Possible Avian Botulism Outbreak At Laguna Niguel Regional Park

Suspected botulism victims —all birds— are now being treated in Huntington Beach at the Wetlands and Wildlife Care Center.

Late modat  afternoon, six Mallard ducks and one American Coot were transported from Laguna Regional Park and admitted to the Wetlands and Wildlife Care Center with possible avian botulism.  

Rescuers estimate that around 20 more birds will be transported to the WWCC in Huntington Beach today, according to Debbie McGuire, the facility's director.   

"So far, 30 deceased birds were taken to O.C. Animal Control and three more live Mallards were taken to WWCC," McGuire said Wednesday morning. "I'm told there is a broken aerator pump at the park's lake. This means that there is low oxygen in the environment, and things die off. The water is also warm, and it can be the perfect set up for germination and more things to grow like botulism."

At post time, Patch was waiting to for a comment from park rangers.

McGuire said ithat there was another outbreak in 2009 at the lake and "hundreds of birds died after being tested positive for botulism."

She said the carcasses of the dead birds should be tested some time on Wednesday.

According to officials at , water is not the culprit when it comes to a possible botulism outbreak.

"I can assure residents that recycled water that we provide throughout the area is properly maintained. It goes through rigorous testing, and the water we provide to meets all the state requirements.  How that water is maintained is the responsibility of the facility’s owner.  If water does sit around and is not aerated, it can go stagnate and attract critters and other things that could eventually lead to algae and odors," said Moulton Niguel Water District General Manager Joone Lopez. 

What is Botulism?

Avian botulism is a paralytic and potentially fatal disease that affects birds after ingestion of a botulinum toxin. There are seven strains of botulinum toxin designated by the letters A to G; all of which are produced by the bacterium, Clostridium botulinum, McGuire said.  

Botulism is a neurotoxin, and types A, C and E have been identified as the strains that produce the toxin responsible for avian deaths. Avian botulism kills quickly, McGuire said.  

Of all the diseases that afflict waterfowl, Botulism has caused the most massive and visible losses.  The c. botulinum spore, or resting stage of the bacteria, naturally occurs in the environment.  

It is commonly found in wetland soils, and can survive for years, withstanding freezing and drying.  The botulism bacteria is an anaerobic (oxygen-intolerant) bacterium developing when high temperatures cause spores to germinate at the time there is a suitable nutrient medium and an environment devoid of oxygen.  

The nutrient medium consists almost entirely of animal matter.  Avian botulism results when a virus infects actively growing type c. botulinum bacteria and causes toxin production.

What Birds are Affected 

Ducks are most frequently affected, but avian botulism is known to affect all waterfowl including pelicans, geese, and swans.  Most groups of birds are susceptible, including loons, gulls, shorebirds, raptors as well as herons, egrets, songbirds, pheasants and other upland birds. 

Outbreaks develop as a result of one or more of the following conditions:

  • Flooding of dry land during warm weather, resulting in the drowning of terrestrial invertebrates that then provide a nutrient medium for the bacterium.
  • Receding water levels that expose mud flats, causing aquatic invertebrates to die which then provides a suitable nutrient medium.
  • Changes in water quality that result in the death of invertebrate fauna.
  • Decaying animal carcasses that provide maggots.

Many birds inadvertently eat spores while feeding, and the spores live in their tissues with no effect on the birds’ health. When a bird dies, however, its decaying carcass often offers three conditions that botulism need to grow and produce toxin:  high temperatures, protein rich material, and an absence of air, she said.         

Botulism toxin is transferred to birds by maggots and other invertebrates that feed on the decaying carcasses.  The botulism toxin does not harm the invertebrates but it accumulates in their tissues to levels where one maggot can kill a duck.  Large numbers of maggots on a bird carcass can attract live birds that then become poisoned by ingesting toxic maggots, she said.  

The cycle repeats itself, each time involving more and more birds. Bacterial blooms are often initiated or exacerbated by human influence. Any action which results in the death of vertebrates or aquatic invertebrates increases the nutrient base the bacteria feeds upon, therefore increasing the size of the botulism outbreak. For example, fertilizer and pesticide runoff, sewage and other pollution entering the water or the habitats around it.  

"Even the bread many people feed to ducks is one of the factors that feed a bacterial bloom," she said.  "If you must feed the ducks, consider lettuce which is a much safer choice, both for the environment and for the ducks. And, don’t throw the food in the water! Avian botulism poisoning causes progressive paralysis."  

Affected birds gradually lose control over their muscles and initially they appear weak and limp.  Symptoms include the inability to fly, followed by an inability to walk.  At this latter stage, the bird often can propel itself by using its wings to “paddle” over land or water.  

Eventually the bird loses control over the muscles in its neck and it cannot hold its head upright.  One of the common names for botulism intoxication is limber neck. The nictating membrane (third eyelid) that sweeps across the eye ceases its rhythmic function. Ultimately, the bird dies from drowning or suffocation.

The effect on the bird depends on the quantity of toxin ingested. The Wetlands and Wildlife Care Center follows a labor intensive protocol to care for their botulism patients, she said. Each patient receives a thorough physical exam and is assigned a classification based on certain criteria: 


STAGE CONDITION 1 Critical  completely down, unable to hold up head; wings, legs and feet out; no eyelid response.  Bird is prostrate. 2 Serious body intermittently down, attempts to move; can hold up head; wing, legs and feet out; little or no eyelid response 3 Moderate difficulty walking and holding head erect; able to swim but not able to fly; good, but possibly slow, eyelid response 4 Non-critical standing, good balance but cannot fly; normal eyelid response. 5 Releasable flying and swimming proficiently; good weight (same or great than intake); PCV = >38;  waterproof!

The patients then receive aggressive fluid therapy to begin flushing the toxin from their bodies. Depending on their classification, the fluid therapy can include IV boluses of lactated ringers. Medications are given if indicated and include antibiotics, vitamins, and ophthalmic eye drops.  

"With a little luck and the labor intensive care given by our tireless volunteers, our botulism patients will recover in just a few days.  The average recovery time is 7 to 10 days," she said.

How You Can Help

 If you notice a large number of sick birds, contact the Orange County Animal Control as soon as possible. The quicker the sick birds can begin to get care, the better their prognosis for recovery. The Orange County Animal Control does the testing of the carcasses for confirmation of botulism. Even before confirmation is reported, local authorities such as the park management are encouraged to properly dispose of all dead animals as soon as possible. Throwing the carcasses into the trash only promotes the cycle of botulism to increase. Proper disposal includes cremation or deep burial of at least six feet.  Regular sweeps of the park is needed in order to collect and remove the dead birds.

"Please keep the wildlife in mind during your activities. Avoid anything that will pollute the water or surrounding habitats, including bread.  If you notice a sick or injured wild animal please contact your local animal control or our care center," McGuire said.  "If we all do our part to care for the environment and its inhabitants then we will all be able to enjoy them for many years to come."

The Wetlands and Wildlife Care Center is a 501(C) non-profit and operates on donations only. You may give your donation by doing one of the following: 

1.  Visit the website at ccoc.org and pay via PayPal;

2.  Mail your donation to: WWCC, 21900 Pacific Coast Hwy., Huntington Beach, CA, 92646; or

3.  Drop off your donation in person.

For further information, please contact Debbie McGuire, wildlife director at (714) 713-1155.


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