Lake Hayes Estate resident Dan Gerard said barley grass appeared to be increasing exponentially around the resort, particularly near walking tracks.
The barbed seeds stuck to dogs’ coats and feet and could burrow into their skin if they were not licked out by the dogs, or removed by their owners.
They could also easily enter their ears, as happened to one of his dogs last year.
"We’ve removed numerous [seeds] ourselves from our dogs, between their paws and on their coats last year, and one of them had to go into the vet because it got in his ear ... They had to put him to sleep to get it out.
"It’s spread a lot — it’s quite a noxious pest and it’s spreading very quickly," Mr Gerard said.
Remarkables Vet owner Dr Geoff Woodhouse said the issues with barley grass, and speargrass, were not new in the Queenstown Lakes and Central Otago districts, but because of the wetter spring and summer the "dry-off" was yet to happen.
"The seeds have to come to that point of the growth cycle, dry off and then be easily dislodged.
"That’s when they’ll get caught in the dogs’ coats [and] become risky.
"If they’re not pulled out early, or got early by the dogs ... licking it out, or it falling out, or by someone finding it ... then it can penetrate into the skin and be gone, essentially...
"That’s when they’ll become problematic."
People should regularly inspect their dog’s paws, in between their toes and their armpits and consider clipping shaggy-coated and long-haired dogs, he said.
If a seed burrowed in, a dog would lick at the entry point, and there might be some weeping coming from that area, and swelling and tenderness around it.
"We do get cases where the dogs are just unwell and they’re not showing any external signs ... and that’s because the seed has penetrated and maybe sealed over and is travelling.
"They are very tricky to find, but that’s the exception rather than the rule."
The most at-risk part of a dog was its ears — if a seed got in it was "immediately painful".
"The dogs go down [in long grass], they go out of sight, they come out with their head on one side and shaking their head.
"That deserves attention very smartly so the least damage has been caused."
