April 2014

Downer calves

Two 6-month-old, male, red angus with a 6-week history of lethargy, weight loss, and progressive weakness were found down, and died a week later. Previous blood work was negative for Anaplasma and leukemia. Fecal flotations were positive for Trichostrongyle eggs, with egg per gram counts of 8,650 and 10,550. 

At necropsy, abomasal contents contained numerous nematodes:

Microscopic examination of the posterior end of a male:

Microscopic examination of the anterior end an adult:

What is your diagnosis?

Clinical case and photos provided by Dr. Eileen Johnson and Becky Duncan-Decocq, Oklahoma Animal Disease Diagnostic Laboratory, Oklahoma State University

Answer

These are Haemonchus sp adults. Haemonchus spp., commonly known as the barber's pole worm, feed on blood in the abomasum. In fresh necropsy samples, the blood-filled gut of female worms can be seen intertwined with the ovaries, giving them a barber's pole or candy cane appearance. The blood-feeding from the adult Haemonchus can lead to anemia and loss of productivity, and in animals with large numbers of adults feeding in the abomasum, death.