bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy of prosthetic laryngoplasty with and without bilateral ventriculocordectomy as treatments for laryngeal hemiplegia in horses
Authors: Tetens Joanne , Derksen Frederik J. , Stick John A. , Lloyd James W. , Robinson N. Edward
Published: January 2024

Objective

To evaluate the efficacy of prosthetic laryngoplasty with and without bilateral ventriculocordectomy for treatment of experimentally induced left laryngeal hemiplegia (LLH).

Animals

15 adult Standardbreds.

Procedure

Horses were allotted to 3 equal groups. Sham operation (group 1), prosthetic laryngoplasty (group 2), or prosthetic laryngoplasty with bilateral ventriculocordectomy (group 3) was performed after induction of LLH. Upper airway function testing was performed prior to left recurrent laryngeal neurectomy (LRLN), 14 days after LRLN, and 60 and 180 days after surgical treatment. Measurements were obtained at rest and at treadmill speeds corresponding to 75 and 100% of maximal heart rate. Videoendoscopy was performed at rest and during exercise in all horses prior to LRLN and 60 and 180 days after surgical treatment. Upper airway endoscopy was performed immediately after LRLN to document induction of grade-IV LLH. Also, horses in group 3 were endoscopically examined at 7, 14, 21, 28, and 120 days after surgical treatment to evaluate healing of the ventriculocordectomy sites.

Results

When horses were at rest, significant differences were not apparent between groups at any period or between periods for any measured variable. LRLN induced airway obstruction in all horses during exercise. In sham-operated horses, this obstruction was unaffected by time. In contrast, 60 and 180 days after surgical treatment, inspiratory flow limitations induced by LRLN were reversed in horses of groups 2 and 3. There were no significant differences between the 2 treatment groups. Endoscopy revealed the left arytenoid cartilage abducted beyond the intermediate position, but not touching the pharyngeal wall in all horses with a laryngeal prosthesis. After surgical treatment, 4 group-2 horses had filling of both ventricles with air during exercise. There was moderate to marked swelling of the ventriculocordectomy sites immediately after surgery, and this swelling resolved by 7 days after surgery. The ventriculocordectomy sites looked best at 14 and 180 days.

Conclusions

60 and 180 days after prosthetic laryngoplasty, upper airway function returned to pre-LRLN values in horses with experimentally induced LLH exercising at 100% of maximal heart rate. Combining ventriculocordectomy with prosthetic laryngoplasty does not further improve upper airway function in these horses. (Am J Vet Res 1996;57:1668–1673)
Effects of a high-protein diet on mineral metabolism and struvite activity product in clinically normal cats
Authors: Funaba Masayuki , Hashimoto Masashi , Yamanaka Chieko , Shimogori Yoichiro , Iriki Tsunenori , Ohshima Seinosuke , Abe Matanobu
Published: January 2024

Objective

To examine effects of high-protein diets (>50% crude orotein of dry matter) on urinary mineral excretion and struvite activity product ([Mg2+] × [NH4+] × [PO43-]).

Animals

14 clinically normal cats, 4 adult female and male cats for experiments 1 and 2, respectively, and 6 female kittens aged 4 months for experiment 3.

Procedure

Relations between dietary protein amount (25.9, 38.3, 51.4, and 65.4% crude protein [dry matter]) and urinary excretion of Mg, P, and Ca were examined in a 4 × 4-Latin square design (experiment 1). Struvite activity product, the index of solubility of struvite crystals, was determined when a high-protein diet (54.9%) was fed (experiment 2). Utilization of minerals in cats fed a high-protein diet long term was examined (experiment 3).

Results

Water intake and urine volume increased with increasing dietary protein concentration. Urinary Mg2+ excretion was not affected (experiment 1) or was decreased (experiment 3) by higher protein intake, leading to lower urine Mg2+ concentration in groups fed higher protein amounts. Urine pH was decreased by high-protein intake. As a result, PO43- concentration was decreased by high-protein intake (experiment 2), although total daily urinary excretion of P was increased. Consequently, struvite activity product tended to decrease in cats fed high-protein diets, indicating increase in struvite solubility. High-protein intake decreased Ca and P retention by increasing their fecal and urinary excretions, respectively.

Conclusion

As a consequence of the increase in urine volume and urine acidification, high-protein diets have potential ability to increase solubility of struvite crystals. (Am J Vet Res 1996;57:1726–1732)
Alterations in specific activity of glucose-6-phosphatase in laboratory rats after leptospiral exposure followed by triiodothyronine administration
Authors: Dobrosielski-Vergona Kathleen
Published: January 2024

Objective

To determine the effect of leptospirosis on thyroid hormone induction of the specific activity of hepatic microsomal glucose-6-phosphatase in laboratory rats.

Animals

Male Fisher 344 rats, 6 and 24 months old, healthy and infected with leptospirosis.

Procedure

The maximal velocity of glucose-6- phosphatase in intact and detergent-disrupted hepatic microsomes was assayed in duplicate or triplicate at 5 substrate concentrations, by monitoring the release of inorganic phosphate at 0-, 5-, and 10-minute intervals. The method of least squares was used to determine the velocity of the reactions. The level of statistical significance was determined, using the Student's t-test for unpaired data. Thyroid hormone (40 µg of T3/100 g of body weight) was administered for 5 consecutive days prior to sacrifice.

Results

Leptospirosis significantly increased the specific activity of the translocase component of glucose-6-phosphatase in old, but not young, rats. The activity of the translocase increased more than threefold in untreated, infected old animals, compared with untreated, healthy old animals. Thyroid hormone induced a two- and threefold increase in the specific activities of the translocase in young and old healthy animals, respectively. Thyroid hormone did not increase the activity of the translocase in old animals infected with leptospirosis.

