bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of protein, lipid, or carbohydrate supplementation on hepatic lipid accumulation during rapid weight loss in obese cats
Authors: Biourge Vincent C. , Massat Bruno , Groff Joseph M. , Morris James G. , Rogers Quinton R.
Published: January 2024

Effects of restricted tube-feeding (25% of energy requirements) of protein, lipid, or carbohydrates on body weight loss; hematologic and clinical chemical variables; plasma lipid and amino add concentrations; nitrogen balance; and hepatic histologic features and lipid concentrations were compared with values in voluntary-fasting cats (control, con). Twelve obese cats (6.1 ± 0.1 kg, > 40% above optimal body weight) were randomly assigned to 4 matched treatment groups (n = 3)—protein (pro), lipid (lip), carbohydrate (cho), and con—and were offered a low-palatability diet for 4 weeks. Cats of the pro, lip, and cho groups were also tube-fed isocaloric amounts (88 kcal of metabolizable energy) of a casein-soybean protein mixture, com oil, or a dextrin-dextrose mixture, respectively, during the 4 weeks. All cats fasted, rather than eat the low-palatability purified diet. Cats of the pro group lost weight at a lower rate (P < 0.05) than did cats of other groups. After 4 weeks of fasting, serum alkaline phosphatase activities were higher than reference values in all cats of the con and lip groups and in 2 cats of the cho group. At that time, 1 cat of the lip group had lethargy, hepatomegaly, and hyperbilirubinemia. Total hepatic lipid and triglyceride concentrations increased in all groups during the study, but the increase was significantly (P < 0.05) less in cats of the pro group, compared with those of the con and lip groups, and those of the cho group, compared with those of the lip group. Hepatic total lipid and triglyceride concentrations correlated well with lipid score for liver biopsy specimens when lipidosis was mild or severe, but not as well in association with the intermediate lipidosis. Cats of the PRO group were in nitrogen balance after 2 weeks of fasting. All other cats remained in negative nitrogen balance during the fast, although less nitrogen was lost by cats of the cho and lip groups than by cats of the con group. Plasma aminograms indicated that methionine and arginine might become limiting for protein synthesis during fasting in cats.

Results indicate that dietary protein reduces hepatic lipid accumulation and nitrogen balance is maintained during rapid weight loss in obese cats. Ingestion of only lipids increases the risk of inducing hepatic lipidosis. Ingestion of carbohydrates reduces hepatic lipid accumulation, but is not as effective as protein in preventing all the clinical manifestations of hepatic lipidosis.
Residual nematocidal effectiveness of ivermectin in cattle
Authors: Yazwinski T. A. , Featherston H. , Tucker C. , Johnson Z.
Published: January 2024

We assessed the duration of ivermectin persistence by measuring posttreatment nematocidal effectiveness; topical and injectable formulations of ivermectin were evaluated. Thirty-five nematode-free calves were randomly allocated to 1 of 5 treatment groups (7 calves/group). The treatment (Trt) group designations were: Trt 1, nonmedicated; Trt 2, injectable ivermectin administered at the rate of 0.2 mg/kg of body weight on day 0; Trt 3, injectable ivermectin administered at the aforementioned rate, but on day 7; Trt 4, topically administered ivermectin at the rate of 0.5 mg/kg on day 0; and Trt 5, topically administered ivermectin at the aforementioned rate, but on day 7. All calves were subsequently given infective larvae of Haemonchus, Cooperia, Trichostrongylus, and Oesophagostomum spp on day 21. One week later, each calf was additionally administered infective larvae of Dictyocaulus and Ostertagia spp. Trial calves were euthanatized on trial days 49 to 52 for nematode quantitation. On the basis of geometric mean comparisons, total nematode burdens were reduced from control group counts by 98.9 and 86.3% for calves treated on days 7 and 0 with injectable formulations, respectively, and 97.2 and 64.7% for calves treated on days 7 and 0 with pour-on formulations, respectively. Trichostrongylus colubriformis infections were most refractory to the persistent activity of ivermectin, with H placei also proving to be persistence limiting. All treatments were easily administered, and adverse behavioral or tissue reactions were not observed.
Evaluation of total serum bile acids concentration and bile acid profiles in healthy cats after oral administration of ursodeoxycholic acid
Authors: Day Deborah G. , Meyer Dennis J. , Johnson Susan E. , Weisbrode Steven E. , Thudium Douglas T. , Rhodes Diane C.
Published: January 2024

Ursodeoxycholic acid (udca; 10 mg/kg of body weight) was administered orally to 5 healthy cats for 3 months. Signs of illness were not apparent in any cat during treatment with udca. Results of monthly CBC, serum biochemical analysis, and urinalysis were unchanged during drug administration. There was a decrease in serum cholesterol concentration in 4 cats. Total postprandial serum bile acids (ppsba) concentration was significantly (P = 0.0003) increased over total preprandial serum bile acids (prsba) concentration at all sample collection periods. The PRSBA and PPSBA concentrations were significantly (P < 0.05) increased at all sample collection periods after administration of udca, compared with baseline values. Ursodeoxycholic and tauroursodeoxycholic acids were not detected in serum prior to initiating administration of udca. Both bile acids were detected in the serum of all cats 1 and 2 months after udca administration and were detected in the serum of 2 cats 3 months after initiating UCDA administration. Hepatic ultrasonographic findings were normal before and after completion of udca administration. A mild, focal lymphocytic infiltrate was observed in 3 cats 3 months after initiating udca administration. Results of the study indicate that udca is absorbed into the systemic circulation of cats after oral administration, undergoes hepatic conjugation, and appears to be safe.
Rate of change of QT interval in response to a sudden change in the heart rate in dogs
Authors: Oguchi Yoko , Hamlin Robert L.
Published: January 2024

