Hair bitten off close to skin. Release of red porphyrin pigments from nasolacrimal glands. Associated with various stressors including chronic disease. Continuous growth of incisor teeth. Mammary gland neoplasms.
Pituitary adenomas are relatively common in old rats.
Usually asymptomatic but may be associated with nervous signs. Lymphosarcomas occur sporadically. Affects many strains of albino rats. Severity increases with age and it is more common in males. Ringtail' is characterised by annular constrictions of the tail with or without necrosis and sloughing in un-weaned rats.