The publisher of a new calendar which features a model breastfeeding a puppy said she was getting letters and emails threatening her life and accusing her of bestiality and animal cruelty.

Melissa Hayward, a model from Co Dublin, pioneered the project and also modelled as the December girl with her own dog.

The calendar has sparked outrage among animal rights activists and has received media coverage in India, Singapore and the United States.

However, Hayward rejected the criticisms and said she was "shocked and a bit hurt by the level of negativity. I never envisaged that people would have such an issue with the calendar at all. I am getting threatening messages and people accusing me of bestiality, people saying they would like me to get the death penalty and then people who are quoting parts of the bible at me. I am being accused of cruelty to animals for forcing the puppies to pose, which is something I entirely reject."

Hayward said she got the idea for the project last summer to raise money for animal protection charity ASH. "ASH was suffering a decline in donations because of the recession. The charity does the most amazing things and they get no funding and as I am a model and I know a lot of photographers I decided that I could arrange this idea to raise funds. It did not start from wanting to make any money for myself as some people are suggesting – it all goes to the charity."

Facebook has now removed Hayward's modelling fan page, on which she had 3,000 fans, and all her modelling shots, claiming it was "hateful" after a barrage of complaints from users about the model's presence on the site.

Meanwhile, two of the 12 sponsors have pulled out after controversy erupted last week over the content of the calendar.

"Logistically, that has been a bit of a nightmare, funding the project and then dealing with the backlash from sponsors and even online, but for every person who complains there are nine people who are in favour and who like the idea. We are appealing to these people to buy the calendar from the 'puppy love' website for the sake of the charity," said Hayward.

The model said she believed the root of the problem was a discomfort with breastfeeding, and not with animal cruelty.

"At the heart of the issue, I think breastfeeding itself still makes people uncomfortable and part of the problem is actually stemming from this. I am a pet lover myself and have a dog of my own who I posed with for the December girl shot. There is no way you could look at those pictures and say that any of the models are guilty of animal neglect or abuse."