Although it is known that the QT interval is dependent on the preceding RR interval, QT interval does not vary during respiratory sinus arrhythmia, despite a wide variation in heart rate. To assess the rate of change of the QT interval following an abrupt increase or decrease in heart rate, QT intervals were measured from ecg of healthy, anesthetized, thoracotomized dogs in which a junctional rhythm had been induced by destroying the sinoatrial node. Atria were paced at 800- or 600 -millisecond cycle durations until a steady state was reached, and then the cycle duration was changed suddenly to a new cycle duration (600 or 800 milliseconds, respectively). The time and number of heart beats required until the QT interval achieved a value of 63% (1 time constant) of the new steady state were calculated. Time constants for change in QT interval vs the number of beats following the change were 2.8 (sd = 1.3 s) seconds when heart rate was accelerated and 4.7 (sd = 2.1 s) seconds when heart rate was slowed. Differences were not statistically significant. The time constants for change in QT interval duration vs duration after the sudden change in heart rate were 1.7 (sd = 0.8 s) seconds when heart rate was accelerated and 3.7 (sd = 1.7 s) seconds when heart rate was slowed. These time constants differed significantly (P < 0.01). Response of QT interval, therefore, depended on the number of heart beats following sudden change in heart rate, but not time, except as time determined the number of heart beats. The QT interval did not change until 3 to 5 beats after the heart rate was suddenly changed. This number of beats would be more than that which would occur in 1 respiratory cycle in dogs; therefore, QT interval memory would prohibit changes in QT intervals that occur during respiratory sinus arrhythmia.
Critical appraisal of pressure-frequency relation for estimation of diaphragm function in conscious calves
Authors: Desmecht Daniel J.-M. , Linden Annick S. , Lekeux Pierre M.
Published: January 2024

A method yielding functional diaphragmatic variables in conscious animals is crucially needed to determine whether concepts and conclusions drawn from deeply anesthetized, highly instrumented clinically normal animals can be extrapolated to patients. Transdiaphragmatic pressure (Pdi) was, therefore, measured in 20 conscious calves during supramaximal transvenous bilateral stimulations of the phrenic nerves (pulse duration, 0.2 milliseconds; pulse frequency, 1, 10, 20, 30, 40, 70, and 100 Hz). Constancy of phrenic activation and precontraction length and geometry was ensured by respectively monitoring the amplitudes of right and left mass action potentials and triggering each activation train at end-expiratory lung volume against an occluded airway. Repeated phrenic activation and pressure recording procedures were well tolerated, safe, specific, and able to achieve constant and symmetric diaphragmatic tetanic contractions for prolonged periods. The Pdi increased with frequency of stimulation, so that, at 10, 20, 40, and 70 Hz, the mean ± sd generated Pdi was 33 ± 5, 65 ± 8, 82 ± 6, and 94 ± 6% of Pdi at 100 Hz, respectively. The general shape of the Pdi-frequency relation and the absolute values of the generated Pdi were reproducible at 10-hour intervals despite CO2- or resistor-induced substantial changes in breathing pattern. It is concluded that this experimental model provides a reliable assessment of diaphragm function in conscious animals and can be used to study diaphragmatic contractility.
Immunomodulatory effects of staphylococcal antigen and antigen-antibody complexes on canine mononuclear and polymorphonuclear leukocytes
Authors: DeBoer Douglas J.
Published: January 2024

Staphylococcal antigens and immune complexes (ic) prepared from antigen and hyperimmune canine serum were tested for their effects on certain functions of mononuclear (mn) and polymorphonuclear (pmn) leukocytes (cells) obtained from healthy dogs. The effect on mn cells was studied by determining the ability of antigen or ic to augment or inhibit mitogenesis induced by phytohemagglutinin (pha). The effect of antigen or ic on pmn cells was studied by measurement of H2O2 production as an indicator of respiratory burst. Neither the antigen nor the ic, when cultured with mn cells, was mitogenic. Coincubation of antigen or ic with mn cells and pha resulted in a concentration-dependent decrease in mitogenesis. The decreased mitogenesis could not be overcome by addition of excess pha, and may in part have been related to toxic effects of the antigen or ic on mn cells. When mn cells were instead preincubated with antigen or ic, then washed and stimulated with pha, there was still a concentration-dependent inhibition of mitogenesis, although toxicity to the cells was not observed. Low concentrations of staphylococcal antigen or IC stimulated slight H2O2 production by pmn cells. When pmn cells were co-incubated with ic and another stimulus (opsonized zymosan or phorbol myristate acetate), ic appeared to augment phorbol myristate acetate-, but not zymosan-induced stimulation. These results suggest that staphylococcal antigens, either alone or complexed with antibody, have the ability to stimulate pmn cells and inhibit mn cell function. Such actions may have a role in the pathogenesis of recurrent staphylococcal infection in canine patients.
Characterization of a pseudorabies virus that is defective in the early protein 0 and latency genes
Authors: Cheung Andrew K. , Fang Jing , Wesley Ronald D.
Published: January 2024

A recombinant pseudorabies virus that is defective in the early protein 0 (EP0) and large latency transcript (LLT) genes was constructed. A portion of the EP0 and LLT genes was replaced by the lacZ gene of Escherichia coli that had been placed under the control of the pseudorabies virus gX gene promoter. This recombinant virus produces smaller size plaques and yields less virus than does the parent virus on Madin-Darby bovine kidney cells. Although the time course of virus replication and release into the medium of the recombinant and parent viruses are similar, the recombinant virus did not reach as high a titer. Similar to the parent virus, the recombinant virus replicates in the upper segment of the respiratory tract of swine, but the amount of progeny viruses produced is significantly reduced. The data indicated that the EP0 and LLT genes of pseudorabies virus are nonessential for replication. Virus that lacks these 2 genes has impaired growth in tissue culture and is attenuated for swine, compared with the parent virus.
Characterization of a murine monoclonal antibody generated against Neospora caninum tachyzoites by use of western blot analysis and immunoelectron microscopy
Authors: Cole Rebecca A. , Lindsay David S. , Dubey J. P. , Toivio-Kinnucan Maria A. , Blagburn Byron L.
Published: January 2024

