Large intestinal nutritional and physicochemical parameters from different dog sizes reshape canine microbiota structure and functions in vitro

Different dog sizes are associated with variations in large intestinal physiology including gut microbiota, which plays a key role in animal health. This study aims to evaluate, using the CANIM-ARCOL (Canine Mucosal Artificial Colon), the relative importance of gut microbes versus physicochemical and nutritional parameters of the canine colonic environment in shaping microbiota structure and functions. CANIM-ARCOL was set up to reproduce nutrient availability, bile acid profiles, colonic pH, and transit time from small, medium, or large dogs according to in vivo data, while bioreactors were all inoculated with a fecal sample collected from medium size dogs (n = 2). Applying different dog size parameters resulted in a positive association between size and gas or SCFA production, as well as distinct microbiota profiles as revealed by 16S Metabarcoding. Comparisons with in vivo data from canine stools and previous in vitro results obtained when CANIM-ARCOL was inoculated with fecal samples from three dog sizes revealed that environmental colonic parameters were sufficient to drive microbiota functions. However, size-related fecal microbes were necessary to accurately reproduce in vitro the colonic ecosystem of small, medium, and large dogs. For the first time, this study provides mechanistic insights on which parameters from colonic ecosystem mainly drive canine microbiota in relation to dog size. The CANIM-ARCOL can be used as a relevant in vitro platform to unravel interactions between food or pharma compounds and canine colonic microbiota, under different dog size conditions. The potential of the model will be extended soon to diseased situations (e.g. chronic enteropathies or obesity).

Canine Mucosal Artificial Colon: development of a new colonic in vitro model adapted to dog sizes

Differences in dog breed sizes are an important determinant of variations in digestive physiology, mainly related to the large intestine. In vitro gut models are increasingly used as alternatives to animal experiments for technical, cost, societal, and regulatory reasons. Up to now, only one in vitro model of the canine colon incorporates the dynamics of different canine gut regions, yet no adaptations exist to reproduce size-related digestive parameters. To address this limitation, we developed a new model of the canine colon, the CANIne Mucosal ARtificial COLon (CANIM-ARCOL), simulating main physiochemical (pH, transit time, anaerobiosis), nutritional (ileal effluent composition), and microbial (lumen and mucus-associated microbiota) parameters of this ecosystem and adapted to three dog sizes (i.e., small under 10 kg, medium 10-30 kg, and large over 30 kg). To validate the new model regarding microbiota composition and activities, in vitro fermentations were performed in bioreactors inoculated with stools from 13 dogs (4 small, 5 medium, and 4 large). After a stabilization period, microbiota profiles clearly clustered depending on dog size. Bacteroidota and Firmicutes abundances were positively correlated with dog size both in vitro and in vivo, while opposite trends were observed for Actinobacteria and Proteobacteria. As observed in vivo, microbial activity also increased with dog size in vitro, as evidenced from gas production, short-chain fatty acids, ammonia, and bile acid dehydroxylation. In line with the 3R regulation, CANIM-ARCOL could be a relevant platform to assess bilateral interactions between food and pharma compounds and gut microbiota, capturing inter-individual or breed variabilities. KEY POINTS: • CANIM-ARCOL integrates main canine physicochemical and microbial colonic parameters • Gut microbiota associated to different dog sizes is accurately maintained in vitro • The model can help to move toward personalized approach considering dog body weight.

Outcomes and complications of prophylactic incisional gastropexy in 766 dogs (2009-2019)

OBJECTIVE

To report the outcomes and complications associated with prophylactic incisional gastropexy performed in dog breeds at risk for GDV.

RESULTS

Seven hundred and sixty-six dogs underwent prophylactic incisional gastropexy of which 61 were electively performed at the time of castration or spay and 705 were adjunctively performed at the time of emergency abdominal surgery. All dogs had short-term follow-up, and 446 dogs (58.2%) had additional follow-up with a median long-term follow-up time of 876 days (range 58-4450). Only 3 dogs (0.4%) had a direct complication associated with the gastropexy site including hemorrhage causing hemoabdomen (2) and infection with partial dehiscence (1). No dogs with long-term follow-up experienced gastric dilatation (GD), gastric dilatation volvulus (GDV), or persistent GI signs following gastropexy. Results of this study found that complications directly associated with prophylactic gastropexy were rare and limited to hemorrhage causing hemoabdomen and infection with partial dehiscence. Transient postoperative GI signs may occur. Gastropexy malpositioning and bowel entrapment were not encountered. There was no occurrence of GD or GDV.

Comparison of total laparoscopic gastropexy with the Ethicon Securestrap fixation device versus knotless barbed suture in dogs

BACKGROUND

This study evaluated the feasibility and efficacy of a laparoscopic absorbable fixation device (Securestrap) in total laparoscopic gastropexy in dogs susceptible to gastric dilatation-volvulus (GDV) compared to laparoscopic gastropexy performed with a barbed suture. We hypothesised that both techniques provide suitable gastropexy.

METHODS

The gastropexy was performed by straps (TLG-SS group, n = 6) or with a barbed suture (TLG-Vloc group, n = 6). The total surgery time, gastropexy time, the number of straps used and suture bites were recorded. Clinical and ultrasound investigations were performed during follow-up.

