I have a 4 and a half year old mad cross staffie/boxer who 4 months ago was kicked by a horse. He suffered bruising and a collapsed lung but recovered well and quickly too.
Since then he has developed small red lumps that pop up all over his body and others that seem to be deeper under the skin. Some change shape , some disappear, others pop up in the course of an hour or so. The vet believes they are like blood blisters - blood collecting at the site of an injury. He has one inside his mouth - at the back on the right hand side.
He is gradually going off his food (I wonder if the lump in his mouth is painful?) so I have swapped it. He did not eat at all yesterday but has had some today.
He has had several unexplained nose bleeds and sometimes will be completely lame in a leg but the next day the leg is fine.
He has had blood tests done and he has a slow clotting time. He has also been tested for lungworm and whilst the test was negative , we are still treating him for it.The vet is thinking possibly a type of hemophilia. I just wondeered if anyone else had any ideas? He is my wonderful mad best friend and some days he is so in pain its heart breaking - and hours later he's back to 100%.

It seems strange to me that blood blisters and nose bleeds would be happening 4 months after the injury, they may not be linked at all. But I am not a vet, just experienced with dogs, I have to say that first. We do have a retired vet and several vet techs on board who will hopefully give their insight here.

In regards to the limping, that is possibly a result of the injury. Has he been back to the vet for an x-ray since the injury healed? It's possible healing didn't happen correctly and their was a fracture or break that has not set properly and occasionally causes pain. There could also be muscle or ligament damage.
The injury may have also causes arthritis in the joint... There are many different options for limping, even more when there has been a pre existing injury.

I'm no Vet either, but I tend to think like Shaz here about the lameness possibly being a result of the injury. I would think that otherwise the lameness wouldn't affect only one leg.
Have they done any testing to look for other blood disorders?
And have you noticed any other issues that could go along with the nosebleed/clotting issue, such as bloody urine or unexplained bruises, bleeding gums or pale gums?

Oh, my, its not going well. On Saturday he had a massive internal bleed and went into shock. He had a blood transfusion, and is slowly making a recovery.
Stll the thinking is that this is lung/heart worm.
He is improving but I'm not so sure we are on the right lines. He had x-rays taken to find the site of the internal bleed - (his stomach ) and his chest x-ray was just a mass of dots - lumps that have developed internally, to say the least I am very worried.
Thanks for your help. I will keep you posted.

Ps the lameness seems to be an interna bleed to the joint.

I'm sorry to hear this, best wishes for recovery.
Keep us posted, my thoughts are with you.