A murine monoclonal antibody (mab) 6G7 generated against tachyzoites of Neospora caninum recognized 8 major and several minor antigens, as observed by western blot analysis. Relative rate of migration of the 8 major antigens ranged from 31 to 97.4 kd. In addition, mab 6G7 recognized a Toxoplasma gondii tachyzoite antigen with a relative rate of migration of 107 kd. Immunogold labeling of N caninum tachyzoites grown in human foreskin fibroblast cells indicated that mab 6G7 binds to micronemes, dense granules, basal portions of rhoptries, and intravacuolar tubules within the parasitophorous vacuole. Monoclonal antibody 6G7 also bound to micronemes and basal portions of rhoptries within tachyzoites of T gondii. Monoclonal antibody 6G7 did not significantly inhibit development of tachyzoites in vitro.
Effect of topically applied 2% pilocarpine and 0.25% demecarium bromide on blood-aqueous barrier permeability in dogs
Authors: Krohne Sheryl Greve
Published: January 2024

The effect of topically applied 2% pilocarpine and 0.25% demecarium bromide on aqueous humor flare was evaluated while treating normal eyes of dogs 3 times daily for 8 days. Fifteen clinically normal Beagles were allotted to 2 drug treatment groups, and flare was measured/using laser flaremetry. Pilocarpine caused an increase of flare to 167 photon counts (pc)/ms at 7 hours, compared with the nontreated control eye mean value 3.7 pc/ms. By 31 hours, flare had decreased to 70 pc/ms with 3 daily topical treatments. By 55 hours, the flare measurement was in the normal range. Intraocular pressure (iop) decreased in the treated eyes, compared with the non-treated eyes, and maximal decrease in iop was observed at the same time as maximal flare. Demecarium induced a similar increase in flare and decrease in iop, with peak effect seen at 31 hours. At that time, the flaremetry result was 28 pc/ms, compared with 3.4 pc/ms in the nontreated control eyes. After 8 days of 3 times daily treatment, flare values had returned to normal in eyes of dogs in both treatment groups. The transient increase in aqueous humor protein concentration did not result in ocular or visual damage, and long-term changes were not seen. The amount of flare increase attributable to topical application of pilocarpine was greater than the increase in human eyes when measured by use of laser flaremetry.
Effect of succinylcholine, diazepam, and dantrolene on the urethral pressure profile of anesthetized, healthy, sexually intact male cats
Authors: Straeter-Knowlen Ingrid M. , Marks Steven L. , Speth Robert C. , Wirth W. , Knowlen Grant G.
Published: January 2024

Effects of the neuromuscular blocking agent succinylcholine (n = 9), the centrally acting skeletal muscle relaxant diazepam (n = 11), and the direct-acting skeletal muscle relaxant dantrolene sodium (n = 8) on the urethral pressure profile were evaluated in anesthetized, healthy, sexually intact, adult male cats. Intravenous administration of succinylcholine (0.075 mg/kg of body weight) significantly decreased mean absolute pressure in the prostatic and post-prostatic/penile intraurethral segments by −9.5 and −6.5 mm of Hg, respectively (P = 0.0002 and P = 0.0006, respectively). Dantrolene (1.0 mg/kg, iv) significantly decreased mean prostatic and postprostatic/penile intraurethral segmental pressures by −3.5 and −2.8 mm of Hg, respectively (P = 0.005 and P = 0.0181, respectively). Diazepam (0.8 mg/kg, iv) did not significantly alter mean intraurethral segmental pressures. None of the drugs caused a change in segmental lengths of the urethra. These results indicate that skeletal muscle makes a substantial contribution to intraurethral tone in anesthetized, healthy, sexually intact male cats and that skeletal muscle relaxation may be successful in reducing prostatic and post-prostatic/penile urethral segmental tone in male cats. These results also suggest that dantrolene sodium may be valuable for the pharmacologic management of urethral disorders in male cats.
Comparison of ethanol and 4-methylpyrazole as treatments for ethylene glycol intoxication in cats
Authors: Dial Sharon M. , Thrall Mary Anna Hull , Hamar Dwayne W.
Published: January 2024

The efficacy of 4-methylpyrazole (4-mp) and ethanol as treatment for ethylene glycol (eg) intoxication in cats was compared. Twenty-two cats were assigned at random to 6 experimental groups. Cats of 1 experimental group were given only 4-mp; those of another experimental group were given only eg. Cats of 3 experimental groups were intoxicated with eg and given 4-mp at 0 hour or 2 or 3 hours after eg ingestion, and those of 1 experimental group were given eg and treated with ethanol 3 hours after eg ingestion. Physical, biochemical, hematologic, blood gas, serum and urine eg concentrations, and urinalysis findings were evaluated at 0, 1, 3, 6, 9, 12, 24, 48, and 72 hours, 1 week, and 2 weeks after eg ingestion or 4-mp treatment in cats of the 4-mp only group. The half-life of eg and percentage of ingested eg excreted unchanged were determined for each group.

4-Methylpyrazole treatment at 0 hour was most effective at preventing metabolism of eg. 4-Methylpyrazole was not effective in preventing development of renal failure when given 2 or 3 hours after eg ingestion. Ethanol given 3 hours after eg ingestion was successful in preventing development of renal dysfunction in 2 of the 6 cats treated 3 hours after eg ingestion. Of the remaining 4 cats treated with ethanol, 2 developed transient renal dysfunction and 2 developed acute oliguric renal failure and were euthanatized.

