased random migration under agarose, enhanced cytochrome C reduction, and enhanced iodination activity. Other measures of neutrophil function evaluated (chemotactic index, Staphylococcus aureus ingestion, and antibody-dependent and - independent cell-mediated cytotoxicity) were not affected. After 30 days of decoquinate feeding, half of the cattle in each group received 5 daily im injections of dexamethasone (0.04 mg/kg of body weight). The dexamethasone-treated steers from the group that did not have decoquinate in the diet developed clinical coccidiosis, whereas the decoquinate-treated steers remained clinically normal. Lymphocyte and neutrophil function were again evaluated for a 3-day period beginning 4 days after dexamethasone treatment was halted. Neutrophils from the steers that developed clinical coccidiosis after dexamethasone administration had significantly (P < 0.05) inhibited random migration under agarose, cytochrome C reduction, and iodination activity, but significantly (P < 0.01) enhanced S aureus ingestion. The feeding of decoquinate prevented the inhibition of neutrophil cytochrome C reduction and lessened the inhibition of neutrophil iodination in the dexamethasone-treated group. Dexamethasone treatment was associated with an inhibition of lymphocyte blastogenic responsiveness to phytohemagglutinin in principals as well as controls.
Infection of the middle nasal meatus of calves with Pasteurella haemolytica serotype 1
Authors: Frank Glynn H. , Nelson Sandra L. , Briggs Robert E.
Published: February 2025

Eight healthy nonstressed calves were inoculated with Pasteurella haemolytica serotype 1, by instilling a broth culture into the middle nasal meatus of the left nostril. The inoculated left nostrils shed P haemolytica from the ventral nasal meatus at a steady rate for a mean of 7 days, whereas the uninoculated right nostrils of the same calves shed P haemolytica sporadically and in lower concentrations. The duration, frequency, and concentration of P haemolytica shed from the inoculated nostrils was significantly (P < 0.05) greater than from the nostrils of other healthy calves that had been exposed by instilling the culture into the ventral nasal meatus of both nostrils in a previous study. The concentration of antibodies (IgG, IgA, and IgM) to P haemolytica increased significantly (P < 0.05) in serum and nasal secretions after exposure.

Four weeks after initial P haemolytica exposure, calves were exposed to infectious bovine rhinotracheitis virus and became clinically ill. Four calves were induced to shed P haemolytica from both nostrils by the virus infection; thus, they were harboring the bacterium and were susceptible to active recolonization. Four calves were not induced to shed P haemolytica. The apparent reason was not that they were resistant to active colonization, but that they were no longer harboring the bacterium, because they became active shedders after they were reinfected with P haemolytica.
Furosemide and sodium bicarbonate-induced alkalosis in the horse and response to oral KCl or NaCl therapy
Authors: Freestone John F. , Carlson Gary P. , Harrold Doris R. , Church Gabie
Published: February 2025

Metabolic alkalosis was induced in 10 clinically normal horses by administration of furosemide (1 mg/kg of body weight, im) followed 4.5 hours later by sodium bicarbonate (NaHCO3; 500 g in 8 L water) via nasogastric tube. Furosemide diuresis resulted in a mean weight loss of 21.1 kg, which was associated with small, but significant, increases in venous blood pH, bicarbonate, and plasma protein concentrations (P < 0.001), while plasma potassium, chloride, and calcium concentrations declined significantly (P < 0.001).

Oral administration of the hypertonic NaHCO3 solution resulted in clinical evidence of hypovolemia, which was accompanied by a marked increase (P < 0.001) in plasma protein concentration. Seven of the 10 horses developed signs of neuromuscular excitability, as evidenced by muscle fasciculations, and 5 of the horses developed diaphragmatic flutter. Hypernatremia was transiently induced, but it resolved as the horses were allowed access to water.

