Adult Beagle Research Articles

PSIX-6 The Effects of Hydrolyzed Protein on Macronutrient Digestibility, Fecal Metabolites, Oxidative Stress and Inflammatory Biomarkers, and Skin and Coat Quality in Adult Dogs

Abstract Research on protein hydrolysates has observed various properties and functionalities of these ingredients depending on the type of hydrolysate. The objective of this study was to evaluate the effects of hydrolyzed chicken protein that was incorporated into diets on digestibility, gut health, skin and coat health, oxidative stress, and inflammation in healthy adult dogs. Five complete and balanced treatment diets were manufactured: 1) CONd: chicken meal diet; 2) 5% CLHd: 5% substitution of chicken liver hydrolysate of chicken meal diet; 3) CLHd: chicken liver hydrolysate diet; 4) 5% CHd: 5% substitution of chicken hydrolysate of chicken meal diet; and 5) CHd: chicken hydrolysate diet. A 5×5 Latin square design was used which included 10 neutered adult beagles. Each of the 5 periods consisted of a 7-d washout time and a 28-d treatment period. All diets were well accepted by the dogs. There was greater (P < 0.05) fecal butyrate (226.8 μmol/g DMB) concentration as well as decreasedr isovalerate (6.8 μmol/g DMB), 4-ethylphenol (1.4 μmol/g DMB), and indole (0.7 μmol/g DMB) in dogs fed CLHd than CONd (149.3, 10.8, 2.5, and 1.5 μmol/g DMB, respectively). Doges fed CHd had greater (P < 0.05) fecal immunoglobulin A concentration (2.86 mg/g) when compared with CLHd (0.91 mg/g); however, both groups were comparable to the control. There was no difference among groups in serum cytokine concentrations, serum oxidative stress biomarkers, or skin and coat health analyses (P > 0.05). In conclusion, chicken protein hydrolysate could be incorporated into canine extruded diets as a comparable source of protein to traditional chicken meal. The test chicken protein hydrolysates may have potential to support gut health by modulating immune response and fermentative activity; however, more research is needed to confirm the effect.

Effects of two commercial diets and two supplements on urinary pH in dogs.

Urinary pH manipulation by therapeutic foods or supplements is part of the treatment for urolithiasis. The effectiveness of these diets and supplements should be studied to determine which of these strategies is most effective. To assess the effect of the oral supplementation of potassium citrate, an ammonium chloride solution (Urical) and two dry therapeutic foods-Hill's® Prescription Diet® u/d® Canine (u/d diet) and Royal Canin® Urinary S/O dog (S/O diet)-on a dog's urinary pH at different time points over 8 h. Seven healthy adult male research beagle dogs. A prospective interventional study lasting 31 days. The dogs either received a supplement (potassium citrate or rical) with a dry adult maintenance diet (control diet) or the therapeutic diet (u/d diet or S/O diet). Each treatment had a duration of 2-5 days, with 2- to 4-day washout periods in between. Urinary pH measurements were performed every 2 h between 07h00 and 15h00, with the food being given at 07h00 and 15h00, right after urine collection. The pH measurements obtained in each of the four treatments were compared to control (same dogs fed the control diet exclusively). When compared to the control diet at the same time points, biologically relevant changes in urinary pH (defined as ≥0.5) were: increase with potassium citrate at 7h00 and 13h00; increase with u/d diet at 9h00, 13h00, and 15h00; decrease with S/O diet at 9h00 and 11h00; Urical did not have a detectable effect on urinary pH. The present study confirms that therapeutic foods S/O and u/d, and potassium citrate supplement affected acid-base balance in healthy adult male beagle dogs, with the tested diets being more effective than the administered doses of the tested supplements at influencing urinary pH.

Cannabidiol plasma determination and pharmacokinetics conducted at beginning, middle and end of long-term supplementation of a broad-spectrum hemp oil to healthy adult dogs.

