19-05-2025
Botulism alert: Northland vets urge caution for dog owners
The dogs were also known to have been eating a rotten carcass – a risk for contracting the disease, Harrison-Wilde said.
Botulism, which can also affect humans and a range of animals, including birds and fish, is a rare but potentially fatal illness caused by the neurotoxin produced by Clostridium botulinum.
Botulinal toxins are the most potent, naturally-occurring, acutely toxic substances known.
They can be destroyed if exposed to temperatures above 85C for at least five minutes. However, C. botulinum spores are resilient, capable of surviving in soil and aquatic sediments for extended periods, potentially years, under favourable conditions.
Warm temperatures, high humidity, and anaerobic environments – such as those found in decomposing organic matter – created ideal conditions for the bacteria to thrive.
Dogs typically got botulism by ingesting the toxin from decomposing carcasses, spoiled food, rotting vegetation, or contaminated water and mud.
'In the Bay of Islands, the abundance of marine life means that fish or bird carcasses washed ashore can be a significant source of contamination. Additionally, improperly stored pet food or exposure to garbage can also pose risks,' Harrison-Wilde said.
She urged owners to keep their dogs away from high-risk situations.
'Always supervise them around beaches, bush tracks, and paddocks,' Harrison-Wilde said.
A dog usually showed signs of having the disease within 12-72 hours of ingesting the toxin, and the earlier those signs appeared, the more serious the disease, she said.
Recovery typically took two to three weeks, but dogs on the mend should show marked signs of improvement within a week.
With proper medical care and support (maintaining hydration, controlling symptoms, etc.), the expected outcome for most patients was positive, although some dogs could die from respiratory paralysis, Harrison-Wilde said.
If the amount of ingested toxin was not large and there were no other infections, dogs often recovered naturally without medical intervention.
The two dogs presented to Bay of Islands Vets were treated with supportive care, intensive nursing and intravenous fluid therapy, she said.
An antitoxin was available for cases confirmed by laboratory testing, but was not readily stocked by most veterinary hospitals in New Zealand. And to be effective, it needed to be administered before signs of paralysis appeared.
Previously documented cases included working dogs that had swum in muddy water after a hard day's work in warm weather. The water was suspected to have been contaminated during an outbreak of avian botulism.
During 2024, about 60 ducks died from an outbreak of avian botulism in the Whangārei suburb of Totara Parklands.
Sarah Curtis is a news reporter for the Northern Advocate, focusing on a wide range of issues. She has nearly 20 years' experience in journalism, much of which she spent court reporting. She is passionate about covering stories that make a difference.
