Ultrasound-guided catheterization of the portal vein in 11 cows using the Seldinger technique

Physiological parameter values for physiologically based pharmacokinetic models in food-producing animals. Part I: Cattle and swine

Physiologically based pharmacokinetic (PBPK) models for chemicals in food animals are a useful tool in estimating chemical tissue residues and withdrawal intervals. Physiological parameters such as organ weights and blood flows are an important component of a PBPK model. The objective of this study was to compile PBPK‐related physiological parameter data in food animals, including cattle and swine. Comprehensive literature searches were performed in PubMed, Google Scholar, ScienceDirect, and ProQuest. Relevant literature was reviewed and tables of relevant parameters such as relative organ weights (% of body weight) and relative blood flows (% of cardiac output) were compiled for different production classes of cattle and swine. The mean and standard deviation of each parameter were calculated to characterize their variability and uncertainty and to allow investigators to conduct population PBPK analysis via Monte Carlo simulations. Regression equations using weight or age were created for parameters having sufficient data. These compiled data provide a comprehensive physiological parameter database for developing PBPK models of chemicals in cattle and swine to support animal‐derived food safety assessment. This work also provides a basis to compile data in other food animal species, including goats, sheep, chickens, and turkeys.

Ultrasonography of the liver in cattle

Ultrasonography is a valuable tool for the diagnosis of liver disease. Discrete or diffuse lesions can be imaged, aspirated, and biopsied under visual guidance. The ultrasonographic examination of the liver is performed on the right side of the standing animal using a real-time 3.5 to 5.0 MHz linear or convex transducer. This imaging modality also can be used to aspirate bile from the gallbladder for the diagnosis of liver flukes. Ultrasonography cannot be used to evaluate liver regions obscured by the lungs, however.

Comparison of blood glucose concentrations after administration of a glucose solution via the jugular vein and portal vein in cows

The goals of the present study were to determine whether the infusion of a glucose solution into the portal vein is tolerated in cows and whether the glucose concentration differs after administration of glucose into the jugular vein and portal vein. Fifteen healthy Swiss Braunvieh cows were used. An indwelling catheter was placed in both jugular veins and a balloon-tipped indwelling catheter with a diameter of 2 mm was placed in the portal vein under the guidance of ultrasonography. Three cows received 500 ml of 20% glucose solution over 60 min via the left jugular vein. Three other cows received the same solution over 60 min via the portal vein. Blood samples were collected from the right jugular vein before and for 24 h after the infusion of glucose for the determination of the concentrations of glucose and bilirubin and the activities of glutamate dehydrogenase, sorbitol dehydrogenase and gamma-glutamyl transferase. Infusion via the portal vein did not result in abnormalities in the general condition of the cows or increases in the concentration of bilirubin or the activities of liver enzymes. The blood glucose concentration increased to the same extent after both intraportal and intrajugular infusion. Over a 12-h period, three cows received 10 l of 20% glucose solution via the left jugular vein and three others received the same solution over a 12-h period via the portal vein. Blood samples were collected from the right jugular vein before and for 30 h after the start of infusion. Infusion via the portal vein did not affect the general condition of the cows or the activities of the liver enzymes. There was no significant difference in the blood glucose concentration between the two groups throughout the study.

Development, advances and applications of diagnostic ultrasound in animals

Ultrasound has many industrial applications but it was first introduced as a medical diagnostic aid in the 1940s with its first veterinary application, the detection of ovine pregnancy, being reported in 1966. Since then, improvements in equipment quality combined with an increased awareness of the benefits of ultrasound as an imaging technique have led to its widespread use in the veterinary field. Recent advances in computer technology have significantly influenced equipment design and the miniaturization of transducers allows intra-operative and intra-vascular applications. Software advances have improved the ability to manipulate and process data, leading to an increased amount of information being obtained from each examination and the advent of 'remote diagnosis'. Ultrasound guided interventional techniques can now be used for diagnostic or therapeutic purposes. Many of these developments have been introduced by equipment manufacturers but have found specific applications in the veterinary field. Ultrasound is currently employed in a very diverse range of situations, not just as a diagnostic tool in the routine clinical workup of a range of species, but also for disease screening, conservation projects, commercial services, herd management and clinical research.