Theme: A Girl's Best Friend - The theme entries' first word can be ahead of the unifier.
17A. Illegal activity admitted by Lance Armstrong in January 2013 : BLOOD DOPING. Blood diamonds are used to fuel violent conflict and human rights abuses. Also, a 2006 film.
24A. Singer with Crosby, Stills & Nash : NEIL YOUNG. Neil Diamond (plus a little something for Bill G)
37A. ESPN show with an "Inside Pitch" segment : BASEBALL TONIGHT
50A. Trousseau holder : HOPE CHEST. Hope Diamond
61A. Volcanic Hawaiian landmark, and a hint to the first word of 17-, 24-, 37- and 50-Across : DIAMOND HEAD
Argyle here. Another C.C. offering with long entries, including a spanner, but a little tougher than the NW indicated. At this point, Cruciverb is still down but there aren't any circles anyway. YouTube isn't co-operating either.
Across:
1. Mooing critter : COW
4. Ancient region surrounding Athens : ATTICA
10. Reagan era mil. program : SDI. (Strategic Defense Initiative)
13. Disgusted grunts : UGHs
15. Resident of Tibet's capital : LHASAN
16. Muscle spasm : TIC
19. Writer for whom the Edgar award is named : POE
20. Not sacred : SECULAR
21. Secret matters : ARCANA
23. Baba who stole from thieves : ALI
27. Glass container : JAR
29. Actress Cannon : DYAN
30. Peter Fonda's title beekeeper : ULEE
31. Opposed (to) : AVERSE
34. Hurts with a tusk : GORES
42. Willem of "Platoon" : DAFOE
43. 100-lawmakers group : SENATE
44. "Peter Pan" pirate : SMEE
47. Hang around : STAY
49. Pretoria's land: Abbr. : RSA. (Republic of South Africa) (City)
53. Stomach-punch response : [OOF!]
55. Start of the line that includes "wherefore art thou" : "O, ROMEO"
56. Female star : HEROINE. Juliet
60. Comfy room : DEN
64. Night's opposite : DAY
65. __ Pie: ice cream treat : ESKIMO
66. Reached base in a cloud of dust : SLID
67. "Tasty!" : "YUM!"
68. Unsettling looks : STAREs. could be 2D. Look at lasciviously : OGLE
69. Arid : DRY
Down:
1. Baby bears : CUBS
3. "So what?" : "WHO CARES?"
4. Alan of "M*A*S*H" : ALDA
5. Like rosebushes : THORNY. "Don't let the fear of the thorn keep you from the rose." - Groucho Marx
6. Pub spigot : TAP
7. "Woe __": Patricia T. O'Conner grammar book : IS I
8. Gondolier's "street" : CANAL
9. Hopping mad : ANGRY
10. One of Minn.'s Twin Cities : ST. PAUL. Adjoins Minneapolis.
11. Singer Warwick : DIONNE
12. Frigid historic period : ICE AGE
14. Aretha's genre : SOUL
18. 551, at the Forum : DLI. 500+50+1
22. Dad's nephew : COUSIN
25. Aerie hatchlings : EAGLETS
26. Playing an extra NBA period, say : IN OT. (overtime)
27. Quick blow : JAB
28. Gardner once married to Sinatra : AVA
29. Refusing to listen : DEAF
32. Use, as a coupon : REDEEM
33. Entrepreneur-aiding org. : SBA. (Small Business Administration)
35. Optimistic : ROSY
36. Opposite of WSW : ENE
38. Come in last : LOSE
39. Lasagna-loving cat : GARFIELD
40. Growth chart nos. : HTs
41. Brewed drink : TEA
44. Poorly made : SHODDY
45. Wells' "The Island of Dr. __" : MOREAU
46. Arnold Palmer or Shirley Temple, drinkwise : EPONYM
48. Where charity begins : AT HOME
51. Formally gives up : CEDES
52. Raise, as a sail : HOIST
53. Old fort near Monterey : ORD
54. Sounds of wonder : OOHs
57. Grandson of Adam : ENOS
58. Depilatory brand : NAIR
59. Hot tub swirl : EDDY
62. Alias letters : AKA
63. Former Russian space station : MIR
Argyle