The alkalosis induced by furosemide and NaHCO3 was profound and persisted for a 24-hour period and was associated with marked hypochloremia and hypokalemia. Partial replacement of the electrolyte deficits and correction of the metabolic alkalosis was attempted, using 1,000 mEq of NaCl or KCl given as an isotonic solution via nasogastric tube. In the KCl-treated group, there was a prompt and significant decline in venous blood pH and bicarbonate concentration (P < 0.001) accompanied by a significant increase in plasma potassium concentration (P < 0.001). Reductions in sodium concentration and increases in chloride concentration followed the KCl therapy, but these responses were variable and less significant (P < 0.05). In the NaCl-treated group, there was a slight reduction in venous blood pH (P < 0.05), but no significant changes in plasma bicarbonate or potassium concentrations. Plasma chloride concentration was slightly increased 2 and 5 hours after NaCl therapy (P < 0.05).
Cardiovascular effects of butorphanol administration in isoflurane-O2 anesthetized healthy dogs
Authors: Tyner C. Lee , Greene Stephen A. , Hartsfield Sandee M.
Published: February 2025

Cardiovascular consequences of butorphanol tartrate (0.2 mg/kg of body weight, iv) administration during isoflurane (1.7% end-tidal concentration) anesthesia were determined in mechanically ventilated healthy dogs. Butorphanol administration caused significant (P ≤ 0.05) reductions in mean, systolic, and diastolic arterial blood pressures; cardiac output; and rate-pressure product.
Evidence for the involvement of α2-adrenoceptors in the emetic action of xylazine in cats
Authors: Hikasa Y. , Takase K. , Ogasawara S.
Published: February 2025

Intramuscular injection of xylazine induced dose-dependent vomiting in cats (ed50 = 0.277 mg/kg); administration of standard dose of xylazine (2 mg/kg, 2 times the 100% emetic dose) induced vomiting in 100% of the cats studied. The xylazine-induced vomiting was antagonized by adrenoceptor antagonists possessing α2-blocking activity, which were yohimbine, tolazoline, and phentolamine. Of these antagonists, yohimbine was the most effective; the maximal antagonistic effect was seen at 1 mg of yohimbine/kg, a dose at which the other drugs had little or no effect. At the doses studied, prazosin and phenoxybenzamine, adrenoceptor antagonists with α1-blocking activity, did not prevent vomiting induced by xylazine. β-Adrenoceptor (propranolol), dopamine receptor (domperidone and chlorpromazine), a cholinoceptor (atropine), an opiate receptor (naloxone), and a histamine-receptor (diphenhydramine) antagonists, at the doses studied, did not prevent xylazine-induced vomiting. Pre-treatment with 6-hydroxydopamine failed to prevent xylazine-induced vomiting. These results indicated that xylazine-induced vomiting in cats is mediated by α2-adrenoceptors and suggested that the α2-adrenoceptors mediating the vomiting attributable to xylazine may not be presynaptic α2-receptors located on noradrenergic nerve terminals.
Immunologic and hematologic responses in ponies with experimentally induced Strongylus vulgaris infection
Authors: Bailey M. , Martin S. C. , Lloyd S.
Published: February 2025

Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixing antibody response, then biphasic eosinophilia. Antibody titer to S vulgaris antigen was higher in ponies inoculated with 700 larvae, compared with that in ponies given 200 larvae of S vulgaris. Also, the second peak in antibody titer and in absolute number of eosinophils was observed earlier in ponies inoculated with 700 larvae, compared with ponies inoculated with 200 S vulgaris larvae, and subsided before or from about 24 weeks after inoculation. The prepatent period for S vulgaris infection was 24 to 25 weeks. After reinoculation with S vulgaris, a degree of increased lymphocyte responsiveness was apparent but, by 17 weeks after reinoculation, only the primary peak in the absolute number of eosinophils indicated an anamnestic response. Essentially, antibody was not detectable after reinoculation.
Toxicosis in pigs fed selenium-accumulating Astragalus plant species or sodium selenate
Authors: Baker Dale C. , James Lynn F. , Hartley William J. , Panter Kip E. , Maynard H. F. , Pfister James
Published: February 2025

