If an animal has eaten this plant, the ASPCA Animal Poison Control Center is (888) 426-4435, as printed on the record this page reproduces. A consultation fee may apply.
This page quotes a published document. Everything below in quotation marks is copied word for word from ASPCA Animal Poison Control Center: Rosebay, published by ASPCA APCC and retrieved on 2026-09-16. The quotations are excerpts; the document itself is linked and is the authority. Nothing has been reworded.
According to the ASPCA Animal Poison Control Center record, Rosebay (Rhododendron spp, family Ericaceae) is toxic to dogs, cats and horses. Toxic principles: Grayantoxin. Clinical signs listed: Vomiting, diarrhea, hypersalivation, weakness, coma, hypotension, CNS depression, cardiovascular collapse and death. Ingestion of a few leaves can cause serious problems. Rhododendron is typically not very palatable to horses unless it is the only forage available, but sheep and goats may graze readily on the plant. The toxic principle interferes with normal skeletal muscle, cardiac muscle and nerve function. Clinical effects typically occur within a few hours after ingestion, and can include acute digestive upset, excessive drooling, loss of appetite, frequent bowel movements/diarrhea, colic, depression, weakness, loss of coordination, stupor, leg paralysis, weak heart rate and recumbency for 2 or more days; at this point, improvement may be seen or the animal may become comatose and die. The record was retrieved on 2026-09-16 and is linked below.
The record
- Scientific name
- Rhododendron spp
- Family
- Ericaceae
- Additional common names
- Rhododendron, Azalea
- Toxicity
- Toxic to Dogs, Toxic to Cats, Toxic to Horses
- Toxic principles
- Grayantoxin
- Clinical signs
- Vomiting, diarrhea, hypersalivation, weakness, coma, hypotension, CNS depression, cardiovascular collapse and death. Ingestion of a few leaves can cause serious problems. Rhododendron is typically not very palatable to horses unless it is the only forage available, but sheep and goats may graze readily on the plant. The toxic principle interferes with normal skeletal muscle, cardiac muscle and nerve function. Clinical effects typically occur within a few hours after ingestion, and can include acute digestive upset, excessive drooling, loss of appetite, frequent bowel movements/diarrhea, colic, depression, weakness, loss of coordination, stupor, leg paralysis, weak heart rate and recumbency for 2 or more days; at this point, improvement may be seen or the animal may become comatose and die.
Where this comes from
This is the ASPCA Animal Poison Control Center record for Rosebay, at https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/rosebay, retrieved on 2026-09-16. The fields above are the record’s own, shown without change. The ASPCA keeps the record current; the page here is a copy from that date.
This page is information, not a prescription. The right dose for an animal depends on its weight, its age, what else it is taking and what is wrong with it. Those are judgements only the veterinarian who has examined your animal can make. Ring your practice before giving anything.
Sources
- ASPCA Animal Poison Control Center: RosebayASPCA APCC · retrieved 2026-09-16
“Vomiting, diarrhea, hypersalivation, weakness, coma, hypotension, CNS depression, cardiovascular collapse and death. Ingestion of a few leaves can cause serious problems. Rhododendron is typically not very palatable to horses unless it is the only forage available, but sheep and goats may graze readily on the plant. The toxic principle interferes with normal skeletal muscle, cardiac muscle and nerve function. Clinical effects typically occur within a few hours after ingestion, and can include acute digestive upset, excessive drooling, loss of appetite, frequent bowel movements/diarrhea, colic, depression, weakness, loss of coordination, stupor, leg paralysis, weak heart rate and recumbency for 2 or more days; at this point, improvement may be seen or the animal may become comatose and die.” (Clinical Signs)
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