Healthy Adult Domestic Shorthair Cats Research Articles

Progression of cyclosporine A-blood levels in experimental cats receiving a high-dose treatment protocol.

Cyclosporine A (CsA) is used as a steroid-sparing or alternative immunosuppressing agent in cats with various immune-mediated diseases such as immune-mediated hemolytic anemia. Daily treatment dosages of 5-20 mg/kg have been described. Interindividual variations in CsA blood levels are known to occur. To determine when steady-state conditions are reached and thus the earliest advisable time for monitoring CsA blood levels during the course of treatment, a prospective experimental study was conducted in six healthy adult Domestic Shorthair cats. Cats were treated with an oral dosage of 7 mg/kg CsA q 12 h for 10 days. On days 1, 2, 3, 5, 7, and 10 after the start of CsA administration (i.e., after 1, 3, 5, 9, 13, and 19 CsA administrations), EDTA blood was collected to measure the CsA level 12 h after the CsA administration (trough values) using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). Statistical analysis revealed a significant increase in mean CsA blood levels up to day 5 (2,050 ± 964.2 ng/mL [mean ± SD], 832-3,203 ng/mL [minimum-maximum]; repeated-measures ANOVA: p = 0.0021), while values on days 5 and 7 did not differ significantly from CsA concentrations on day 10. CsA concentrations showed markedly interindividual variability. Cyclosporine A blood levels reached a steady state on day 5 of high dosages of CsA q 12 h (i.e., after nine CsA administrations), indicating that this time point is suitable for monitoring blood levels in clinical patients. Results confirmed the well-known remarkable interindividual variability of CsA, indicating the need for treatment monitoring. The assessed treatment regime resulted in significantly higher mean CsA trough levels than the target range for immunosuppressive therapy (200-600 ng/mL).

Dietary enrichment of resistant starches or fibers differentially alter the feline fecal microbiome and metabolite profile

BackgroundCats are strict carnivores but possess a complex gastrointestinal (GI) microbial community that actively ferments dietary substrates that are not digested and reach the colon. The GI microbiota responses to dietary inclusion of resistant starches versus fibers have not been tested in cats. Thus, our objective was to evaluate the effects of diets enriched in resistant starch or fibers on the fecal characteristics, microbiome, and metabolite profiles of cats. Twelve healthy adult domestic shorthair cats (age = 9.6 ± 4.0 year; body weight = 3.9 ± 1.0 kg) were used in a replicated 3 × 3 Latin square design to test diets that were enriched with: (1) resistant starch (ERS), (2) a fiber-prebiotic-probiotic blend (FPPB), or (3) a fiber-prebiotic-probiotic blend + immune-modulating ingredients (iFPPB). In each 28-day period, 22 days of diet adaptation was followed by fecal and blood sample collection. Fecal samples were used for shotgun metagenomic sequencing. In addition, fecal and blood metabolite measurements and white blood cell stimulation was performed to assess immune function.ResultsA total of 1690 bacterial species were identified, with 259 species differing between fiber-rich and ERS treatments. In comparison with fiber-rich treatments that increased diversity and promoted Firmicutes and Bacteroidetes populations, resistant starch reduced microbial diversity and fecal pH, led to a bloom in Actinobacteria, and modified Kyoto Encyclopedia of Genes and Genomes orthology (KO) terms pertaining to starch and sucrose metabolism, fatty acid biosynthesis and metabolism, epithelial cell signaling, among others. Resistant starch also differentially modified fecal metabolite concentrations with relevance to GI and overall host health (increased butyrate; decreased propionate and protein catabolites - branched-chain fatty acids; phenols and indoles; ammonia) and reduced blood cholesterol, which correlated strongly with microbial taxa and KO terms, and allowed for a high predictive efficiency of diet groups by random forest analysis.ConclusionEven though domestic cats and other carnivores evolved by eating low-carbohydrate diets rich in protein and fat, our results demonstrate that the feline microbiome and metabolite profiles are highly responsive to dietary change and in directions that are predictable.

Effects of topical instillation of 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, and 0.03% flurbiprofen sodium on corneal sensitivity in ophthalmologically normal cats.