RESULTS

The total surgery time was 30 minutes in the TLG-SS, while it was 46.66 minutes in the TLG-Vloc. In the TLG-SS group, gastropexy time was 13 minutes, while 36.3 minutes in the TLG-Vloc. The number of straps employed in TLG-SS was 9, while seven bites were employed in TLG-Vloc. Linear regression analysis of gastropexy time versus the number of procedures was highly correlated (r² = 0.84) in the TLG-SS. Complications, clinical and ultrasound findings did not differ between the two techniques at 90 days post-surgery.

CONCLUSION

TLG-SS laparoscopic technique can be employed safely and effectively in less time and is associated with a relatively short learning curve, which could encourage the widespread use of prophylactic laparoscopic gastropexy.

Absorbable fixation straps for laparoscopic gastropexy in dogs

OBJECTIVE

To evaluate the feasibility and efficacy of laparoscopic absorbable fixation straps (AFS) for laparoscopic gastropexy in dogs.

STUDY DESIGN

Cadaveric and prospective clinical study.

ANIMALS

Five dog cadavers for the cadaveric study; 12 dogs for the clinical study.

METHODS

The pyloric antrum was affixed to the abdominal wall laparoscopically by applying a series of straps. The cadaveric study assessed potential challenges during the procedure and stomach mucosal penetration. For the clinical study, the total duration of surgery, time to complete the gastropexy, and the number of straps used were recorded. Ultrasound evidence of adhesion, complications, and weight were monitored at 7, 30, and 90 days after surgery. Owner satisfaction was evaluated at the 6-month follow-up.

RESULTS

The total duration of surgery was 25.8 minutes (range, 19-39; SD, 6.7), and the time to complete the gastropexy was 10.1 minutes (range, 7-19; SD, 3.9). The linear regression analysis revealed an inverse correlation between the time to complete the gastropexy and the order of the surgeries (r²  = 0.75, P < .05). No complications were recorded. Ultrasound examination was used to confirm gastropexy at all follow-ups.

CONCLUSION

Laparoscopic gastropexy with AFS was performed in both cadavers and clinical animals with minimal complications. Persistent adhesion was demonstrated during ultrasound evaluations and in one postmortem evaluation.

CLINICAL SIGNIFICANCE

This novel laparoscopic technique can be employed safely, effectively, and reasonably quickly, and the learning curve is expected to be relatively short.

Biomechanical evaluation of an absorbable fixation strap for use in total laparoscopic gastropexy in dogs

OBJECTIVE

To compare load-to-failure results for laparoscopic absorbable fixation straps (AFSs) deployed at various angles and for AFSs versus absorbable knotless (barbed) suture when used in simulated total laparoscopic gastropexy (TLG) in specimens from cadaveric dogs.

SAMPLE

30 stomach and abdominal body wall specimens.

PROCEDURES

Specimens were assigned to 1 of 3 groups for use in simulated TLG constructs for comparisons of load-to-failure results for single AFSs deployed at 30°, 60°, or 90° (AFS-angle group; n = 10) or for a gastropexy span of 4 to 5 cm achieved with 3-0 absorbable knotless (barbed) monofilament suture applied in a simple continuous pattern (TLG-1; 10) versus 8 AFSs applied with a deployment angle > 30° (TLG-2; 10). A 1-way ANOVA was used to compare results among AFS deployment angles (30°, 60°, or 90°) and between TLG-1 and TLG-2.

RESULTS

Mean ± SD load to failure for the AFS-angle group was significantly higher for the AFS deployment angles of 60° (8.00 ± 3.90 N) and 90° (12.71 ± 8.00 N), compared with 30° (5.17 ± 1.90 N). However, no substantial difference was detected in the mean ± SD load to failure for TLG-1 (39.18 ± 7.1 N) versus TLG-2 (31.43 ± 10.86 N).

CONCLUSIONS AND CLINICAL RELEVANCE

Results of the present study supported the potential use of AFSs in gastropexy in dogs; however, prospective clinical research with adequate long-term follow-up is warranted before recommendations can be made.

Effect of Laparoscopic-assisted Gastropexy on Gastrointestinal Transit Time in Dogs

Background

Prophylactic gastropexy has been promoted as a means of preventing gastric volvulus during gastric dilatation and volvulus (GDV) syndrome. Little is known about the impact of gastropexy on gastrointestinal transit time.

Hypothesis

Laparoscopic‐assisted gastropexy (LAG) will not alter gastrointestinal transit times when comparing gastric (GET), small and large bowel (SLBTT), and whole gut transit times (TTT) before and after surgery.

Animals

10 healthy client‐owned large‐breed dogs.

Methods

Prospective clinical trial. Before surgery, all dogs underwent physical examination and diagnostic evaluation to ensure normal health status. Dogs were fed a prescription diet for 6 weeks before determination of gastrointestinal transit with a wireless motility capsule. LAG was then performed, and dogs were fed the diet for 6 additional weeks. Measurement of transit times was repeated 6 weeks after surgery.

Results

Ten dogs of various breeds at‐risk for GDV were enrolled. No complications were encountered associated with surgery or capsule administration. There were no significant differences in GET 429 [306–1,370] versus 541 [326–1,298] (P = 0.80), SLBTT 1,243 [841–3,070] versus 1,540 [756–2,623] (P = 0.72), or TTT 1,971 [1,205–3,469] versus 1,792 [1,234–3,343] minutes (median, range) (P = 0.65) before and after LAG.

Conclusions and Clinical Importance

An effect of LAG on gastrointestinal transit time was not identified, and wireless motility capsule can be safely administered in dogs after LAG.