Three groups of 5 pigs each were fed a high selenium (Se) diet by mixing either Astragalus praelongus (31.6 ppm Se in feed), A bisulcatus (31.7 ppm Se in feed), or sodium selenate (26.6 ppm Se in feed) with commercial hog feed. Ten control pigs were fed only commercial hog chow containing trace selenium (0.44 ppm Se). Pigs were fed for 9 weeks and necropsied when they had ataxia or paralysis. Blood was collected for hematologic and serum biochemical determinations, and samples of various tissues were collected and fixed in neutral-buffered 10% formalin for histologic evaluation or frozen for determination of selenium concentration. All forms of selenium induced clinical signs of weight and hair loss, with cracked hooves and inflamed coronary bands developing in all Na2SeO4-fed pigs and 1 A praelongus-fed pig, but not in A bisulcatus-fed pigs. Serum calcium, phosphorus, and albumin concentrations were unchanged or significantly decreased from prefeeding values in groups fed selenium. Serum aspartate transaminase (ast) activities in Astragalus species-fed groups, and amylase activities and PCV in all groups of pigs fed selenium, were increased. Serum alkaline phosphatase and creatine kinase activities were significantly increased in the A praelongus-fed pigs and significantly decreased in Na2SeO4-fed pigs. Terminal tissue and body fluid selenium concentrations were determined in all groups of pigs fed selenium and compared with values in control pigs. Urine and bile concentrations were increased by the greatest factor (40 to 100 ×), with tissue concentrations of selenium increased by a lesser factor (6 to 17 ×). All groups developed poliomalacia of the spinal cord and brain stem. The marked increase in AST activity in Astragalus-fed groups was attributed to the presence of swainsonine in these plants.
Repair of full-thickness defects in the femoral trochlea of dogs after trochlear arthroplasty
Authors: Moore Jayma A. , Banks William J.
Published: February 2025

Trochlear arthroplasty was performed on one stifle in each of 18 Greyhounds; their contralateral pelvic limbs and the pelvic limbs of 2 dogs treated with sham surgery were controls. At 2, 4, 8, and 16 weeks, radiography, glycosaminoglycan histochemical analysis, histologic examination, and scanning electron microscopy of the trochlear surface were done.

All dogs used the limb and walked without an observable limp within 2 weeks after surgery. Radiography at euthanasia did not reveal degenerative changes. Well-vascularized, highly cellular, loose fibrous connective tissue was reorganized with time into a dense fibrous connective tissue covering the entire wound. Scanning electron microscopy revealed that the replacement tissue surface was rough, torn, and debris-covered.

Differential histologic staining established that change to fibrocartilage had begun deep within the replacement tissue. Histochemical analyses corroborated those observations.
Serum amyloid A protein concentration measured by radial immunodiffusion in Abyssinian and non-Abyssinian cats
Authors: DiBartola Stephen P. , Reiter Jolene A. , Cornacoff Joel B. , Kociba Gary J. , Benson Merrill D.
Published: February 2025

Serum amyloid A (saa) protein concentration was determined by use of radial immunodiffusion (rid) in 4 groups of cats: Abyssinian cats with amyloidosis, healthy Abyssinian cats without clinical evidence of amyloidosis, hospitalized non-Abyssinian cats, and clinically normal non-Abyssinian cats. Mean saa concentration in Abyssinian cats with amyloidosis was significantly (P = 0.05) higher than mean saa concentration in healthy Abyssinian cats without clinical evidence of amyloidosis and in hospitalized non-Abyssinian cats. Mean saa concentration in clinically normal non-Abyssinian cats was significantly (P = 0.05) lower than mean saa concentration in healthy Abyssinian cats without clinical evidence of amyloidosis and in hospitalized non-Abyssinian cats. Affected and healthy Abyssinian cats, however, could not reliably be distinguished on the basis of saa concentration, because of the wide range of saa values in these 2 groups of cats.
In vitro testing of a potential retroviral vector for producing transgenic livestock
Authors: Squire K. R. E. , Embretson J. E. , First N. L.
Published: February 2025

The amphotropic murine leukemia virus (mlv) has been shown to infect mammalian species other than mice. If this virus infects and expresses genes in cells of livestock species (cattle, sheep, and pigs) it has potential for use as a vector to produce transgenic livestock. Because the gene-injection technique for producing transgenic animals is inherently inefficient, our laboratory was interested in identifying or constructing retroviral vectors capable of infecting livestock embryos.

