Peta has employed its usual subtle marketing tactics by erecting the billboard outside Southern General Hospital in Glasgow, where the UK's only swine flu fatality to date was a patient.
Behind the main slogan are phrases such as "e.coli", "mad cow disease" and "swine flu". Peta says the ad aims to remind Glaswegians of the "dangers presented by filthy factory farms that supply the country with meat".
Jacqueline Fleming, a 38-year-old mother, was the first person in Europe to die from swine flu. Pregnant at the time she was admitted to hospital, she went in to labour prematurely, delivering a son who died the day after she passed away in the Royal Alexandra Hospital in Paisley.
According to government advice on the swine flu outbreak, the disease is common among pigs but does not normally infect humans.
There has been speculation that a Mexican pig farm is the source of the global pandemic.
Peta advocates vegetarian lifestyles through a mixture of messages about the healthiness of vegetarian diets compared with omnivorous ones, as well as using shocking images from the meat industry.
Poorva Joshipura, a Peta spokesperson, said: "Everyone already knows that eating meat is linked to heart disease, diabetes, obesity and certain types of cancer, but factory farms are also breeding grounds for swine flu and diseases that could be the death of us.
"The best way to protect our health -- individually and globally -- is to go vegetarian."