Veterinarians in western Wellington suburbs have reported treating dogs poisoned by karaka berries, according to the New Zealand Veterinary Association (NZVA). …
Karaka is an endemic tree to New Zealand and found spread throughout both the North Island and northern South Island. Karaka trees are fairly well distributed throughout Wellington city suburbs, as well as the Hutt Valley.Karaka berries are orange, 25-45mm long and produced January to April, says Dr Bullen. …
Owing to their foraging nature, dogs will often hunt out and consume berry kernels, which are plentiful right now across bushy areas in Wellington suburbs. NZVA advises dog owners to take extreme care when walking their dogs, as even consumption of older berry kernels carries toxic risk. …
Clinical signs of karaka poisoning in dogs are neurological.Signs include weakness, hind leg paralysis, proprioceptive deficits, progressive dystonia and convulsions which can lead to death, Dr Bullen explains.There is often a delay of 24-48 hours between ingestion and clinical signs, he adds.
Google helped me understand some of the symptoms:
proprioceptive deficits: the loss a patient’s ability to accurately detect the positioning of their limbs in space. Despite being non-specific in terms of cause, such deficits are important to recognise as they are often a precursor to more serious neurological impairment.
Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. [http://en.wikipedia.org/wiki/Dystonia]
To me, that says a dog with Karaka berry poisoning will have obvious trouble walking and running around, and may have convulsions.