The infectivity of an amphotropic mlv-based vector for ovine, bovine, and porcine cells was tested. Experiments were also conducted to test the ability of the amphotropic mlv promoter, compared with known strong promoters, to express genes in cells from these species. Results indicated that amphotropic mlv infects and expresses genes efficiently in porcine cells and is, therefore, a potential vector for producing transgenic pigs. Infection was not detected in cells from adult bovine and ovine species; however, low levels of infection, with subsequent gene expression, were detected in cells derived from bovine embryos.
Infectious bovine keratoconjunctivitis epizootic associated with area-wide emergence of a new Moraxella bovis pilus type
Authors: Vandergaast Nadia , Rosenbusch Ricardo F.
Published: February 2025

Pilus-mediated adherence is a virulence attribute of Moraxella bovis. Several pilus types have been shown to exist among strains of this bacterium, but correlation between pilus type and specific field cases of the disease has not been done. During the summer of 1987, an epizootic of infectious bovine keratoconjunctivitis was reported in 7 Iowa counties. Eight isolates of M bovis were secured from 12 episodes studied. All 8 of the isolates were nearly homogeneous in biochemical properties and had the same plasmid biotype. Pilus typing performed by immunofluorescence and immunogold electron microscopy identified a single new pilus type among 5 of the 8 isolates. This pilus type was identified in field cases that developed within a narrow time frame and over large distances. The implication of these findings is that infectious bovine keratoconjunctivitis epizootics may be associated with emergence of a novel pilus type, and that rapid dissemination over wide distances can occur, presumably by transportation of carrier cattle.
Influence of temperature and age on the recovery of pseudorabies virus from houseflies (Musca domestica)
Authors: Zimmerman Jeff J. , Berry William J. , Beran George W. , Murphy Dorothy P.
Published: February 2025

In laboratory experiments, pseudorabies virus was readily recovered from within the body of houseflies (Musca domestica L) that had ingested the virus. Age of the fly and ambient temperature affected the rate of virus inactivation within the houseflies. Virus half-life in 3-day-old flies was 6.36 hours vs 2.81 hours in flies 8 or 13 days old. Half-life in 5-day-old flies was 12.92 hours at 10 C, 5.95 hours at 20 C, and 2.69 hours at 30 C. Virus half-life in dead flies was 9.06 hours at 10 C, 4.28 hours at 20 C, and 1.71 hours at 30 C. The data did not provide any evidence of virus replication in either living or dead flies.
Decreased protein kinase C activity in fatty liver from cattle
Authors: Katoh Norio , Kimura Kazuhiro
Published: February 2025

Protein kinase (pk) C activity in the liver of cattle with fatty liver syndrome was evaluated and compared with that in liver of healthy cattle. The pkc activities in cytosolic and particulate fractions were reduced in fatty livers, compared with those in livers from healthy cattle. The decrease of pkc activity was more distinct in cytosolic (P = 0.0016) than particulate (P = 0.069) fractions. Protein kinase activities other than pkc were not substantially changed. Seemingly, pkc was involved in the pathogenesis of fatty liver syndrome in cattle.
Jejunal mucosal lactase activity from birth to 3 weeks in conventionally raised calves
Authors: St. Jean Guy D. , Rings D. Michael , Schmall L. Michael , Hoffsis Glen F. , Hull Bruce L.
Published: February 2025

The descending portion of the duodenum of 6 Holstein calves < 24 hours old was cannulated. Sequential biopsy specimens of the proximal jejunal mucosa were obtained every other day for 3 weeks. Lactase activity in the mucosal specimens was determined and was highest at day 1, but decreased with age. Mean lactase activity was significantly (P < 0.05) higher for days 1, 3, 5, and 7, compared with days 19 and 21.
Form and development of the umbilical cord in pigs and their association with delivery of viable pigs
Authors: Randall Geoffrey C. B.
Published: February 2025