Veterinary hemp products containing cannabidiol (CBD) and negligible psychoactive (THC) have increased popularity since hemp (with <0.3% THC) was removed from schedule 1 substances under the Controlled Substances Act in 2018. This was accompanied by increased CBD research, mostly on the short-term safety and efficacy for inflammatory and neurological conditions. It is imperative to understand how CBD is metabolized or accumulated in the body long-term, thus the goal of the present work was to determine monthly plasma CBD concentrations, as well as changes in pharmacokinetic (PK) parameters in chronically dosed dogs. The study was a masked, placebo-controlled, randomized design. Six adult beagles were assigned to placebo, 5 and 10 mg/kg/day CBD treatment groups. Dogs received oral oil treatment once daily for 36 weeks. Blood was collected once every 4 weeks pre- and postprandially for CBD plasma determination (at 0 and 2 h). Pharmacokinetics were conducted at 0, 18 and 36 weeks. Pharmacokinetics and monthly CBD plasma data of dogs who received CBD were analyzed as repeated measures over time using a mixed model, with significance at α = 0.05. Average plasma CBD at 5 and 10 mg/kg were 97.3 ng/mL and 236.8 ng/mL pre-prandial, 341 ng/mL and 1,068 ng/mL postprandial, respectively. PK parameters suggested CBD accumulation over time, with significant increases in Cmax and AUC at both the 18 and 36-week timepoints. Cmax and AUC were dose proportional. Half-life demonstrated large inter-individual variations and increased (p < 0.05) at weeks 18 and 36 compared to baseline. Volume of distribution was not affected by time or treatment, while MRT increased, and clearance decreased over time (p < 0.05). Chronic administration of CBD to healthy adult dogs led to a dose-proportional accumulation in the body for 36 weeks, which was confirmed by an increased half-life, total exposure, mean residence time and plasma peak. Our data also suggests that CBD plasma levels may have less daily variation if administered twice daily.

Effects of microalgae as dietary supplement on palatability, digestibility, fecal metabolites, and microbiota in healthy dogs.

The current trend of dog owners increasingly favoring the functional value of food to assure preventive health and wellbeing of their pets has been raising the interest in microalgae as natural additives with bioactive properties. However, scientific studies addressing the effects of microalgae supplementation in diets for dogs are scarce. This study aimed to evaluate the effects of dietary supplementation with three microalgae species (Chlorella vulgaris, Nannochloropsis oceanica, and Tetradesmus obliquus) on diet palatability, total tract digestibility, metabolizable energy content, fecal metabolites and microbiota of dogs. Twelve adult Beagle dogs were used in three two-bowl tests to compare the palatability of a commercial complete diet for adult dogs without (reference diet) and with 1.5% supplementation of each microalgae. From the results obtained, three digestibility trials were performed according to a replicated Latin square 3 × 3, with six adult Beagle dogs, three experimental periods of 10 days each, and three dietary supplementation levels of microalgae (0.5, 1.0, and 1.5%). In each trial, effects of microalgae supplementation levels on total tract digestibility, metabolizable energy content, fecal metabolites and microbiota of dogs were evaluated. First diet approached or tasted was not significantly affected by microalgae inclusion, but dogs showed a preference for the reference diet over the diets with 1.5% inclusion of C. vulgaris and N. oceanica, no difference being observed with 1.5% T. obliquus. In all digestibility trials, dietary supplementation with microalgae up to 1.5% did not greatly affected the dietary chemical composition and kept unaffected food intake, fecal output and metabolites, and digestibility of nutrients and energy. Compared with the reference diet, supplementation with C. vulgaris increased protein digestibility. Fecal characteristics and metabolites were affected by microalgae supplementation, being the effects dependent on the species. Fecal microbiota composition of dogs fed with microalgae-supplemented diets was modified by promoting the beneficial Turicibacter and Peptococcus genera associated with gut health and activation of the immune system. Overall, the results support C. vulgaris, N. oceanica, and T. obliquus as sustainable functional supplements that potentially enhance gastrointestinal health of dogs through the selective stimulation of microbiota without detrimental effects on food intake and digestibility.

A Novel Fluorescence-Based Leak Test Method for Rectal Anastomoses Using Aerosolized Indocyanine Green.

The intraoperative air leak test is commonly performed during rectal surgery to evaluate anastomotic integrity. However, its drawbacks include occasional difficulties in visualizing the exact point of the leak while maintaining the pelvis under saline, the need for repeat testing to identify the leak point, and a lack of continuous visualization of the leak point. To evaluate the feasibility and clinical applicability of using aerosolized indocyanine green, a fluorescent tracer, for detecting rectal anastomotic leakage. Animal preclinical study. Animal laboratory at Kagawa University. Six healthy adult female beagles were included. An anastomotic leakage model with a single air leak point was created in each dog. Indocyanine green was aerosolized using a nebulizer kit with a stream of carbon dioxide flowing at 1.5 to 2.0 L/min. The aerosol was administered into the rectum transanally, and laparoscopic observations were performed. Air leak points were observed using a near-infrared fluorescence laparoscope, after which the presence of corresponding indocyanine green fluorescence was verified. Aerosolized indocyanine green was visualized laparoscopically at all anastomosis sites but not elsewhere. The median time from the administration of the aerosol to its visualization was 4.5 seconds. Pathological examinations were performed 4 weeks postsurgery in all dogs, and no histological abnormalities related to aerosolized indocyanine green administration were observed at the anastomosis sites. The leak points were surgically created and did not occur naturally. Visualization of air leaks at the sites of rectal anastomosis was laparoscopically achievable by administering aerosolized indocyanine green transanally into the rectum in our canine model. This novel fluorescent leak test could be a valid alternative to established methods.