Conclusions and Clinical Relevance

Leptospirosis alters the specific activity and induction by thyroid hormone of the translocase component of hepatic microsomal glucose-6-phosphatase in old male Fisher 344 rats. It is necessary to be aware of possible alterations in hepatic membrane-bound enzymes after leptospiral infection of older laboratory animals. (Am J Vet Res 1997;58:143–145)
Cardiopulmonary effects of propofol infusion in llamas
Authors: Duke Tanya , Egger Christine M. , Ferguson James G. , Frketic Magda M.
Published: January 2024

Objective

To evaluate selected cardiopulmonary responses to propotol 2 infusion rates in nonpretreated llamas breathing room air.

Animals

5 adult llamas (3 males, 2 females) with mean ± SD body weight of 135 ± 17.7 kg.

Procedure

After anesthesia induction with propofol (2 mg/kg of body weight, IV), llamas received either propofol infusion 0.2 mg/kg/min (group 1) or 0.4 mg/kg/min (group 2) for 60 minutes. Measurements, taken before anesthesia induction and at regular intervals during infusion were: direct blood pressures, heart and respiratory rates, cardiac output, and arterial blood gas tensions. Systemic and pulmonary vascular resistance, cardiac and stroke indices, and plasma bicarbonate and base excess concentrations were calculated.

Results

At 3 to 60 minutes after either dosage of propofol, PaCO2 and heart rate increased in all llamas; at the same time, PaO2 and arterial pH decreased. Mean pulmonary artery and central venous pressures, and stroke index decreased at 3 to 60 minutes after either dosage of propofol. Mean arterial pressure decreased at 30 to 60 minutes after infusion of 0.4 mg of propofol/kg/min; pulmonary arterial wedge pressure decreased at 20 to 40 minutes and 3 to 60 minutes after infusion of 0.2 and 0.4 mg of propofol/kg/min, respectively. Mean time from termination of infusion to sternal recumbency was 7 (group 1) and 13 (group 2) minutes. Standing was achieved in a mean 11 (group 1) and 22 (group 2) minutes.

Conclusion

Propofol infusion rate of 0.2 mg/kg/min was considered too low to maintain a suitable depth of anesthesia, but 0.4 mg/kg/min was considered sufficient for noninvasive procedures with minimal cardiopulmonary depression. (Am J Vet Res 1997;58:153–156)
Decreased pulmonary arterial endothelium-dependent relaxation in heartworm-infected dogs with pulmonary hypertension
Authors: Matsukura Yoshihito , Washizu Makoto , Kondo Motoki , Motoyoshi Shigekatsu , Itoh Akiko , Nakajyo Shinjiro , Shimizu Kazumasa , Urakawa Norimoto
Published: January 2024

Objective

To investigate the contractility of pulmonary arterial smooth muscle and the relation between pulmonary hypertension and endothelium-derived relaxing factor in canine heartworm disease.

Animals

18 noninfected control and 9 heartworm-infected dogs.

Procedure

Mean pulmonary arterial blood pressure was measured in vivo, and tension of pulmonary arterial strips was measured by use of the isometric tension method.

Results

After phenylephrine (10−5M)-induccd contraction of the pulmonary vascular smooth muscle, carbamylcholine chloride (CCh, 10−6M) caused more relaxation of the vascular smooth muscle of noninfected dogs than that of heartworm-infected dogs. Furthermore, the degree of CCh-induced relaxation was inversely correlated with mean pulmonary arterial blood pressure in the noninfected and the heartworm-infected dogs. The CCh-induced relaxation was inhibited by pretreatment with Ng-nitro-l-arginine methyl ester hydrochloride (10−5M), and in reversed dose-dependent manner by l-arginine (10−4 to 3 × 10−2M). Sodium nitroprusside (10−8 to 10−5M) caused a dosedependent relaxation in all vessels, and there was no significant difference in the relaxation responses in both groups except at 10−7M for vessels with intact endothelium from noninfected dogs.

Conclusion

The depression of endothelium-dependent relaxation is correlated with the pulmonary arterial blood pressure in heartworm-infected dogs, suggesting that the decrease is one of the essential factors for the genesis of pulmonary hypertension in canine filariasis. (Am J Vet Res 1997;58:171–174)
Active and passive immune responses to transmissible gastroenteritis virus (TGEV) in swine inoculated with recombinant baculovirus-expressed TGEV spike glycoprotein vaccines
Authors: Shoup David I. , Jackwood Daral J. , Saif Linda J.
Published: January 2024

Objective

Baculovirus-expressed transmissible gastroenteritis virus (TGEV) spike (S) glycoprotein vaccines were inoculated parenterally in swine to determine whether such vaccines could induce serum and whey virus-neutralizing (VN) antibodies and protective lactogenic immunity for TGEV-challenge-exposed pigs.

Animals and Procedures

3 recombinant baculoviruses that expressed full or partial length TGEV Miller strain S glycoproteins were inoculated SC in 17 conventionally raised 11-day-old TGEV-seronegative pigs to determine whether the recombinant S glycoproteins would elicit serum VN antibodies. Eleven TGEV-seronegative pregnant sows were inoculated SC or intramammarily with subunit vaccines (R2-2 or R3-5) or control proteins. Pigs born to 9 of the 11 sows were challenge exposed at 4 to 5 days of age with the virulent Miller strain, and passive immunity was assessed. Serum and whey antibody responses to TGEV were analyzed by VN and ELISA testing.

Results

Recombinant S glycoproteins (R2-2 or R3-5) containing the 4 major antigenic sites induced similar VN antibody titers to TGEV in serum and colostrum, but low (some sows) or no VN antibody titer was detected in milk. Subcutaneous inoculation of sows with R2-2 or R3-5 elicited IgG, but not IgA antibodies to TGEV in colostrum. Morbidity was 100%, and mortality ranged from 20 to 80% in TGEV challenge-exposed pigs nursing sows inoculated SC or intramammarily with TGEV S glycoprotein vaccines.

