BIOLOGY BULLETIN, cilt.52, sa.314, ss.1-12, 2026 (SCI-Expanded, Scopus)
Myxobolus cerebralis (Hofer, 1903), a myxosporean parasite, is the etiological agent of whirling disease
in salmonids, which is responsible for high mortality and significant economic losses in rainbow trout
(Oncorhynchus mykiss) populations. Тhis investigation was conducted to establish the blood biochemical
changes caused by M. cerebralis in rainbow trout and fill the gaps from insufficient studies on the changes in
blood parameters. Furthermore, the investigation aimed to identify the negative effect of M. cerebralis on
some key physiological parameters to monitor its effects on the animal’s metabolism. The infection was confirmed
by clinical, histopatological and qPCR screening. Histopathological changes were observed in the
vertebrae, brain, gills, eyes, and muscles of the infected fish. The infection was confirmed by clinical, histopatological
and qPCR screening. Histopathological changes were observed in the vertebrae, brain, gills, eyes,
and muscles of the infected fish. Mononuclear inflammatory cells were determined around ossifying and cartilage
tissue of the vertebra; hyperplasia of the retina and giant cell-like structures in the granular brain tissue
were also observed. Levels of total protein, globulins, cholesterol, alkaline phosphatase, and cortisol were
greater than normal, while levels of creatinine, uric acid, albumin, calcium, and prolactin were lower than references
for the species.