The aim of this study was to determine the evacuation of sand from the equine intestine after a double treatment with psyllium and mineral oil or just mineral oil in a cross over study design. Twelve healthy horses were fed one kg sand daily from day one to five.
Subsequently the horses were divided into group A and B. From day six to ten both groups were treated with two litre mineral oil once daily and group B additionally received 0.5 kg psyllium semen. The trial was repeated after a wash out period of two weeks with treatment swap of group A and B. The horses were housed sand free and hay was offered to meet the requirement.
Prior the sand administration, faeces were collected from each horse for 3 days and the crude ash was analysed for establishing the baseline output of the crude ash.
The horses were auscultated for sand noises twice a day and abdominalultrasound was perormed before and after sand administration. On the first day of treatment 25g of Chrom (III)-oxid were administered to determine the gastro intestinal transit time.
There was no difference between the baseline crude ash output of the 1st and 2nd treatment. From day six to ten, total amount of faeces was collected daily, weighed and the crude ashes determined. Sand and psyllium were mixed with one litre of mash and offered. Mineral oil was administered via nasogastric tube.
All horses showed higher crude ash excretion when treated with psyllium and mineral oil compared treatment with mineral oil. On the 2nd, 3rd and 4th day of treatment the differences were significant. Faeces crude ash weight minus the baseline crude ash output for psyllium plus oil treatment and oil solely reached a mean of 43 (SD 25.5) and 38 (SD 22,2) % of the administered sand mass, respectively. There were high individual differencesof the crude ash masses between the horses.
Detection of Sand by auscultation of the colonwas possible but false negative results appeared. Ultrasonography patterns of the abdomen before sand administration did not show recognizable differences to Ultrasonography patterns after the sand administration.
Chrome (III)-oxide recovery out of the faeces was between 31 and 84 %.
No conclusions about the transit time could be drawn as the Chrome (III)-oxide detection with photometry did not lead to reliable results due to the large amount of faeces and inherent losses of menure.
The results of this trial strongly suggest that psyllium semen used with mineral oil does increase the speed of sand evacuation of the equine intestine.