Conclusions and Clinical Relevance

Parenterally administered TGEV S glycoprotein vaccines elicit VN antibodies to TGEV in serum and colostrum that do not fully provide active or passive immunity in swine. (Am J Vet Res 1997;58:242–250)
Effect of bilateral tenectomy of the tensor veli palatini muscle on soft palate function in horses
Authors: Holcombe Susan Jane , Derksen Frederik Jan , Stick John Alan , Robinson N. Edward
Published: January 2024

Objective

To determine the effect of bilateral tenectomy of the tensor veli palatini muscle on soft palate and nasopharyngeal function in exercising horses.

Animals

5 Standardbreds.

Procedure

Treadmill videoendoscopy was performed on 5 Standardbreds exercising at 50, 75, and 100% of the speed that produced maximum heart rate; tracheal and pharyngeal pressures were measured before and after surgery, Tenectomy of the tensor veli palatini muscle was performed bilaterally on each horse while under general anesthesia, using a transoral approach.

Results

Peak inspiratory tracheal pressures were significantly (P = 0.016) more negative and there was a trend (P = 0.06) for peak pharyngeal inspiratory pressure to be less negative following bilateral tenectomy of the tensor veli palatini muscle, compared with preoperative values. The rostral half of the soft palate was unstable and collapsed dorsally into the nasopharynx during inspiration, causing partial obstruction of the nasopharynx. The caudal free margin of the soft palate remained ventral to the epiglottis, and dorsal displacement of the soft palate did not occur in any horse.

Conclusions

Bilateral tenectomy of the tensor veli palatini muscle did not cause dorsal displacement of the soft palate in horses while exercising at maximum heart rate, but resulted in collapse of the nasopharynx during inspiration.

Clinical Relevance

Results of our study indicate that the tensor veli palatini muscle functions to support and dilate the nasopharynx during intense inspiratory efforts in horses by tensing the palatine aponeurosis. (Am J Vet Res 1997;58:317–321)
Purification and characterization of bovine complement component C3 and its cleavage products
Authors: Di Carlo A. L. , Paape M. J. , Hellman J. , Lilius E-M.
Published: January 2024

Objective

To purify complement component C3 from bovine serum, characterize and analyze NH2-terminal amino acid sequences from its various cleavage products, and do cross-species homology comparisons.

Animals

2 healthy lactating Holstein cows, and 2 healthy adult female New Zealand White rabbits.

Procedure

Bovine C3 was isolated from serum, and was cleaved to C3b. The resulting protein was analyzed to determine apparent molecular mass of resulting protein segments. Bands were electroblotted onto a membrane and excised, then NH2-terminal amino acid sequences were determined.

Results

The C3 preparation consisted of 6 segments, with molecular mass of 30, 40 (2 bands, a and b), 70, 75, and 115 kd. Via sequence comparisons, the 115-kd band was identified as the α chain; the 75-kd segment was determined to be the NH2-terminal portion of α chain; the 70-kd piece was identified as the intact β chain; and the two 40-kd bands are believed to be located at the C-terminal portion of the α chain, at the cleavage site that yields C3f. The 30-kd band is the NH2-terminal portion of the α chain (minus the C3a segment). Sequence analysis of each band revealed a high degree of homology with human, rat, mouse, and horse C3. Polyclonal antibodies raised in rabbits yielded sera that reacted to the purified sample in manner similar to that of commercially available antibodies.

Conclusions

The purified preparation contained intact C3, C3b, and the degradation products iC3b and C3c, which had high sequence homology with those of other species. The C3a and C3d, and C3g segments of the protein were not detected and may have been lost during the purification, lyophilization, or transfer steps. Structure and cleavage characteristics of bovine C3 can be used to better understand immune responses to bacterial pathogens in the mammary gland. (Am J Vet Res 1997;58:585–589)
Nematocidal efficacy of eprinomectin, delivered topically, in naturally infected cattle
Authors: Yazwinski T. A. , Johnson E. G. , Thompson D. R. , Drag M. D. , Zimmerman G. L. , Langholff W. K. , Holste J. E. , Eagleson J. S.
Published: January 2024

Objective

To assess the nematocidal efficacy of eprinomectin in naturally infected cattle.

Animals

62 (31 eprinomectin-treated and 31 control) beef mixed-breed or Holstein cattle, either 6 to 11 or 48 to 96 months old.

Procedure

Cattle were housed 21 to 27 days before treatment to allow parasites to reach maturity. Animals were grouped by sex, ranked by weight, and randomly assigned to treatment group. Fecal flotation was done to identify cattle with intestinal nematode infections. Treatment groups were: 1—eprinomectin topical vehicle (1 ml/10 kg) and 2—eprinomectin topical solution (1 ml/10 kg). Cattle were euthanatized by replicate on day 14 or 15, and standard procedures were used to recover of pulmonary, abomasal, small intestinal, and large intestinal nematodes.

Results

Eprinomectin efficacy across all trials was 100% against adult Trichostrongylus axei, Haemonchus placei, Oesophagostomum radiatum, and Dictyocaulus viviparus, as well as fourth-stage larval Oes radiatum, Ostertagia ostertagi, Nematodirus helvetianus, and Cooperia spp. Efficacy against adult O ostertagi, Cooperia oncophora, C punctata, C surnabada, C spatulata, N helvetianus, Trichuris sp, and Trichuris fourth-stage larvae was 99.9, 99.8, 99.6, 98.9, 98.3, 99.7, 97.8, and 84.3%, respectively. All results were significant (P < 0.01) except those for C spatulata. Adverse reactions were not observed.

