Page 899 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

854 SECTION | XIV Poisonous Plants

VetBooks.ir Toxicology summer or fall or after getting caught in early snowstorms
that covered herbaceous vegetation. Hungry sheep nonse-
lectively grazed lupine pods, which are highest in alka-
H
loids, and were poisoned. Large losses have also occurred
when lupine hay harvested in the seed pod stage was fed
N
in winter. Seeds alone can be toxic to sheep at
0.25 1.5% of their body weight depending on alkaloid
composition. A few cases of poisoning occurred on young
N
plants. Losses of 80 100 sheep in multiple bands have
H
been reported during the past 5 years in Idaho and
H
Wyoming (Panter, personal communication, 2005).
O
Poisoning by lupine plants should not be confused
(3)
Anagyrine with lupinosis reported in Australia. This condition is
entirely different and is a mycotoxicosis of livestock
caused by toxins produced by the fungus Phomopsis lep-
tostromiformis, which colonizes domestic lupine stubble.
It affects livestock that graze lupine stubble and limits the
use of this animal feed in Australia.
N

H
N

N N
O
H 3 C H
(5)
(4) Coniine N
Ammodendrine (6)
Most lupine species contain quinolizidine alkaloids, a Anabasine
few contain piperidine alkaloids, and some contain both. The lupine-induced crooked calf syndrome was first
The specific alkaloids responsible for crooked calf reported in 1959 and 1960 and experimentally confirmed
syndrome are anagyrine (3), ammodendrine (4), and in 1967 (Panter et al., 1999a). Crooked calf disease
N-methyl ammodendrine. Hence, risk is based on chemi- includes various skeletal contracture-type birth defects
cal profile and the presence and concentration of these and occasionally cleft palate. The skeletal defects are sim-
teratogenic alkaloids. It is known that chemical profile ilar to an inherited genetic condition reported in Charolais
and concentration differ, resulting in changing levels of cattle. Based on epidemiologic evidence and chemical
toxicity within and between species and populations. The comparison of teratogenic and nonteratogenic lupines, the
chemical phenology has been studied in L. caudatus and quinolizidine alkaloid anagyrine was determined to be the
L. leucophyllus (Lee et al., 2007b). Total alkaloid concen- teratogen (Keeler, 1973). A second teratogen, a piperidine
tration is high in the new early growth but diluted as the alkaloid called ammodendrine found in Lupinus formosus,
plant biomass increases. Pools of total alkaloids increase was also demonstrated to cause the condition (Keeler and
during the phenological growth stages and peak at the Panter, 1989). Further research determined that the
pod stage, concentrating in the pods. The teratogenic anagyrine-containing lupines only caused birth defects in
alkaloid anagyrine appears to be an end product in the cattle and did not affect sheep or goats; however, the
biosynthetic pathway and accumulates in the floral parts piperidine-containing lupine L. formosus induced similar
and is stored in the seed. Following seed shatter, both birth defects in cattle and goats (Keeler and Panter,
concentration and pools of all alkaloids decline precipi- 1989). This led to interesting speculation about possible
tously, leaving the senescent plant relatively nontoxic. metabolism or absorption differences between cattle and
Stockmen recognize the toxicity of lupines in the fall small ruminants. Keeler and Panter (1989) hypothesized
when the pods and seeds are ripe. Historically, lupines that perhaps the cow was metabolizing the anagyrine to a
were responsible for more sheep deaths than any other complex piperidine, meeting the structural characteristics
single plant in Montana, Idaho, and Utah. Most losses determined for a teratogenic piperidine. This was sup-
occurred from hungry sheep grazing seed pods. Poisoning ported by feeding trials with other piperidine-containing
occurred following trucking or trailing bands in late plants, extracts, and pure compounds. Coniine (5),a