Pests cause seizures for pets

Not long after Jennifer Croezen applied flea and tick drops to the back of her Chihuahau, Saki, earlier this month, the dog's back began to turn red.

The next day, Saki seemed tired and lost her appetite. Ms. Croezen, a 26-year-old medical assistant, took her dog to the vet the following morning, where Saki was treated for chemical burns on her back and diagnosed with a dangerous anemia. "It makes me really mad," Ms. Croezen says. "If I would have known it could have done this to my dog, I would have never put it on her."

Central Life Sciences, manufacturer of the Bio Spot brand Spot On Flea & Tick Control used on Saki, says its product isn't responsible for the anemia. "Skin sensitivity could have been exacerbated by the presence of severe anemia which led to blistering of the skin," said Laura Petree, manager of technical services at Central Life Sciences, in a statement.

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Saki's Sickness

Some pet-owners are taking action because they believe their animals had reactions to fleas treatments applied directly to the pet's back.

An increasing number of pet owners are reporting what they believe to be harmful side effects from over-the-counter and prescription flea and tick treatments. The Environmental Protection Agency, which regulates topical pet treatments, says the number of reported incidents stemming from so-called spot-on flea and tick treatments -- drops that are applied directly to a pet's skin, usually on the back -- increased 53% to 44,263 in 2008 from the previous year. As a result of the increase, the EPA said last month that it is intensifying an evaluation of spot-on products.

Product manufacturers are required by law to pass along reported incidents to the EPA. In its advisory on the topic, the agency said it is evaluating all spot-on products and posted a list of those it is examining. The list includes products by major manufacturers such as Sumitomo Corp.'s Hartz Mountain Corp., Central Life Sciences, Bayer AG, maker of Advantage, and Merial Ltd., a joint venture between Merck & Co. and Sanofi-Aventis SA, that makes Frontline products. EPA advises consumers who buy treatments from any of these companies to read the label closely and apply the products as instructed.

Incidents reported to EPA range from skin irritation to seizures and sometimes death, the agency says. The reason for the rise in incidents is unclear, the agency says, adding that it is investigating the size of the market relative to the increase in reported incidents. "We are investigating and having discussions to learn more about the problem and will take action when we determine that it is warranted," EPA spokesman Dale Kemery said in an email.

Spot-on treatments generally kill fleas and ticks by affecting their nervous systems, and some products contain chemicals that keep flea eggs from developing. Veterinarians consider them more effective than other treatments, such as shampoos and sprays, and say their use has increased in recent years. "The market has moved dramatically toward spot-ons in the last 10 to 15 years," says Steven Hansen, a veterinary toxicologist and director of the Animal Poison Control Center at the American Society for the Prevention of Cruelty to Animals.

Manufacturers are required to submit safety and efficacy studies of their flea and tick products to the EPA before they go on the market. The EPA says safety standards are the same for brands sold at pet retailers -- such as Hartz and Bio Spot -- as they are for those that are sold at veterinary offices, like Frontline and Advantage.

Consumers who believe their pets have had reactions to spot-on treatments are increasingly questioning the products' safety. "I will never put flea and tick medication ever again on my dog," Ms. Croezen says. She says Saki is doing better, but is still taking medication for her anemia.

As spot-on treatments have grown in popularity in the past decade, online forums like HartzVictims.org and BioSpotVictims.org have popped up for people who say their pets have experienced side effects following the use of flea and tick products. The Natural Resources Defense Council, an environmental group, has a site called Greenpaws.org that advocates ways to take care of fleas without chemical treatment, such as using flea combs and washing a pet's bedding once a week.

Dr. Hansen of the ASPCA says that in general, most spot-on treatments have good safety records. He says that if used appropriately, "in healthy animals we are not going to have very many reactions." Veterinarians and manufacturers say that most of the problems they see are cases where the treatment has been misused.

Manufacturers emphasize that their treatments are safe only for the pet profile listed on the box. Product labels specify the species, age requirements and weight range of the animal to which the treatment should be applied.

One common misuse that veterinarians see is that consumers apply flea treatments meant for dogs on cats by mistake. A review of toxicity studies published in the Veterinary Journal last year concludes that cats are "most often affected by inappropriate application of the spot-on" treatments, though misuse can occur in other species.

For example, the chemical permethrin, found in spot-on treatments such as Bayer's K9 Advantix, is safe for dogs but not for cats. In cats, "it causes their nervous system to go into overdrive," says Mark Stickney, director of general surgery services at the Texas A&M College of Veterinary Medicine and Biomedical Sciences. "They can develop seizures." Dr. Stickney says he sees such cases once or twice a month in the emergency room.

Also, certain animals may be more susceptible to side effects than others, veterinarians say. If an animal is pregnant, heavily flea infested or has an illness, for instance, the owner should consult with a veterinarian before applying flea treatments.

Dr. Hansen of the ASPCA advises against applying flea powders and sprays in addition to a spot-on treatment because chemicals in different products could interact with each other. "You probably do not want to double up on these," he says.

Consumers whose pets experience unusual reactions following treatment should wash the animal with soap, unless the product label specifies otherwise, and immediately contact a veterinarian, the EPA says. They should also contact the manufacturer via the number on the product label. Manufacturers advise saving the box so that consumers can describe exactly what product was used. Companies like Central Life Sciences and Hartz say that they review complaints and decide whether to cover veterinary bills on a case-by-case basis.

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Josh Anderson for The Wall Street Journal

The chemical burn on Saki's back, which appeared soon after the dog received its spot-on treatment, continues to heal.

Sometimes pet owners and manufacturers disagree about whether the animal had a reaction to the flea treatment or if the pet had a pre-existing condition.

Richard Parsons, 64, of La Quinta, Calif., applied Hartz Advanced Care 4-in-1 Flea & Tick Drops for Dogs on his Scottish terrier Duffy in May 2007 and dropped the dog off at a kennel the next morning. He says he received a call two days later from the kennel saying that Duffy was experiencing seizures and vomiting. Duffy died the next day.

"It was a torturous, tragic, painful death," says Mr. Parsons, who believes the death resulted from the Hartz treatment. He says he believes the product should be taken off the market.

Hartz reached a different conclusion after investigating the case. The company says Duffy's illness and death was directly related to elevated sodium levels in the blood that resulted from an undiagnosed, pre-existing disease. The company says its spot-on products are safe. "You can't get a product to market without showing a high level of safety and efficacy," says Bill Ecker, Hartz's chief executive.

Write to Anjali Athavaley at anjali.athavaley@wsj.com

Printed in The Wall Street Journal, page D1