  We present detailed radio observations of the tidal disruption event (TDE)
AT2019dsg, obtained with the Very Large Array (VLA) and the Atacama Large
Millimeter/submillimeter Array (ALMA), and spanning $55-560$ days
post-disruption. We find that the peak brightness of the radio emission
increases until ~200 days and subsequently begins to decrease steadily. Using
the standard equipartition analysis, including the effects of synchrotron
cooling as determined by the joint VLA-ALMA spectral energy distributions, we
find that the outflow powering the radio emission is in roughly free expansion
with a velocity of $\approx 0.07c$, while its kinetic energy increases by a
factor of about 5 from 55 to 200 days and plateaus at $\approx 5\times 10^{48}$
erg thereafter. The ambient density traced by the outflow declines as $\approx
R^{-1.6}$ on a scale of $\approx (1-4)\times 10^{16}$ cm ($\approx 6300-25000$
$R_s$), followed by a steeper decline to $\approx 6\times 10^{16}$ cm ($\approx
37500$ $R_s$). Allowing for a collimated geometry, we find that to reach even
mildly relativistic velocities ($\Gamma=2$) the outflow requires an opening
angle of $\theta_j\approx 2^\circ$, which is narrow even by the standards of
GRB jets; a truly relativistic outflow requires an unphysically narrow jet. The
outflow velocity and kinetic energy in AT2019dsg are typical of previous
non-relativistic TDEs, and comparable to those from Type Ib/c supernovae,
raising doubts about the claimed association with a high-energy neutrino event.
