Changes in clinical condition were evaluated first by the subjective scoring of the investigator, then by masked assessment of videotapes of the neurological examination. At 5 mg/kg for 28 days, 28 of 47 horses (60%) improved at least one grade by Day 118. Seventy-five percent (75%) of those improved, that had also been videotaped, were corroborated successes by videotape assessment. At 10 mg/kg, 32 of 55 animals (58%) improved at least one grade by Day 118 and 56% of those improved, that had also been videotaped, were corroborated successes using videotape assessment. With respect to the clinical investigators’ scores there was no statistical difference between 5 mg/kg and 10 mg/kg treatment group results (p = ).
The follow-up singles were also successful. The second single, "No", features Argentinian singer-songwriter Gustavo Cerati and reached numbers two and eleven, respectively, on the Billboard Latin Pop Songs and Latin Songs charts.   The video was filmed in a black-and-white effect,  and was directed by Jaume de Laiguana .  After the release of " Don't Bother " as the lead single from Oral Fixation, Vol. 2 in late 2005,  " Día de Enero " was the third single from Fijación Oral, Vol. 1 .  It peaked at numbers seven and twenty-nine on the Billboard Latin Pop Songs and Latin Songs charts, respectively.  Like "No", its accompanying video was directed by de Laiguana. The clip refers to Shakira's then-boyfriend Antonio de la Rúa as she writes the letters "S y A" in a heart drawn in the sand.