Bovine and Equine Umbilical Ultrasound G. Dykstra March 24, 2010

Bovine Umbilicus 2 umbilical arteries Allantoic stalk (urachus) 2 umbilical veins anastomose within the body wall

Equine Umbilicus 2 umbilical arteries Allantoic stalk (urachus) 1 umbilical vein

After Parturition

vein → round ligament of liver arteries → round ligament of bladder urachus → atrophies Fetal Structure Destiny

If things go wrong… Omphalitis Omphalophlebitis Omphaloarteritis Omphalourachitis Umbilical hernia Patent urachus Remember, even if the external umbilicus looks normal there is could still be an infection!

Preparation Standing +/- sedation Hair clip 4 cm width Xiphoid to prepuce/udder Umbilicus to inguinal ring 7.5-MHz transducer Calves are clipped more on the RIGHT side

Foal Anatomy

Umbilical Vein Calves Travels more to RIGHT side cranially May need left lateral recumbency Largest diameter near stalk intraabdominally Atrophies over time in calves Foals Scan on ventral midline Little change for first month

Calf External Umbilicus VU = Umbilical Vein US = Umbilical Stalk

Calf Umbilical Vein at Liver VU = Umbilical Vein LI = Liver VP = Portal Vein

Foal Anatomy

Umbilical Arteries & Urachus Calves Scanned adjacent to the bladder Arteries end abruptly near apex of bladder Urachus not visualized Foals Scanned near bladder Arteries outline the urachus at bladder apex Urachus not really well defined

Foal Anatomy

Foal Umbilical Arteries & Urachus

But what does it all mean? Calf abnormality Vein > 1.5 – 2.5 cm diameter Artery > 1 cm diameter Visualizing the urachus Foal abnormality Vein > 1 cm diameter Artery > 1.3 cm diameter Combined urachus and arteries > 2.5 cm diameter

Mean diameter (mm) of umbilical structures in clinically normal calves over time from birth Location24 hours1 wk2 wk3 wk Umbilical stalk24.67 ± ± ± ± 3.78 Vein within stalk9.61 ± ± ± 1.52n/a Vein near stalk17.67 ± ± ± ± 4.56 Vein at midpoint11.22 ± ± ± ± 2.44 Vein near liver10.44 ± ± ± ± 2.83 Arteries10.33 ± ± ± ± 1.03 Watson E, Mahaffey MB et.al Am J Vet Res, 55(6);

Calf Umbilical Stalk

Calf Infected Umbilical Vein Immediately Cranial to Umbilicus

Calf Infected Umbilical Vein 10 cm Cranial and Right of Umbilicus

Calf Umbilical Vein - Saggital

Calf Urachal Abscess