The effect of photobiomodulation therapy (PBMT) or sham light therapy on pain, nonsteroidal anti-inflammatory drug (NSAID) requirement, and lameness was studied in 20 dogs with naturally occurring elbow osteoarthritis. Dogs ( = 20) were randomly assigned to receive either PBMT (group PBMT; = 11) 10 to 20 J/cm or a placebo treatment (sham light group S; = 9) treatment 0 J/cm, to both elbows for 6 weeks. Lameness score, pain score, and NSAID dose were recorded by blinded study personnel before and 7 to 10 days after last treatment. Reduction in NSAID dose occurred in 9/11 dogs in the PBMT group, and in 0/9 of group S dogs ( = 0.0003). There was greater improvement in lameness score post PMBT S therapy ( = 0.001). A greater reduction in pain score was detected in 9/11 parameters in group PBMT ( < 0.05). Regularly scheduled PBMT at 10 to 20 J/cm per joint for 6 weeks was successful in improving lameness and pain scores, and in lowering NSAID requirement in canine elbow osteoarthritis patients.