4-Methylpyrazol given 2 or 3 hours after eg ingestion was less effective in preventing eg metabolism than was ethanol given 3 hours after eg ingestion. Therefore 4-mp, at the dose found to be effective in dogs, cannot be recommended as an alternative to ethanol for treatment of eg intoxication in cats.
Effect of exercise intensity on plasma prostaglandin concentrations in horses
Authors: Mitten L. A. , Hinchcliff K. W. , Pate J. L. , Kohn C. W. , McKeever K. H.
Published: January 2024

Exertion has an effect on plasma, serum, and/or urine prostanoid concentrations in many species. We investigated the effect of exercise intensity on plasma prostaglandin concentrations during and after exercise in horses. Six Thoroughbreds completed 4 trials: 3 exercise trials (low-, medium-, and high-speed) and 1 nonexercise (control) trial on a high-speed treadmill. Blood samples were collected from a jugular catheter before, during, and after exercise. The pcv and blood lactate, plasma protein, plasma prostacyclin (6-keto-pgf1α), thromboxane B2 (txb2), and prostaglandin E2 (pge2) concentrations were measured before, during, and after exercise. Exercise significantly (P = 0.001) increased plasma txb2 concentration during and after exercise in the low-, medium-, and high-speed trials, although effect of exercise intensity was not detected. Exercise was associated with an increase in pcv and blood lactate and plasma protein concentrations. There was no effect of exercise on plasma 6-keto-pgf1α concentrations; pge2 was not detected in plasma from any horse in any trial.
Cardiorespiratory effects of acepromazine maleate and buprenorphine hydrochloride in clinically normal dogs
Authors: Stepien Rebecca L. , Bonagura John D. , Bednarski Richard M. , Muir William W.
Published: January 2024

Cardiorespiratory effects of the combination of acepromazine maleate (acp) and buprenorphine hydrochloride (bpn) were studied in 11 healthy, conscious dogs. Values for systemic and pulmonary artery blood pressure, cardiac output, arterial and venous pH and blood gas tensions, and invasive and noninvasive estimates of ventricular systolic function, preload, and afterload were obtained before sedation and after administration of each drug. Acepromazine maleate (0.1 mg/kg, iv) depressed cardiac function, compared with baseline values for unsedated dogs. Cardiac output decreased from a mean (± sd) value of 4.2 (± 1.5) L/min to 3.1 (± 0.8) L/min (P < 0.001), a change not attributed to heart rate. Pulmonary capillary wedge pressure decreased from 8.3 (± 4.2) mm of Hg to 6.5 (± 4.3) mm of Hg (P < 0.01), but mean right atrial pressure did not change. Left ventricular measurement of the maximal positive rate of pressure change (dP/dtmax) decreased from 2,668 (± 356)/mm of Hg/s to 2,145 (± 463) mm of Hg/s (P < 0.001), and ventricular stroke volume decreased from 43.2 (± 15.2) ml/beat to 32.3 (± 8.6) ml/beat. Noninvasive indices of left ventricular function, ventricular shortening fraction, peak aortic velocity, and aortic average acceleration were decreased after acp administration, but were not statistically different from baseline values. Mean systemic arterial blood pressure decreased from 121 ± 12 mm of Hg to 96 ± 13 mm of Hg 15 minutes after acp administration (P < 0.001). Total systemic vascular resistance was not significantly different from the baseline value. Sequential administration of cumulative doses of bpn (0.005, 0.01, and 0.1 mg/kg of body weight, iv), initiated 15 minutes after administration of acp, did not cause statistically significant depression of hemodynamic variables, except for heart rate, which decreased after bpn, and left ventricular dP/dtmax, which decreased slightly at the highest dose of bpn. Small, clinically insignificant changes in blood pH, venous bicarbonate concentration, and Paco2 were observed after administration of acp and bpn. Respiratory rate decreased from 60 ± 48 breaths/min to 24 ± 12 breaths/min, and sedation level was significantly (P < 0.05) increased from baseline values by administration of acp. Sedation level was further increased by administration of bpn at the lowest dose (P < 0.05). The combination of acp and bpn resulted in good to excellent sedation, but depressed ventricular function; however, most of the hemodynamic effects could be attributed to administration of acp and withdrawal of sympathetic activity.
Cardiopulmonary responses in healthy dogs during endoscopic examination of the gastrointestinal tract
Authors: Jergens Albert E. , Riedesel Dean H. , Ries Philip A. , Miles Kristina G. , Bailey Theodore B.
Published: January 2024

Cardiopulmonary responses were evaluated in 12 dogs undergoing endoscopy (gastroscopy and enteroscopy). Constant endoscopic insufflation was used to distend the stomach and small intestine for 30 minutes in groups of small (< 10 kg; n = 4), medium (10 to 20 kg; n = 4), and large (> 20 kg; n = 4) dogs. Cardiopulmonary measurements within groups prior to gastric distention (preendoscopy) were compared with postendoscopy measurements and with those made during endoscopy. After distending the stomach and small intestine, increased luminal pressure within the body of the stomach and in the descending duodenum (P < 0.05) and increased abdominal girth (P < 0.05) were observed, with the greatest changes in small dogs. Caudal vena cava pressures and mean arterial and pulmonary artery pressures increased (P < 0.05) during endoscopy. Cardiac index varied, with small dogs having greater cardiac index (P < 0.05) during endoscopy, compared with that in medium and large dogs. Minute volume remained unchanged during insufflation, despite a decrease in tidal volume (P < 0.05), because of an increase in respiratory rate (P < 0.05). Arterial blood gas analysis revealed a mild, mixed metabolic/respiratory acidosis in all groups. Although cardiopulmonary changes associated with gastrointestinal tract endoscopy were common, the changes were often small and of little clinical significance.
Administration of recombinant human interleukin 1 receptor antagonist during endotoxin-induced mastitis in cows
Authors: Shuster D. E. , Kehrli M. E.
Published: January 2024

