Kenya government spokesman Alfred Mutua said "Kenyan kids are not so desperate as to eat dog food."
He was responding to a front-page story in the east African country's leading daily.
Kenya's Daily Nation newspaper said Christine Drummond of the Mighty Mix company in New Zealand had offered to send dog food powder to hungry children in western Kenya.
The information appeared to be coming from a New Zealand newspaper, which said Drummond had been moved to make a donation of 6000 emergency packs of dog food mixture after the daughter of a friend visited the drought-hit country.
When mixed with water, the powder would provide sustainable meals, said an article posted on the website of The Press newspaper, helping to ease a growing problem of food shortages.
"I made it out of ingredients they (children) are used to eating, so the main bulk product is corn," Drummond was quoted as saying.
"The offer was very naive and culturally insulting given the meaning of dogs in our culture"
Kenyan government spokesman
Another representative of Mighty Mix said the food would be distributed through a charity in Kenya, as a "nutritional supplement" rather then dog food, the article said.
But government spokesman Mutua said it was unacceptable.
"The offer was very naive and culturally insulting given the meaning of dogs in our culture," he said.
"We understand where she was coming from, and we appreciate, but it is culturally unacceptable."
Being called a dog is one of the worst insults in Africa where people generally do not keep dogs as pets.
The government says four million people are facing hunger in Kenya due to severe drought. Aid agencies say dozens of people and thousands of livestock have died in recent months.