In Snyder’s natal horoscope (born May 12, 1936 at 5:30 AM CST, in Milwaukee, WI; Asc 8 Gem 12), we see potential concerns with ailments ruled by Neptune/Pisces (such as those involving the blood; Snyder was diagnosed with Leukemia): natal NEPTUNE is square the health-center Ascendant, and as well square Mercury the Ascendant ruler (the chart’s final dispositor conjunct the Ascendant in the 1st house [i.e. the physical body]). We also see that Saturn in PISCES is pulled into a wide t-square with Neptune, Mercury and the Ascendant (that signals two strong references to Neptune/Pisces health concerns).
According to what I’ve read, Snyder learned of his diagnosis in April 2005, just two years ago. At that time we see SA Venus semisquare Mars (SA Venus=Mars; Feb ‘05), both planets co-ruling the 12th house of critical illness.
In terms of tracking the illness back to its initial manifestation in the physical body, we see potential health concern in the beginning of 2002 (3 years prior to diagnosis): Tr. Saturn was conjunct the Ascendant and Mercury, along with the first hit of tr. Neptune square Venus (in the 12th house and co-ruling the 12th)!
In 2003, tr. Neptune makes its final conjunction with the Midheaven at the very same time as tr. Pluto is square Saturn for its first contact. Concern is heightened further in 2004 with tr. Saturn conjunct Pluto (last hit June ‘05). We know that Pluto-Saturn and Saturn-Pluto contacts suggest difficulty, hard work and potential loss. Even more difficult when the two measurements occur at the same time as they did in Sept/Oct ’04.
We can also note in the natal horoscope that natal Pluto is semisquare Mercury and the Ascendant, therefore when any outer planet conjuncts Pluto, it also forms a hard aspect with the Ascendant and its ruler Mercury.
Such was the case with tr. Saturn throughout 2004 and 2005 (conjunct Pluto, semisquare Mercury and the Ascendant).
In 2006, tr. Saturn was square the Sun (life energy) and Venus (co-r. 12th), and opposed the MC. Moreover, SA Neptune was opposed the Sun (Dec ’06) with tr. Neptune square the Sun in the 2007, its retrograde hit now in July 2007 at the time of his passing. Neptune (signaling blood concerns) was front-and-center within the last year of his life.