Influence of food composition on splanchnic blood flow during digestion in unsedated normal dogs: a Doppler study P. Kircher a, * , J. Lang a , J. Blum d , F. Gaschen b , M. Doherr c , C. Sieber e , L. Gaschen a a Division of Clinical Radiology, Department of Clinical Veterinary Medicine, University of Berne, Laenggassstrasse 128, 3012 Berne, Switzerland b Division of Internal Medicine, Department of Clinical Veterinary Medicine, University of Berne, 3012 Berne, Switzerland c Division of Animal Neurology, Department of Clinical Veterinary Medicine, University of Berne, 3012 Berne, Switzerland d Division of Animal Nutrition, Department of Clinical Veterinary Medicine, Institute of Animal Genetics, Nutrition and Housing, Faculty of Veterinary Medicine, University of Berne, 3012 Berne, Switzerland e Medizinische Klinik 2, Klinikum N€ urnberg Nord, 90419 N€ urnberg, Germany Accepted 11 February 2003 Abstract The effect of dietary components in gastrointestinal blood flow was investigated non-invasively in dogs. Doppler ultrasound (US) waveform analysis of the celiac artery (CA) and the cranial mesenteric artery (CMA) of eight healthy dogs was performed both in the fasting state and at 20, 40, 60 and 90 min after feeding maintenance, high protein, high carbohydrate and high fat diets. Resistive index (RI), pulsatility index (PI) and the percentage differences between measurements were calculated. In fasted dogs, the CA showed significantly (p < 0:05) lower resistance than the CMA. With all diets, post-prandial RI and PI values decreased significantly in both vessels (CA: RI ¼ )12–13%; PI ¼ )25–29%; CMA: RI ¼ )13–15%; PI ¼ )27–29% [p < 0:05]), and in all cases significantly earlier in the CA than in the CMA (p < 0:05). With all diets except high fat the maximum decrease in RI and PI was reached in the CA at 40 min and in the CMA at 60 min. High fat diets were unique in that the maximum decrease in RI and PI in the CMA occurred earlier (at 20 min) and values were slower to return to normal (p < 0:05). We conclude that Doppler US can be used in dogs to quantify significant differences in the response of splanchnic blood flow to different dietary components. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: Doppler ultrasound; Celiac artery; Cranial mesenteric artery; Diets; Gastrointestinal blood flow 1. Introduction In the 1930s, early investigators sought to improve the understanding of digestion by attempting to quan- tify splanchnic blood flow (Herrick et al., 1934). It was believed at the time that an increased flow of blood to the viscera during digestion occurred at the expense of the somatic tissues. Fronek and Stahlgren (1968) used implanted electromagnetic flow transducers and showed a significant increase in heart rate, cardiac output and arterial blood pressure during food ingestion. During digestion a significant increase in blood volume in the cranial mesenteric artery was seen whereas the blood flow in the vessels supplying the somatic tissues de- creased significantly. These early findings were later supported by other investigators using newer invasive methods in dogs (Gallavan et al., 1980; Hahnloser et al., 1970a). Various hypotheses have been presented to explain what factors might be responsible for the physiological changes in gastrointestinal blood flow during digestion. Mechanical, hormonal and neuronal influences as well as the effects of food composition and exercise have been investigated and shown (Burns and Schenk, 1969; Finke and Seifert, 1986; Hahnloser et al., 1970a; Hahnloser et al., 1970b; Qamar and Read, 1987; Sieber et al., 1991). Today, however, the vasodilatatory influence of both hormonal and neuronal control pathways on gas- trointestinal blood flow is well accepted both in the physiological as well as pathological state (Guyton, 2000). The Veterinary Journal 166 (2003) 265–272 The Veterinary Journal www.elsevier.com/locate/tvjl * Corresponding author. Tel.: +31-631-2315; fax: +31-631-2275. E-mail address: patrick.kircher@knp.unibe.ch (P. Kircher). 1090-0233/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S1090-0233(03)00049-2