A Re‐evaluation of the D (+) Xylose Absorption Test in the Horse

Abstract

SUMMARY The absorption of d‐xylose forms the basis of a useful screening test in the investigation of small intestinal disorders in the horse. A comparison has been made of different assay methods and there was no significant difference between the results obtained with the parabromoaniline (PBA) method or the ferric chloride‐orcinol (FCO) method. The orthotoluidine method was unsatisfactory. The anticoagulant agent did not affect the test. A dose of 0.5 g commercial grade xylose/kg body weight as a 10 per cent solution given by stomach tube, produced a peak plasma xylose level after 90 min and should discriminate normal from abnormal absorption. The FCO method was preferred for the occasional test performed in practice, and a 2‐hour sampling period would be adequate. RÉSUMÉ L'absorbtion du D xylose, constitue la base utile d'un test permettant d'apprécier les troubles de l'intestin grěle chez le cheval. Une comparaison est faite des différentes méthodes et les RÉSultats obtenus ne diffèrent point d'une fačon significative lorsqu'on utilise la méthode de para‐bromoaniline et celle du chlororcinol ferrique. La méthode à l'orthotoluidine ne fut pas satisfaisante. L'anticoagulant utilisé ne modifia point les RÉSultats. Le xylose à raison de 0,5 gramme par kilo de poids vif, est administréà la sonde naso‐oesophagienne. On obtient un niveau maximum de xylose dans le plasma apRÉS 90 minutes, ce qui permet d'apprécier les anomalies d'absorption. Le test au chlororcinol ferrique a paru plus adaptéà la pratique. ZUSSAMMENFASUNG Die Absorption der D‐Xylose kann als nützlicher Screening‐Test bei der Untersuchung von Dünndarmstörungen beim Pferd verwendet werden. Es wurde ein Vergleich angestellt zwischen verschneidenen Bestimmungsmethoden; es fand sich keine signifikante Differenz zwischen den Resultaten, die erhalten wurden mit der Parabromanilin‐Methode oder mit der Ferrichlorid Orcinol‐Methode. Die Orthotoluidinmethode dagegen erwies sich als unbefriedigend. Das verwendete Coaguans beeinträchtigte den Test nicht. Eine Dosis von 0,5 g Xylose pro Kilogramm Körpergewicht in einer 10%igen Lösung wird durch die Nasen‐schlundsonde eingegeben; 90 Minuten nach der Gabe wird der Gipfel der Plasmakonzentration erreicht, was die Unterscheidung einer normalen von der abnormalen Absorption erlaubt. Die FCO‐Methode wurde für einen gelegentlich in der Praxis durchzuführenden Test bevorzugt, wobei eine 2stündige Entnahmeperiode genügen dürfte.

Dietary fibre in dogs diet: comparisons between cellulose, pectin, guar gum, and between two incorporation rates of guar gum

“…Plasma xylose concentrations were determined by Autoanalyzer (Tarrytown, NY, USA) colorimetry using the ferric chloride‐orcinol technique (R oberts and N orman 1979). The dry matter, ash and ether extract in the feed and faeces were analysed by standard methods (AOAC 1975).…”

Quantitation of Intestinal D-Xylose Absorption in Normal Turkeys

“…Turkey plasma D-xylose concentrations following oral administration of D-xylose (.5 g/kg body weight) most closely resemble those seen in normal humans (Wolfish et al, 1955;Dawson, 1965), are lower than values commonly observed in dogs (Hill et al, 1970), but are greater than those seen in cattle (Pearson and Baldwin, 1981) and horses (Roberts, 1974;Bolton et al, 1976;Roberts and Norman, 1979). Variation between individual xylose absorption curves, regardless of species, suggests that results obtained from testing a single animal could be difficult to interpret.…”

“…The plasma D-xylose test has been used in the study of intestinal malabsorption in dogs (Hill et al, 1970;Hill and Kelly, 1974), horses (Roberts, 1974;Bolton et al, 1976;Roberts and Norman, 1979;Dietz, 1981), cattle (Mavromichalis et al, 1977;Woode et al, 1978;Pearson and Baldwin, 1981), and cats (Merritt, 1980;Emms et al, 1983), but not in fowl. In animals, determination of percent xylose recovered in urine is severely limited by problems associated with prolonged urine collection periods (8 hr in man) and the fact that not all animals produce urine that can be readily collected or separated from feces (birds, reptiles, fish).…”

Clinical Approach to Commonly Encountered Problems

“…160,619 Although the plasma concentration of glucose may reflect glucose metabolism as well as absorption from the gastrointestinal tract, the assay is reliable in the diagnosis of significant malabsorptive conditions. Absorption tests are used primarily in horses with chronic diarrhea or weight loss to evaluate the small intestinal absorptive capacity.…”