To investigate the effects of short-term and prolonged topical instillation of 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, and 0.03% flurbiprofen sodium on corneal sensitivity (CS) in ophthalmologically normal cats. 12 healthy adult domestic shorthair cats. In the first of 2 study phases, each cat received 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, 0.03% flurbiprofen sodium, and saline (0.9% NaCl; control) solutions (1 drop [0.05 mL]/eye, q 5 min for 5 treatments) in a randomized order with a 2-day washout period between treatments. For each cat, an esthesiometer was used to measure CS before treatment initiation (baseline) and at 15, 30, 45, and 60 minutes after the last dose. There was a 2-day washout period between phases. The second phase was similar to the first, except each treatment was administered at a dosage of 1 drop/eye, twice daily for 5 days and CS was measured before treatment initiation and at 15 minutes and 24 and 48 hours after the last dose. The Friedman test was used to evaluate change in CS over time. None of the 4 treatments had a significant effect on CS over time in either study phase. Results indicated that neither short-term nor prolonged topical instillation of 3 NSAID ophthalmic solutions had any effect on the CS of healthy cats. Given potential differences in cyclooxygenase expression between healthy and diseased eyes, further investigation of the effects of topical NSAID instillation in the eyes of cats with ocular surface inflammation is warranted.

PSVI-27 Novel dietary blends improve stool quality and alter fecal microbiota, metabolites, and immune markers of healthy adult cats

Abstract Functional ingredients may support gastrointestinal and immune health, but little is known in cats. Our objective was to evaluate the effects of diets containing a blend of fibers, prebiotics, probiotics, and/or immune mediators on stool quality and fecal microbiota, metabolites and immune markers of cats. Twelve healthy adult domestic shorthair cats (age = 9.6±4.0 yr; BW = 3.9±1.0 kg) were used in a replicated 3x3 Latin square design to test diets containing 1) no prebiotics or probiotics (Control), 2) a fiber-prebiotic-probiotic blend-containing formula (Test1), and 3) a fiber-prebiotic-probiotic blend + immuno-modulating ingredient-containing formula (Test2). In each 28-d period, 22d of diet adaptation was followed by fecal and blood sample collection. All procedures were approved by the Kennelwood, Inc. IACUC prior to experimentation. All data were analyzed using Mixed model procedures of SAS 9.4, with significance set at P< 0.05. Fecal pH and SCFA, phenol + indole, and ammonia concentrations were lower in cats fed Control vs. Test1 or Test2 diets. Fecal score was higher (looser stools) and fecal DM was lower in cats fed Control vs. Test2 diet. Fecal butyrate was lowest in cats fed Test2 and highest in cats fed Control. Fecal total BCFA and 7-methylindole were lower in cats fed Control vs. Test1 diet. Fecal IgA concentration was lower in cats fed Test2 vs. Control or Test1 diets. Fecal bacterial alpha-diversity measures of species richness were higher in cats fed Test1 or Test2 vs. Control diet. Fecal Actinobacteria and Megasphaera were higher, and Bacteroidetes, Firmicutes, and Prevotella were lower, in cats fed Control vs. Test1 or Test2 diets. Our results suggest that dietary fibers, prebiotics, and probiotics affect fecal microbiota, metabolites, and immune markers that may impact gastrointestinal health of cats.

Hemodynamic effects of MK-467 following intravenous administration to isoflurane-anesthetized cats concurrently receiving dexmedetomidine.

