Introduction Dog-assisted therapy is a method that facilitates rehabilitation and therapy of persons with disabilities. Therapy sessions are attended by a patient, a therapist, and a trainer with a dog specially selected and trained for this purpose. Aim The aim of the study is to evaluate the impact of a dog’s presence on the therapy, and consequently on the motor development of children with physical and intellectual disabilities. Material and methods This study was conducted during a period from January 2014 to May 2014. We enrolled 25 children with various disorders. The subjects were students of “Always Together” Private Elementary and Middle School in Poznań. The majority of the children have been diagnosed with cerebral palsy or meningomyelocele. Three tests were used for the assessment of the results of the therapy: The EUROFIT Special Test, an original Manual Skills Test, and a Satisfaction Survey. Results The results show significant improvement both in the EUROFIT and the manual skills tests accompanied by a high level of satisfaction. The results were not affected by the severity of intellectual disability, sex, or the type of the disorder. Conclusions The presence of a specially trained and selected dog had a positive impact on the results of physical fitness tests achieved by children with disabilities