Uninstalling freetds from OS X Mavericks
I was able to successfully uninstall freetds and tiny_tds gem.

first I uninstalled tiny_tds gem as below:

 gem uninstall tiny_tds


To uninstall freetds follow the instructions to configure and build the freetds before running make uninstall.(otherwise it will give this error: make: *** No rule to make target `uninstall'. Stop. )

cd freetds-'0.91'  
./configure --preifx=/usr/local   
make
sudo make uninstall
sudo make clean


You will have to remove freetds.conf file manually as below:

sudo rm /usr/local/etc/freetds.conf


To ensure you have successfully uninstalled freetds run the following:

tsql -C


It should not report freetds details.