OBJECTIVE To evaluate the efficacy of each of 3 incremental doses of MK-467 for alleviation of dexmedetomidine-induced hemodynamic depression in isoflurane-anesthetized cats. ANIMALS 6 healthy adult domestic shorthair cats. PROCEDURES Each cat was anesthetized with isoflurane and received a target-controlled infusion of dexmedetomidine estimated to maintain the plasma dexmedetomidine concentration at 10 ng/mL throughout the experiment. Heart rate (HR) and direct arterial pressures were measured at baseline (isoflurane administration only), during dexmedetomidine infusion, and before and after IV administration of each of 3 serially increasing doses (15, 30, and 60 μg/kg) of MK-467. Cardiac index (CI) and systemic vascular resistance (SVR) were recorded at baseline, during dexmedetomidine infusion, and at the mean arterial pressure nadir after administration of the 30- and 60-μg/kg doses of MK-467. RESULTS Compared with baseline values, the dexmedetomidine infusion significantly decreased HR and increased arterial pressures. Each dose of MK-467 caused a significant decrease in arterial pressures and a significant, albeit clinically irrelevant, increase in HR (≤ 10%). Following administration of the 30- and 60-μg/kg doses of MK-467, all cats developed clinical hypotension (mean arterial pressure, < 60 mm Hg) even though CI and SVR returned to baseline values. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated administration of small doses of MK-467 to isoflurane-anesthetized cats receiving dexmedetomidine restored CI and SVR, but caused a substantial decrease in arterial pressures and only a marginal increase in HR. Therefore, caution should be used when MK-467 is administered to alleviate dexmedetomidine-induced hemodynamic depression in isoflurane-anesthetized cats.

Effect of oral administration of robenacoxib on inhibition of paracentesis-induced blood-aqueous barrier breakdown in healthy cats

OBJECTIVE To determine the effect of oral administration of robenacoxib on inhibition of anterior chamber paracentesis (ACP)-induced breakdown of the blood-aqueous barrier (BAB) and assess whether robenacoxib can cross an intact BAB in healthy cats. ANIMALS 12 healthy adult domestic shorthair cats. PROCEDURES Cats received robenacoxib (6-mg tablet in a treat, PO; n = 6) or a control treatment (treat without any drug, PO; 6) once daily for 3 days, beginning 1 day before ACP. One eye of each cat served as an untreated control, whereas the other underwent ACP, during which a 30-gauge needle was used to aspirate 100 μL of aqueous humor for determination of robenacoxib concentration. Both eyes of each cat underwent anterior chamber fluorophotometry at 0 (immediately before), 6, 24, and 48 hours after ACP. Fluorescein concentration and percentage fluorescein increase were used to assess extent of ACP-induced BAB breakdown and compared between cats that did and did not receive robenacoxib. RESULTS Extent of BAB breakdown induced by ACP did not differ significantly between cats that did and did not receive robenacoxib. Low concentrations of robenacoxib were detected in the aqueous humor (mean, 5.32 ng/mL; range, 0.9 to 16 ng/mL) for 5 of the 6 cats that received the drug. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that oral administration of robenacoxib did not significantly decrease extent of BAB breakdown in healthy cats. Detection of low robenacoxib concentrations in the aqueous humor for most treated cats indicated that the drug can cross an intact BAB.

Hemodynamic effects of low-dose atipamezole in isoflurane-anesthetized cats receiving an infusion of dexmedetomidine.

Objectives The objective of this study was to evaluate the cardiovascular effects of low-dose atipamezole administered intravenously to isoflurane-anesthetized cats receiving dexmedetomidine. We hypothesized that atipamezole would increase heart rate (HR) and reduce arterial blood pressure in isoflurane-anesthetized cats receiving dexmedetomidine. Methods Six healthy adult domestic shorthair cats were anesthetized with isoflurane and instrumented for direct arterial pressures and cardiac output (CO) measurements. The cats received a target-controlled infusion of dexmedetomidine (target plasma concentration 10 ng/ml) for 30 mins before administration of atipamezole. Two sequential doses of atipamezole (15 and 30 μg/kg IV) were administered at least 20 mins apart, during dexmedetomidine administration. The effects of dexmedetomidine and each dose of atipamezole on HR, mean arterial blood pressure (MAP), CO and systemic vascular resistance (SVR) were documented. Results Dexmedetomidine reduced the HR by 22%, increased MAP by 78% (both P ⩽0.01), decreased CO by 48% and increased SVR by 58% (both P ⩽0.0003). Administration of atipamezole 15 and 30 μg/kg intravenously increased HR by 8% ( P = 0.006) and 4% ( P = 0.1), respectively. MAP decreased by 39% and 47%, respectively (both P ⩽0.004). Atipamezole 30 μg/kg returned CO and SVR to baseline values. Conclusions and relevance Low doses of atipamezole (15 and 30 μg/kg) administered intravenously to anesthetized cats decreased arterial blood pressure with only marginal increases in HR. Atipamezole 30 μg/kg restored CO and SVR to baseline values before dexmedetomidine administration.