Length, extensibility, and absolute strength of umbilical cords were determined in litters of pigs at term. Length was also determined in fetuses earlier in gestation and in hypophysectomized fetuses. Mean cord length at term was 34.6 cm (range, 17 to 50 cm) and its length was correlated with length and birth weight of pigs. Cords were significantly (P < 0.01) shorter in hypophysectomized fetuses, but cord length was not influenced by sex, position in the uterus, or twisting of the cord. Although the umbilical cord was capable of being stretched considerably, the degree varied among pigs. Tension required to break portions of the cord ranged from 545 to 2,000 g. Variations in length, elasticity, and strength of the cord may influence safe delivery, birth asphyxiation, and perinatal mortality in pigs.
Use of conjunctival oxygen index for evaluation of cardiac output in dogs
Authors: Faulkner J. E. , Hauptman J. G.
Published: February 2025

The relationship between the palpebral conjunctival oxygen (Pcjo2) index, mixed venous oxygen tension (

), and cardiac index were compared, using a canine hemorrhagic shock model. The cardiac output was reduced by reducing the blood volume in 5% increments until the initial cardiac output was reduced by one half. In each of 7 dogs, the Pcjo2, index and

were found to have good correlation with cardiac index; however, the correlation coefficients were markedly reduced when the data from all of the dogs were combined, It was concluded that Pcjo2 index provides an excellent means of assessing changes in cardiac index over time in the same dog; however, it cannot be used to estimate cardiac index in an individual dog with a degree of accuracy that would be clinically significant.
Transconjunctival oxygen index in healthy awake dogs
Authors: Faulkner J. E. , Hauptman J. G.
Published: February 2025

Transconjunctival oxygen tension (Pcjo2) has been used clinically in human beings and experimentally in dogs to evaluate tissue perfusion and to estimate arterial O2 tension (Pao2); however, normal values in awake healthy dogs have not been reported. In this study, transconjunctival oxygen tension and arterial oxygen tension were measured once a week in 6 healthy conditioned dogs (15 to 28 kg) for 8 weeks. The conjunctival oxygen index (Pcjo2 index = Pcjo2/Pao2) was calculated. Mean Pcjo2 index for all dogs was 0.47 ± 0.08 x̄(

± sd). The variability of repeated measurements on the same dog and between dogs was evaluated. A difference (P < 0.05) in Pcjo2 index among dogs was evident, and although there was not a difference in the same dog over time, there was a high coefficient of variability.
Complement activity and selected hematologic variables in newborn foals fed bovine colostrum
Authors: Lavoie Jean-Pierre , Spensley Michael S. , Smith Bradford P. , Bowling Ann T. , Morse Susan
Published: February 2025

Serum complement activity and selected hematologic variables were evaluated in 5 newborn foals fed bovine colostrum (principal group) and 6 foals allowed to nurse their dam (control group). Also, bovine colostrum was evaluated for anti-equine antibodies. Precolostral serum hemolytic and conglutinating complement activities were low and increased similarly in foals of both groups to reach adult values between 1 and 3 weeks after birth.

Bovine colostrum strongly agglutinated, but did not hemolyse principal foals’ rbc and blood containing all known equine blood group alloantigens. Hemolysis was not detected after administration of bovine colostrum. Physiologic anemia developed in foals of principal and control groups during the first week of life. Erythrocyte osmotic fragility in foals of the principal group prior to and after the ingestion of colostrum remained unchanged. However, at 36 hours after birth, there was a significant decrease in erythrocyte osmotic fragility in foals fed homologous colostrum.
Transplacental Neospora caninum infection in dogs
Authors: Dubey J. P. , Lindsay D. S.
Published: February 2025