The role of interleukin 1 (il-1) as an inflammatory mediator during mastitis and the therapeutic effect of recombinant human il-1 receptor antagonist (il-1ra) for bovine mastitis was studied. Cows were intramammarily infused with lipopolysaccharide (25 μg) in 1 mammary gland. Half the cows also received infusions of 5 mg of il-1ra into the same mammary gland just prior to endotoxin infusion and 4, 8, and 12 hours later. After endotoxin infusion, tumor necrosis factor and high il-1 bioactivity were detected in whey from infused glands. Vascular permeability changes and neutrophil accumulation in milk paralleled the appearance of cytokines. A systemic reaction, characterized by pyrexia and an increase in blood cortisol concentration, also were observed. Milk yield was inhibited and milk composition was altered in infused and noninfused glands. The increase in il-1 bioactivity in milk after endotoxin infusion was almost completely prevented in glands receiving il-lra. However, il-lra had no effect on local inflammation, systemic reaction, or impairment in productive performance. These results indicate that il-1 does not mediate its effect within the milk compartment, and suggest either that il-1 is not critical to the mastitic response or that intramammary infusion of il-1ra does not place the antagonist where il-1 interacts with its receptor.
Histochemical and morphometric study of fiber types in ten skeletal muscles of healthy young adult cats
Authors: Braund Kyle G. , Amling Karen A. , Mehta Jagjivan R. , Steiss Janet E. , Scholz Carole
Published: January 2024

A histochemical and morphometric study of fiber types in a variety of skeletal muscles of healthy young adult cats was undertaken to provide normative data not available previously. Using a standardized system of nomenclature, fiber types 1, 2A, 2B, and 2C were identified in most cat muscles on the basis of myosin ATPase staining at pH 4.45. Type-2M fibers were present in temporalis (tem) and masseter (mas) muscles. Type-1 fibers predominated in medial head of triceps (mht) and soleus muscles. Type-2B fibers were dominant in biceps femoris, lateral head of gastrocnemius, cranial tibial, long head of triceps, and superficial digital flexor muscles; type-2A fibers were dominant in buccinator muscle samples; and type-2M fibers were dominant in tem and mas muscles. Numbers of type-2C fibers did not exceed 2 to 3% of the myofiber population in any muscle. In CT and LHT muscles, a gradient of fiber type distribution was observed, with significant (P < 0.05) increase in numbers of type-1 and type-2A fibers in deeper regions of the muscles. The distribution of fiber types was compartmentalized in mht and mas specimens. Diameter of type-2B fibers was significantly (P < 0.05) larger than that of type-1 and type-2A fibers in biceps femoris, lateral head of gastrocnemius, cranial tibial, long head of triceps, and superficial mht muscles. Diameter of type-2M fibers was significantly (P < 0.05) larger than that of type-1 fibers in tem and mas muscles. The soleus type-1 muscle fibers were the largest fibers encountered in any muscle. In mht muscle, fiber diameter of type-1 and type-2B fibers varied significantly (P < 0.05) in oxidative and glycolytic compartments. Variability coefficients were less than 200 in all muscles. In every muscle specimen, the number of fibers with internal nuclei was less than or equal to 2%.
Enzyme-linked immunosorbent assay for apolipoprotein A-I in the serum of cattle
Authors: Oikawa Shin , Katoh Norio
Published: January 2024

An elisa was developed to evaluate the concentration of apolipoprotein A-I, a major apoprotein in high-density lipoprotein, in the serum of cattle. Serum apolipoprotein A-I was purified electrophoretically, and antibodies to this protein were raised in rabbits. The specificity of the antiserum was assessed by use of several immunologic techniques including western blotting. The elisa was sensitive (detection limit was 70 ng of apolipoprotein A-I/ml) and reliable (coefficients of variance were in the range of 3.5 to 8.2%). By use of this method, the serum apolipoprotein A-I concentration was higher in 2- to 6-year-old Holstein cows (mean ± SD, 0.580 ± 0.304 mg/ml) than in 7- to 15-month-old heifers (0.339 ± 0.237 mg/ml), 6-month-old heifers (0.238 ± 0.188 mg/ml), and 6-month-old steers (0.173 ± 0.146 mg/ml). The concentration, however, is not largely different in cows in early, middle, and late lactation and in nonlactating stages. Results also indicated that apolipoprotein A-I concentration was decreased in cows with hepatic lipidosis (fatty liver) induced by administration of ethionine, suggesting that this method is a useful tool for the pathophysiologic study of lipid metabolism and its impairment in cattle.
Efficacy of injectable doramectin against natural Boophilus microplus infestations in cattle
Authors: Muniz R.A. , Hernandez F. , Lombardero O. , Leite R.C. , Moreno J. , Errecalde J. , Goncalves L. C. B.
Published: January 2024

