Sand impaction of the small intestine in eight dogs

Objective : To describe signalment, clinical findings, imaging and treatment of intestinal sand impaction in the dog. Methods : Medical records of dogs with radiographic evidence of small intestinal sand impaction were reviewed. Results : Sand impaction resulting in small intestinal obstruction was diagnosed in eight dogs. All dogs presented with signs of vomiting. Other clinical signs included anorexia, lethargy and abdominal pain. Radiographs confirmed the presence of radio-opaque material consistent with sand causing distension of the terminal small intestine in all dogs. Four dogs were treated surgically for their impaction and four dogs were managed medically. Seven of the eight dogs survived. Clinical Significance : Both medical and surgical management of intestinal sand impaction in the dog can be effective and both afford a good prognosis for recovery.     

仔猪小肠肌间神经丛中神经元数量的定量测定

自1921年Langley提出“肠道神经系统”(enteric nervous system，ENS)这一概念以来，肠道神经系统对肠道运动的控制和功能调节的重要性已日益引起人们的注意。国内外学者对ENS的形态结构、神经元的性质等做了广泛而深入的研究。不过从现有资料看，有关猪的ENS资料较少。     

Activities of gastric,pancreatic, and intestinal brush-border membrane enzymes during postnatal development of dogs

OBJECTIVE: To measure activities of digestive enzymes during postnatal development in dogs. SAMPLE POPULATION: Gastrointestinal tract tissues obtained from 110 Beagles ranging from neonatal to adult dogs. PROCEDURE: Pepsin and lipase activities were measured in gastric contents, and amylase, lipase, trypsin, and chymotrypsin activities were measured in small intestinal contents and pancreatic tissue. Activities of lactase, sucrase, 4 peptidases, and enteropeptidase were assayed in samples of mucosa obtained from 3 regions of the small intestine. RESULTS: Gastric pH was low at all ages. Pepsin was not detected until day 21, and activity increased between day 63 and adulthood. Activities of amylase and lipase in contents of the small intestine and pancreatic tissue were lower during suckling than after weaning. Activities of trypsin and chymotrypsin did not vary among ages for luminal contents, whereas activities associated with pancreatic tissue decreased between birth and adulthood for trypsin but increased for chymotrypsin. Lactase and gamma-glutamyltranspeptidase activities were highest at birth, whereas the activities of sucrase and the 4 peptidases increased after birth. Enteropeptidase was detected only in the proximal region of the small intestine at all ages. CONCLUSIONS AND CLINICAL RELEVANCE: Secretions in the gastrointestinal tract proximal to the duodenum, enzymes in milk, and other digestive mechanisms compensate for low luminal activities of pancreatic enzymes during the perinatal period. Postnatal changes in digestive secretions influence nutrient availability, concentrations of signaling molecules, and activity of antimicrobial compounds that inhibit pathogens. Matching sources of nutrients to digestive abilities will improve the health of dogs during development.     

Postnatal development of nutrient transport in the intestine of dogs

OBJECTIVE: To measure nutrient absorption by the intestine during postnatal development of dogs. ANIMAL: 110 Beagles ranging from neonatal to adult dogs. PROCEDURE: Rates of absorption for sugars (glucose, galactose, and fructose), amino acids (aspartate, leucine, lysine, methionine, and proline), a dipeptide (glycyl-sarcosine), and linoleic acid by the proximal, mid, and distal regions of the small intestine were measured as functions of age and concentration (kinetics) by use of intact tissues and brush-border membrane vesicles. Absorption of octanoic acid by the proximal portion of the colon was measured in intact tissues. RESULTS: Rates of carrier-mediated transport by intact tissues decreased from birth to adulthood for aldohexoses and most amino acids but not for fructose and aspartate. Kinetics and characteristics of absorption suggest that there were changes in the densities, types, and proportions of various carriers for sugars and amino acids. Saturable absorption of linoleic acid in the small intestine and octanoic acid in the proximal portion of the colon increased after weaning. CONCLUSIONS AND CLINICAL RELEVANCE: Rates of absorption decreased between birth and adulthood for most nutrients. However, because of intestinal growth, absorption capacities of the entire small intestine remained constant for leucine and proline and increased for glucose, galactose, fructose, aspartate, and proline but were less than predicted from the increase in body weight. Although postnatal ontogeny of nutrient absorption was consistent with changes in the composition of the natural and commercial diets of growing dogs, rates of amino acid and peptide absorption were lower than expected.     

