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Examining The Risk of Toxic Algae And Poison In The Wanaka Area

Unfortunately for us, and our beloved dogs, there are a lot of algae and poisons around, especially this time of year, which can discourage us from making the most of the beautiful walking tracks we have in and around Wanaka. It can be tough keeping up with where potentially toxic algae live or where poison has been put down, but it's very important that pet owners are aware of the risk and avoid areas that are affected.

These algae and poisons are harmful to dogs, causing them to become seriously ill and may even cause death if not treated swiftly. We want our canines to be happy and healthy and kept out of harm's way so we are writing this post to raise awareness about the issue.


What you need to know:

Toxic algae are naturally occurring in waterways such as river and lakes. Most of the time it is barely detectable but can thrive and bloom during the summer months due to the rise in temperature and nutrients in the water. The algae can affect dogs, humans, livestock and wildlife alike.

LAWA (Land, Air, Water Aotearoa) say, "Dog deaths associated with potentially toxic algae living on the bottom of rivers have become increasingly common around New Zealand. In most instances these deaths have been associated with dogs eating a mat forming cyanobacteria called Phormidium. Phormidium mats produce a deep earthly odour that dogs seem to be attracted to," This is alarming as Phormidium has been found in the Upper Clutha area.

Where to avoid in Wanaka:

Cardrona River / Photo by Nikki Heath, Wanaka Sun

Cardrona River: As mentioned above, Phormidium has an odour that is alluring to dogs, yet when made contact with the algae can cause them a lot of harm. Phormidium was found at the beginning of this year, and previous years, in the Cardrona river. To this day, it is best to keep away from the Cardrona river with your dog as it's difficult to know when/if the algae has cleared up. We have personally heard first-hand accounts of tragedies occurring when local dogs have come into contact with this algae at the Cardrona River.  

Albert Town Lagoon: Last year the Albert Town lagoon was identified as an area where they may be a possibility of toxic algae occurring. Whilst testing came back with the all-clear, it may be wise to continue to monitor this area and look out for signs and media articles.  

What to do about it:

For a factsheet on this algae, visit the LAWA website. Look out for articles in the local media highlighting the presence of toxic algae in Wanaka's waterways, they will usually announce when an area is clear of the toxins too.

Toxic Algae / Photo from

If you are taking your furry friend on a casual walk, a hike or a swim please double check that the area is clear and safe for them (and for yourself). The way to do this is to know what the algae looks like (see left), toxic algae looks different to the harmless green fluff-like algae that appears in a lot of rivers and lakes. Also look out for warning signs that the council may have put up near source of water. If you have a spot that you visit regularly with your dog and a sign has gone up, take notice of it... sadly a lot of dogs are affected by toxic algae because their humans ignore the signs.

If your dog is showing signs of illness, or is acting strange after being in any type of water in and around Wanaka - call your vet immediately for advice, and be prepared to take your dog in to be treated. Not taking action could be fatal.


What you need to know:

Regrettably, there are several kinds of poisons present around the Wanaka area and it's hard to keep track with what's being put down where. Cyanide baits are commonly used in the Upper Clutha area to reduce the number of possums, whilst Pindone is used for rabbit-control. The controversial poison 1080 is also dropped in some locations at a certain point in the year.

These poisons are incredibly harmful to canines, and some can cause death within a matter of minutes. Secondary poisoning is a common thing as well, so not only can dogs be poisoned from the baits themselves, but from eating carcasses.

What is so disturbing about having poisons deadly to our beloved pets laying around is that, it's not just planned operations that can take place. Anyone can poison their own land, so even if you have access or permission to private lands, check for warning signs. It's easy to walk past a sign and not take notice of what it says, but it's best to read every sign you come across when out with your furry friend to ensure their safety.

Where to avoid in Wanaka:

Mt. Iron: This track is regularly coated with poison for rabbit-control which was laid in July this year (2018). The most recent warning from the DOC came on November 28th 2018, the private lands that are attached to the track (and the track runs through at one point) was covered with Pindone. DOC generally advise avoiding the area for up to 12 months to allow carcasses to fully decompose.  

Luggate (potentially in the near future): There was a planned 1080 drop covering a huge area in Luggate earlier this year. Fortunately it didn't end up going ahead due to less than ideal weather conditions, but it is still planned for the next available window of opportunity (OSPRI were not able to confirm dates at this time, however it is likely to be during the early winter months based on this year's postponed plans).

Private land (various in the Wanaka area): You can check the DOC Pesticide Summary Map ( for details about poison use by private land owners. If you live close to these its advisable to be vigilant when allowing your dog off lead. It's important to remember that poison baits can be carried to other neighbouring areas in waterways or in the wind, by wildlife, or the poisoned animals can become disoriented and travel to other areas to die. Just because it's behind a fence on private land, doesn't mean the public are not at risk.

What to do about it:

Thankfully, the local media and government sectors such as the DOC (department of conservation) are good at announcing when poison has been laid. This recent article from The Otago Daily Times is an example of how they are keeping the public in the loop. You can also head onto the DOC website and have a look at the main page for Wanaka, here you can see 'alerts' for the area (the red strip under image), and this is where they will advise which tracks have poison laid near them.

It's best to make sure your dog knows how to move along when they come across a bait or a carcass on a walk or if you come across something unexpected - "leave it" or "drop" works well when trained to those commands. If you're in an area where there are warning signs for poison, do not let your dog off lead, even if they are well behaved... it's not worth the risk. Better yet, don't take your dog for a walk on a track that has a sign stating clearly that there is poison on the land. As Wanaka's professional pet care providers, we hate that poison is so easily accessible to our favourite pets, and we steer clear of tracks that may have any poison near it. We recommend avoiding tracks or lands that have been poisoned for 12 months, to ensure there aren't any still accessible to dogs.

Alexandra / Photo by Pam Jones, Otago Daily Times

Keep an eye out for anything that looks out of the ordinary, such as things that are coloured green (green carrots were used as bait on the Mt. Iron track) or any other could-be poisons that may be laying around the place like slug baits.

If you suspect that your furry friend has been poisoned, you need to call your local vet and get the dog to them immediately so that they can start purging them and give them an antidote (e.g. Vitamin K is given if Pindone was ingested). If the poison has no antidote (such as 1080), you still need to do the same (call the vet to say that you're on your way, and let them know what the emergency is) - the dog still has a chance of being saved if early action is taken.

Even if your dog looks ok after eating poison, take them to the vet without hesitation. The poison will still be in their system and can cause harm on the inside, meaning if you wait it out, it could cost them their life.

Dogs are part of the family, and having them by our side on walks or days out is amazing. But before you embark on great adventures with your dog this summer, please take a look at the Department of Conservation's website, along with Land Air Water Aotearoa's site for more in-depth information on toxic algae and poisons, as well as alerts for the Wanaka area.

We know that was a long read but if you've made it to the end - thank you! We really just want to make sure that our local dogs have a full and happy life with no dramas!

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