States reminding veterinarians to be on alert for blue-green algae toxicity

As summer temperatures continue toward their peak, many pet owners will take their pets to cool off in local lakes and ponds. These owners are unknowingly exposing their pets to the potentially harmful effects of toxins such as microcystins and anatoxins often contained in blue-green algae (also known as cyanobacteria).

Several states including Kansas, Rhode Island, Indiana, and the regions surrounding Lake Erie have already issued warnings this year about the presence of blue-green algae in bodies of fresh water. In fact, some experts are predicting that the blue-green algae problem at Lake Erie will be the worst ever in 2013, according to

Scott Marshall, DVM, Rhode Island State Veterinarian, discussed blue-green algae toxicity with NEWStat and explained how the nation's veterinarians can help to keep local pets safe from it.

Blue-green algae toxicity may be an under-reported event

Marshall works diligently to keep Rhode Island's pet owners informed about blue-green algae, and he said so far he has not received any reports of blue-green algae toxicity in pets or farm animals.

According to Marshall, the lack of reports doesn't necessarily mean animals in Rhode Island aren't being affected by the algae.

"We have had this similar program of outreach now for three years. I have not received any reports of blue-green algae toxicity in pets or farm animals," Marshall said. "That leaves one of three possibilities: Toxicity isn't happening, toxicity is happening but isn't reported even though it is recognized, or toxicity is happening but not recognized. I hope it is mostly the first possibility that is prevalent, but my guess is that it is a combination of three."

Marshall explained that his state has limited resources and is unable to test every body of water, so the possibility for toxicity exists in water that the state has not tested.

"We remain hopeful that people have received the message and have avoided allowing animals to have contact with questionable water sources, but we are also aware that it is quite possible for toxicities to have gone unreported or misdiagnosed," he said.

How veterinarians can help

According to Marshall, veterinarians can act as the first line of defense for keeping their local pets safe from blue-green algae toxicity. 

"Veterinarians can play the role of sentinels in this situation. Animal contact is a lot more likely than human contact with microcystin since a dog would gladly swim in or drink from a water source that a human would avoid. Therefore, veterinarians have a central role in protecting their patients by informing their clients of the risk, and, if they make a diagnosis of blue-green algae toxicity, reporting of that finding will mitigate the risk to other dogs and potentially people," Marshall said.

Although blue-green algae toxicity is not commonly seen in many veterinary clinics, Marshall said he encourages veterinarians to keep it in mind "so that they will consider toxicity from blue-green algae as a differential and that they will report a diagnosis so that state authorities can investigate the suspected water source."

Symptoms of blue-green algae toxicity

According to Pet Poison Helpline, common symptoms of blue-green algae toxicity include:

  • Vomiting 
  • Diarrhea 
  • Blood in stool or black, tarry stool 
  • Pale mucous membranes 
  • Jaundice 
  • Seizures 
  • Disorientation 
  • Coma 
  • Shock 
  • Excessive secretions (e.g., salivation, lacrimation, etc.) 
  • Neurologic signs (including muscle tremors, muscle rigidity, paralysis, etc.) 
  • Blue discoloration of the skin and mucous membranes 
  • Difficulty breathing 
  • Death