Conclusion and Clinical Relevance

Eprinomectin is a safe and effective nematocide against naturally acquired nematode infections in cattle when administered at a dosage of 500 μg/kg. Milk and meat withholding is not necessary when using this product. (Am J Vet Res 1997;58:612–614)
Effects of bilateral hypoglossal and glossopharyngeal nerve blocks on epiglottic and soft palate position in exercising horses
Authors: Holcombe Susan Jane , Derksen Frederik Jan , Stick John Alan , Robinson N. Edward
Published: January 2024

Objective

To determine the effect of bilateral hypoglossal and glossopharyngeal nerve block on epiglottic and soft palate position and tracheal and pharyngeal pressures in exercising horses.

Animals

5 Standardbreds.

Procedure

Tracheal and pharyngeal pressures were measured in 5 Standardbreds exercising at the speed at which the horses achieved 50, 75, and 100% of maximal heart rate after bilateral hypoglossal and glossopharyngeal nerve block and without nerve block. Nerve block was achieved by injection of 1 to 2 ml of 2% mepivicaine hydrochloride between the glossopharyngeal and hypoglossal nerves, as they coursed through the medial compartment of the diverticulum of the auditory tube (guttural pouch), using videoendoscopic guidance and an injection apparatus.

Results

Compared with control values, peak inspiratory tracheal pressure was significantly (P = 0.02) more negative, and peak pharyngeal inspiratory pressure was less negative (P = 0.004) after bilateral hypoglossal and glossopharyngeal nerve block. Respiratory frequency was significantly (P = 0.024) lower after nerve block, compared with control values. The epiglottis was unstable and retroflexed through the rima glottis during inspiration after bilateral hypoglossal and glossopharyngeal nerve block. Despite loss of contact between the epiglottis and the caudal free margin of the soft palate, dorsal displacement of the soft palate did not occur.

Conclusions and Clinical Relevance

Loss of contact of the epiglottis with the soft palate did not affect soft palate position, suggesting that when the soft palate is normal, the epiglottis does not function as a support, holding the soft palate in a ventral position. Therefore, epiglottic dysfunction is not solely responsible for intermittent dorsal displacement of the soft palate in horses, and neuromuscular dysfunction involving the hyoepiglotticus muscle, geniohyoideus muscle, or the hypoglossal nerve may cause epiglottic retroflexion in horses. (Am J Vet Res 1997;58:1022–1026)
Electroretinographic evaluation of Papillons with and without hereditary retinal degeneration
Authors: Narfström Kristina , Ekesten Björn
Published: January 2024

Objective

To evaluate the function of the outer retina in Papillons with and without hereditary retinal degeneration.

Animals

45 Papillons, median age 1.7 (range, 0.8 to 5.1) years.

Procedure

Complete physical and ophthalmic examinations were done prior to performing electroretinography under general anesthesia. Full-field electroretinograms (ERG) were recorded, using a special-purpose computer system. Eleven specific ERG responses were recorded, graphed, and evaluated, using age-matched Papillons.

Results

Severely decreased retinal function was detected in 8 Papillons. The youngest affected dog was 1.2 years old. In affected dogs, amplitudes of responses mainly originating from the rod system were severely decreased, compared with those originating from the cone system.

Conclusions

Papillons represent another breed of dog affected by a hereditary photoreceptor degeneration that can be detected at an early age by using ERG. A reliable age for diagnosis using ERG is considered to be 1.5 years.

Clinical Relevance

Thorough and precise ERG procedures and protocols are needed to reliably obtain an early diagnosis of progressive retinal atrophy. (Am J Vet Res 1998;59:221–226)
Influence of tidal volume and positive end-expiratory pressure on inspiratory gas distribution and gas exchange during mechanical ventilation in horses positioned in lateral recumbency
Authors: Moens Y. , Lagerweij E. , Gootjes P. , Poortman J.
Published: January 2024

Objective

To study effects of intermittent positive-pressure ventilation (IPPV) with large tidal volumes and addition of positive end-expiratory pressure (PEEP) on maldistribution of ventilation in anesthetized horses positioned in lateral recumbency.

Animals

6 healthy adult horses.

Procedure

Anesthesia was induced by IV infusion of thiopental sodium and guiafenesin and was maintained with supplemental doses of thiopental and IV infusion of chloral hydrate. Functional separation of the lungs was achieved, using a tube-in-tube intubation technique. Intermittent positive-pressure ventilation of both lungs with air was done by use of an anesthetic circle system and a ventilator. Data were collected during spontaneous respiration and during IPPV, using increasing tidal volumes with and without PEEP of 10 and 20 cm of H2O.

Results

Uneven distribution of inspired gas between the lungs that existed during spontaneous respiration was not altered by IPPV and large tidal volumes. Addition of PEEP caused a significant and reversible shift of inspired gas to the dependent lung and preferentially increased functional residual capacity of the nondependent lung. This was accompanied by significant increase in Pao2. With IPPV, the combined effects of PEEP and large tidal volume caused an increase of the fractional distribution of inspired gas to the dependent lung from 34% to 50%, accompanied by an increase in Pao2 and alveolar dead space of both lungs.

Conclusions and Clinical Relevance

Use of PEEP during IPPV changes distribution of inspired gas. Increased in Pao2 can be attributed to improved ventilation-perfusion, especially in the dependent lung, in which previously collapsed lung units might have been reopened and participated again in gas exchange after redistribution of inspired gas. The most pronounced effects of IPPV and PEEP were associated with high airway pressures, which are likely to offset the beneficial effects of the increase of Pao2 on total oxygen availability to the tissues because of the expected negative effects on cardiac output. (Am J Vet Res 1998;59:307–312)
Bacterial flora in the duodenum of healthy cats, and effect of dietary supplementation with fructo-oligosaccharides
Authors: Sparkes A. H. , Papasouliotis K. , Sunvold G. , Werrett G. , Clarke C. , Jones Μ. , Gruffydd-Jones T. J. , Reinhart G.
Published: January 2024

Objective

To investigate changes in the duodenal flora of healthy cats over time, and evaluate the effect of dietary supplementation with fructo-oligosaccharides (FOS).

