This study aimed to compare physical therapy with toys with dog-assisted therapy in the neuromotor development of 4-month-old infants with and without neuromotor alterations. This is a qualitative descriptive and observational study carried out with 10 infants, who were evaluated by the Alberta Infant Motor Scale, divided into Group 1 (G1) and Group 2 (G1), and subdivided into Toy Group (TG1 and TG2) and Dog Group (DG1 and DG2) for the performance of fortnightly interventions. By the Affordances in the Home Environment for Motor Development - Infant Scale, we assessed the opportunities present in the home environment. Qualitative data were analyzed using photos and videos. The presence of a dog in DG1 and DG2 resulted in a relaxed and fun environment, infants interested in touching the animal’s fur, alternating limb movements, eye contact, sound production, increased social interaction, and feeling of security. In TG1 and TG2, decrease in motivation was observed as well as the absence of sound production and eye contact by infants, and interest in touch restricted to toys that had different colors and sounds, with little agitation and motivation for motor skills in those groups. We concluded that the dog’s presence promoted better motor, social, affective, and cognitive results. Animal-assisted therapy can be an effective method to support conventional physical therapy for infants with delayed neuropsychomotor development.