The dogs were found in far northwest suburban Deer Park.
Eldrup was charged with felony animal cruelty charges and was in custody Friday night.
The Kildeer Police Department is investigating the case since it has jurisdiction and provides police services for Deer Park.
The deadly discovery was made inside Muddy Paws Kennels and Rescue. Police say Eldrup's business has been closed for a year.
Police say the Eldrup and her husband are in the midst of a divorce.
Authorities also say the dead animals were discovered when Mr. Eldrup went to the home to collect some of his belongings.
"He opened the door and saw the condition and he immediately called us and then we went in," said Kildeer Police Chief Louis Rossi.
Friends of Diane Eldrup say she has an 8-year-old son. They say they have never noticed any problems in the past and that Eldrup has helped them with their own animals.
"She works with our horses sometimes, and she tells us how to treat them, how to take care of them.," said Bryan Costello, a friend of Eldrup. "One of the little kittens got hurt, and she fixed his paw up really good and the cat's doing fine. She knew a lot about animals and how to take care of them."
In the meantime, Kildeer police say four dogs and two cats were found alive and are now being cared for by Lake County Animal Control.
Officials hope others can learn from this situation.
"I think the most important point is that these types of situations are not situations that only happen in a specific type of community. They are universal, and when we find out about these situations we should make it known so that we can learn from them and hopefully not have them repeated," said Kildeer Village President Nandia Black.
The Building Department has also shut down that building so no one can live in it right now.
Kildeer police say they will be looking at all of the dead dogs and that some of them have chips, so they will be tracking down the owners.
Eldrup is due in court in January.