\[ \boxed { \left ( \left ( y \left ( x \right ) \right ) ^{2}-{x}^{2} \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +2\,xy \left ( x \right ) =0} \]
Mathematica: cpu = 0.036005 (sec), leaf count = 61 \[ \left \{\left \{y(x)\to \frac {1}{2} \left (e^{c_1}-\sqrt {e^{2 c_1}-4 x^2}\right )\right \},\left \{y(x)\to \frac {1}{2} \left (\sqrt {e^{2 c_1}-4 x^2}+e^{c_1}\right )\right \}\right \} \]
Maple: cpu = 0.047 (sec), leaf count = 45 \[ \left \{ y \left ( x \right ) ={\frac {1}{2\,{\it \_C1}} \left ( 1+\sqrt {-4\,{{\it \_C1}}^{2}{x}^{2}+1} \right ) },y \left ( x \right ) =-{\frac {1}{2\,{\it \_C1}} \left ( -1+\sqrt {-4\,{{\it \_C1}}^{2}{x}^{2}+1} \right ) } \right \} \]