Three experiments were conducted in Latin America—1 in Brazil, 1 in Venezuela, and 1 in Argentina—using a common protocol to investigate the efficacy of a single SC injection of doramectin (200 μg/kg of body weight) for treatment and control of Boophilus microplus infestations in grazing cattle. In each experiment, 2 groups of 20 to 27 cattle were allocated on the basis of tick burdens present 24 hours before treatment to a treated or control group, which received saline solution (1 ml/50 kg). All cattle were injected in the mid-dorsal cervical region and examined on treatment day and on posttreatment days (ptd) 8, 14, 21, and 28. On each observation day, the number of engorged and semiengorged ticks on half of each animal was counted and recorded. Doramectin was highly efficacious in removing tick burdens and controlling reestablishment of B microplus under field conditions of continuous reinfestation. Compared with tick counts in the control group, doramectin-treated cattle began to eliminate ticks after treatment and efficacy improved on subsequent observation days. In Brazil, efficacy was 91% at ptd 8 and 14, and increased to 99% or higher at ptd 21 and 28. In Venezuela, efficacy was 100% at ptd 8, 14, and 21 and 92% at ptd 28. In Argentina, efficacy progressed from 94.5% at ptd 8 to 99 and 98.5% at ptd 21 and 28, respectively. The reduction of the number of ticks in the doramectin-treated cattle was significant (P < 0.05) at each observation day. None of the doramectin-treated cattle had clinical signs of adverse reactions to treatment in any of the 3 experiments.
Pharmacokinetics and residues of enrofloxacin in chickens
Authors: Anadón A. , Martínez-Larrañaga M. R. , Díaz M. J. , Bringas P. , Martínez M. A. , Femández-Cruz M. L. , Fernández M. C. , Fernández R.
Published: January 2024

The pharmacokinetic properties of enrofloxacin were determined in broiler chickens after single IV and orally administered doses of 10 mg/kg of body weight. After IV and oral administrations, the plasma concentration-time graph was characteristic of a two- compartment open model. The elimination half-life and the mean ± SEM residence time of enrofloxacin for plasma were 10.29 ± 0.45 and 9.65 ± 0.48 hours, respectively, after IV administration and 14.23 ± 0.46 and 15.30 ± 0.53 hours, respectively, after oral administration. After single oral administration, enrofloxacin was absorbed slowly, with time to reach maximal plasma concentration of 1.64 ± 0.04 hours. Maximal plasma concentration was 2.44 ± 0.06 μg/ml. Oral bioavailability was found to be 64.0 ± 0.2%. Statistically significant differences between the 2 routes of administration were found for the pharmacokinetic variables—half-lives of the distribution and elimination phase and apparent volume of distribution and volume of distribution at steady state. In chickens, enrofloxacin was extensively metabolized into ciprofloxacin. Residues of enrofloxacin and the major metabolite ciprofloxacin in fat, kidney, liver, lungs, muscles, and skin were measured in chickens that received an orally administered dose of 10 mg/kg once daily for 4 days. The results indicate that enrofloxacin and ciprofloxacin residues were cleared slowly. Mean muscle, liver, and kidney concentrations of the metabolite ciprofloxacin ranging between 0.020 and 0.075 μg/g persisted on day 12 in chickens after dosing. However, at the time of slaughter (12 days), enrofloxacin residues were only detected in liver and mean ± SEM concentration was 0.025 ± 0.003 μg/g.
Adrenocortical function in neonatal and weanling Beagle pups
Authors: Randolph John F. , Center Sharon A. , Reimers Thomas J. , Scarlett Janet M. , Corbett Julie R.
Published: January 2024

Adrenocortical function was assessed in 27 Beagle pups at 2, 4, 6, 8, 10, and 12 weeks of age by determination of plasma sodium, potassium, and chloride concentrations; serum aldosterone and cortisol concentrations; and plasma ACTH concentrations. Serum cortisol concentration was measured before and 1 and 2 hours after IM administration of 2.2 IU of acth/kg of body weight. Serum progesterone concentration also was determined for all pups at 2, 4, and 6 weeks of age.

Mean baseline cortisol concentration was lower for pups 8 weeks old or younger than for mature dogs. Nevertheless, mean serum ACIH-stimulated cortisol concentration in dogs of all age groups increased into the adult reference range after administration of acth. For pups 4 weeks old or younger, increase in cortisol concentration was maximal at 2 hours after acth administration. However, in pups between 6 and 12 weeks of age, the increase in cortisol concentration was maximal 1 hour after acth administration in about a third of the pups, whereas the remaining pups had peak values at 2 hours.

Mean plasma sodium, potassium, and chloride concentrations for each age group were within the reference ranges established for mature dogs, with the exception of lower mean plasma sodium and chloride concentrations in pups 4 weeks old or younger. Mean serum aldosterone concentration in pups of each age group was substantially higher than the range of aldosterone concentrations for clinically normal mature dogs. Median progesterone concentration was uniformly less than 0.2 ng/ml for all pups 6 weeks old or younger.

The normal endogenous acth concentration and adequate cortisol responses to exogenous acth seen in our pups would support functional pituitary gland and adrenal cortex for cortisol production. The low baseline cortisol concentration observed in the pups of this study may be related to reduced binding of cortisol to plasma proteins, as exists in human infants. The hyponatremia and increased aldosterone concentration may be explained by reduced renal tubular response to aldosterone, as also evidenced in the human infant kidney.
Effects of age, sex, reproductive status, and hospitalization on serum α1-antitrypsin concentration in dogs
Authors: Hughes Dez , Elliott Denise A. , Washabau Robert J. , Kueppers Friedrich
Published: January 2024

