Inclusion keratoconjunctivitis ('pink eye') in sheep. A proposal for a new name for chlamydial keratoconjunctivitis in sheep and comment on recent clinical trials.
The cytoplasmatic inclusion bodies, which, in 1931, Coles discovered in the corneal cells of sheep suffering from contagious keratoconjunctivitis are now considered to be the reticulate bodies of a chlamydia, Colesiota conjunctivae (synonym: Chlamydia psittaci ovis). According to the postulates of Koch Colesiota conjunctivae is a primary cause of contagious keratoconjunctivitis in sheep, but the clinical picture is complex and is a result of the interaction between the infecting chlamydiae, host resistance factors, and secondary infections caused by opportunistic bacterial ocular pathogens. The clinical syndrome might also be caused by other micro-organisms, such as Mycoplasma conjunctivae or environmental factors, such as dust. However, in these cases, cytoplasmatic inclusion bodies cannot be found in the corneal cells of diseased eyes. To differentiate chlamydial keratoconjunctivitis from keratoconjunctivitis due to other causes, it is proposed to include in the name the laboratory findings typical for this disease: Sheep Inclusion Keratoconjunctivitis. Chlamydia are Gram-negative bacteria, which are obligate intracellular parasites. Prolonged treatment seems to be required to eradicate chlamydiae from a host and antibiotics must reach intracellular levels that are higher than their minimum inhibitory concentration for chlamydiae. Tetracyclines are the drugs of choice. This means that for a microbiological cure, diseased sheep must be injected several times a day for a week or more. Because the disease is usually self-limiting and economic losses are considered low, this seems unnecessary and control of the disease by local treatment of secondary infections seems sufficient. However, this will not prevent spreading of the disease in a herd and relapses may occur.
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002986:Clinical Trials as Topic / Q000662:veterinary; D003315:Cornea / Q000473:pathology; D005260:Female; D002479:Inclusion Bodies / Q000648:ultrastructure; D007637:Keratoconjunctivitis / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D009956:Psittacosis / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000473:pathology; D009626:Terminology as Topic
D000900:Anti-Bacterial Agents