Your photo (jpeg anyway) is blurry and very noisey. My steps:
1. ACR noise reduction at default settings.
2. Wand/lasoo a quick path around spike.
3. Duplicate layer, soft light, Opacity 90 / Fill 60.
4. Levels layer, input 200.
steps 3 and 4 were only to improve contrast and depth of otherwise dull contrast photo.
5. Review rgb channels for contrast: red dull, green contrasty, blue contrasty but noisey.
6. Channel mixer layer with settings Red20, Green 60, Blue 40, Contrast -2.
7. Select the path and sharpen spike a little bit, I forgot acctual amount but it was a big brush, one swipe across him at about 20%. This step, as well as step 1, usually isn't necessary when the image is well exposed; maybe your RAW file is better.
8. Invert the path then Burn a very slight shadow under spike. This is strictly my artistic preference: figure ground!
9. Flatten / Greyscale / Duotone with black and warm grey and adjusted each curve / RGB.
10. Resize, save.
I've been doing a lot of black and white work recently, so the above was pretty quick for me. Overall, I believe when converting digital color to Black and white two things are vitally important: a very contrasty image (original exposure or modified in post processing; toned: straight black and white conversion is always very flat, lacking depth, pop, 3d, etc.
By the way, nice looking dog. Greatness can only be achieved with a great model!