Corneal ulcer (CU) is an ophthalmopathy characterized by depression of the corneal surface with at least one stromal loss. CU is common in canine and feline species and is usually caused, among others, by trauma, infections, toxic contamination and endocrine disorders. They usually result from an increased inflammatory response and are associated with some clinical signs such as blepharospasm, photophobia, epiphora, pain and loss of corneal transparency. Despite advances in conventional and pharmacological therapy, in many cases indolent and recurrent ulcer treatments still lead to loss of visual acuity of the animal. This paper aims to report the effect of topical application of canine adipose tissue-derived mesenchymal stem cell (cATMSCs) as treatment of recurrent CU in a Poodle dog breed that showed clear difficulty in the healing process associated with diabetes. The animal was submitted to two applications of cATMSCs and showed improvement in the blepharospasm, conjunctival hyperemia, mucopurulent ocular secretion, photophobia, corneal opacity, chemosis, pigmentation, neovascularization, and pain parameters. Besides, Fluorescein test, Schirmer test and ocular fundus exam also showed improvement in their values concomitantly with lesion resolution. Due this, we showed that cATMSC therapy contribute to the regeneration of corneal tissue in CU and may contribute to the treatment to others ophthalmopathies.