Investigation of the association between oxygen reserve index and arterial partial oxygen pressure in anesthetized dogs

ObjectiveTo evaluate the relationship between oxygen reserve index (ORI) and arterial partial pressure of oxygen (PaO2) in anesthetized dogs. Study designProspective experimental study. AnimalsA total of eight healthy adult Beagle dogs with a median age of 38 (range 20–87) months and a median body mass of 8.6 (range 7.0–13.8) kg. MethodsAfter induction of general anesthesia with propofol, dogs were mechanically ventilated and anesthesia maintained with isoflurane carried in oxygen. Arterial blood samples were collected from a catheter placed in the femoral artery. ORI was measured by placing a CO-oximeter sensor on the tongue. Inspired oxygen fraction (FiO2) was increased from 21% to > 95% in increments of 5%. PaO2 and ORI were recorded and compared at different times. The relationship between ORI and PaO2 was investigated using a nonlinear function, the Hill equation, and a linear regression analysis was performed, as appropriate. ResultsA total of 128 pairs of values were compared for all dogs. Applying the Hill equation to the relationship between ORI and PaO2 resulted in R2 = 0.80 (p < 0.001) with a Hill coefficient of 3.7. It was predicted that ORI ranged 0.1–0.9 as PaO2 ranged 127.0–417.9 mmHg and that in the more linear portion of the range, PaO2 of 127.0–289.9 mmHg ORI ranged 0.1–0.7. Linear regression analysis in the more linear portion showed a weak correlation (R2 = 0.29, p = 0.006). Conclusions and clinical relevanceIn the present study, the Hill equation predicted the relationship between PaO2 and ORI for PaO2 ranging 127.0–417.9 mmHg in anesthetized dogs. However, in the linear portion of the PaO2, the coefficient of determination was low, indicating that ORI is not a surrogate for PaO2.

Experimental study of a 3D-printing technique combined with biphasic calcium phosphates to treat osteonecrosis of the femoral head in a canine model

ObjectiveThis study was aimed to use a digital design of 3D-printing technology to create a surgical navigation template. At the same time, biphasic calcium phosphate (BCP) was applied to treat osteonecrosis of the femoral head (ONFH) in animal models, based on accurate positioning of necrotic lesions in the navigation templates and observation of its therapeutic effect.MethodsFifteen healthy adult male and female beagle dogs weighing 20 + 2 kg were randomly divided into three groups (n = 5) after establishing a model of ONFH using the liquid nitrogen freezing method. Each model underwent necrotic lesion creation and BPC implantations on one side of the femoral head and only necrotic lesion creation on the other side of the femoral head. Each group underwent CT examination, gross observation, histological examination and immunohistochemical staining at 6 weeks, 12 weeks and 18 weeks postoperatively.ResultsAt weeks 6, 12, and 18, CT and gross examination showed that the necrotic area in the experimental group was basically intact and had been completely raised by BCP material. In the control group, there were signs of bone repair in the femoral head, but there were still large bone defects and cavities. At week 18, extensive collapse of the cartilage surface was observed. Through histological examination, in the experimental group at 12 and 18 weeks, a large number of new and reconstructed bone trabeculae containing a large amount of collagen fibres were observed (P < 0.05), while in the control group, there was extensive necrosis of the bone trabeculae without cellular structural areas. Immunohistochemical examination observation: A large number of CD31-positive cells were observed in the experimental group at 6 weeks, gradually decreasing at 12 and 18 weeks (P < 0.05), while a small number of CD31-positive cells were observed in the control group at 18 weeks.ConclusionThe 3D-printed navigation template can accurately locate ONFH lesions. Implantation of BCP material can effectively play a supporting role, prevent the collapse of the loading surface, and induce bone formation and angiogenesis to some extent.

