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Biomedical subjects

A M Merritt

Publications and source records attributed to A M Merritt.

At least 73 records · Page 4Linked to original sources
PubMed1980

In vitro fermentation of feces from normal and chronically diarrheal horses.

Feces from 13 healthy horses and 8 horses with chronic diarrhea were subjected to an in vetro fermentation procedure that had been developed for rumen fluid. Fermentations were conducted over 6 hours in a closed system, with and without an essential amino acid (EAA) mixture being added to the basic starch-buffer medium. The addition of EAA caused no significant difference in results of fermentation of feces from healthy horses. For diarrheic animals, there was a significant (P less than 0.01) increase in gas and total volatile fatty acids production whether EAA were present or not, and alpha-amino nitrogen was utilized in significantly (P less than 0.01) greater amounts only if EAA was present. Fermentations were repeated on feces from five of the eight diarrheal horses after they had been treated with oral iodochlorhydroxyquin for 1 week, and had shown desirable clinical response. A significant difference was not shown between pre- and posttreatment fermentations, except for decreased butyrate production. The results are consistent with the hypothesis that chronic equine diarrhea is primarily a colonic disease and indicates that colonic maldigestion may, in part, be responsible for excess fecal water.

Amino Acids, Essential↗
PubMed1980

Osmolarity and volatile fatty acid content of feces from horses with chronic diarrhea.

The concentrations of acetate (C2), propionate (C3), isobutyrate (iC4), butyrate (nC4), isovalerate (iC5), and valerate (nC5) were measured in the feces of 16 clinically normal horses and 44 horses with chronic diarrhea of at least 1-month's duration. The diarrheal horses were categorized diagnostically as: (1) no discernible clinical abnormalities other than diarrhea and in some cases, weight loss (open); (2) clinical evidence of strongyle larval migrans; and (3) Salmonella organisms recovered from the feces. Osmolarity of the feces of 14 of the normal and 15 of the sick horses also was measured. The mean concentration of C2 was significantly less (P < 0.05) in feces from horses of all diagnostic categories, whereas there was a significantly increased isobutyrate concentration (P < 0.01) in feces from horses in the open category. When individual volatile fatty acids (VFA) were expressed as percentage of total, only isobutyrate in feces from horses in the open category was significantly different (P < 0.01) from normal and was increased. Some horses were monitored sequentially for a number of weeks. Fecal VFA concentrations showed considerable variability, and a transient decrease of isobutyrate concentration was not necessarily coincidental with cessation of diarrhea. Horses responding to empirical therapy had a more stable reestablishment of a normal fecal VFA distribution. Correlation between total fecal VFA concentration and osmolarity was significant (P < 0.05) for diarrheal horses, but was not significant for normal horses.

Animals↗
PubMed1979

Fecal fat and trypsin in dogs fed a meat-base or cereal-base diet.

Fat balance studies and quantitative analysis of fecal trypsin were done on 2 groups of Beagles fed either a meat-base (8.8% fat) or a cereal-base (10.5% fat) diet. In the amount fed, the meat-base diet provided 2.5 to 3 times more fat than the cereal-base diet, yet the mean daily fecal fat output of the 2 groups was not significantly different. Thus the percentage assimilation of fat in cereal-base diet (90.0%) was significantly (P less than 0.01) lower than that in the meat-base diet (96.9%). Dietary composition made no significant difference in fecal trypsin output, although the mean output from dogs fed the meat-base diet 4 times higher than that from dogs fed the cereal-base diet.

Animals↗
PubMed1979

Determination of fecal fat and trypsin output in the evaluation of chronic canine diarrhea.

Quantitative fat and trypsin analysis was done on the feces of dogs with chronic diarrhea. The results of clinical examination, quantitative fecal analysis, and other laboratory tests permitted assignment of the dogs into one of 4 groups: (1)pancreatic exocrine insufficiency,(2)small intestinal malabsorption,(3)colitis, and(4)other nonspecific or incompletely diagnosed diarrhea. The mean 24-hour fat output was significantly higher (p less than 0.01) in dogs with malabsorption or pancreatic insufficiency than in clinically normal dogs, dogs with colitis, or dogs with nonsteatorrheic diarrheas. The mean 24-hour trypsin output with pancreatic insufficiency was significantly (P less than 0.01) lower, and in dogs with malabsorption, significantly (P less than 0.05) higher than in clinically normal dogs. Normalization of the output data for body weight enhanced the value of fat and trypsin analyses in the differentiation of pancreatic insufficiency and intestinal malabsorption from other causes of chronic canine diarrhea.

Animals↗
PubMed1978

Effects of gastrin on emptying and composition of digesta of the omasum of sheep.

