The complaint contends her gray tabby, Gumbie, became ill after eating food from an Iams Select Bites pouch in early February. Gumbie became lethargic, refused food and lost weight, she said, and a veterinarian diagnosed acute renal failure. The cat was "pet-hospitalized" and prescribed intravenous fluids.

Johnson told CNN she considers herself lucky. "Thankfully we got her to the vet in time. My cat was very ill, but there are lots of people around the country whose pets have died or been euthanized."

Since coming home, Gumbie has required a great deal of care. "It is stressful to have to stick a needle in the cat every day," said Johnson, who has had to administer daily subcutaneous fluid-and-drip injections since bringing Gumbie home.

Gumbie is likely to require medical tests and monitoring every few months, and Johnson expects this will increase her expenses considerably. She said she already has paid more than $3,000 in veterinary bills.

Johnson's attorney, Frank Jablonski of Progressive Law Group, said more than 95 people have joined the suit since it was filed, and he expects many more.

"We have all the clients we need," he said. "We wouldn't bring a lawsuit that we are not confident we will win." The lawsuit is seeking an unspecified amount of damages. Courts will have to certify the class and what venue will hear the case.

Menu Foods spokesperson Sam Bornstein declined to comment on the lawsuit but said the company has received tens of thousands of consumer inquiries and is doing its best to respond to them. "Our hearts go out to many thousands of pet owners, some of them for their losses and some for their worry," he said.

Menu Foods announced the precautionary recall March 16. The recall affects dog and cat food manufactured between December 3 and March 6, and is limited to "cuts and gravy" style pet food in cans and pouches produced at its plants in Kansas and New Jersey. The food is packaged under a wide variety of brand names.

Both the Food and Drug Administration and Menu Foods have been unable to identify the root cause of the problem, but the FDA said Tuesday that officials were focusing on a recent supply of wheat gluten as the likely culprit.