Ramaria flavo-brunnescens is found exclusively in eucalyptus
woods in North America, Australia, Brazil, and Uruguay, and is easily identified
from the spore print color of pale buff to brownish yellow. It is reported to be
poisonous to ruminants (cattle and sheep). The toxin is an unknown, volatile
compound or compounds found throughout the plant that is reported to interfere
with sulfur-containing amino acid incorporation. Drying decreases
Signs may appear as early as 3 days but as long as 6
days after exposure and include anorexia, diarrhea, salivation,
hyperthermia, depression, hyperemic coronary band, hemorrhage (anterior
chamber of eyes), oral ulceration, altered keratinization (hair/hoof loss,
similar to selenium poisoning), and recumbency. Death or recovery may be
expected in 3–15 days.
These mushrooms grow exclusively among eucalyptus
plants, so history of exposure to eucalyptus is key. Selenium exposure and
toxicity causes similar signs. The duration and outcome of the clinical
expression helps to confirm diagnosis.
Treatment involves removing the affected animal from
the source and offering supportive care. Recovery requires time.
Paxillus involutus has a dry or slimy, brownish cap with an
in-rolled margin and yellowish gills descending a short distance on the brown,
smooth stalk. The spore print is clay-brown. P involutus is
widely distributed in North America. It may appear singly or in groups of
several, near or on wood in mixed woods in the spring/autumn. The toxin is
unknown, but it may cause hypersensitivity over time, leading to kidney
Vomiting, diarrhea, cardiovascular irregularity, and
RBC destruction may be noted 1–3 hr after ingestion. Recovery generally
takes 2–4 days but could be longer. Acquired sensitivity develops over
Diagnosis and Treatment
A diagnosis can be made based on mushroom
identification, consistent clinical signs, and response to supportive care.
Treatment involves symptomatic and supportive measures.
Last full review/revision August 2014 by Cecil F. Brownie, DVM, PhD, DABVT, DABFE, DABFM, FACFEI