The 2009 H1N1 influenza virus has claimed the life of another pet, the American Veterinary Medical Association (AVMA) said today.

The virus is now blamed for the deaths or illnesses of at least 11 pets nationwide, including four ferrets and seven cats, the AVMA said. In every case, the pets' owners had flu-like symptoms before the animals became sick.

The latest confirmed pet death linked to the virus is a 12-year-old cat in Pennsylvania, which died in early November. The domestic shorthair developed a respiratory illness on November 3 after four members in the household became sick with flu-like symptoms, the AVMA said. The cat then became lethargic, lost its appetite, and had difficulty breathing.

X-rays taken by the veterinarian revealed the cat had pneumonia. Nasal samples from the cat tested negative for H1N1, but samples taken during a necropsy tested positive for the virus, the AVMA said.

Iowa health officials in November confirmed the first case of H1N1 in a pet -- a 13-year-old indoor cat in Iowa. Since then, the AVMA has tracked cases of the virus in animals.

Tracking the virus

Among the findings of the AVMA's investigation:

• An 8-year-old female cat in Oregon died from H1N1 on November 24, according to Oregon's public health veterinarian. The cat's owner had previously tested positive for the virus. When the cat arrived at the veterinarian's office, the AVMA said, she was hypothermic, dehydrated, weak, and had nasal discharge and blue-tinged mucous membranes. X-rays revealed the cat had severe pneumonia and fluid in her chest, the AVMA said. A nasal sample taken from the cat tested positive for the H1N1 virus.

• The week of December 7, France confirmed that a cat in that country tested positive for the virus. Health officials said the cat developed a respiratory illness shortly after two children in the household became ill. The cat recovered in six days.

• On December 4, Colorado health officials confirmed two cats from different households in that state tested positive for H1N1. Veterinarians suspect the cats, ages 10 and 11, became sick after someone in their households contracted the virus. The cats are now recovering. "These cases serve as a reminder to pet owners to seek veterinary attention as soon as possible if their pet seems ill," said veterinarian Kristy Pabilonia, an expert on H1N1 testing in animals at Colorado State University.

• In November, preliminary tests for H1N1 on a California cheetah came back positive. Final tests are pending. "There are no reported cases of Influenza A: H1N1 (2009-H1N1) transmission from animals to humans in a zoological setting," the The Association of Zoos and Aquariums (AZA) said. "Animal collections at zoological institutions, therefore, do not present a concern for public health."

• The United States Department of Agriculture (USDA) in November confirmed the H1N1 virus in Virginia turkeys. A worker had previously been sent home with flu-like symptoms. USDA officials said the turkeys were still safe to eat. That case marked the first time heath officials had confirmed the virus in U.S. turkeys. Officials had previously confirmed H1N1 in domestic turkeys in Canada and Chile.

• On November 28, published reports in China stated two dogs in Beijing tested positive for the H1N1 virus. The AMVA said there are no confirmed reports at this time of H1N1 in dogs in the United Sates. But there is another bug, the H3N8 influenza (canine influenza) virus, that targets U.S. dogs, the AVMA said. At present, the H3N8 virus has only spread among canines, the AVMA said. Dogs infected with the canine influenza virus have such symptoms as fever, lethargy, loss of appetite, and coughing.

• Oregon's public health veterinarian said a cat in that state died on November 7 from an H1N1 infection. The cat became sick shortly after a child in the household had flu-like symptoms. Three other cats in the household became sick, but have since recovered. Tests revealed those three cats were not infected with the virus.

• Utah health officials in November confirmed a cat in Park City had contracted the H1N1 virus. The cat's owner had previously been sick with flu-like symptoms, but is now recovering.

• Pigs in the United States, Finland, Indonesia, and Taiwan have also tested positive for H1N1, the AVMA said. The organization said it would continue to track cases of H1N1 in animals and post its findings on its Web site.

What you can do

• What measures can pet owners take to protect their animals and prevent the spread of this virus? recently posed that question to Dr. Ann Garvey, a veterinarian with the Iowa Department of Public Health. Garvey recommended the following:

• Wash your hands frequently.

• Cover your mouth when you cough and your nose when you sneeze.

• Minimize your contact with your dogs, cats, or other household pets if you have any flu-like symptoms.

• Pet owners who notice any signs of respiratory illness or other influenza-like symptoms in their animals should contact their veterinarians, Dr. Garvey said.