Pharmacokinetic and pharmacodynamic evaluation of oral rivaroxaban in healthy adult cats.

To determine the pharmacodynamics and pharmacokinetics of rivaroxaban (RVX), in healthy cats and to evaluate the clinicopathologic effects of various plasma RVX concentrations within target therapeutic ranges established for people. Prospective randomized cross-over study performed between July 2013 and November 2014. Veterinary university teaching hospital. Six healthy adult domestic shorthair cats (3 males, 3 females). Cats were treated with oral RVX at single, fixed doses (1.25, 2.5, 5 mg PO), q 12 h for 3 days (1.25 mg); q 24 h for 7 days (2.5 mg); and q 24 h for 28 days (1.25 mg). Blood samples were collected for complete blood count, blood chemistry, and RVX anticoagulant activity based on prolongation of dilute prothrombin time, activated partial thromboplastin time (aPTT), activated Factor X (FXa) inhibition (anti-Xa activity [aXa]) and high-pressure liquid chromatography tandem mass spectrometry determination of drug concentration. Treated cats had no signs of hemorrhage or clinicopathologic off-target adverse effects. There were dose-dependent prolongations of coagulation times and increase in aXa, with peak effect at 3 hours postadministration. There was a direct correlation between plasma RVX concentration and dilute prothrombin time and aXa. Coagulation parameters returned to baseline by 24 hours after the last dose. Oral RVX was well tolerated by healthy cats with predictable pharmacokinetics and anticoagulant effects. Clinical studies of RVX are warranted in cats with heart disease.

Pharmacokinetic and pharmacodynamic evaluation of high doses of buprenorphine delivered via high-concentration formulations in cats.

To evaluate the potential benefits of high-dose buprenorphine formulations for analgesia in cats, serial and crossover studies were undertaken to investigate their pharmacokinetics and thermal antinociceptive effects. Twelve healthy adult domestic shorthair cats (6.0 ± 1.1 kg body weight) were studied. Aqueous solutions of buprenorphine hydrochloride at 0, 0.02, 0.06, 0.12 and 0.24 mg/kg body weight and formulations containing 0, 0.3, 0.6 and 1.2 mg/ml with and without preservatives were given subcutaneously. Blood samples were taken and thermal threshold (TT) measured prior to and at regular time points up to 72 h after dosing. Descriptive statistics and analyses of variance were applied as appropriate. Baseline TT was 47.6 ± 4.1°C, which increased in all groups treated with all buprenorphine dosages and formulations. After doses of 0.12 mg/kg and above, TT was significantly higher than baseline at most time points from 1-30 h post-treatment. The time to maximum effect (Tmax) ranged between 0.25 and 2.00 h; and plasma concentrations associated with maximum antinociceptive effect (Cmax) were 1.01-1.72 ng/ml after the 0.02 mg/kg dose, 1.4-4.9 ng/ml after the 0.06 mg/kg dose, 4.6-51.4 ng/ml after the 0.12 mg/kg dose and 5.3-22.3 ng/ml after the 0.24 mg/kg dose. The range of estimates for the buprenorphine elimination half-life were as follows: 0.02 mg/kg = 1.35-5.33 h; 0.06 mg/kg = 16.1-31.2 h; 0.12 mg/kg = 10.1-34.0 h; and 0.24 = mg/kg 16.1-31.6 h. The mean 'plasma concentration for the offset of analgesia' was 2.3 ± 2.0 ng/ml. No adverse effects were seen. The addition of preservatives to a high-concentration buprenorphine formulation had no impact on antinociception nor any side effects. Aqueous high-concentration buprenorphine formulations administered at 0.12 or 0.24 mg/kg have potential for clinical use in cats, providing prolonged antinociception in a single subcutaneous injection of minimal dose volume.

Effect of gantacurium on evoked laryngospasm and duration of apnea in anesthetized healthy cats.