A Beagle bitch was inoculated sc and im with 1.5 million Neospora caninum tachyzoites on the 35th day of gestation. Eight pups were born alive 28 days after N caninum inoculation of the bitch. Pup 1 did not breathe and died while still enclosed in fetal membranes. Pup 2 died 2 days after birth (dab). Pups 3, 4, and 5 were euthanatized on 2, 3, and 20 dab, respectively, because they were hypothermic and not nursing. Pups 6, 7, and 8 remained clinically normal. Indirect fluorescent N caninum serum antibody titers were: < 50 (pups 1 and 8 at 17 dab, and the bitch before inoculation ), 50 (pups 2 and 3 on 2 dab), 200 (pups 6 and 7 on 17 dab), and 800 (bitch on day 17 after parturition ). Neospora caninum was recovered in cultured cells inoculated with placenta and tissues from all 5 pups necropsied, and N caninum was seen in histologic sections of the heart of pup 5. Results indicate that N caninum can be transplacentally transmitted in dogs.
Diagnosis of recent Toxoplasma gondii infection in cats by use of an enzyme-linked immunosorbent assay for immunoglobulin M
Authors: Lappin Michael R. , Greene Craig E. , Prestwood A. K. , Dawe Donald L. , Tarleton Rick L.
Published: February 2025

Subclinical Toxoplasma gondii infection was induced in young and adult cats by oral administration of tissue cysts. An antibody-capture elisa to detect anti-Toxoplasma IgM-class antibodies in the serum of cats was developed. The serologic response to experimental infection was followed in the 2 groups of cats by use of anti-Toxoplasma IgM and IgG detection. This study shows that anti-Toxoplasma IgM-class antibody titers develop early in the course of experimental infection in cats and that the combination of IgM- and IgG-class antibody titer measurement can aid in the detection of recent subclinical toxoplasmosis.
Absorption of bovine colostral immunoglobulins G and M in newborn foals
Authors: Lavoie Jean-Pierre , Spensley Michael S. , Smith Bradford P. , Mihalyi Judy
Published: February 2025

The uptake of colostral IgG and IgM, their serum half-lives, and the rates of endogenous synthesis of IgG and IgM were evaluated in 6 newborn foals fed bovine colostrum (principals) and 6 foals allowed to suckle their dams (controls). The principal foals were fed 400 ml of bovine colostrum (IgG, 10,000 mg/dl and IgM, 200 mg/dl) at 2-hour intervals, from 2 to 20 hours after foaling (total dose, 4 L). Serum IgG and IgM concentrations were determined by single radial immunodiffusion from birth to 98 days of age. At foaling, principal foals had no detectable serum equine IgG, but 1 control foal had serum equine IgG of 185 mg/dl. After ingestion of colostrum, there was no significant difference in the maximal serum bovine IgG concentration (range, 1,350 to 3,300 mg/dl) in the principal foals, and maximal serum equine IgG concentration in the control foals (range, 500 to 6,000 mg/dl). The calculated biological bovine and equine IgG half-life in the principal and control groups was 9.4 and 26 days, respectively. Endogenous IgG synthesis was first detected in 1 principal foal at 3 days of age, but was detected first between 28 and 42 days in the other principal foals. Starting on day 56 there was no significant difference in serum equine IgG concentration between groups.

At foaling, foals in both groups had low equine IgM concentrations. In the control foals, there was marked individual variation in the increases in equine IgM concentration (range, 5 to 73 mg/dl) after ingestion of colostrum. With the exception of day 49 after foaling, there was no statistical difference between groups for serum IgM concentration after day 3, and both groups had parallel rates of IgM synthesis. Bovine IgM was undetectable at foaling and maximal serum concentration ranged from 200 to 350 mg/dl following ingestion of colostrum. The calculated bovine and equine IgM half-lives were 8 and 5 days, respectively. The coefficients of absorption of bovine IgG and IgM were 30.9 and 84, respectively, in the principal foals. In the control foals, the coefficient of absorption of equine IgG and IgM was 35 and 30, respectively. One principal foal was excluded from the study because it died of aspiration pneumonia at 2 days of age.
Fiber digestion and voluntary intake in horses after adaptation to extensive large-colon resection
Authors: Bertone Alicia L. , Ralston Sarah L. , Stashak Ted S.
Published: February 2025

Each of 3 digestion trials (3 forage diets) was performed on 2 groups of horses 6 to 12 months after sham operation (group 1; n = 3) or large-colon resection (group 2; n = 5). Diets were alfalfa pellets, alfalfa hay, and grass hay. Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, and crude protein and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables determined were percentage of fecal water, total fecal water, metabolic organic matter, metabolic crude protein, and metabolic nitrogen.

