Many 501(c)3 organizations are reluctant to get involved with lobbying because of misconceptions about laws that govern lobbying by nonprofits.. A common question from them is, "Isn't it illegal for nonprofits to lobby?" The answer to that is a resounding, "that depends."
There are two different kinds of lobbying. One, the kind we are talking about here, relates to lobbying on behalf of issues or policies. Within some simple budgetary guidelines (nonprofits should not spend more than 10% of their operating budget on lobbying), this is perfectly legal. In fact it could be argued that nonprofits that are mission-focused have a social responsibility to work to implement public policies in support of their missions.
The other kind of lobbying relates to advocacy on behalf of political parties or candidates for office. While there are certainly times when animal advocates can and should get involved in this kind of political action, they should not do so as part of a 501(c)3 organization. They can do this as private citizens, or as part of a 501(c)4 entity.
On the left side of this page is an audio recording of Shep Harris from the Government Relations Department at the prestigious Fredrikson & Byron Law Firm. He offers great advice for those wanting to lobby on behalf of animals. Most importantly he suggests being prepared and patient. It is generally not easy to pass new laws, which is probably a good thing. Legislators are obligated to hear from all sides of an issue. And, given that at most state legislatures have, literally, thousands of bills introduced each session, each legislator has a very small amound of bandwidth with which to hear each issue. For this reason alone, the help of a professional lobbyise who has strong relationships with the key legislators that will need to hear your issue, will be an important component of any effective lobbying strategy.