Welcome! Thanks for asking your question. My name is***** am a licensed veterinarian and I will be assisting you today. First I need to ask you a few questions so that I can be well informed and give you the best advice.
1- Are you seeing any swelling?
2- How long has this been going on?
3- How much does he weigh?
4- Is he on any medications?
Friend, as you have suspected what you are describing is consistent with a soft tissue (muscle, tendon or ligament) injury. This is what you can try:
1- Rest him for the next couple of weeks. No running or jumping even if he is not lame. Activity should be limited to urinate and defecate on a leash.
2- Buffered aspirin 325mg every 12 hours for 1 week. You can buy buffered aspirin over the counter in any pharmacy.
3- If no improvement within 2-3 days I would have him checked by family vet for an orthopedic examination and xrays.
Note: Sorry for the delay in response had some technical issues at this end.
My goal is to provide you with excellent service - I hope I've provided the information you were seeking, if you feel you have received anything less, please reply back as I am happy to address follow-up questions. Kindly rate me when you are done.
Buffered aspirin tends to be gentle on the stomach when compared to regular aspirin, this is why I recommended buffered and not regular. But, if he has a sensitive stomach just rest him as described above.
If the CCL was completely torn the lameness would not improve. But, if it is just injured the lameness will improve. For this reason I recommended to rest him for a couple of weeks even if he is not lame. You see, soft tissue injury take weeks to completely heal. So, the patient may appear to be better but re-injure themselves if they put a lot of pressure on the tissue.
No actually, when there is a full CCL tear not always do we see swelling in the joint from the outside. Meaning, if you are only looking at the joint it may appear normal, though there is some inflammation within the joint. The fact that he has improved in 2 days I feel comfortable in saying he does not have a complete acl tear.
It will be difficult restraining a 10 month old puppy I know, but, do your best.
I am glad I was here to help.
You're welcome. :)