Large-colon resection decreased the digestion of plant cell wall because of decreased digestion of cellulose in alfalfa pellet and grass hay diets, but not in alfalfa hay diet. Insufficient digestible energy and/or protein from grass hay was obtained by horses with colon resection, and significant (P < 0.05) weight loss was observed. Voluntary intake was significantly (P < 0.05) increased by horses with colon resection. Of the diets studied, alfalfa hay was the most appropriate forage diet, compared with average grass hay and alfalfa pellet diet, for horses after extensive large-colon resection. Additionally, horses with colon resection may have higher levels of feed intake than do horses without colon resection.
Synergistic antiviral activities of acyclovir and recombinant human leukocyte (alpha) interferon on feline herpesvirus replication
Authors: Weiss Richard. C.
Published: February 2025

The antiviral activities of 9-(2-hydroxyethoxymethyl)guanine (acyclovir; acv) either alone or combined with recombinant human leukocyte (alpha) a/d interferon (rHuifn-α) against feline herpesvirus type 1 (fhv-1) were evaluated in feline embryo cell cultures, using an infectivity-inhibition assay. In acv-treated cultures, the 50% inhibitory dose (id50) was approximately 10 to 20 μg of acv/ml. Maximal inhibition of fhv-1 infectivity (range, 3.4 to 4.2 log10tcid50) was observed when high test doses of acv (125 or 250 μg/ml) were given 1 to 6 hours after infection. Although mild inhibition (range, 0.3 to 1.6 log10tcid50) of virus was observed at lower drug doses (10 to 62.5 μg/ml), fhv-1 was relatively resistant to acv and required higher minimal inhibitory doses than those reported for other herpesviruses. However, when acv was combined with 10 or 100 U of rHuifn-α/ml, synergistic antiviral effects were associated with acv dosage of 10 to 62.5 μg/ml. Antiviral activities resulting from use of the combined drugs permitted nearly eightfold reduction in the dose of acv required to achieve maximal inhibition of fhv-1. Significant (P < 0.01) synergistic interactions with acv resulted when the rHuifn-α was given before or after infection; at the lower doses of acv, however, rHuifn-α pretreatment was more effective. Although dosages of either ≥ 62.5 μg of acv/ml or 100 U of rHuifn-α/ml were cytosuppressive in control cell cultures, additive anticellular effects were not observed at synergistic combinations of acv and 10 U of rHuifn-α/ml.
Molecular cloning of serogroup- and serotype-specific genome segments from bluetongue virus serotype 11
Authors: Dunn Stephen J. , Oberst Richard D. , Stott Jeffrey L. , Osburn Bennie I.
Published: February 2025

Genome segments 2, 6, 8, and 9 of bluetongue virus (btv) serotype 11, coding for P2, NS1, NS2, and P6, respectively, were cloned into pUC 8. Sizes of segment-2 and segment-6 clones indicated partial copies (55% and 80% of full length, respectively), whereas segment 8 and 9 clones represented full-length copies. Northern blot hybridizations of the clones to the 5 United States btv prototypic serotypes (2, 10, 11, 13, and 17) revealed segment-2 clone to be serotype-specific to btv-11, whereas segment 6, 8, and 9 clones were able to detect all serotypes to varying degrees. All clones failed to detect the related orbivirus, epizootic hemorrhagic disease virus.
Serum amyloid A concentrations in cows given endotoxin as an acute-phase stimulant
Authors: Boosman Roel , Niewold Theo A. , Mutsaers Cornelius W A. A. M. , Gruys Erik
Published: February 2025