Comparative analysis of anchorage strength and histomorphometric changes after implantation of miniscrews in adults and adolescents: an experimental study in Beagles

ObjectivesThis study aimed to explore the differences in anchorage strength and histomorphometric changes in orthodontic miniscrews between adult and adolescent beagles.Material and methodSix adult beagles and six young beagles were used as experimental subjects, and eight miniscrews were symmetrically placed in the posterior mandible of each dog. Measurement of the displacement (mm) of two adjacent miniscrews after load application was performed to compare the anchorage strength between the adult and adolescent groups. Three intravital bone fluorochromes (oxytetracycline, calcein green, xylenol orange) were administered postoperatively to mark the active bone-forming surface. Subsequently, the mineral apposition rate and bone-implant contact ratio were measured for dynamic and static histomorphometry. Finally, the expression levels of the RANKL/OPG ratio were evaluated by immunohistochemistry.ResultsThe average displacement of miniscrews in the adult group was significantly less than that in the adolescent group after load application. For histomorphometry analysis, the mineral exposure rate in the adolescent group was higher than that in the adult group with or without force application. In addition, more fractures and new bone formation but deceased bone-implant contact ratios were observed in the adolescent group than in the adult group. The ratio of RANKL/OPG expression increased more in the adolescent group than in the adult group.ConclusionMiniscrews do not remain in the same position as skeletal anchors, and the amount of displacement was higher in adolescent group than that in adult group, reflecting the weaker anchorage strength of miniscrews in adolescents due to the higher bone turnover rate and active bone remodelling. Therefore, it is feasible to apply orthodontic loading to the miniscrews in adult patients earlier, even immediately, but it is recommended to wait a period for the adolescents.

Sugammadex for reversal of rocuronium-induced neuromuscular blockade during alfaxalone anesthesia in dogs

ObjectiveTo investigate the reversal effect of sugammadex on neuromuscular blockade induced by a single bolus of rocuronium in dogs under alfaxalone anesthesia. Study designRandomized, prospective, crossover experimental study. AnimalsA group of six adult Beagle dogs (three females and three males), weighing 11.3–15.8 kg and aged 6–8 years, were used. MethodsDogs were anesthetized twice with a 1.25 times minimum infusion rate of alfaxalone, with a washout period of at least 14 days between experiments. Neuromuscular function was monitored using acceleromyography with train-of-four (TOF) stimulation of the peroneal nerve. After recording the control TOF ratio (TOFRC), rocuronium (0.5 mg kg–1) was administered intravenously. Subsequently, sugammadex (4 mg kg–1) or an equal volume of saline (control treatment) was administered intravenously when the TOF count returned from 0 to 1 after neuromuscular blockade. Time from rocuronium injection to TOF count = 0 (onset time), time from TOF count = 0 to TOF count = 1 (maximum blockade period), time of first twitch amplitude recovery from 0.25 to 0.75 (recovery index), and time from sugammadex or saline administration to TOF ratio/TOFRC ≥ 0.9 (recovery time) were recorded. ResultsThe onset time and maximum blockade duration did not differ between sugammadex treatment [1.2 (0.7–1.5) minutes and 9.9 (6.3–10.5) minutes, respectively] and control treatment [median (range); 1.0 (0.7–1.1) minutes and 9.9 (8.8–11.5) minutes, respectively] (p = 0.219 and 0.844, respectively). Recovery index was 0.5 (0.3–0.7) minutes in sugammadex treatment, which was shorter than that in control treatment [4.5 (3.7–4.9) minutes] (p = 0.031). Recovery time was 0.8 (0.5–2.8) minutes in sugammadex treatment, which was shorter than that in control treatment [10.5 (6.8–14.3) minutes] (p = 0.031). Conclusions and clinical relevanceRocuronium-induced neuromuscular blockade was effectively reversed by sugammadex in dogs anesthetized with alfaxalone.

Hippocampal transcriptome analysis reveals mechanisms of cognitive impairment in beagle dogs with type 1 diabetes.

Diabetic encephalopathy is a common complication of type 1 diabetes. However, there have been few studies on cognitive impairment and hippocampal damage in type 1 diabetes mellitus (T1DM) using dogs as experimental animals. To investigate the effects of diabetes on the CNS, 40 adult beagles were divided into streptozotocin/alloxan type 1 diabetes model and control groups. The duration of diabetes in the model group was 120 days. A cognitive dysfunction scale was used to assess cognitive function. Hematoxylin and eosin and Golgi-Cox staining methods were used to observe morphological damage to the hippocampus. Transcriptomics was used to investigate differential gene expression in the hippocampus. The results showed that the cognitive dysfunction score of the model group was significantly higher than that of the control group. In addition, the number of normal neurons, the complexity of dendritic morphology, and the density of dendritic spines were decreased in the hippocampus of diabetic dogs. A total of 672 differentially expressed genes (DEGs) were identified, 289 of which were upregulated, and 383 were downregulated. Modified genes included DBH, IGFBP2, AVPR1A, and DRAXIN. In conclusion, type 1 diabetic dogs exhibit cognitive dysfunction. The DEGs were mainly enriched in metabolic, PI3K-Akt signaling, and neuroactive ligand-receptor interaction pathways.

