Queensland health authorities have warned parents of the dangers of treating children with pet products after a child became sick from an animal treatment.

Chief Health Officer Jeannette Young said the warning came after a child became sick from a pet flea and tick product, applied to cure head lice.

Queensland Health would not release details of the child because of privacy guidelines, but said poisons contained in pet treatments had serious side-effects if used on people.

"Animal products are poisons and are not safe for human use," Dr Young said.

"There are often serious side-effects, including nose and throat irritations, respiratory conditions, vomiting, dizziness and abdominal pain.

"The effects can be even more serious for young children or women who are pregnant and breastfeeding."

She said parents must exercise common sense when treating their children and use a lice comb or specially formulated shampoos and conditioners.