Animals are often said to be extremely sensitive to changes in the weather.
Last week, Ms Valerie Goh found that to be true when her eight-year-old dog, Buddy, began displaying some odd symptoms.
The pet's eyes "got really sore and red" before the Pollutant Standards Index (PSI) hit the unhealthy range, said the 23-year-old National University of Singapore law student.
Last Friday, when the PSI hit record levels, the dog "couldn't open its eyes and they produced a lot of discharge", she said.
She consulted a vet, and was surprised to learn that this "was a normal reaction to the haze for dogs", said Ms Goh.
Dr Denise Poh, a veterinarian from the Mount Pleasant Animal Medical Centre, has seen more pets being brought in for care, with symptoms like eye irritation and runny noses.
Dr Poh said: "The haze contains particles that will irritate the eyes and respiratory systems of animals. Animals with pre-existing medical conditions would also be more prone to these effects."
She added that brachycephalic (short-headed) breeds - such as bulldogs and pugs - would be more susceptible to the effects of the haze.
According to Dr Daphne Ang, smaller animals - such as hamsters and guinea pigs - are also susceptible, as their "lung capacity is much smaller".
Dr Ang, a veterinarian at Vet Practice, said that putting an air purifier near your pets might help.
However, putting a mask on the animal is unlikely to work, as "the pet would most probably paw it off", said Dr Ang.
Dr Poh added that it would be hard to say if there are any long-term detrimental effects of the haze on pets, as there haven't been many studies done.
A check with Wildlife Reserves Singapore - which runs the Singapore Zoo - revealed that its attractions are "not facing any pressing health issues with the animals" as a result of the haze.
A spokesman said: "The zookeepers and vets at Wildlife Reserves Singapore will continue to monitor the health and behaviour of the animals and carry out prompt action when necessary."
Mount Pleasant Animal Medical Centre advises pet owners to keep their animals indoors when possible, and to turn on the air-conditioner or fan.
If walks are necessary, do so within the house. Wipe down the face, body and paws of the animal thoroughly with a damp cloth after walks.
Use eye drops two to three times daily to flush away possible eye irritants. Also monitor the pet for redness of the eyes, abnormal eye discharge, and excessive sneezing or coughing. If conditions persist, take the animal to a vet.