Evaluation of graded levels of corn fermented protein on extrusion processing and diet utilization in healthy adult dogs

There has been increased interest among pet owners to feed vegetarian diets to their pets. However, the primary protein sources used in pet food today are animal based, warranting a need to evaluate novel plant-based ingredients to meet the protein demand. Corn fermented protein (CFP), a coproduct from ethanol production, may provide a plant-based alternative protein source for pet food. Therefore, the objectives of this study were to determine the effects of increasing levels of CFP on extrusion processing, stool quality, apparent total tract digestibility, and palatability in dog diets. Four extruded diets were fed to 12 adult beagle dogs in a replicated 4 × 4 Latin square design. The control diet contained 15% soybean meal (0C) and CFP was exchanged at either 5%, 10%, or 15% of soybean meal (5C, 10C, and 15C, respectively). Dogs were fed each dietary treatment for 9 days of adaption followed by 5 days of total fecal collection. Feces were scored on a 1–5 scale, with 1 representing liquid diarrhea and 5 representing hard pellet-like. Titanium dioxide (0.4%) was added to all diets as an external marker to estimate digestibility. Data were analyzed using orthogonal contrasts in SAS (version 9.4; SAS Institute, Inc., Cary, NC, USA). Dry bulk density of kibble decreased (P &amp;lt; 0.05), whereas kibble toughness increased (P &amp;lt; 0.05) with CFP inclusion. Fecal dry matter, dry fecal output, and defecations per day increased (P &amp;lt; 0.05) when dogs were fed increased levels of CFP. Dry matter and crude protein digestibility of CFP treatments were comparable (P &amp;gt; 0.05) to 0C. There was a decrease (P &amp;lt; 0.05) in organic matter, crude fat, gross energy, and total dietary fiber digestibility in the CFP treatments compared with 0C. A cubic relationship (P &amp;lt; 0.05) was observed in the digestibility of all nutrients except crude fat, indicating that 10C resulted in the lowest digestibility. For the palatability assessment, dogs had no preference when comparing the 5C treatment with the 0C treatment. Even with the differences in dietary treatments, inclusion of CFP at 5%, 10%, and 15% still resulted in acceptable processing parameters, kibble characteristics, and utilization when fed to dogs.

Dilution of maropitant (Cerenia) in lactated Ringer solution prolongs subcutaneous drug absorption and reduces maximum plasma concentration.

The aim of this study was to determine whether the pharmacokinetics of maropitant, administered SC as a commercially available maropitant-containing injectable product (Cerenia Injectable), differ when combined with lactated Ringer solution prior to administration. We used 6 adult spayed female Beagle dogs between 3 and 6 years of age, with a mean weight of 9.58 kg. In this randomized crossover study, the dogs underwent 2 treatment protocols separated by a 14-day washout period: (1) an SC injection of 1 mg/kg of Cerenia Injectable (maropitant citrate; 10 mg/mL) and (2) 1 mg/kg of Cerenia Injectable diluted in 10 mL/kg of lactated Ringer injectable solution (LRS) given SC. Plasma maropitant concentrations were assessed by mass spectrometry. Pharmacokinetic analysis was performed using pharmacokinetic and pharmacodynamic data-analysis software to determine maximum plasma concentration (Cmax), time to reach maximum concentration, half-life, total exposure to the drug, mean residence time, clearance rate per fraction absorbed, and absorption and elimination kinetic parameters. Cmax was reduced by 26% (P = .002), the absorption rate constant decreased 80% (P = .031), and the absorption half-life increased when Cerenia was administered diluted in LRS. Administration of maropitant (Cerenia) diluted in LRS had a pharmacokinetic impact, resulting in a significantly reduced Cmax and slower absorption. Clinical efficacy was not assessed in this study.

Shoulder magnetic resonance arthrography in dogs: Comparison of craniolateral and caudolateral approach for ultrasound-guided contrast injection.