Animals

12 healthy, barrier-maintained, specific pathogen-free cats.

Procedure

Duodenal juice for bacteriologic examination was collected via oral endoscopy 5 times from each cat over a 32-week period. Cats were allotted randomly to 2 groups, and a crossover design study, during which they were fed either a replete dry (basal) diet or, for 12 consecutive weeks, basal diet supplemented with 0.75% FOS, was done. Samples (3 from cats fed the basal and 2 from cats fed the FOS diet) were collected for a minimum of 6 weeks after commencement of feeding, and a minimum of 6 weeks apart.

Results

Mean aerobic, anaerobic, and total bacterial counts did not differ significantly among sample collection times. After pooling of the results, mean (± SD) log10 colony-forming units (CFU) of aerobic, anaerobic, and total bacteria/ml were 5.5 ± 1.1, 4.8 ± 1.0 and 5.6 ± 1.1, respectively. However, individual cats had considerable variation in counts: mean (range) intraindividual coefficients of variation were: 19.0 (6.1 to 34.2), 19.9 (4.8 to 35.5), and 18.1 (5.5 to 32.6)%, respectively. In 1 cat, total bacterial count varied between < 3.0 and 6.3 CFU/ml. Bacterial flora varied qualitatively: only Enterococcus faecalis, Clostridium perfringens, Bacteroides, Pasteurella, and Streptococcus spp, and unidentified gram-negative (aerobic) rods were present in > 50% of the samples.

Conclusions

Wide quantitative and qualitative variation in the duodenal flora of healthy cats was observed over time, which was not affected by dietary supplementation with FOS. (Am J Vet Res 1998;59:431–435)
Oral inoculation of cats with tissue cysts of Neospora caninum
Authors: McAllister Milton Μ. , Jolley William R. , Wills Rebecca A. , Lindsay David S. , McGuire Angela Μ. , Tranas Jennifer D.
Published: January 2024

Objective

To test the hypothesis that cats are definitive hosts of Neospora caninum.

Animals

6 weaned male kittens obtained from 2 sources, and several dozen outbred mice.

Procedure

Cats were fed large numbers of 3 strains of N caninum: tissue cysts in buffered saline solution, mouse brain homogenates, and whole carcass homogenates from seropositive mice. Fecal specimens were examined for 4 weeks by use of flotation tests, and bioassays were performed in mice. One cat was inoculated parenterally with tachyzoites, to determine whether cats could respond serologically to N caninum. Tissue cysts from portions of oral inocula were cultured to verify viability. Indirect fluorescent antibody serologic testing, histologic and immunohistologic examinations, cell culture, and polymerase chain reaction procedures were performed 4 to 8 weeks after oral exposure, to seek evidence of infection of cats and mice.

Results

None of the cats or mice seroconverted to N caninum, with the exception of the single cat inoculated parenterally. Fecal shedding of oocysts was not observed, except for Isospora felis oocysts that were shed by 2 cats beginning prior to oral challenge exposure. Evidence of infection was not detected in tissues of cats or mice, with the exception of the parenterally inoculated cat.

Conclusions

The hypothesis that cats are definitive hosts of N caninum is not supported.

Clinical Relevance

Extermination of cats in efforts to control bovine neosporosis is not warranted. (Am J Vet Res 1998;59:441–444)
Polymorphism of feline β-globins studied by reversed-phase high-performance liquid chromatography
Authors: Kohn Barbara , Reilly Michael P. , Asakura Toshio , Giger Urs
Published: January 2024

Objective

To characterize the feline β-globin system with respect to the number and genetics of adult β-globin chains.

Animals

84 domestic and purebred cats (9 breeds); 14 cats were mildly to severely anemic. For genetic analyses, 12 litters with 1 to 5 offspring for a total of 29 kittens.

Procedure

Feline globins from erythrocyte lysates were separated by reversed-phase high-performance liquid chromatography and analyzed on the basis of retention time and area of each β-globin peak. Mixing studies with half the amount of hemoglobin (Hb) from 2 cats were performed to assign the β-globin peaks in each cat. The Hb from 60 cats were also separated by standard isoelectric focusing methods.

Results

Heme and α- and β-globins were effectively separated by high-performance liquid chromatography. Although there was only 1 α-globin, a total of 6 β-globins (I through VI) were identified, with each cat having 1 to 4 β-globin chains. From analysis of the number of β-globins, their relative amounts, and Hb mixing studies, 17 β-globin patterns were observed. The β-globin pattern in healthy and anemic cats was identical. Family studies documented an autosomal codominant mode of inheritance of the adult β-globins and a linkage of 2 β-chains forming haplotypes.

Conclusions

Biochemical and genetic evidence for the greatest polymorphism of adult β-globins thus far described in any species is provided. A feline β-globin gene region with 2 linked β-globin gene loci and 2 and 5 alleles is proposed.

Clinical Relevance

Better understanding of feline Hb will likely be helpful for diagnosis of hemoglobinopathies in anemic cats. (Am J Vet Res 1998;59:830–835)
Effect of synovitis and corticosteroids on transcription of cartilage matrix proteins
Authors: MacLeod James N. , Fubini Susan L. , Gu Da Nian , Tetreault Jonathan W. , Todhunter Rory J.
Published: January 2024

Objective

To determine whether steady-state levels of type-II procollagen, aggrecan core protein, or fibronectin mRNA in articular chondrocytes are altered by synovitis or administration of methylprednisolone acetate (MPA).

Sample Population

Articular cartilage specimens collected from 10 ponies, 2.5 to 3.5 years old and 200 to 300 kg.

Procedure

4 experimental groups were compared, using the cartilage specimens: control, MPA-treated, lipopolysaccharide-induced synovitis, and lipopolysaccharide-induced synovitis with MPA treatment. RNA was isolated from articular cartilage and compared by northern blot analysis, using equine-specific cDNA probes.