To evaluate whether the ultrashort-acting neuromuscular blocking agent gantacurium can be used to blunt evoked laryngospasm in anesthetized cats and to determine the duration of apnea without hemoglobin desaturation. 8 healthy adult domestic shorthair cats. Each cat was anesthetized with dexmedetomidine and propofol, instrumented with a laryngeal mask, and allowed to breathe spontaneously (fraction of inspired oxygen, 1.0). The larynx was stimulated by spraying sterile water (0.3 mL) at the rima glottidis; a fiberscope placed in the laryngeal mask airway was used to detect evoked laryngospasm. Laryngeal stimulation was performed at baseline; after IV administration of gantacurium at doses of 0.1, 0.3, and 0.5 mg/kg; and after the effects of the last dose of gantacurium had terminated. Duration of apnea and hemoglobin oxygen saturation (measured by means of pulse oximetry) after each laryngeal stimulation were recorded. Neuromuscular block was monitored throughout the experiment by means of acceleromyography on a pelvic limb. Laryngospasm was elicited in all cats at baseline, after administration of 0.1mg of gantacurium/kg, and after the effects of the last dose of gantacurium had terminated. The 0.3 and 0.5 mg/kg doses of gantacurium abolished laryngospasm in 3 and 8 cats, respectively, and induced complete neuromuscular block measured at the pelvic limb; the mean ± SE duration of apnea was 2 ± 1 minutes and 3 ± 1.5 minutes, respectively. Hemoglobin oxygen saturation did not decrease significantly after administration of any dose of gantacurium. Gantacurium may reduce tracheal intubation-associated morbidity in cats breathing oxygen.

Effect of low dose rate ketamine infusions on thermal and mechanical thresholds in conscious cats

ObjectiveTo determine the thermal and mechanical antinociceptive effects of two different subanesthetic constant rate infusions of racemic ketamine in cats. Study designProspective, randomized, blinded, experimental study. AnimalsEight healthy adult domestic shorthair cats (two intact females and six neutered males). MethodsThe thorax and the lower thoracic limbs of each cat were shaved for thermal (TT) and mechanical threshold (MT) testing and a cephalic catheter was placed. Three intravenous treatments of equivalent volume were given as loading dose (LD) followed by an infusion for 2 hours: (K5) 0.5 mg kg−1 ketamine followed by 5 μg kg−1 minute−1 ketamine infusion, (K23) 0.5 mg kg−1 ketamine followed by 23 μg kg−1 minute−1 ketamine infusion or (S) 0.9% saline solution. Effects on behavior, sedation scores, MT and TT were obtained prior to drug treatment and 0.25, 0.5, 0.75, 1, 1.5, 2, 2.25, 2.5 2.75, 3 hours then every 0.5 hours for 7 hours and 10, 12, 14 and 26 hours after loading dose administration. ResultsKetamine induced mild sedation for the period of the infusion, no adverse behavioral effects were observed. Thermal threshold was significantly higher than baseline (K5: 44.5 ± 0.7 °C; K23: 44.5 ± 0.5 °C) at 15 minutes in the K5 group (46.8 ± 3.5 °C) and at 45 minutes in the K23 group (47.1 ± 4.1 °C). In the K23 group TT was significantly increased compared to S and K5 at 45 minutes. In K5 at 15 minutes MT (9.6 ± 4.0 N) was different to baseline (6.1 ± 0.8 N) and to the S group (5.9 ± 2.3 N). Conclusion and clinical relevanceLow dose rate ketamine infusions minimally affect thermal and mechanical antinociception in cats. Further studies with different nociceptive testing methods are necessary to assess whether ketamine could be a useful analgesic in cats.

Ultrasonographic evaluation of preprandial and postprandial gallbladder volume in healthy cats

