Human cases of a rare type of salmonella illness have caused the state Department of Health to issue a warning to pet owners.

The health department says 21 cases of the illness in Pennsylvania residents might be linked to dry dog food and advises using safe-buying and handling practices.

The illness being investigated by the health department is caused by an uncommon strain of salmonella called schwarzengrund. Most of the infections occurred in households with pets or where people are in close contact with pets, but there is no evidence any human consumed pet food.

"While the department is working very closely with federal investigators to identify a specific cause and source for these illnesses, it is important that pet owners understand and follow steps to prevent salmonella infection from occurring," state Health Secretary Dr. Calvin B. Johnson said.

Many of the salmonella cases linked to the strain have occurred in infants and young children, who are particularly vulnerable to infection.

Salmonellosis is a bacterial infection affecting the intestinal tract, according to the health department. It also can affect the bloodstream and other organs. It is one of the most common causes of gastroenteritis, the symptoms of which may include diarrhea and vomiting.

After infection, onset of illness usually occurs in 24 to 72 hours. Patients typically recover in five days to a week, the health department said. Patients may recover without treatment unless they become severely dehydrated from diarrhea or the infection spreads from the intestines, in which case antibiotics may be needed.

The health department recommends the following to reduce risk of infection:

• Purchase canned or bagged products with no signs of damage to the packaging, including dents, tears or discolorations.



• If possible, feed pets in an area other than the kitchen.



• Before and after feeding pets food and treats, wash hands for 20 seconds with hot water and soap.



• Wash pet bowls and scooping utensils with soap and hot water after each use. If possible, don't wash them in a kitchen sink, or properly sanitize the sink area after pet-food dishes are cleaned and removed.



• Don't use a pet's feeding bowl to scoop food. Instead, use a clean, dedicated scoop.



• Throw away old or spoiled pet food in a safe manner — in a securely tied plastic bag in a covered trash receptacle.



• Don't store or handle pet food in areas where human food is prepared because it increases the chance of cross-contamination.



• Promptly refrigerate or discard leftover wet pet food to prevent growth of most harmful bacteria. Set refrigerators at 40 degrees Fahrenheit and periodically check a refrigerator's temperature setting.



• Store dry pet food and treats in a cool, dry place that's less than 80 degrees.



• Store dry pet food in its original bag inside a clean plastic container with a lid, keeping the top of the bag folded closed.



• Keep pets away from food-storage and preparation areas.



• Keep pets away from garbage and household trash.

E-mail: slindt@lnpnews.com