\[ \boxed { {x}^{3} \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+{x}^{2}y \left ( x \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +a=0} \]
Mathematica: cpu = 0.400551 (sec), leaf count = 123 \[ \left \{\left \{y(x)\to -\frac {e^{-\frac {c_1}{2}} \left (2 a e^{c_1}+x\right )}{\sqrt {2} x}\right \},\left \{y(x)\to \frac {e^{-\frac {c_1}{2}} \left (2 a e^{c_1}+x\right )}{\sqrt {2} x}\right \},\left \{y(x)\to -\frac {e^{-\frac {c_1}{2}} \left (2 a x+e^{c_1}\right )}{\sqrt {2} x}\right \},\left \{y(x)\to \frac {e^{-\frac {c_1}{2}} \left (2 a x+e^{c_1}\right )}{\sqrt {2} x}\right \}\right \} \]
Maple: cpu = 0.686 (sec), leaf count = 66 \[ \left \{ y \left ( x \right ) =-2\,{\frac {\sqrt {ax}}{x}},y \left ( x \right ) =2\,{\frac {\sqrt {ax}}{x}},y \left ( x \right ) ={\frac {{{ \it \_C1}}^{2}+4\,ax}{2\,{\it \_C1}\,x}},y \left ( x \right ) ={\frac {{ {\it \_C1}}^{2}x+4\,a}{2\,{\it \_C1}\,x}} \right \} \]