Results

Synovitis increased steady-state levels of type-II procollagen mRNA fivefold and of aggrecan mRNA twofold. Administration of a single intra-articular injection of MPA (0.1 mg/kg of body weight) decreased type-II procollagen transcripts in normal cartilage sixfold, without significant effect on aggrecan or total fibronectin mRNA values. MPA treatment of inflamed joints decreased type-II procollagen and aggrecan mRNA to levels that were not significantly different from those in untreated control specimens.

Conclusions

Articular chondrocytes increase type-II procollagen and aggrecan synthesis in response to synovitis. MPA alters chondrocyte function in normal and inflamed cartilage, suggesting that potential changes in cartilage matrix protein synthesis should be considered when evaluating the therapeutic value of intra-articular administration of corticosteroids.

Clinical Relevance

Knowledge of how synovitis and corticosteroids (independently and in combination) affect synthesis of cartilage matrix proteins is relevant to understanding pathogenesis of traumatic osteoarthritis and improving therapeutic strategies. (Am J Vet Res 1998;59:1021–1026)
Characterization of intestinal morphologic, biochemical, and ultrastructural features in gluten-sensitive Irish Setters during controlled oral gluten challenge exposure after weaning
Authors: Manners H. K. , Hart C. A. , Getty B. , Kelly D. F. , Sørensen S. H. , Batt R. M.
Published: January 2024

Objective

To characterize histologic, biochemical, and ultrastructural changes in the intestine of Irish Setters susceptible to gluten-sensitive enteropathy (GSE) during controlled oral challenge exposure with gluten after weaning.

Animals

Six gluten-sensitive and 12 healthy Irish Setters and 3 healthy Greyhounds.

Procedure

Jejunal biopsy specimens were taken at 4 and 12 months of age from the 6 gluten-sensitive Irish Setters, which had been reared on a gluten-free diet to which a controlled dose of gluten (0.5 g/kg of body weight/d) was added. Control specimens were obtained at 4 (n = 5) and 12 (7) months of age from the healthy Irish Setters, which had been fed a conventional gluten-containing diet, and at 4 months of age from the healthy Greyhounds fed the controlled dose of gluten. The specimens were subjected to histologic and ultrastructural examinations and assay of brush border enzymes.

Results

Gluten-sensitive Irish Setters developed abnormalities characteristic of GSE at 4 months. Abnormalities were comparable to changes not seen previously until 12 months in dogs with GSE fed a conventional gluten-containing diet. In addition, microvilli were stunted and irregular, and a few were vesiculated and reduced in number; the glycocalyx was reduced or absent. By 12 months of age, there was improvement in morphologic and biochemical parameters, indicating partial recovery despite continued exposure to gluten.

Conclusions

Relative early onset of intestinal damage, compared with that previously reported, and subsequent partial recovery suggestive of oral tolerance to gluten may be attributable to oral administration of gluten as a purified extract rather than in dietary cereal, but alternative explanations include differences in environment or genetic susceptibility to gluten. (Am J Vet Res 1998;59:1435–1440)
Pharmacokinetics of tolfenamic acid and its detection time in urine after intravenous administration of the drug in camels (Camelus dromedarius)
Authors: Wasfi I. A. , ElGhazali M. , Hadi A. A. A. , Zorob O. , Boni N. S. , Alkatheeri Nawal A. , Barezaiq Ishar M.
Published: January 2024

Objective

To document tolfenamic acid disposition variables, identify its major phase-1 metabolite and fragmentation pattern, and establish detection time in urine after single IV bolus administration to make recommendations on avoiding violative residues in racing camels.

Animals

7 healthy camels (6 males, 1 female), 8 to 11 years old and weighing from 300 to 480 kg.

Procedure

Blood samples were collected at 0, 5, 10, 15, 30, 45, and 60 minutes and at 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8, 12, 13, 14, 15, and 16 hours after IV administration of tolfenamic acid (2.0 mg/kg of body weight). Urine samples were collected daily for 14 days after drug administration. Serum tolfenamic acid concentration was measured; limit of quantification was 50 ng/ml. A metabolite of tolfenamic acid in urine was isolated and identified, and its major fragmentation pattern was verified. Screening for tolfenamic acid and its metabolite in urine was performed.

Results

Mean ± SEM tolfenamic acid elimination half-life was 5.76 ± 0.26 hours. Total body clearance was 0.109 ± 0.011 L/kg/h, and steady-state volume of distribution was 0.68 ± 0.06 L/kg. Detection time for tolfenamic acid and its hydroxylated metabolite in urine after IV administration of a dose of 2.0 mg/kg was 5 and 7 days, respectively.

Conclusions

Camels eliminate tolfenamic acid mainly via metabolism more slowly than do cattle. The extrapolated dose regimen from cattle to camels appears inappropriate. Veterinarians are advised not to use tolfenamic acid in camels for at least 8 days prior to racing. (Am J Vet Res 1998;59:1451–1458)
Clinical consequences of exposing pregnant gilts to strains of porcine reproductive and respiratory syndrome (PRRS) virus isolated from field cases of “atypical” PRRS
Authors: Mengeling William L. , Lager Kelly M. , Vorwald Ann C.
Published: January 2024

Objective

To determine clinical consequences of exposing pregnant gilts to strains of porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) isolated from field cases of “atypical” or “acute” PRRS in vaccinated herds.

Animals

20 pregnant gilts and their pigs and fetuses.

Procedure

8 pregnant gilts (principals: 4 groups [2 gilts/group]) were exposed oronasally at or about 45 days of gestation to 1 of 4 strains of PRRSV and necropsied 6 weeks later. Nonexposed controls (2 additional pregnant gilts) were kept under otherwise similar conditions. The experiment was repeated, except that principals were exposed at or approximately 90 days of gestation and allowed to farrow. Clinical observations were made at least twice daily, and samples and specimens from gilts and their fetuses and pigs were tested for PRRSV and homologous antibody.

