The Biology of the Goat Laboratory

How to do your own fecal exams


oocytes under low power

Under low power (about 80X), the image above shows debris and oocytes.
A points to strongylid types of oocytes, B and C are Moniezia species
D points to oocytes of Strongyloides papillosus which are identifiable
by the already developed larvae coiled inside..

strongylid oocytes

The image shows eggs from common species of worms at the same magnification, 300X.

Images adapted from Ross and Gordon, The Internal Parasites and Parasitic Diseases of Sheep).

eimeria oocystsThe image represent 3 oocysts of a species of Eimeria approximately compared in size to a Haemonchus contortus oocyte. While the oocysts of different species of Eimeria vary in size they are approximately 1/2 to 1/3 the size of the large H. contortus oocyte.

Liver fluke eggs are large, almost twice the size of H. contortus but usually you will not see liver fluke eggs in a flotation. The fluke egg has a cap on the end of the egg which opens to allow the young larvae to escape. This cap opens in the flotation solution causing the egg to sink. Rarely, you may see an empty fluke egg with a visibly open cap on the end.

Lung worm eggs hatch in the intestine. A different technique is required to see the larvae in the feces.

Veterinary Parasitology by William J. Foreyt has good photos and covers life cycles and treatments for parasites found in most species of domestic animals.

View animations of the life cycles of these and other parasites that infect goats.