An imperforate lacrimal punctum is a congenital disorder of dogs involving the lack of an opening to the nasolacrimal duct (tear duct) in the conjunctiva. Dogs normally have two lacrimal puncta, the superior and inferior. This condition can affect either or both. Symptoms include excessive tearing and tear staining of the hair around the eye. Affected breeds include the American Cocker Spaniel, Bedlington Terrier, Golden Retriever, Poodle, and Samoyed. Imperforate lacrimal puncta can be corrected by surgical opening of the punctum. See also
Congenital lacrimal duct obstruction


== References ==
A preureteric vena cava, also known as a retrocaval ureter, is a rare congenital malformation of the right human ureter, in which the ureter passes behind the inferior vena cava, causing compression possibly leading to hydronephrosis. The prevalence of this condition is approximately 1 per 1,000 persons, with males 2-3 times more likely than females to develop the condition. Symptoms often do not manifest until those with the condition are aged in their 20s or 30s. References
"preureteric vena cava" (PDF). Retrieved 15 July 2019. Morganstern, S. L.; Seery, W. H.; Cole, A. T. (1977). "Preureteric vena cava". Urology. 9 (6): 664–666. doi:10.1016/0090-4295(77)90317-x. ISSN 0090-4295. PMID 883067.