To noninvasively assess the influence of ingestion of a standard meal on gallbladder volume (GBV) in healthy cats. 10 healthy adult domestic shorthair cats (4 neutered females, 5 neutered males, and 1 sexually intact male). Nonsedated cats were positioned in dorsal and left lateral recumbency to obtain ultrasonographic measurements of the gallbladder via the subcostal and right intercostal acoustic windows, respectively. Gallbladder volume was calculated from linear measurements by use of an ellipsoid formula (volume [mL] = length [mm] × height [mm] × width [mm] × 0.52). Measurements were recorded after food was withheld for 12 hours (0 minutes) and at 5, 15, 30, 45, 60, and 120 minutes after cats were fed 50 g of a standard commercial diet (protein, 44.3%; fat, 30.3%; and carbohydrate, 15.6% [dry matter percentage]). Agreement between gallbladder linear measurements or GBV obtained from the subcostal and right intercostal windows was good. Feeding resulted in linear decreases in gallbladder linear measurements and GBV. Via the subcostal and intercostal windows, mean ± SD GBV was 2.47 ± 1.16 mL and 2.36 ± 0.96 mL, respectively, at 0 minutes and 0.88 ± 0.13 mL and 0.94 ± 0.25 mL, respectively, at 120 minutes. Gallbladder width most closely reflected postprandial modification of GBV. Results indicated that ultrasonographic assessment (via the subcostal or right intercostal acoustic window) of postprandial changes in GBV can be used to evaluate gallbladder contractility in cats. These data may help identify cats with abnormal gallbladder emptying.

Thermal antinociceptive effect of orally administered gabapentin in healthy cats

To determine the thermal antinociceptive effect of various single doses of gabapentin administered orally in cats. 6 healthy adult domestic shorthair cats. Baseline skin temperature and baseline thermal threshold were determined via application of a thermal probe to the thorax of each cat prior to oral administration (in random order) of an empty capsule (placebo) or a capsule containing 5, 10, or 30 mg of gabapentin/kg (4 experiments/cat). After each treatment, thermal threshold was determined at intervals during an 8-hour period. Plasma gabapentin concentration was measured prior to and at 1-hour intervals after drug administration. Dose and time effects were analyzed by use of a repeated-measures ANOVA. Peak plasma gabapentin concentration increased with increasing gabapentin dose. After administration of the 5, 10, and 30 mg/kg doses, median interval until the greatest gabapentin concentration was detected was 60, 120, and 90 minutes, respectively (interval ranges were 60 to 120 minutes, 60 to 120 minutes, and 60 to 180 minutes, respectively). In the experiments involving administration of the placebo or increasing doses of gabapentin, mean+/-SD baseline skin temperature and thermal threshold were 36.8+/-1.21 degrees C and 45.8+/-4.4 degrees C, 36.9+/-1.1 degrees C and 43.1+/-2.4 degrees C, 37.0+/-0.7 degrees C and 44.0+/-1.5 degrees C, and 36.1+/-1.7 degrees C and 43.3+/-3.3 degrees C, respectively. There was no significant effect of treatment on thermal threshold. At the doses evaluated, orally administered gabapentin did not affect the thermal threshold in healthy cats and therefore did not appear to provide thermal antinociception.

Effects of tramadol hydrochloride on the thermal threshold in cats

OBJECTIVE-To determine the thermal antinociceptive effect of oral administration of tramadol hydrochloride at doses between 0.5 and 4 mg/kg in cats. ANIMALS-6 healthy adult domestic shorthair cats. PROCEDURES-Baseline (before drug administration; time 0) thermal threshold was determined by applying a thermal probe to the thorax of each cat. Tramadol (0.5, 1, 2, 3, or 4 mg/kg) or a placebo was then administered orally in accordance with a Latin square design. Thermal threshold was determined by an observer who was unaware of treatment at various times until thermal threshold returned to baseline values or 6 hours had elapsed. Plasma tramadol and O-desmethyl-tramadol concentrations were measured prior to drug administration and at 1-hour intervals thereafter. Effect-concentration data were fitted to effect maximum models. RESULTS-Highest plasma tramadol and O-desmethyl-tramadol concentrations increased with increasing tramadol dose. Significant effects of dose and time on thermal threshold were detected. Thermal threshold was significantly higher than the baseline value at 80 and 120 minutes for the 0.5 mg/kg dose, at 80 and from 120 to 360 minutes for the 2 mg/kg dose, from 40 to 360 minutes for the 3 mg/kg dose, and from 60 to 360 minutes for the 4 mg/kg dose. CONCLUSIONS AND CLINICAL RELEVANCE-Tramadol induced thermal antinociception in cats. Doses of 2 to 4 mg/kg appeared necessary for induction of significant and sustained analgesic effects. Simulations predicted that 4 mg/kg every 6 hours would maintain analgesia close to the maximum effect of tramadol.

