A Libby veterinarian is concerned about the impact a recent change in rat poison may have on pet owners.

Doug Griffiths of Treasure Valley Veterinary Clinic says a new ingredient in rodenticides has no antidote, no antemortem test, is more expensive to treat than previous ingredients and is more toxic to pets.

The new ingredient, bromethalin, is a neurotoxin that leads to swelling of the brain. Bromethalin has largely replaced long-acting anticoagulants after the Environmental Protection Agency requested rodenticide makers to make the switch by June 2011. The change stems from concern about the substance’s impact on non-target wildlife, children and pets.

According to Griffiths, his clinic sees 15 cases of dogs suffering from the side-effects of rodenticide consumption per year. In years past, Griffiths has consistently been able to save the pet. This year, Griffiths has seen three dogs displaying the side-effects of the new poison. All three dogs have died.

“People often recognize the signs of anticoagulants early. Within three to seven days you notice bleeding, Griffiths said. “However, with the new poison you need to get the dog to vomit within four hours. Otherwise the prognosis is pretty grave.”

Bromethalin has been a concern for pet owners nationwide for several years.

According to a February article posted on the American Veterinary Medical Association website, the American Society for the Prevention of Cruelty to Animals received about 1,300 bromethalin-related calls in 2012. That is more than 2011 and 2010, but less than 2009 when 1,600 calls were received.

From 1993 until 2008, the American Association of Poison Control Centers received between 12,000 and 15,000 reports of rat- and mouse-poison exposures each year to children less than six years of age.

Griffiths said the silver lining in the change to bromethalin is that its fatal dose is slightly higher than long-acting anticoagulants. A fatal dose of bromethalin is about four-and-a-half squares compared to three squares of anticoagulants.

Sympotoms of lethal-level bromthalin consumption are muscle tremors, hyper-excitability and rigidity of the front legs.

Reckitt Benckiser Inc., the maker of the 12 separate d-CON products, continues to use second-generation anticoagulants. The EPA has responded by cancelling and removing from the consumer market the 12 d-Con products.