Results

Exposure of pregnant gilts to PRRSV at or approximately 45 days' gestation resulted in low prevalence of transplacental infection and fetal death. Exposure of pregnant gilts to PRRSV at or approximately 90 days' gestation resulted in higher prevalence of transplacental infection and fetal death. Moreover, 1 gilt aborted and many liveborn pigs of other litters were weak and unthrifty. Clinical signs of disease and reproductive failure were especially severe for a field strain of PRRSV isolated from an epizootic that fit the strictest definition of atypical PRRS. Controls remained clinically normal and free of PRRSV.

Conclusion and Clinical Relevance

Some strains of PRRSV now circulating in US swine herds are more virulent than those encountered in the past. Clinical PRRS in vaccinated herds suggests need for a new generation of vaccines. (Am J Vet Res 1998;59:1540-1544)
Survey for antibodies to bovine adenoviruses in six- to nine-month-old feedyard cattle
Authors: Lehmkuhl Howard D. , Briggs Robert E. , Cutlip Randall C.
Published: January 2024

Objective

To determine the prevalence of antibody to bovine adenovirus (BAdV) serotypes 1-8 and 10 in calves at a farm and after 5 weeks in a feedyard.

Animals

2- to 5-month-old calves of mixed English breeding (n = 100) from 4 farms.

Procedure

Serum BAdV antibody was measured by use of a microtitration test.

Results

Serum antibodies were found to the 9 BAdV serotypes studied. Seroconversion to each virus had occurred in some calves by the time the second serum sample had been obtained, indicating that the BAdV were present and inducing active infection in these calves.

Conclusions

Antibody to BAdV serotypes 1-8 and 10 are present in cattle populations of the United States, indicating existence of these serotypes, although only BAdV serotypes 1-4, 7, and 10 have been isolated. (Am J Vet Res 1998;59:1579-1580)
Anatomic and surgical approach to the ethmoidal nerve and parasympathetic innervation of the nasal and cerebral circulation in sheep
Authors: Acocella Fabio , Carù Francesco , Farabola Mario , Addis Flaminio , Cozzi Bruno
Published: January 2024

Objective

To describe an anatomic and surgical approach to the efferent parasympathetic branches of the pterygopalatine ganglia in sheep, with particular reference to the ethmoidal nerve and innervation of nasal and cerebral blood vessels.

Animals

12 adult sheep used for monolateral (n = 7) or bilateral (n = 5) ethmoidal neurectomy; 2 sheep used for angiography (1 live sheep for digital subtraction angiography, 1 embalmed cadaver for injection studies); and 5 embalmed cadavers, 4 frozen specimens, and 2 dry skulls used for dissection, x-rays, and computed tomographic (CT) or magnetic resonance (MR) scans.

Procedure

Transverse (coronal) MR scans, transverse, sagittal, and dorsal CT scans, radiography, angiography, photographic images, and dissections of embalmed material were used to study the topographic anatomy of the temporal and pterygopalatine fossae of the head.

Results

Images were stored, then compared with photographs of frozen sections from the same or a similar specimen to plan a surgical approach to the ethmoidal nerve. Mono- and bilateral experimental ethmoidal neurectomies were performed, allowing characterization of a safe and reliable method. The series of pterygopalatine ganglia typical of this species was localized, dissected, and analyzed for topographic relations.

Conclusions

From the results, a new approach to the efferent branches of the pterygopalatine ganglia (ethmoidal nerve) for experimental parasympathectomy of the cerebral and nasal circle is proposed. This experimental approach could be used for studies involving thermoregulation of the face, and in experimental control of blood flow in the nasal cavity and rostral part of the brain. (Am J Vet Res 1999;60:105–108)
Morphologic comparisons among equine endometrium categories I, II, and III, using light and transmission electron microscopy
Authors: Ferreira-Dias G. M. , Nequin L. G. , King S. S.
Published: January 2024

Objective

To evaluate whether the pathologic changes observed by light microscopy in endometrium of categories II and III were reflected by cellular changes and to describe differences in the endometrial cell ultrastructure during estrus and diestrus.

Animals

18 healthy mares.

Procedure

Endometrial tissues biopsied during the physiologic breeding season were categorized, using light microscopy, and were studied, using transmission electron microscopy (TEM).

Results

Using TEM, glycogen granules were associated with giant mitochondria for all endometrial types during diestrus. Development of rough endoplasmic reticulum (RER) and Golgi apparatus suggested protein synthesis in the endometrial glands during diestrus. TEM did not reveal major ultrastructural differences, between endometrium of categories I and II. This was unlike differences identified by light microscopy. The most extensive pathologic changes were seen in category-III tissue (TEM and light microscopy). Category-III endometria had a large number of light cells with more degenerative structures and fewer organelles, and lacked cilia in the lumen of the glands. This tissue had extensive fibrotic tissue in the lamina propria and many inflammatory cells in most tissue layers.

Conclusions

The severe ultrastructural changes may be one of the many factors decreasing the fertility of mares with category-III, compared with category-1 and -2, endometrium. (Am J Vet Res 1999;60:49–55)
Comparison of forced oscillation with the conventional method for histamine bronchoprovocation testing in horses
Authors: Mazan M. R. , Hoffman A. M. , Manjerovic N.
Published: January 2024

Objective

To compare response of horses to histamine bronchoprovocation (HBP), using total respiratory resistance (Rrs) measured by forced oscillatory mechanics (FOM) with dynamic compliance (Cdyn) and pulmonary resistance (RL) measured by the esophageal balloon method.

Animals

10 horses with various degrees of airway reactivity.