We performed a study to determine a reference range for serum α1-antitrypsin (α1at) in dogs by specific immunoassay; to evaluate whether serum α1at concentration varied with age, sex, or reproductive status in healthy dogs; and to investigate whether the serum α1at concentration in hospitalized dogs differed from that of healthy, nonhospitalized dogs. Serum α1at was quantitated by radial gel immunodiffusion for 60 healthy dogs and 311 hospitalized dogs. In healthy dogs, serum α1at concentration was 2.33 ± 0.41 mg/ml (mean ± sd), yielding a reference range (mean ± 2 sd) of 1.51 to 3.15 mg/ml. A correlation was not found between serum α1at concentration and age in healthy dogs. The serum α1at concentration (mean ± sem mg/ml) was significantly higher in healthy, sexually intact females (2.64 ± 0.1) than in healthy, spayed females (2.22 ± 0.12; P < 0.004); healthy, sexually intact males (2.14 ± 0.1; P < 0.0006); and healthy, castrated males (2.25 ± 0.14; P < 0.02). Hospitalized, sexually intact females had a lower serum α1at concentration (1.93 ± 0.07) than healthy, sexually intact females (2.64 ± 0.1; P < 0.0002). Likewise, the serum α1at concentration in hospitalized, sexually intact males (1.92 ± 0.04) was less than in healthy, sexually intact males (2.14 ± 0.1; P < 0.04). A difference in α1at concentration was not found between healthy and hospitalized, neutered dogs.
Improved early and long-term detection of bovine lentivirus by a nested polymerase chain reaction test in experimentally infected calves
Authors: Suarez David L. , Van Der Maaten Martin J. , Whetstone Cecelia A.
Published: January 2024

A nested polymerase chain reaction (pcr) test was developed to examine infection with the bovine lentivirus, bovine immunodeficiency-like virus (biv), in cattle. Primers were designed to amplify 2 separate regions of the pol and env segments of the biv genome. Two calves were experimentally infected with an isolate derived from the original strain of biv, R29, or with a recent field isolate, FL491. Serial blood samples were collected and examined by virus isolation, protein immunoblot, and nested pcr. The nested pcr test detected biv infection by 3 days after inoculation, earlier than the other 2 methods, and continued to identify infected cattle 9 to 15.5 months after inoculation, even when results from virus isolation and serology became negative. Nested pcr also detected multiple-size env products in samples obtained later in the infection from the calf that received FL491, giving evidence that viral quasispecies were selected during in vivo replication of the virus. Results indicated that the nested pcr test is more sensitive than virus isolation or serology for the detection of biv infection in cattle.
Detection of Toxoplasma gondii-specific IgA in the aqueous humor of cats
Authors: Lappin Michael R. , Burney Derek P. , Hill Steven A. , Chavkin Matthew J.
Published: January 2024

Toxoplasma gondii-specific IgA, IgM, and IgG were measured by ELISA in the serum and aqueous humor of 29 client-owned cats with endogenous uveitis and 7 specific-pathogen-free cats tested sequentially for 20 weeks after inoculation with T gondii. Local antibody production in aqueous humor was estimated by multiplying the aqueous humor-to-serum T gondii-specific antibody ratio by the serum-to- aqueous humor total IgG (C value) or calicivirus-spe- cific IgG (CTC value) ratio. Evidence for local production of antibody in aqueous humor was defined as C value greater than 8 or CTC value greater than 1. Toxoplasma gondii-specific IgM CTC values, IgG CTC values, or IgA CTC values greater than 1 were detected in the aqueous humor of 18 of 29 (62.1%) client- owned cats with endogenous uveitis; 2 cats had IgA CTC values greater than 1 without detectable IgM or IgG in aqueous humor. Toxoplasma gondii-specific IgM was not detected in the aqueous humor of experimentally inoculated cats before or after inoculation. Immunoglobulin G C values greater than 8 were detected in all 7 experimentally inoculated cats and ranged from 10.4 to 145.5.

Immunoglobulin G C values greater than 8 were first detected 4 to 8 weeks after T gondii inoculation and were undetectable by week 16 after inoculation. Immunoglobulin A C values greater than 8 were detected in 4 of 7 cats and ranged from 12.7 to 264.3. Immunoglobulin A C values greater than 8 were first detected 4 to 8 weeks after inoculation, and were detected in 2 cats during week 20 after inoculation. It was concluded that some cats infected with T gondii develop detectable concentrations of T gondii-specific IgA in aqueous humor.
Biomechanical properties of canine corticocancellous bone frozen in normal saline solution
Authors: Griffon Dominique J. , Wallace Larry J. , Bechtold Joan E.
Published: January 2024

Eleven pairs of canine metacarpal bones, 10 pairs of metatarsal bones, and 7 pairs of ribs were harvested cleanly and prepared for banking at −20 C for 1 year. One bone of each pair was randomly assigned to 1 type of storage: plastic pack vs immersion in a normal solution of sodium chloride. The contralateral bone was assigned to the opposite treatment.

Six pairs of metacarpal bones and 5 pairs of metatarsal bones were tested in torsion to failure. No significant difference was found within pairs. All ribs, 5 pairs of metacarpal bones, and 5 pairs of metatarsal bones were loaded in 4-point bending to failure. The energy absorbed at failure and the ultimate displacement of ribs and metacarpal and metatarsal bones were increased by 25 to 30% and 18 to 24%, respectively, when the bones were frozen in isotonic saline solution. Corticocancellous grafts frozen in normal saline solution are biomechanically less fragile and brittle than grafts stored in plastic without saline solution.
Urinary indices in llamas fed different diets
Authors: Lackey Margaret N. , Belknap Ellen B. , Salman Mo D. , Tinguely Laura , Johnson LaRue W.
Published: January 2024

Indices of renal function and damage were measured in 12 healthy male adult llamas fed a diet of mixed alfalfa/grass hay (mixed hay) and water ad libitum. Using a collection bag fitted over the preputial area, urine samples were collected at 6, 12, and 24 hours. Serum samples were obtained concurrently to determine endogenous creatinine clearance (cl), total (te) and fractional excretion (fe) of electrolytes (Na, K, Cl, P), electrolyte cl, urine and serum osmolality, urine enzyme activities (γ-glutamyltransferase and N-acetyl-β-D-glucosaminidase), and urine protein concentration. Urine production was quantified. Three months later, 10 of the 12 llamas were fed a grass hay diet and water ad libitum. Similar samples were obtained, and similar measurements were made.

