The MOdified Newtonian Dynamics ( MOND ) is an attempt to modify the gravitation theory to solve the Dark Matter problem .
This phenomenology is very successful at the galactic level .
The main effect produced by MOND in the Solar System is called the External Field Effect parametrized by the parameter Q _ { 2 } .
We have used 9 years of Cassini range and Doppler measurements to constrain Q _ { 2 } .
Our estimate of this parameter based on Cassini data is given by Q _ { 2 } = ( 3 \pm 3 ) \times 10 ^ { -27 } { s ^ { -2 } } which shows no deviation from General Relativity and excludes a large part of the relativistic MOND theories .
This limit can also be interpreted as a limit on a external tidal potential acting on the Solar System coming from the internal mass of our galaxy ( including Dark Matter ) or from a new hypothetical body .