The concentrations of serum amyloid A (saa) in 4 cows given Escherichia coli endotoxin as an acute-phase stimulant were quantitatively evaluated by use of an indirect micro-elisa method and compared with other clinical hematologic values. Serum amyloid A concentration changed minimally after intradermal infection of endotoxin. The concentration of saa was increased 5 hours after iv injection of endotoxin, with maximal concentration after 17 to 20 hours. The increase in saa concentration coincided with decreasing serum Zn and Fe concentrations; however, Zn and Fe concentrations appeared to be restored when saa concentration was still maximal. It was concluded that the saa response of cattle is comparable with that of other species and can be used for monitoring the activity of clinical inflammation and tissue injury.
Diagnostic importance of vitamin K1 and its epoxide measured in serum of dogs exposed to an anticoagulant rodenticide
Authors: Mount Michael E. , Kass Philip H.
Published: February 2025

Administration of vitamin K1, sc, to anticoagulant-poisoned (diphenadione) dogs provided diagnostic information within 4 hours, when vitamin K1 and its epoxide were measured in canine sera. Twelve dogs (2 groups of 6) were given 2.5 mg of diphenadione/kg of body weight for 3 days. Dogs were treated with vitamin K1, 2.5 (n = 6) or 5 mg/kg/day (n = 6) sc for 21 days, and their responses were compared. Four nonexposed control dogs were given 5 mg of vitamin K1/kg/day.

Serum concentration of vitamin K epoxide was significantly (P < 0.02) higher in diphenadione-exposed dogs than in control dogs 1 to 4 hours after the initial vitamin K1 treatment on day 4. Vitamin K epoxide/vitamin K1 ratios were similarly higher and became more distinct.

Cessation of vitamin K1 therapy on day 24 resulted in prolongation of one-stage prothrombin times in diphenadione-exposed dogs, becoming clearly evident on day 27. Serum vitamin K1 concentrations were not detectable on day 27 in diphenadione-exposed dogs, whereas serum vitamin K1 concentrations were readily detectable in control dogs. One-stage prothrombin time changes, during days 24 to 32, indicated 5 mg of vitamin K1/kg provided better protection than did 2.5 mg of vitamin K1/kg. Coagulopathy in the dogs was resolved by day 32.
Transretinal mass receptor potentials recorded from the canine retina in vitro
Authors: Millichamp Nicholas J. , Arden Geoffrey B.
Published: February 2025

A transretinal method for recording the summed potentials generated by photoreceptors of the isolated canine retina in vitro is reported. Pieces from 10 retinas of 5 clinically and visually normal dogs were maintained in a recording chamber and superperfused with a modified cell culture medium. Sodium glutamate added to the medium eliminated electrical responses from retinal glia and allowed the summed receptor potentials to be recorded. The response to flashes of light consisted of a negative potential, which increased in amplitude in a graded manner and in complexity with increased stimulus intensity. The response was similar in waveform to that reported in other vertebrate species, using intracellular and extracellular techniques. This method of recording the mass transretinal receptor potentials in vitro will be of value for investigating abnormal photoreceptor functions in dogs in the early stages of inherited retinal degeneration.
Continuous electromyographic recordings of pharyngeal muscle activity in normal and previously denervated muscles in dogs
Authors: Venker-van Haagen A. J. , Hartman W. , van den Brom W. E. , Wolvekamp W. Th. C.
Published: February 2025

Continuous electromyographic recordings of pharyngeal muscle activity were made in 5 clinically normal control dogs and in 7 dogs 3 years after partial denervation of the pharyngeal muscles.

Electromyographic recordings were made of the sequence of actions of each muscle and of the combined muscle activity, at rest and during swallowing of food. During 30-second periods, the recordings were digitalized and stored on diskette for further analysis.

All control dogs had a distinct pattern of muscle activity during swallowing, the onset being in a constant order (hyopharyngeal, thyropharyngeal, and cricopharyngeal) and bilaterally synchronous. While eating, each dog had about 5 to 12 short periods of synchronous activity in each muscle, between the swallowing actions. During the resting period, there were longer periods of activity, which were synchronous with respiration.

In each denervated dog, there were normal and irregular swallowing actions. Swallowing activity was recognized, but the sequence of hyopharyngeal, thyropharyngeal, and cricopharyngeal muscle activity was irregular and different from that in control dogs.

Partial denervation of the pharyngeal muscles does not seriously impair motor activity of the muscles, but does alter the sequence of activity in the pharyngeal muscles during swallowing.