Three adult sheep were prepared with a denervated pouch of fundus of the abomasum and a reentrant fistula system that connected the remaining proximal and distal portions of the abomasum. The proximal cannula of the reentrant system was close to the omasoabomasal orifice, allowing for easy collection of fluid leaving the omasum. Intravenous injection of 0.5, 1.0, or 2.0 microgram/kg/hr of synthetic human gastrin I caused a marked decrease in flow rate of fluid from the omasum. The concentration of particulate matter in the digesta was inversely related to rate of omasal outflow. An increase in acid output from the denervated abomasal pouch during gastrin injection indicated that the hormone was given at pharmacologically effective doses. Results indicate that gastrin has a modulating effect on the flow of ingesta through the ruminant forestomachs. Actual sites of action were not identified.

Animals↗
PubMed1977

Plasma clearance of [51Cr] albumin into the intestinal tract of normal and chronically diarrheal horses.

Five clinically normal, mature horses and 11 with chronic diarrhea were given 51Cr-tagged Cohn fraction V equine albumin intravenously. All urine and feces were collected separately, and blood for plasma analysis was taken periodically for 5 to 8 days after injection of the isotope. Plasma clearance of albumin into the intestinal tract of normal horses was calculated as 0.67 +/- 0.23 (SD) ml/kg of body weight/day, with 1.33 +/- 0.69% of the 51Cr dose appearing in the feces in 5 days. Of the 11 diarrheal horses, 8 had a plasma clearance of 0.49 +/- 0.21 ml/kg/day with 1.12 +/- 0.68% of the dose of 51Cr in a 5-day fecal collection, suggesting that excessive losses of plasma protein into the bowel was not a component of their intestinal disease. The 3 other diarrheal horses had a marked protein-losing enteropathy; 1 of these horses had granulomatous enteritis due to Mycobacterium avium infection; another had severe intercellular edema of small and large intestinal mucosa, cause unknown; and intestinal biopsies were not obtained from the 3rd horse. The results suggest that: (1) as with other species that have been studied, daily loss of plasma protein into the bowel of horses is small; (2) most horses with chronic diarrhea do not have protein-losing enteropathy.

Albuminuria↗
PubMed1976

Granulomatous enteritis in nine horses.

Granulomatous enteritis was diagnosed in 9 horses between 1 and 11 years of age. The complaint in all cases was persistent weight loss. Four of the horses had chronic diarrhea. Two consistent diagnostic features were hypoalbuminemia and decreased phagocytic activity of mesothelial cells in the peritoneal fluid. In 2 cases the diagnosis was confirmed by biopsy of the rectal mucosa. Remaining cases were definitively diagnosed by exploratory laparotomy and biopsy or at necropsy.

Animals↗
PubMed1976

Normal and abnormal xylose absorption in the horse.

The D-xylose absorption test was applied to clinically normal horses and to horses with signs of gastrointestinal disease. A dosage of 0.5 grams of xylose per kilogram of bodyweight was useful in detecting horses that absorbed the pentose abnormally. The clinical findings were correlated with gross and microscopic findings by biopsy and at necropsy. Gastrointestinal lesions associated with abnormal xylose absorption were classified as: 1) villous atrophy; 2) edema of the lamina propria or 3) necrosis of the lamina propria.

Animals↗
PubMed1976

Normal abomasal electromyography and emptying in sheep and the effects of intraabomasal volatile fatty acid infusion.

Electromyographic activity and emptying of the abomasum were studied in 3 sheep. Pacesetter potentials (PP), with a frequency of 6.06 +/- 0.05 (X +/- SEM) cycles/minute and propagated distally with an increased conduction velocity approaching the pylorus, were recorded from the distal 11 cm of the antrum. Spike burst and fused action potentials (AP) were superimposed on a variable percentage of PP. The aborad propagation of both types of AP was associated with abomasal emptying at the net rate of 12.61 +/- 1.38 (X +/- SEM) ml/minute. Intraabomasal infusion of 50 ml of a 300 mM solution of either acetic, propionic, or butyric acid was associated with a marked decrease in abomasal AP activity and in the emptying rate. Butyric acid was most effective, followed by propionic and acetic acids. The importance of the results in relation to the pathogenesis of left displaced abomasum (LDA) in dairy cows was noted.

Abomasum↗
PubMed1975

Differential diagnosis of diarrhoea in horses over six months of age.

Pertinent questions regarding the history of a horse with diarrhoea are listed, as are diagnostic procedures that might be included in a complete clinical work-up. For purposes of discussion, diarrhoea is regarded as "acute" or "chronic" wherein the former concerns cases where the features of the disease are severe with progressive electrolyte imbalance, dehydration, toxaemia, or other life-threatening manifestations and the latter refers to cases that have been prolonged for a month or more. Patterns of disease, including results of diagnostic techniques, are stressed. In the "acute" category, salmonellosis, haemorrhagic and oedematous colon (Colitis X), acute peritonitis, and Corynebacterium equi infection are discussed in some detail. In the "chronic" group, strongyle larval migrans, granulomatous enteritis, chronic liver disease, Corynebacterium equi infection and chronic salmonellosis are emphasized.

Acute Disease↗