Early postnatal development of central corneal thickness in dogs

Objective To investigate the changes in corneal thickness that occur during maturation of the canine eye over the first months of life. Animals studied Dogs of two different breeds with ages ranging from 14 days to 42 weeks of age. Procedures The central corneal thickness was measured by ultrasonic pachymetry every week for the first month after eyelid opening (around 14 days) and then every month until 42 weeks of age. Segmented regression was applied to capture the two phases observed in the central corneal thickness plotted against age. Breed, eye and gender were also included in the model. Results Mean central corneal thickness (CCT) values initially decreased following eyelid opening, with the lowest point being reached at around 6 weeks of age. Then CCT gradually increased as the dogs matured. Differences between left and right eye were not significant. Breed and gender effects were significant factors in the statistical model. Conclusions Following eyelid opening there is an initial decrease in corneal thickness until approximately 6 weeks of age, which presumably mirrors maturation of corneal endothelial cell function. After 6 weeks of age the CCT increases with age until approximately 30 weeks of age after which there was only a gradual increase over the remainder of the study period. A similar pattern of changes in corneal thickness in humans has been previously recorded.     

Prevalence and identification of fungal DNA in the small intestine of healthy dogs and dogs with chronic enteropathies

Limited information is available about the prevalence and phylogenetic classification of fungal organisms in the gastrointestinal tract of dogs. Also, the impact of fungal organisms on gastrointestinal health and disease is not well understood. The aim of this study was to evaluate the prevalence of fungal DNA in the small intestine of healthy dogs and dogs with chronic enteropathies. Small intestinal content was analyzed from 64 healthy and 71 diseased dogs from five different geographic locations in Europe and the USA. Fungal DNA was amplified with panfungal primers targeting the internal transcriber spacer (ITS) region. PCR amplicons were subjected to phylogenetic analysis. Fungal DNA was detected in 60.9% of healthy dogs and in 76.1% of dogs with chronic enteropathies. This prevalence was not significantly different between the two groups (p=0.065). Fungal DNA was significantly more prevalent in mucosal brush samples (82.8%) than in luminal samples (42.9%; p=0.002). Sequencing results revealed a total of 51 different phylotypes. All sequences belonged to two phyla and were classified as either Ascomycota (32 phylotypes) or Basidiomycota (19 phylotypes). Three major classes were identified: Saccharomycetes, Dothideomycetes, and Hymenomycetes. The most commonly observed sequences were classified as Pichia spp., Cryptococcus spp., Candida spp., and Trichosporon spp. Species believed to be clinically more important were more commonly observed in diseased dogs. These results indicate a high prevalence and diversity of fungal DNA in the small intestine of both healthy dogs and dogs with chronic enteropathies. The canine gastrointestinal tract of diseased dogs may harbor opportunistic fungal pathogens.     

Developmental changes in morphometry of the small intestine and jejunal sucrase activity during the first nine weeks of postnatal growth in pigs

The objective of this study was to investigate the development of small intestinal size and digestive capacity of the jejunum in growing pigs. The weight, length, surface area, and mucosa weight of the small intestine were measured when pigs were 1, 3, 5, and 9 wk of age. Sucrase and alkaline phosphatase (ALP) activities of the jejunal brush-border membrane, prepared by differential centrifugation and Mg2+ precipitation, were determined at the respective postnatal stages. Body weights increased 7-fold from 2.7 kg at 1 wk to 23.32 kg at 9 wk postnatal. Body weight gains were greater (P < 0.05) from wk 3 to 5 than from wk 1 to 3. Weights of the small intestine and of the intestinal mucosa increased faster (P < 0.05) from 3 to 5 wk than from 1 to 3 wk; the slowest increase occurred from 5 to 9 wk. Weights of the duodenum, jejunum, and ileum, and mucosa from the respective sections increased (P < 0.05) as pigs grew from 3 to 9 wk. Mucosa weight relative to the weight of the section was greater (P < 0.05) for the duodenum and jejunum than for the ileum at 9 wk of age. Between the ages of 3 and 9 wk, the increase in mucosa weight was highest for the jejunum followed by the duodenum and the ileum. The increase was greatest for the duodenum followed by the jejunum and the ileum when mucosal weight was expressed per unit of appropriate intestinal section weight. There was a 55-fold increase in jejunal sucrase activity from 1 to 9 wk; the greatest rate of increase occurred between 5 and 9 wk. Total jejunal ALP activities in pigs at 9 wk was greater (P < 0.05) than at 5 wk, which in turn was greater than at 1 wk of age. In summary, increases in BW during the first 9 wk of postnatal growth in pigs are accompanied by significant developmental changes in digestive capacity including intestinal weights, length, and area as well as jejunal brush-border sucrase and ALP activities.     

