Tea tree, or Melaleuca alternifolia oil, does have toxic potential, depending on the circumstances of exposure. Clinical effects that may occur following dermal exposure to significant amounts of tea tree oil include loss of coordination, muscle weakness, depression, and possibly even a severe drop in body temperature, collapse and liver damage. If the oil is ingested, potential effects include vomiting, diarrhea and, in some cases, seizures. If inhalation of the oil occurs, aspiration pneumonia is possible.
When it comes to flea control, we always recommend that pet owners consult with their veterinarian to get advice on the proper product to use, based on the individual pet's species, age, size and health history. Additionally, reading the label first and following the product’s directions exactly are key in helping to avoid any potentially problematic situation.