Characterization of the digestive tract of wild ayu

ABSTRACT: The gut and gut contents of ayu Plecoglossus altivelis caught in the Ohta River in Hiroshima prefecture, Japan were examined. Relative intestine length (intestine length/body length) was almost constant. Except for relative intestine length, characteristics of the gut of wild ayu were not significantly different from those of cultured ayu. The height of intestinal folds increased and their width declined from stomach to anus. Cyanobacteria ( Homoeathrix sp. and Calothrix sp.) and diatoms ( Cymbella sp., Gomphonema sp., Melosira sp., Navicula sp., and Synedra sp.) were well digested during passage through the gut despite a lack of apparent destruction. In contrast, green algae ( Dictyosphearium sp., Coelastrum sp., and Pediastrum sp.) exhibited little degradation. The pH of stomach contents ranged from 2.8 to 7.4 (mean ± SD = 4.1 ± 1.0), whereas that of the posterior intestine was 7.0–8.5 (7.9 ± 0.4). Gut contents of wild ayu increased with bodyweight, and were more than threefold greater than those of cultured ayu, suggesting that wild ayu compensate for low nutrient content of algae through the continuous ingestion of large quantities of feed organisms.     

A Comparison of Laparoscopic and Belt-Loop Gastropexy in Dogs

A simplified technique for laparoscopic gastropexy (group 1) was compared to belt-loop gastropexy (group 2) in eight adult male dogs randomly divided into two groups of four dogs each. Our hypothesis was that a satisfactory laparoscopic gastropexy would approximate the strength and operative time required for belt-loop gastropexy. Operative time, surgical complications, postoperative morbidity, gross and histological appearance, radiographic microvascularization, and maximal tensile strength were measured and compared between the two groups. All dogs recovered from surgery. No morbidity was associated with either procedure. The mean (±SD) duration of surgery was 69.75 ± 7.23 minutes for group 1 and 58.75 ± 7.63 minutes for group 2. Fifty days after surgery, the microvascular appearance of the gastropexy site was similar for both groups. Blood vessels were observed within each seromuscular flap but vascular ingrowth to the abdominal musculature was observed in only two dogs, one from each group. The maximum tensile strength at 50 days was 76.55 ± 22.78 for group 1 and 109.21 ± 22.29 N for group 2. Differences between surgical duration and maximum tensile strength were not statistically significant ( P >.05). Histologically, all gastropexies consisted of an adhesion composed of dense fibrous connective tissue. The results of this study indicate that laparoscopic gastropexy provides a minimally invasive alternative to open abdominal prophylactic gastropexy in dogs.     

A Procedure for Permanent Tracheostomy and Its Effects on Tracheal Mucosa

Permanent tracheostomies were performed on six dogs which were evaluated clinically and histologically. One dog had abnormal tracheal cartilages and died following tracheal collapse three days postoperatively. Problems with coughing, swallowing, and infection were not noted in the remaining five dogs. The exposed tracheal epithelium temporarily underwent squamous metaplasia but returned to a relatively normal appearance within 16 weeks.     

The Effects of Implant Orientation, Canal Fill, and Implant Fit on Femoral Strain Patterns and Implant Stability During Catastrophic Testing of a Canine Cementless Femoral Prosthesis

Cementless femoral stems were placed into 12 normal greyhound femora. The implanted femora were divided into three groups by stem orientation and implant size and loaded in axial compression at a rate of 25 newtons (N) per second until failure. Rosette strain gauges were used to measure femoral principal strains at 500 N, 1,000 N, 1,500 N, and at maximum load. During maximum load, varus orientation of the femoral stem had significantly higher tensile hoop strains in the proximomedial cortex, whereas neutral orientation had higher tensile hoop strains along the cranial cortex. Femoral fractures occurred in these areas of peak tensile strain. There was no difference in maximum load between groups, therefore varus orientation did not predispose to fracture. Maximizing canal fill and implant fit increased implant stability.     

Comparison of Aerobic Culturette, Synovial Membrane Biopsy, and Blood Culture Medium in Detection of Canine Bacterial Arthritis

Canine joints were cultured 24 hours after inoculation with Staphylococcus intermedius using synovial membrane biopsy, synovial fluid on aerobic culturette and in blood culture medium, and synovial fluid incubated 24 hours in blood culture medium before being cultured. A mildly virulent strain consistently yielded positive cultures when incubated in blood culture medium 24 hours and negative cultures with the other techniques. A highly virulent strain also yielded positive cultures when incubated in blood culture medium 24 hours, which was significantly better than synovial membrane biopsy. When both strains were considered together there was no significant difference between the first three techniques; blood culture medium incubated 24 hours was significantly more reliable. These results suggest that the trauma of synovial membrane biopsy is not justified because synovial fluid culture is more reliable. Synovial fluid should be placed on an aerobic culturette and in blood culture medium, and the samples cultured immediately upon arrival at the laboratory to allow the most rapid results of culture and antibiotic sensitivity testing. The blood culture medium should be recultured after 24 hours of incubation to permit culture and antibiotic sensitivity testing of those samples (approximately 50%) that have no growth on initial culture.