I wanted to start a blog post on this disease since it appears we are only the third ones on the site to be dealing with this. There is a post here about Caira Sue. From what I understand, she lost her battle shortly after that post, so while it is helpful to read (knowledge is power!) it is a bit grim.

Yes, the diagnosis of H.O. is grim, and I'm not trying to be Suzy Sunshine about it - but for us, we were SO relieved to find out that Abby's cancer hadn't spread (we really thought we would find out it had spread to her lone front leg, and that we'd only have a few days left with her), that we actually felt happy when her x-ray showed HO.

Here are some things I know about the disease, having lived with it two weeks now:

• It's caused by lung mets. Most dogs' lungs are overtaken by the mets, causing the dog to pass. With Abby, either through luck or the combo of things we've done with her (see what all we've done in my sig), we are now going on almost one year (!) since her first met was spotted - and she still only has three (!) mets. This isn't normal. Unfortunately, just when you think you are doing a great job keeping the mets at bay, cancer throws you a curve ball (cancer is a dickweed that way...) - and the mets bring on this other disease that is painful and will likely be the reason we'll ultimately be making her "appointment to get her wings."
• There's no cure - unless you can get rid of the mets. The general rule is that surgery will only be done to remove a single met. And the met has to have been stable (slow growing) for a long time (I believe a year is the standard). Since surgery is not an option for Abby, we are trying to attack the mets one more time - this time with Masitinib (aka Kinavet) and artemisinin .  
• There are various options to help with the pain - at the moment we are doing gabapentin in the a.m and tramadol at night before bed. Apparently a shot of biophosphonates (sp?) (e.g. Pamidronate) can help in some dogs, giving a marked improvement in pain relief and mobility. We haven't tried this with Abby, but are keeping it in the back pocket. It is apparently a bit pricey as it has to be given via an IV lasting 2 to 4 hours.
• The pain waxes and wans. This is very true in Abby's case. Over Thanksgiving weekend we thought she was quite close to being a goner. Since then she has really perked up! Just this a.m. we went to the beach and she ran and had a good time - we were down there about 45 minutes and she only laid down to rest once.
• Our onc. told us that walking her will help with the pain, since it gets the blood flowing. This has definitely seemed to be true.
• I spoke to an onc. at CSU via their free phone consultation service and he said dogs usually only last 2 months once they are diagnosed. (personally we are hoping to blow that stat outta the water.)
• Signs that your dog might have it: With Abby, the first thing was a lack of her usual mobility and agility. Because she started to act odd on Thanksgiving day, it was a long weekend before we could get in to see her onc. During that time, her wrist started to swell quite badly. The swelling is a sign of the disease (but please don't completely freak out if you are seeing some swelling - because it also could just be an overuse injury. I just want you to know what it looks like so you can get to the vet if need be). It only attacks the long bones of the limbs, adding new bone, and (oddly) it is symmetrical. That weekend I kept asking my hubby if he thought her back feet looked weird - we thought they did, but since they both looked exactly the same, we thought we were imagining it, and her feet must have always looked that way but we never noticed. So, if you notice symmetrical strange elongated bumps on the limbs, that is also a sign. 

I've posted more here and here about this on Abby's blog if you want to see pics or hear more about her dealings with H.O. and to also read about a Miracle Dog I know of that was actually cured of both OSA and HO!

I'll try to update this topic with other things we try or find out. Hopefully I'll be posting updates here for a long while.

Hope this is helpful to someone coming along later on. PM me with questions.

Jackie, Abby's mom