Urine production was higher when the llamas were fed the mixed hay diet. Total urine volume for llamas fed mixed hay ranged from 628 to 1,760 ml/24 h, with a median of 1,307.5 ml/24 h, compared with a range of 620 to 1,380 ml/24 h and a median of 927.50 ml/24 h for llamas fed grass hay. Median urine osmolality was higher in llamas fed mixed hay (1,906 mOsm/kg of body weight, with a range of 1,237 to 2,529 mOsm/kg), compared with llamas fed grass hay (1,666 mOsm/kg, with a range of 1,163 to 2,044 mOsm/kg). Creatinine cl did not vary significantly over time for either diet. Median creatinine cl was higher for llamas fed mixed hay, compared with llamas fed grass hay-0.78 ml/min/kg, with a range of 0.20 to 1.83 ml/min/kg vs 0.45 ml/min/kg, with a range of 0.13 to 3.17 ml/min/kg. Clearances for K and a varied significantly among the periods. However, median Cl for Na and P did not vary over time for either diet. Overall values for these electrolytes in llamas fed mixed hay and grass hay diets were: clNa, 0.001 and 0.002 ml/min/kg and clP, 0.0006 and 0.0004 ml/min/kg, respectively. The FE rates of K, cl, and P did not vary significantly over time for either diet. Median respective FE for these electrolytes in the llamas fed mixed hay and grass hay diets include: feK, 84.90 and 63.10%; feCl, 0.85 and 1.30%; and feP, 0.10 and 0.10%. Fractional excretion of Na varied over time for both diets and could not be expressed accurately as an overall median. Median respective te of electrolytes for llamas fed the mixed hay and grass hay diets were: teNa, 0.007 and 0.03 mEq/kg/h; teCl, 0.04 and 0.06 mEq/kg/h; and teP, 0.0002 and 0.00 mg/kg/h; teK varied significantly (P < 0.05) over time for both diets. Urine γ-glutamyltransferase activity changed significantly (P < 0.05) over time. Urine N-acetyl-β-D-glucosaminidase activity was influenced by an interaction between diet and time. Median urine protein concentration was 26.0 mg/dl, with a range of 11.0 to 73.0 mg/dl for llamas fed mixed hay, and was 28.0 mg/dl, with a range of 16.0 to 124.0 mg/dl for Hamas fed grass hay.
Microorganisms isolated from the corneal surface before and during topical cyclosporine treatment in dogs with keratoconjunctivitis sicca
Authors: Salisbury Mary-Alice R. , Kaswan Renee L. , Brown John
Published: January 2024

The effect that topical administration of cyclosporine would have on the number and type of microorganisms isolated from the corneal surface of dogs with keratoconjunctivitis sicca was studied. Schirmer tear tests were performed on and corneal swab specimens were collected from 61 eyes of 31 dogs with keratoconjunctivitis sicca prior to and after 3, 6, and 12 months of treatment with cyclosporine.

In eyes that responded to cyclosporine treatment (Schirmer tear test value increased by ≥ 5 mm/min, compared with pretreatment value), the percentage of eyes from which bacteria were isolated after 3, 6, and 12 months of treatment was significantly (P < 0.001) less than the percentage from which bacteria were isolated prior to treatment. However, among eyes that did not respond to treatment, we did not detect a significant change over time in prevalence of bacteria or type of bacteria isolated. The percentage of eyes from which fungi were isolated decreased during treatment; however, the small number of eyes in which fungal culture results were initially positive precluded demonstration of a significant change. For all eyes, we did not detect any significant differences over time in the frequency with which specific bacterial genera were isolated, with the exception of β-hemolytic Streptococcus spp.

Opportunistic comeal infections were not detected even though none of the dogs received antibiotics. An increase in production of tears, which contain anti-infection proteins, was believed to be the primary factor responsible for the decrease in the percentage of eyes from which microorganisms could be isolated.
Effects of topically applied mitomycin-C on intraocular pressure, facility of outflow, and fibrosis after glaucoma filtration surgery in clinically normal dogs
Authors: Glover Tony L. , Nasisse Mark P. , Davidson Michael G.
Published: January 2024

The effects of mitomycin-C on intraocular pressure (iop), facility of outflow (C), and Tenon's capsule fibrosis were studied over 60 days in 10 clinically normal dogs. A 1-piece, silicone glaucoma implant was surgically implanted into both eyes; the filtration site of one eye was treated with a single, 5-minute intra-operative application of mitomycin (0.5 mg/ml), and the fellow eye was treated in a similar manner with balanced salt solution.

There were no significant differences in preoperative iop or C-values between treatment groups. Mean iop in eyes of both groups initially decreased from the preoperative value, but returned to the baseline value by day 21. Mean facility of aqueous outflow (C-value) increased in all eyes during the first 14 days (mitomycin-C-value = 2.26 ± 0.72; control C-value = 2.38 ± 0.81), then reached a plateau that was significantly higher than the baseline value in mitomycin (P = 0.039) and control (P = 0.041) eyes. Histologic evaluation revealed all implants surrounded by a connective tissue capsule composed of regular dense collagen and fibroblasts that was significantly (P = 0.003) thinner in the mitomycin-treated (scleral side = 167 ± 62 μm; conjunctival side = 122 ± 41 μm) than the control (scleral side = 261 ± 92 μm; conjunctival side = 180 ± 48 μm) group. There were, however, no significant differences in iop or C-values between groups at any postoperative time interval. Results of this study indicate that intraoperative treatment with mitomycin suppresses, but does not prevent fibrosis around silicone filtering implants.