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ALCES SUPPL. 2, 2002 KUVSHINOV –  CENTRAL NERVOUS SYSTEM OF MOOSE

63

HISTOPATHOLOGICAL CHANGES IN THE CENTRAL NERVOUS

SYSTEM OF MOOSE (ALCES ALCES) IN THE IVANOVO REGION OF
RUSSIA

Vadim L. Kuvshinov

Ivanovo Agricultural Institute, Ivanovo, Russia

ABSTRACT: This work describes histopathological changes in the central nervous system of

moose (Alces alces) of different ages from various regions of the Ivanovo District.  Moose are
affected in certain parts of the world by a variety of infectious agents, such as anthrax, rinderpest,

necrobacillosis, and foot and mouth disease, which is contracted by coming into contact with

reindeer.  All of these agents are capable of causing serious disease.  Our present work attempted

to detect less conspicuous forms of disease in moose that might reflect disturbances or degradation

of ecological systems comprising their habitat.  We particularly noted lesions in the central system

of moose that were characterized by nonpurulent meningo–encephalitis, edema, perivasculitis in

extracellular spaces, and focal ischaemic necrosis because of thrombosis of small vessels.  Such

changes presumably resulted from neuro–dynamical, vascular, physical–chemical, and fluid distur-

bances and were pronounced in the central nervous system of moose inhabiting regions with

unfavorable environmental conditions.  We observed the most serious changes in regions where

chemical weed–killers, pesticides, and mineral fertilizers were irrationally applied.

ALCES SUPPLEMENT 2: 63-64 (2002)

Key words: biosphere, encephalitis, extracellular edema, herbicides, insecticides, moose, perivas-

culitis, pollution, tolerance

Results were obtained from a study of

histological changes observed in the central

nervous system of moose in relation to the

use of agricultural chemicals in different

regions of Ivanovo District.  The brains of

different–aged moose were obtained from

animals shot by hunters; females predomi-

nated over males.  Routine tissue samples

taken for histological investigation included

the following parts of the brain: medulla,

pons, cerebellum, quadrigeminal bodies,

epithalamus, thalamus, hypothalamus, some

parts of the cerebral cortex, and the vascu-

lar plexus of the lateral ventricles.

METHODS

The tissues were fixed in 10% formalin,

imbedded in paraffin and thin sections were

prepared and stained with haematoxylin–

eosin.  Frozen sections were prepared with

specific histochemical stains, including the

Spilmayer method for myelin, the Naut–

Zeindlow method for nerve fiber degenera-

tion, Alexandrovskaya’s modification of the

Orthega and Miyagava method for micro-

glial cells, and the gold–sublimate method of

Ramon and Kahan for glial astrocytes.

RESULTS AND DISCUSSION

Changes observed in the medulla dif-

fered according to weight and location.  The

soft cerebral membrane was thickened by

edema and infiltrating lymphoid cells.  Peri–

and endovasculitis were visible in the white

matter in pyramidal tracts and consisted

mostly of macrophages and plasma cells.  In

the areas of the thin fasciculi (Goll), the

wedge–shaped fasciculi (Burdah), and the

main ventral fasciculi, there was less perivas-

culitis but some small glial nodules, and



CENTRAL NERVOUS SYSTEM OF MOOSE – KUVSHINOV ALCES SUPPL. 2, 2002

64

demyelinated nerve fibers; mononuclear

cells were present in the spinal canal.

Atypical changes were observed in the

Varolii pons.  Instead of a nidus cell reaction

of the mononuclear type, there were diffuse

accumulations of analogous cells.  They

were located near the soft cerebral mem-

brane, chiefly in the regions of the posterior

long fasciculi, the nuclei of the abducent

vestibular and trigeminus nerves, under the

ependyma, in the area of the cochlear nerve

nuclei, the Gover’s fasciculi, and in the base

of the cerebellum.  Here and there, mono-

nuclear infiltrates extended from the sub–

apsidimal zone into the more profound parts

of the white and gray matter.

Infiltrations of the white and gray mat-

ter by diffuse and focal cell accumulations

were characteristic of some moose.  Such

accumulations consisted of lymphatic–type

cells, mostly glial cells and macrophages.

Proliferating macroglial cells and some

hypotrophic astrocytes were located prima-

rily along vessels.  Some animals had a

lymphocytic perivasculitis in the epiphysis

cerebri.

This histological investigation of the

central nervous system of moose living in

unfavorable ecological regions allowed us

to conclude that pollution of the environ-

ment can disturb internal homeostasis; in

particular, it provokes irreversible changes

in the brain.