The early postnatal pattern of vesicle formation in different regions of the porcine small intestine

In the early postnatal period, the permeability of the piglet small intestine is high to compensate for the absence of trans-placental transfer of immunoglobulins during the fetal period. Vesicles, which mainly reflect the uptake of macromolecules and other colostral/milk components, were studied in three different regions of the small intestine – proximal, mid and distal – in a total of twelve piglets on day 0 (unsuckled and colostrums-fed), 2 and 6 (all suckled). Tissues were sampled and prepared for light microscopy (paraffin and cryo) and trans-electron microscopy. Different methods were applied to visualize cytoplasmatic subcellular components such as fat (Oil red O) and carbohydrates (PAS). Appearance and morphology of the epithelial vesicles were compared.

In the proximal region several small supranuclear and a single large subnuclear electron dense, eosinophilic and PAS+ vesicle were present. They disappeared after 2 days (gut closure) and on day 6 adult-looking epithelial cells were present. In the distal region of day 0 pigs digestion vesicles/flocculent vesicles were observed in the cytoplasma. The vesicles appeared empty but with eosinophilic, PAS+ and electron dense precipitations. The size and variation of these vesicles increased with age. Fat absorption increased markedly from day 2 to day 6.

The observations indicate that in general colostral absorption processes are initiated prenatally, persist after birth and in the distal region also after gut closure. Fat absorption increased after gut closure, and in the distal region the increase correlated with e.g. IgG absorption.     

Development of Sarcocystis alceslatrans Dubey, 1980, in the small intestine of dogs

Laboratory-reared dogs were fed moose musculature infected with Sarcocystis alceslatrans. These dogs shed sporocysts [15.6 X 11.4 microns (14.4 to 15.8 X 10.8 to 11.5)] 11 to 15 days after inoculation. The prepatent period was 10 to 14 days. Two cats and 1 coyote that also ate infected moose musculature did not pass sporocysts. Histologic examination of intestinal tissue from experimentally infected dogs revealed microgamonts, macrogametes, and oocysts. All stages were present in the lamina propria of the small intestine, usually in the luminal third of the villi. Infections were concentrated in the proximal half of the small intestine. Oocysts were first noticed in dogs killed 7 days after inoculation and a sequence of sporogonic development occurred in dogs killed on subsequent days. Ultrastructural observations were made on the oocyst and sporocyst walls during sporogony.     

Comparison of skin staples with sutures for anastomosis of the small intestine in dogs

OBJECTIVES: To develop a technique for approximation of end-to-end intestinal anastomoses by using a disposable skin stapler and to compare the stapling technique with an interrupted hand-sewn approximating end-to-end anastomosis of the canine jejunum. STUDY DESIGN: In vitro evaluation of the stapling technique, followed by an in vivo study of healing and clinical response in dogs. ANIMAL POPULATION: 18 mixed-breed adult dogs. METHODS: The anastomotic technique was developed and tested in fresh canine jejunum. Fourteen stapled approximating anastomoses (SAA) and 14 hand-sewn approximating anastomoses (HAA) were performed in 6 cadavers under simulated surgical conditions. Anastomotic construction times, initial bursting strengths, initial lumen diameters, and gross appearance of the 2 techniques were compared. Healing and clinical response were evaluated in 12 purpose-bred dogs assigned to 2 groups of 6 animals each. Each dog had 1 SAA and 1 HAA performed in the jejunum, 50 cm apart. Six dogs were killed on postoperative day 4, and 6 dogs were killed on postoperative day 21. Anastomotic construction time, gross and histological healing, bursting strength, lumen diameter, and circumference were compared between techniques. RESULTS: Mean construction time for SAA was significantly faster than for HAA (P = .0001). None of the anastomoses leaked, and there were no major clinical complications in any dog. Bursting strengths were not significantly different at any time for the 2 techniques. Initial bursting strength was 31% to 35% of the normal jejunum. A nonsignificant decrease in bursting strength was observed by postoperative day 4 (26% to 28% of normal), and a significant increase in bursting strength was observed by postoperative day 21 (100% to 109% of normal). Neither technique decreased the initial lumen diameter. However, both techniques resulted in a similar degree of luminal stenosis as the anastomoses healed. Anastomotic lumen diameter was significantly decreased from normal in both groups at day 4 (86% to 88% of normal) and day 21 (90% to 91% of normal). There was no significant difference between the circumference of the anastomoses and normal jejunum at any time. Histological analysis showed similar healing for the hand-sewn and stapled techniques at 4 and 21 days after surgery. For both surgical techniques, day 21 anastomoses had significantly less inflammation and necrosis, significantly more fibrosis, and significantly better continuity of histological layers when compared with day 4 anastomoses. CONCLUSION: Approximating end-to-end intestinal anastomosis with a skin stapler is equivalent in bursting strength, lumen diameter, lumen circumference, and healing characteristics to the traditional hand-sewn technique, but it can be performed in significantly less time. CLINICAL RELEVANCE: Skin stapling devices can be used to create technically simple, rapid, and safe end-to-end anastomoses in canine jejunum.     

