On April 5, 2005, new evidence came to light demonstrating that an uncommon lamb and/or ewe-killing ailment is no longer confined to the Rocky Mountain ranges.
Lamb with Cyclopia
A case of cyclopia was identified by veterinarian Debra Visser, from the Dairyland Animal Clinic in Owen, Wisconsin, who assisted the ewe on the farm of Jim Grajkowski. Cyclopia is a deformity of lambs that results in oversized lambs with oversized heads that bear a single eye.
It occurs in rare circumstances. Until now, it was universally agreed that the cause was a ewe’s having eaten six ounces or more of a weed known as the Corn Lily (scientific name: Veratrum californicum) on the 14th or 15th day of gestation. The reason for the deformity is that on the 14th day of gestation the lamb’s ocular field normally divides into primordial.
Poisoning from the Corn Lily also can cause several other deformities, such as abnormal development or absence of the pituitary gland, which adds up to six weeks to gestation periods, killing the ewe.
Corn Lily poisoning on days 28 to 30 can cause shortening of the lamb’s metatarsal and metacarpal bones. Poisoning a little later in gestation leads to development of a closed or constricted throat passage, causing the lamb to die shortly after birth if it is born alive.
Oversize heads with a single eye are a telltale sign of Corn Lily poisoning.
The ailment is named for the legendary “Cyclops”-a race of giant, one-eyed shepherds said to have dwelt in Sicily in the writings of the Greek poet Homer.
Risk Goes Up
Until now, there has been no documentation that other species of the Veratrum family of plants poisoned sheep. Most of the poisonings occurred in southwestern Idaho, and sporadically in other areas of the western states mountains. Corn Lily is found at elevations of 5,000-11,000 feet.
Jim Grajkowski lives in Lublin, Wisconsin, which is low-lying country, with borders of sometimes soggy ground and some local swamps. He keeps about 100 head of Dorset and Polypay ewes, and has raised sheep for about 30 years. He mentioned to me that the 5-year-old Dorset ewe was quite late lambing-the last in the flock to lamb. He had let the ram out in June of last year (you know those “breed-anytime” Dorsets!) so April would have been very late.
Jim said the sheep had not been out west at any time, so they could not have been poisoned with the Corn Lily.
The species most likely to have caused the damage was a close relative of Corn Lily, the False or White Hellebore (Veratrum viride), which ranges from New Brunswick and Quebec west to Minnesota, and southward as far as Maryland (but all the way to Georgia in the uplands) and in the Pacific Northwest. One reason False Hellebore hadn’t been thought to cause the problem is that it causes a painful burning in the mouth when eaten. But we’ve all seen ewes eat wild mustard and other hot plants.
Two other species occur in dry woodlands in the southern half of False Hellebore’s eastern range, which look about the same. Keep an eye out for all Veratrum species. Veratrum can cause poisoning in non-pregnant sheep, too.
Is Your Flock At Risk?
Take a look at the illustrations of these weeds, which grow as tall as seven feet by late fall. They are one of the first plants to sprout, especially in places that are commonly muddy. They flower from May to July, with star-shaped greenish hairy flowers. Don’t let your sheep eat it