Infectious agents involved in infectious keratoconjunctivitis in semi-domesticated reindeer (Rangifer tarandus tarandus) in Fennoscandia.

Abstract

Infectious keratoconjunctivitis (IKC) is one of the most common ocular diseases in ruminants worldwide. Animals affected by this disease can show a wide variety of clinical symptoms, including keratitis, uveitis, corneal ulcer, conjunctivitis and in severe cases, blindness. Moraxella spp., Chlamydia spp. and Mycoplasma conjunctivae have been described as primary causative agents in ruminant species such as cattle (Bos taurus), sheep (Ovis aries) or alpine ibex (Capra ibex), but previous studies indicated that the reindeer alphaherpesvirus (cervid herpesvirus 2; CvHV2) could be associated with IKC as a primary agent in reindeer (Rangifer tarandus spp.). To address this further, 344 semi-domesticated reindeer (R. t. tarandus), with (n = 127) or without (n = 126) clinical symptoms of IKC, or with no details on clinical symptoms provided (n = 91), were sampled in Norway, Sweden and Finland between 2010 and 2014. Serum was tested for antibodies against CvHV2 (enzyme-linked immunosorbent assay; ELISA) and swab samples obtained from conjunctiva were subjected to bacteriological cultivation and also tested (polymerase chain reaction; PCR) for the presence of Chlammydiaceae, M. conjunctivae and CvHV2 specific deoxyribonucleic acid (DNA). This master project summarizes the data obtained from the sampled reindeer populations and evaluates the assumed link between the presence of CvHV2 and clinical symptoms of IKC. The significant association detected in the present study between clinical symptoms of IKC and the presence of CvHV2 in affected eyes, which is not present for any of the other microorganisms studied, leads to the hypothesis that CvHV2 is the primary agent of the IKC in semi-domesticated reindeer in Fennoscandia.