Differences in the development of the small intestine between gnotobiotic and conventionally bred piglets

The effects of age, weaning and breeding conditions on the small intestinal morphology and the distribution of immunocompetent cells were investigated. The villus height and numbers of CD3+ T-lymphocytes, measured in the duodenum, jejunum and ileum, were determined in both the gnotobiotic and conventionally bred piglets. The diet of gnotobiotic piglets was composed of milk-replacement and feed mixtures. The application of milk replacement was finished on day 28. Conventional piglets were fed on sow's milk and feed mixtures. The animals were weaned on day 28. Small intestines were collected from 12 conventional and 12 gnotobiotic piglets slaughtered at the age of 2, 7, 14, 21, 28 and 35 days. The morphology results demonstrated that duodenal and ileal villi were significantly higher (p < 0.001) in gnotobiotic piglets during the entire period of the experiment. However, the weight of conventional piglets was higher during the experiment, in some cases significantly (p < 0.05). A marked reduction, in some cases significant (p < 0.001, p < 0.01 respectively), of the villi height on day 7 after the diet change for both groups of animals was recorded. The results demonstrate the differences in the gut development between both groups and their relationship to the breeding conditions. Nevertheless, the effect of crucial diet changes was observed independently of them. The immunohistochemistry results showed significantly (p < 0.001, p < 0.01 respectively) higher numbers of CD3+ T-lymphocytes in the jejunal villi of conventionally bred piglets. Similar results, in some cases significant (p < 0.001, p < 0.01 respectively), were also obtained from the other parts of the small intestine. These observations confirm reduced microorganism exposure under the gnotobiotic conditions.     

父母代固始鸡小肠的生长发育规律

应用大体解剖学技术,对0～20周龄父母代固始鸡小肠的生长发育进行了研究。结果表明,鸡小肠的长度、质量、周长等指标随周龄的增加而增长;小肠相对生长率和小肠指数则呈下降趋势;通过建立Logistic方程模型模拟小肠质量的生长变化,得到其生长方程：♂∶Y=37.95/（1＋18.35e^-0.35t）,♀∶Y=31.49/（1＋13.63e^-0.31t）     

Renal excretion of drugs during postnatal development in piglets

The renal excretion of organic acids involves three mechanisms: glomerular filtration, active tubular secretion and passive tubular reabsorption. The postnatal development of each of these mechanisms was assessed in piglets. From birth to 8 weeks of life glomerular filtration rate (GFR) and clearance of p-amino-hippurate (PAH) rose twofold while the maximal tubular secretion of PAH (Tm_PAH) rose fourfold. Thus, the active secretion increased in parallel with GFR when the transport mechanism was unsaturated, whereas it increased about twofold more than GFR at saturation point. Age differences in the passive reabsorption were evaluated by using sulphachlorpyridazine (SCP) as test substance. Although the renal handling of SCP includes both secretion and reabsorption, the age-dependent rise in the ratio between clearance of ultrafiltrable SCP and GFR indicated a relative decrease in reabsorption with age.     

Xanthine oxidase formation during experimental ischemia of the equine small intestine.

We hypothesized that xanthine oxidase plays a role in the postischemic reperfusion injury in the equine small intestine. Under anesthesia, four horses and two ponies underwent ischemic strangulating obstructions of segments of the proximal jejunum, mid-jejunum and ileum. Prior to vascular occlusion, and at 1 h and 2 h of ischemia, full-thickness intestinal biopsies were collected for histopathological evaluation and for determination of combined xanthine dehydrogenase (XDH) plus xanthine oxidase (XO) activity, and XO activity alone. The level of XO activity was expressed in percentage according to the ratio of XO/(XDH + XO). We found a nearly threefold increase in the combined level of XDH plus XO activity from ileum to duodenum (p less than 0.04). However, the preischemic level of % XO activity did not vary significantly (p = 0.61) between segments of jejuno-ileum. Likewise, no significant difference was noted between intestinal segments after ischemia. Therefore, the data from all intestinal segments were pooled for each time and analyzed using Wilcoxon's signed rank test (one-tailed). Compared to the pre-ischemic level of % XO activity (median 27%), the % XO activity increased after 1 h of ischemia (median 37.0%), reaching statistical significance (p = 0.016). There were no statistical differences between the preischemic % XO activity and the % XO activity in non-ischemic bowel at the end of the anesthetic period. During ischemia, % XO activity increased, which lends credence to the importance of xanthine oxidase in previously-documented reperfusion injury in the equine small intestine.