Determination of reference intervals for plasma biochemical values in clinically normal adult domestic shorthair cats by use of a dry-slide biochemical analyzer

To establish reference intervals of plasma biochemical values in healthy adult domestic shorthair (DSH) cats by use of controlled conditions. 95 healthy client-owned cats. Food was withheld from the cats overnight. All blood samples were obtained on the same day, at the same location, and by the same investigator. Blood samples were collected from a cephalic vein into lithium heparin tubes. After centrifugation of blood samples, plasma supernatants were harvested and stored at -20 degrees C until assayed for total proteins, albumin, creatinine, urea, glucose, calcium, phosphates, sodium, chloride, potassium, and CO2 concentrations and alkaline phosphatase and alanine aminotransferase activities. Reference intervals in healthy adult DSH cats were 65 to 85 g/L for total proteins, 27 to 39 g/L for albumin, 89 to 207 micromol/L for creatinine, 6.6 to 11.3 mmol/L for urea, 4.1 to 8.2 mmol/L for glucose, 2.4 to 2.9 mmol/L for calcium, 1.1 to 2.1 mmol/L for phosphates, 153 to 161 mmol/L for sodium, 120 to 127 mmol/L for chloride, 3.3 to 4.2 mmol/L for potassium, 15 to 21 mmol/L for CO2, 32 to 147 U/L for alkaline phosphatase, and 34 to 123 U/L for alanine aminotransferase. This study provided reference intervals for plasma analytes in adult DSH cats. The influence of potential confounding factors was minimized through use of controlled preanalytic and analytic conditions. However, these results cannot be extrapolated to other feline breeds or used to interpret results from other biochemical analyzers.

Effects of epidural administration of morphine and buprenorphine on the minimum alveolar concentration of isoflurane in cats

To determine effects of epidural administration of morphine and buprenorphine on the minimum alveolar concentration of isoflurane in cats. Animals-6 healthy adult domestic shorthair cats. Cats were anesthetized with isoflurane in oxygen. Morphine (100 microg/kg diluted with saline [0.9% NaCl] solution to a volume of 0.3 mL/kg), buprenorphine (12.5 microg/kg diluted with saline solution to a volume of 0.3 mL/kg), or saline solution (0.3 mL/kg) was administered into the epidural space according to a Latin square design. The minimum alveolar concentration (MAC) of isoflurane was measured in triplicate by use of the tail clamp technique. At least 1 week was allowed between successive experiments. The MAC of isoflurane was 2.00 +/- 0.18%, 2.13 +/- 0.11%, and 2.03 +/- 0.09% in the morphine, buprenorphine, and saline solution groups, respectively. No significant difference in MAC was detected among treatment groups. A significant effect of epidural administration of morphine or buprenorphine on the MAC of isoflurane in cats could not be detected. Further studies are needed to establish whether epidural opioid administration has other benefits when administered as a component of general anesthesia in cats.

Cloning and sequencing of the canine and feline cardiac troponin I genes

To determine the gene sequences of canine and feline cardiac troponin I (cTnI), express the protein from the cloned gene in vitro, and validate the use of a commercial cTnI serum analyzer in these species via detection of the expressed protein or comparison of sequence homology. Samples of ventricular myocardium from 5 healthy adult mixed-breed dogs and 5 healthy adult domestic shorthair cats. The RNA was extracted from myocardial samples, and cDNA was synthesized via reverse transcriptase polymerase chain reaction and sequenced. The canine cDNA for the coding region was expressed in cell culture and analyzed by western blot and sandwich enzyme-linked immunosorbent assays. Canine and feline cTnI genes were cloned and sequenced. Homology of the nucleotide and amino acid sequences of the canine and feline cTnI genes with human and rodent cTnI genes were high; the greatest homology was detected between canine and feline genes (95% and 96%, respectively). Recombinant canine cTnI protein was detected by a commercial serum cTnI analyzer and by western blot analysis. Results indicated that commercial cTnI analyzers can be used to measure serum cTnI concentration from dogs and cats. Additionally, our preliminary characterization of the feline cTnI gene may facilitate further investigation of cTnI and its role in familial hypertrophic cardiomyopathy in cats.