Procedure

The 2 methods for measuring airway responses to HBP were performed on separate days. Endpoints compared were increase of 150 or 200% of baseline Rrs (PC150Rrs, PC200Rrs) and to 150% of baseline RL (PC150RL) or decrease to 65% of baseline Cdyn (PC65Cdyn). Frequency dependence of respiratory mechanics, using FOM, was evaluated, using the slope of Rrs over 1 to 3 Hz and the ratios of Rrs at 1 Hz to Rrs at 2 and 3 Hz (Rrs1Hz/Rrs2Hz, Rrs3Hz) and of Rrs at 2 Hz to Rrs at 3 Hz (Rrs2Hz/Rrs3Hz) Effect of histamine on frequency dependence was assessed.

Results

Correlation with PC65Cdyn was high for PC150Rrs (rs = 0.93) and PC200Rrs (rs = 0.96). Correlation between PC65Cdyn and PC150RL was weakly positive (rs = 0.61). The slope of Rrs over 1 to 3 Hz changed significantly between baseline (−0.07 ± 0.09 cm H2O/L/s/Hz) and final histamine dose (−0.28 ± 0.10 cm H2O/L/s/Hz). The Rrs1Hz/Rrs3Hz and Rrs2Hz/Rrs3Hz differed significantly (P < 0.05 between baseline [1.27 ± 0.36 and 0.96 ±0.11, respectively] and final histamine dose [1.62 ± 0.37 and 1.09 ± 0.14, respectively]).

Conclusions

Correlation between histamine-induced changes in respiratory mechanics, as measured by FOM and the pneumotachograph-esophageal balloon method, was good. The FOM results indicated frequency dependence of respiratory mechanics during HBP.

Clinical Relevance

A noninvasive method of measuring airway reactivity will facilitate routine evaluation of horses with suspected small airway disease and may be suitable for field studies. (Am J Vet Res 1999;60:174-180)
Detection of portal and systemic bacteremia in dogs with severe induced hepatic disease and multiple portosystemic shunts
Authors: Howe Lisa M. , Boothe Dawn M. , Boothe Harry W.
Published: January 2024

Objective

To determine existence of portal and systemic bacteremia in dogs with induced severe hepatic disease, compared with clinically normal dogs, before and after vena caval banding.

Animals

6 control dogs and 10 dogs with induced severe hepatic disease and multiple portosystemic shunts (PSS).

Procedure

Dogs of the diseased group were given dimethylnitrosamine (2 mg/kg of body weight, PO) twice weekly until multiple PSS developed. Surgery was performed on dogs of both groups, and blood for baseline aerobic and anaerobic bacterial culture was collected from catheters placed in the portal and hepatic veins and caudal vena cava. All dogs underwent vena caval banding, and blood for aerobic and anaerobic bacterial culture was collected from the portal and hepatic venous catheters at 120, 240, and 360 minutes after banding.

Results

Compared with control dogs (16% gram-positive and 84% gram-negative bacteria), diseased dogs had significantly higher percentage of gram-positive bacteria (42% of positive culture results, P ≤ 0.01) and significantly lower percentage of gram-negative bacteria (58% of positive culture results, P ≤ 0.01) isolated. Pseudomonas aeruginosa was isolated most frequently from dogs of both groups; more than 1 organism was isolated from 5 dogs of each group. Antimicrobial susceptibility included that to aminoglycosides (particularly amikacin), fluorinated quinolones, and imipenem.

Conclusions

Portal and systemic, predominantly gram-negative, bacteremia is present in catheterized, clinically normal dogs and dogs with dimethylnitrosamine-induced hepatic disease and multiple PSS. (Am J Vet Res 1999;60:181-185)
Assessment of dorsal nerve root and spinal cord dorsal horn function in clinically normal dogs by determination of cord dorsum potentials
Authors: Cuddon Paul A. , Delauche Agnes J. , Hutchison Jennifer M.
Published: January 2024

Objective

To establish normal predictive values for cord dorsum potential (CDP) onset latency after thoracic and pelvic limb sensory or mixed nerve stimulation in adult dogs.

Animals

26 clinically normal adult dogs.

Procedure

Sensory nerve action potentials (SNAP) were recorded proximally from tibial and lateral superficial radial nerves after distal stimulation. The CDP were recorded from the L4-L5 interarcuate ligament for the tibial nerve and from the C7-T1 interarcuate ligament for the radial nerve. Linear regression analyses were performed for CDP onset latency, and mean ± SD was calculated for CDP onset to peak latency differences and sensory nerve conduction velocities (SNCV).

Results

For the tibial nerve, expected CDP onset latency (CDPOL) = −1.194 + 0.014 × pelvic limb length (mm; R2 = 0.912); CDPOL = −2.156 + 0.011 × pelvic limb/spinal length (mm; R2 = 0.911); and CDPOL = 0.941 + 2.197 × tibial nerve SNAP latency (milliseconds; R2 = 0.903). For the radial nerve, CDPOL = −0.9 + 0.014 × thoracic limb length (mm; R2 = 0.873); and CDPOL = 1.454 + 1.874 × radial nerve SNAP latency (milliseconds; R2 = 0.903). Mean ± SD for CDP onset to peak latency difference for tibial and radial nerves was 3.1 ± 0.3 and 3.0 ± 0.4 milliseconds, respectively.

Conclusions

Strong linear associations exist between CDPOL and a number of easily measured peripheral independent variables in dogs. There is also a narrow range of normal values for CDP onset to peak latency differences that is independent of limb length.

Clinical Relevance

CDP evaluation can be used to accurately assess functional severity and distribution of abnormalities in proximal sensory nerves, dorsal nerve roots, and spinal cord dorsal horns in dogs with suspected neuropathy, radiculopathy, or myelopathy involving the brachial or lumbosacral intumescences. (Am J Vet Res 1999;60:222-226)