Shoulder joint disease is a common cause of forelimb lameness in dogs. To diagnose this condition, shoulder magnetic resonance arthrography (MRA) is performed, which involves the injection of contrast agents into the shoulder joint space under ultrasound (US)-guidance. The objective of this study was to compare the craniolateral and caudolateral approaches for shoulder MRA using US-guided injection techniques, and investigate their clinical feasibility in dogs. Forty shoulder joints from 10 adult beagles were studied in two repetitions. The craniolateral (n = 20) and caudolateral (n = 20) injection techniques were applied randomly under US-guidance. The shoulder MRA was conducted immediately after the contrast agents was injected. The procedure time (scan and injection time), number of attempts, joint distension and degree of extraarticular extravasation were recorded and compared between the two groups. The results showed that the caudolateral approach had significantly more contrast agents extravasation compared to the craniolateral approach (p < 0.05). However, there were no significant differences between the two groups in terms of procedure time (scan time p = 0.80, injection time p = 0.74), number of attempts (p = 0.70) and joint distension (p = 0.23). The craniolateral approach of US-guided contrast injection techniques for shoulder MRA minimizes damage to the juxta-articular structures and reduces extraarticular extravasation, resulting in good-quality images. This study demonstrates the feasibility and advantages of the craniolateral approach under US-guidance for shoulder MRA in dogs.

The Effect of Ethyl Esters of Linseed Oil on the Changes in the Fatty Acid Profile of Hair Coat Sebum, Blood Serum and Erythrocyte Membranes in Healthy Dogs.

The aim of this study was to determine the effect of supplementation with ethyl esters of linseed oil on the fatty acid profile in hair sebum, blood serum and erythrocyte membranes in healthy dogs. The material for the study included hair and blood samples of adult beagle dogs. The experiment was performed in two periods: summer and winter. Each time it lasted 16 weeks. During the first 8 weeks, the dogs received a supplement, the amount of which was determined individually so that the ratio of α-linolenic acid (ALA) to linoleic acid (LA) together in the feed and supplement was 1:1. Hair coat and blood samples were collected on days 0, 56 and 112; i.e., before the start of supplementation, after 8 weeks of supplementation and 8 weeks after supplementation was completed. The study included a determination of the fatty acid profile with a particular emphasis on polyunsaturated fatty acids (PUFAs) and the ratio of omega-6 to omega-3 in hair sebum, blood serum and erythrocyte membranes. As a result of supplementation, a significant decrease in saturated acids and an increase in unsaturated acids was observed in hair sebum both in summer and winter and especially in omega-3 fatty acids; i.e., α-linolenic (ALA) and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The same relationships were observed in blood serum and in erythrocyte cell membranes in all the studied periods. Additionally, 8 weeks after the end of supplementation, the level of polyunsaturated fatty acids was still higher compared to the period before supplementation. Moreover, the supplementation resulted in a favorable decrease in the ratio of omega-6 to omega-3 acids in the tested samples, which persisted even after the withdrawal period.

Evaluation of a three-axial acceleromyography monitor in dogs compared with mechanomyography

ObjectiveTo compare the ratio of the train-of-four (TOF) and double burst stimulation (DBS) obtained with three-axial acceleromyography (AMG) and mechanomyography (MMG) in dogs during recovery from a rocuronium-induced neuromuscular block. Study designProspective, randomized, experimental study. AnimalsA total of six intact healthy adult male Beagle dogs, weighing 9.1 ± 1.9 kg and aged 3–5 years. MethodsDogs were anesthetized with intravenous (IV) dexmedetomidine and propofol, and isoflurane in oxygen. Neuromuscular function was measured with AMG and MMG in the contralateral thoracic limbs. Rocuronium (0.5 mg kg–1) was administered IV, and the TOF and DBS ratios measured. During neuromuscular block offset, MMG values were recorded when AMG first reached ratios of 0.9 and 1.0. True recovery from neuromuscular block was determined as MMG ratio ≥ 0.9. The false-positive (AMG ≥ 0.9 or 1.0, and MMG ratio < 0.9) rate was determined. Paired values were compared, and bias and limits of agreement were calculated. Receiver operating characteristic (ROC) curves were created. ResultsWhen AMG first reached 0.9 and 1.0 during recovery, MMG values were lower (p < 0.040). When AMG reached 0.9, the false-positive rate was 29% with TOF and 27% with DBS. It decreased to 12% (TOF) and 11% (DBS) when a ratio of 1.0 was used. AMG values were higher than paired MMG values (p < 0.001). The AMG overestimated MMG by 24% and 22% for TOF and DBS, respectively. Areas under the ROC curves (95% confidence interval) were 0.91 (0.89, 0.94) and 0.86 (0.81, 0.94) for TOF and DBS, respectively. Conclusionsand clinical relevance The three-axial AMG monitor overestimated neuromuscular function and, in some cases, indicated adequate recovery despite the MMG ratio being < 0.9. A TOF or DBS ratio of at least 1.0 should be considered when monitoring recovery of neuromuscular block with this AMG device.

