Any sick animal, by the PCA Act's legal definition, is "in distress". The PCA Act does not say that the animal can't be seized if it is being treated medically for its sickness.
This is a grave error in the Act that has permitted the SPCA to sweep through people's homes, seizing every animal, even fish in aquariums.
Therefore every single animal that is sick in any way at any point in time, can be seized by the SPCA for being "in distress".
That means that if your cat has a cold the SPCA can seize it - even if your cat is under a vet's care.
That means that if your dog has an ear infection, the SPCA can seize it, even if your dog is under a vet's care.
If sick animals are all "in distress" that means that SPCA's themselves are committing an offence under the Act since SPCAs are sometimes full of animals made sick by the SPCA, especially kennel cough in dogs and upper respiratory syndrome in cats.
Avoidance of committing the offence of "causing or permitting an animal to be in distress" may explain why the SPCA still sometimes kills its sick animals, especially its sick cats.