I will keep the answer short and to the point because I written a lot about the Savannah cat in different articles and you can see the main article by clicking on this link.
The Savannah cat can be illegal in some places because it is a wild cat hybrid. There is wild blood in this cat breed. The father, grandfather etc. is a serval, a medium-sized wild cat species. Some US states consider wild cat hybrids to be similar to the wild cat themselves and all states have laws governing the possession of exotic wild cat species. They can be seen as dangerous. Or if they escape the home they can breed with feral cats creating super-feral cats. That’s the fear from some authorities.
It should be said right away though that it is rather unusual for this cat breed to be illegal. Certainly fifth-generation Savannah cats are not illegal almost everywhere as I the recall. It is the high filial versions, the F1 and F2s which are large domestic cats containing a high percentage of wild cat genes. These are very exotic animals and states often have laws regarding the possession and ownership of exotic animals. But please check both at state and lower jurisdictions on the USA and in the UK and Europe the same advice applies.
As I recall, too, there are restrictive laws on ownership of hybrid cats in Hawaii, Massachusetts, Texas and Georgia. This applies to the Savannah cat. New York also has restrictions in place as I recall. Please check if you live in New York State or city as there may be updates. Here is a quote by me on the Savannah cat page:
“It is important to check the legality of owning a Savannah cat where you live. Most states in the US regard the Savannah cat as a domestic cat in following federal and United States Department of Agriculture advice. New York State doesn’t, although 5 generations from the wild serval are allowed in NY State but not NY city. Other states restrict ownership of hybrid cats (Alaska, Iowa, Hawaii, Massachusetts, and Georgia). Update Feb 2011: Georgia, Hawaii and Massachusetts have banned this cat in addition to New York).”
Conclusion: The Savannah cat is not automatically, by default illegal. It depends on the filial and the place. You should look up the law and/or make inquiries where you are just in case there are restrictions governing the ownership of a Savannah cat especially the high filial types. Don’t just dive in and assume they are authorized because you might be disappointed.
Thanks for commenting. You say this: “The one thing these cats are capable of that’s not desirable, is their ability to escape. Due to the serval heritage, they have a greater desire to run and not come back if they escape.” Your stateemnt strongly indicates that a full-time indoor environment is fundamantally unsuited to this cat breed which can make them unhappy. But as you say they can’t be allowed out as it is too dangerous for them which makes their very existence as a breed, questionable.
I came across this informative article and just had to comment. I absolutely adore Savannah cats. I’m the proud mama of a few early generation SV’s. Although, they are larger and quite the handful; they are a joy to have around. I must admit that before I ever brought them into my home to join my family, I did extensive research and made sure they were allowed in the state I reside in. Although I have F1 generations, I found them to be just like any other cat’s except larger. I would recommend anyone wanting to have one of these beautiful cats join their family, to do research and make sure they are legal in your state. Make sure they are kept indoors at all times except when they’re on a harness or a well built catio. The one thing these cats are capable of that’s not desirable, is their ability to escape. Due to the serval heritage, they have a greater desire to run and not come back if they escape. Especially the F1’s -F3’s. They make wonderful pets imo, as long as you have done the research and are totally prepared to make this commitment.