Protection of laryngeal mucosa and function in laryngeal burns by heat absorption of perilaryngeal tissue.

The laryngeal tissue carries most of the heat during inhalation injury. This study aims to explore the heat transfer process and the severity of injury inside laryngeal tissue by horizontally studying the temperature rise process at various anatomical layers of the larynx and observing the thermal damage in various parts of the upper respiratory tract. The 12 healthy adult beagles were randomly divided into four groups, and inhaled room temperature air (control group), dry hot air of 80°C (group I), 160°C (group II), and 320°C (group III) for 20min, respectively. The temperature changes of the glottic mucosal surface, the inner surface of the thyroid cartilage, the external surface of the thyroid cartilage, and subcutaneous tissue were measured every minute. All animals were immediately sacrificed after injury, and pathological changes in various parts of laryngeal tissue were observed and evaluated under a microscope. After inhaling hot air of 80°C, 160°C and 320°C, the increase of laryngeal temperature in each group was ΔT = 3.57 ± 0.25°C, 7.83 ± 0.15°C, 11.93 ± 0.21°C. The tissue temperature was approximately uniformly distributed, and the difference was not statistically significant. The average laryngeal temperature-time curve showed that the laryngeal tissue temperature in group I and group II showed a trend of "first decrease and then increase", except that the temperature of group III directly increased with time. The prominent pathological changes after thermal burns mainly concluded necrosis of epithelial cells, loss of the mucosal layer, atrophy of submucosal glands, vasodilatation, erythrocytes exudation, and degeneration of chondrocytes. Mild degeneration of cartilage and muscle layers was also observed in mild thermal injury. Pathological scores indicated that the pathological severity of laryngeal burns increased significantly with the increase of temperature, and all layers of laryngeal tissue were seriously damaged by 320°C hot air. The high efficiency of tissue heat conduction enabled the larynx to quickly transfer heat to the laryngeal periphery, and the heat-bearing capacity of perilaryngeal tissue has a certain degree of protective effect on laryngeal mucosa and function in mild to moderate inhalation injury. The laryngeal temperature distribution was in accordance with the pathological severity, and the pathological changes of laryngeal burns provided a theoretical basis for the early clinical manifestations and treatment of inhalation injury.

Probiotic characteristics and whole-genome sequence analysis of Pediococcus acidilactici isolated from the feces of adult beagles.

The beneficial effects of lactic acid bacteria are well known and recognized as functional foods that are health benefits for companion animals. This study, for the first time, reports the probiotic properties, safety, and whole-genome sequence of Pediococcus acidilactici GLP06 isolated from feces of beagles. In this study, candidate probiotic bacteria P. acidilactici GLP02 and GLP06 were morphologically characterized and tested for their antimicrobial capacity, tolerance to different conditions (low pH, bile salts, an artificial gastrointestinal model, and high temperature), antibiotic sensitivity, hemolytic activity, cell surface hydrophobicity, autoaggregation activity, and adhesion to Caco-2 cells. P. acidilactici GLP06 showed better probiotic potential. Therefore, P. acidilactici GLP06 was evaluated for in vivo safety in mice and whole-genome sequencing. The results showed, that the supplemented MG06 group (1010 cfu/mL), GLP06 was not only nontoxic to mice, but also promoted the development of the immune system, improved resistance to oxidative stress, and increased the diversity of intestinal microorganisms and the abundance of Lactobacillus. Whole-genome sequencing showed that P. acidilactici GLP06 was 2,014,515 bp and contained 1,976 coding sequences, accounting for 86.12% of the genome, with no drug resistance genes and eight CRISPR sequences. In conclusion, the newly isolated canine-derived P. acidilactici GLP06 had good probiotic potential, was nontoxic to mice and promoted the development of immune organs, improved the biodiversity of the intestinal flora, and had no risk of drug-resistant gene transfer, indicating that P. acidilactici GLP06 can be used as a potential probiotic for the prevention and treatment of gastrointestinal diseases in companion animals.

Tolerability and pharmacokinetics of intravenous allopregnanolone with and without midazolam pretreatment in two healthy dogs.

