Swelling reaction to cold laser - normal??

[cptrayes]

My horse had a cold laser treatment on a ligament/tendon injury on Friday afternoon and since then his leg has had more fluid in it than it did before, when apparently it should have had less. Can anyone tell me how rare this reaction is, so I can work out whether it was caused by the treatment or whether to worry about it as something going wrong in his rather badly swollen leg??

Thanks!