Visit the following sites to send pet greeting cards

Silly Chilly's Pet Postcards http://www.sillychilly.com/

Pets in Pastel http://www.petsinpastel.com/post.htm

Kritter Cards http://www.krittercards.com/

1001 Postcards http://www2.postcards.org/postcards/cards/animals/

Ecardica http://www.ecardica.com/ecards/Animals.html

Care 2 http://www.care2.com/send/catpets1.html

Card Fountain http://www.cardfountain.com/ecards-index/pet-photo-ecards/

Ze-Card http://www.ze-card.com/images/pets/pets-11.htm