The herb Lavandula angustifolia or Lavandula officinalis "Lavender" originates from the mountains of the Mediterranean and now grows throughout the warmer regions of the world. The shrub grows to about 24 inches in height and produces woody branches with green, leafy shoots. The plant has leaves covered with a silvery down and small, violet-blue flowers that grow in vertical groups of 6 to 10.
Your cat's contact with the lavender plant most likely will not affect its skin, but ingesting the plant could lead to an adverse reaction in your pet. Lavender contains a number of active chemical compounds including benzenoids and flavonoids, and a certain number of these compounds have sedative or anesthetizing effects that could harm your cat.
Humans occasionally have allergic reactions to lavender because of its effect on the central nervous system. Cats also can experience allergic reactions, and the ingestion of large quantities of lavender or prolonged contact with the plant may trigger this type of reaction. An allergic reaction to lavender in your cat can include itching, which could lead to hair loss and open sores.
Avoid applying any undiluted essential oils, including lavender, on your cat. Essential oils get absorbed through the skin and metabolized by the liver. Cats are unable to metabolize certain compounds, and the use of these oils could cause a build-up of toxic waste in the cat's body and result in liver damage.