A foul stench wafting over the city center has pushed the issue into the spotlight in recent days.
The source, according to a local official -- a vessel in the harbor with 19,000 cattle on board.
Animal rights campaigners call it a "death ship."
"...we're just here to you know, be a voice for those that don't have a voice..."
"...why do animals need to suffer in this way, there is another way to do this."
The Kuwaiti ship is traveling from Brazil to Iraq.
The local port operator said the "Al Kuwait" was docked in South Africa to pick up animal feed and medically assess the cattle.
The animals are enduring awful conditions, and that's what's causing the smell, according to the National Council of Societies for the Prevention of Cruelty to Animals, or NSPCA.
The group's inspectors boarded the ship on Sunday evening.
One said several animals had to be euthanized due to injuries.
The cattle have been on board the ship for over two weeks now.
The last estimate from the local port operator suggested the ship would leave Cape Town later on Tuesday.