The neurosteroid allopregnanolone (ALLO) is under investigation as a treatment for benzodiazepine-refractory status epilepticus (SE). Here we assess the cardiopulmonary safety of intravenous ALLO by itself and after a clinically recommended dose of midazolam (MDZ) in two healthy adult beagles. Each dog received ALLO (1 mg/kg, IV), and after a washout period of 2 weeks, the dog was dosed with MDZ (0.2 mg/kg, IV) followed 10 min later by ALLO. Behavioral state, vital signs, arterial blood gasses, blood chemistries, and plasma ALLO concentrations were monitored for up to 6 h after dosing. The dogs appeared sleepy but were fully responsive after both treatments. No depression of mean arterial pressure or respiratory rate was noted. Blood gas measurements failed to show evidence of drug-induced acute respiratory acidosis. Estimated maximum plasma ALLO concentrations were in the range of 1500 to 3000 ng/mL. The results indicate that intravenous ALLO can be used safely to treat benzodiazepine-refractory SE, even when administered shortly after a benzodiazepine.

Different Diet Energy Levels Alter Body Condition, Glucolipid Metabolism, Fecal Microbiota and Metabolites in Adult Beagle Dogs.

Diet energy is a key component of pet food, but it is usually ignored during pet food development and pet owners also have limited knowledge of its importance. This study aimed to explore the effect of diet energy on the body condition, glucolipid metabolism, fecal microbiota and metabolites of adult beagles and analyze the relation between diet and host and gut microbiota. Eighteen healthy adult neutered male beagles were selected and randomly divided into three groups. Diets were formulated with three metabolizable energy (ME) levels: the low-energy (Le) group consumed a diet of 13.88 MJ/kg ME; the medium-energy (Me) group consumed a diet of 15.04 MJ/kg ME; and the high-energy (He) group consumed a diet of 17.05 MJ/kg ME. Moreover, the protein content of all these three diets was 29%. The experiment lasted 10 weeks, with a two-week acclimation period and an eight-week test phase. Body weight, body condition score (BCS), muscle condition score (MCS) and body fat index (BFI) decreased in the Le group, and the changes in these factors in the Le group were significantly higher than in the other groups (p < 0.05). The serum glucose and lipid levels of the Le and He groups changed over time (p < 0.05), but those of the Me group were stable (p > 0.05). The fecal pH of the Le and He groups decreased at the end of the trial (p < 0.05) and we found that the profiles of short-chain fatty acids (SCFAs) and bile acids (BAs) changed greatly, especially secondary BAs (p < 0.05). As SCFAs and secondary BAs are metabolites of the gut microbiota, the fecal microbiota was also measured. Fecal 16S rRNA gene sequencing found that the Me group had higher α-diversity indices (p < 0.05). The Me group had notably higher levels of gut probiotics, such as Faecalibacterium prausnitzii, Bacteroides plebeius and Blautia producta (p < 0.05). The diet-host-fecal microbiota interactions were determined by network analysis, and fecal metabolites may help to determine the best physical condition of dogs, assisting pet food development. Overall, feeding dogs low- or high-energy diets was harmful for glucostasis and promoted the relative abundance of pathogenic bacteria in the gut, while a medium-energy diet maintained an ideal body condition. We concluded that dogs that are fed a low-energy diet for an extended period may become lean and lose muscle mass, but diets with low energy levels and 29% protein may not supply enough protein for dogs losing weight.

Selected biomarkers of oxidative stress in healthy Beagle dogs: A preliminary study.

While oxidative stress has been studied in pathologic conditions in dogs, data in presumably healthy dogs and standardized protocols are lacking. This work purposed to bridge the gap by presenting provisional physiological ranges for oxidative stress biomarkers in a group of Beagle dogs. Based on our long-standing clinical expertise in the field of oxidative stress, nine plasma biomarkers of oxidative stress were evaluated for their concentrations (mean ± SD) in 14 healthy adult Beagle dogs. Selected biomarkers were: vitamins C (7.90 ± 1.36 μg/mL) and E (34.1 ± 6.63 μg/mL), zinc (0.80 ± 0.17 mg/L), copper (0.54 ± 0.048 mg/L), selenium (256 ± 25.7 μg/L), total and oxidized glutathione (822 ± 108 μM and 3.56 ± 1.76 μM), myeloperoxidase (67.4 ± 56.2 ng/mL), and isoprostanes (340 ± 95.3 ng/mL). Glutathione peroxidase activity and superoxide anion production in whole blood were also measured. Glutathione peroxidase activity was 473 ± 34.0 IU/g of hemoglobin and superoxide anion production in whole blood was 18,930 ± 12,742 counts per 30 min. Reduced glutathione/oxidized glutathione and copper/zinc ratios were, respectively, 280 ± 139 and 0.70 ± 0.15. Sex-related differences were recorded for zinc (p = 0.0081), copper/zinc ratio (p = 0.0036) and plasma isoprostanes (p = 0.0045). Provisional physiological norms covering 95% of our group were proposed for each biomarker and should be of interest for future studies of canine oxidative stress.