A wild-born, 34-yr-old female western lowland gorilla (Gorilla gorilla gorilla) was transferred between zoologic collections in the United Kingdom. Adjustment to its new environment was difficult and a series of health problems ensued. Progressive severe illness of multiple etiologies, and a failure to respond to multiple therapies, led to its euthanasia 5 mo later. Disease processes included severe thoracic and axillary cutaneous ulceration of T2–3 dermatome distribution, gastroenteritis, ulcerative stomatitis, emaciation, hind limb weakness or paresis, and decubitus ulcers of the ankles and elbows. Ante- and postmortem infectious disease screening revealed that this animal was not infected with Mycobacterium tuberculosis, simian varicella virus (SVV), simian immunodeficiency virus (SIV), or hepatitis B virus; but was infected with varicella-zoster virus (VZV) and simian T-lymphotropic virus (STLV). It is hypothesized that recrudescence of VZV and other disease processes described were associated with chronic STLV infection and the end of a characteristically long incubation period.