The retinas of several kinds of wild birds were studied to observe the effects of colored oil droplets on their spectral sensitivities. The size, optical density, and distribution of each oil droplet in the fixed area was examined. The retina of the pigeon (Columba livia) was divided into red and yellow areas microscopically. Both areas had red, orange, and pale-green oil droplets. The red area had three times more oil droplets than the other areas, but the distribution of the three kinds of oil droplets was almost the same in both areas. In microspectrophotometric measurements, the red and orange oil droplets showed a very similar spectrum in 4 species: the Japanese jungle crow (Corvus macrorhynchos), night heron (Nycticorax nycticorax), eastern house swallow (Hirundo rustica), and Japanese jungle nightjar (Caprimulgus indicus). The pale green oil droplets of Japanese jungle nightjar, however, showed a different spectrum from the other birds.

Development of Chediak-Higashi Syndrome was observed in a Japanese black cow. Clinical eye examination showed mild photophobia. Ophthalmoscopically, the retina showed lightening of the nontapetal zones. Histologically, a decrease of melanin pigment was noted in the retina.

The inner ear and eye of cats and dog showing symptoms of the Waardenburg syndrome were studied histologically.

No histological abnormality was observed in the external, middle, and internal ear of white cats with blue irides without deafness. Structural disorders were observed in the labyrinthus membrane of the internal ear of a deaf white dog, but no histological abnormality was observed in the external and middle ear. Precipitation of white crystals was observed on the surface of the tectorial membrane, and these were identified as calcium by X-ray elementary analysis. Cochlear nerve fibers were present, but were not observed in and beyond the tunnel. No inner or outer hair cells were found in the organ of Corti.

An electronmicroscopic observation was made of the retina, choroidea, and sclera of the deaf white dog. Histological abnormalities were not present in the pigment epithelium, layer of rods and cones, nerve cells, or sclera. Deletions of pigment granules and tapetum were found in the choroidea at the iris versicolor side.

The iris was not studied electronmicroscopically nor histologically.

Clinical cases of Akita dogs with lesions of the skin, mucosa, and eyes were reviewed. The occurrence was limited to Akita dogs and incidence of several cases in one blood family indicated some relation of a hereditary factor to the pathogenesis of this disorder. The age of the onset was mostly around one year, and there was no sexual bias.

The main clinical signs at onset were lacrimation and/or slight eye discharge. Diffuse to patchy fading of pigment and vitiligo on muzzle and lips were frequently noted following the cloudiness of the cornea. These signs regressed spontaneously at early stages, but there were repeated recurrences. Cloudiness of the cornea frequently developed more intensely and widely with or without conjunctivitis, and pannus was also distinct in some cases. Later, hyphemia, uveal staphyloma, adhesion of iris to cornea, cataract, and clouding of the corpus vitreum were observed, and then panophthalmitis and blindness leading to atrophia bulbi and enophthalmitis developed at the terminal stage. Depigmentation and pigmentation repeatedly occurred on the muzzle, lips, anus, vulva, and around eyes. Hyperkeratinization, bleeding, and crust formation were distinct on the muzzle in some cases. Stomatitis or oral ulcer was sometimes observed, and eczematous dermatosis with exudate and crusts occurred especially around the eyes and on the dorsal nasal surface. Errosive lesions were seen recurrently on the scrotum and around the vulva in some cases. Some patient dogs barked huskily and bent their heads to one direction.

Though examination of the ocular fundus could not be carried out in many cases because of the cloudiness of the cornea, it revealed yellowish gray or gray spots on the fundus in some cases. Chorioditis was confirmed by fluorescein angiography with extensive leakage of dye in the lesions.

Ordinary laboratory examination disclosed no specific changes in these cases. However, cellular and humoral immunity against canine malignant melanoma cells examined by microcytotoxicity assay and indirect immunofluorescent technique suggested that immunological reaction against melanocyte cells might be involved in the pathogenesis of this disorder.

From these findings, the cases were diagnosed as a mucocutaneous ocular syndrome of canine clinical entity due to unknown cause.