Progressive ataxia of Charolais cattle--an oligodendroglial dysplasia

Genotyping KIF1C (c.608G>A) Mutant Reveals a Wide Distribution of Progressive Ataxia in German Charolais Cattle

Bovine progressive ataxia in Charolais cattle was first described in the 1970s; then, cases were reported in Charolais worldwide. A homozygous loss-of-function mutation within the KIF1C gene (c.608G>A) was found to be responsible for this neurodegenerative disease. The aim of this study was to determine whether the mutated KIF1C allele segregates in the German Charolais population and whether the estimated breeding values for growth and muscle conformation are associated with the mutated genotypes. Genetic test results of the KIF1C:c.608G>A variant were available for 1315 Charolais cattle from 35 herds located in Germany. In addition, 324 samples from eight other beef cattle breeds were tested for the mutated KIF1C allele. We were able to demonstrate that the KIF1C mutation is common, with a frequency of 11.75% in the German Charolais population. All but two of the eight (2/8 = 25%) homozygous mutated individuals showed clinical signs consistent with progressive ataxia. The estimated breeding values of muscle conformation in 200- and 365-day-old animals indicated a significant superiority for homozygous mutated animals when compared either with heterozygous or homozygous wild-type genotypes; this was also the case for heterozygous genotypes in comparison with homozygous wild-type genotypes. For the estimated breeding values of daily weight gain in 200- and 365-day-old animals, the significant differences between homozygous mutated and heterozygous or wild-type genotypes were in favour of the homozygous mutant animals. There were no differences in the estimated maternal breeding values among all three KIF1C genotypes. For the first time, two German Angus cattle carrying the KIF1C mutation heterozygous were detected. The breeders' survey highlighted that increased awareness would facilitate increased conviction among breeders of the need for genetic testing in order to eliminate the lethal KIF1C allele.

Spinal Cord and Peripheral Nerve Abnormalities of the Ruminant

In food animals, spinal cord damage is most commonly associated with infection or trauma. Antemortem diagnosis is based on clinical signs, history, cerebrospinal fluid analysis, and imaging. As clinical signs are often severe, and prognosis is grave, necropsy may provide a postmortem diagnosis. Peripheral nerve abnormalities are most often the result of trauma. Calving paralysis or paresis is the most common condition affecting the sciatic or obturator nerve and often concurrently involves the peroneal branch of the sciatic. Damage to peripheral nerves is often transient and resolves within a few days as long as the nerve is not severed.

Clinical and histopathologic characterization of a central and peripheral axonopathy in Rouge-des-prés (Maine Anjou) calves

BACKGROUND

Recently, a progressive pelvic limb ataxia and paraparesis leading invariably to recumbency has been reported in Rouge-des-prés calves.

OBJECTIVES

To characterize the clinical and pathological findings of this newly reported disease and to investigate its potential causes.

ANIMALS

Nine calves from 7 different farms were prospectively studied from initial diagnosis through postmortem examination.

METHODS

Physical and neurological examinations, blood tests, cerebrospinal fluid (CSF) analysis, and myelographic examinations were performed. Neuropathology was carried out on both central and peripheral nervous systems. Copper deficiency and organophosphate intoxication also were investigated. Pedigrees were analyzed.

RESULTS

Age of onset varied from 2 to 6 weeks. Initial signs included pelvic limb ataxia and paraparesis. The neurological signs systematically progressed, over a 1-3-month period, to severe pelvic limb and truncal ataxia along with moderate paraparesis, leading to permanent recumbency. Animals remained alert. Cranial nerve function was normal. Muscle atrophy was not observed and spinal reflexes were normal. Blood tests, CSF analysis, and myelographic examination did not identify any abnormality. Neuropathology indicated neuronal fiber degeneration particularly in the dorsolateral and ventromedial funiculi of the spinal cord and in the peripheral nerves. Degenerative lesions also were observed in lateral vestibular and thoracic nuclei. No environmental factors such as copper deficiency or organophosphate intoxication could be incriminated as the cause of this axonopathy. Pedigree analysis suggested an inherited defect.

CONCLUSIONS AND CLINICAL IMPORTANCE

The first description of a central and peripheral axonopathy is reported in Rouge-des-prés calves. An inherited defect is highly suspected.

Oligodendroglial dysplasia in two bullmastiff dogs

Leukodystrophies are inherited neurological disorders involving central nervous system white matter. They are uncommon in animals but a few, breed-specific entities have been described. In 2002, two young-adult, purebred Bullmastiff dogs from central New York State presented to their referring veterinarians displaying moderate to severe ataxia of all limbs, spastic tetraparesis that was worse in the pelvic limbs, and a diffuse, action-related, whole-body tremor. Clinical signs were insidious in onset and slowly progressive. Anatomic diagnoses considered were a C1-C5 lesion or, based on the whole-body tremor, a diffuse central nervous system disorder. No gross lesions were apparent in the brain or spinal cord. Histopathologically, numerous, multifocal, sharply demarcated, small, ovoid to angular areas of myelin pallor (plaques) were present throughout the major white matter tracts of the brainstem and spinal cord. These plaques, which often were traversed by axons, did not stain with luxol fast blue for myelin and were associated with minimal astrocytosis. Ultrastructural findings include occasional hypertrophic glia in white matter, rare unmyelinated segments of axons, and focal proliferation of tubule-containing cytoplasmic glial cell processes (oligodendroglial). The described clinical and morphological findings and age of onset are similar to the well-characterized, presumably hereditary, bovine syndrome known as Charolais ataxia or oligodendroglial dysplasia. This article presents the first description of a leukodystrophy in the Bullmastiff breed and the first report of oligodendroglial dysplasia in animals other than Charolais cattle.

A familial peripheral neuropathy and glomerulopathy in Gelbvieh calves

Nine Gelbvieh calves originating in four herds and clinically presenting with rear limb ataxia/paresis had histopathologically confirmed peripheral neuropathy and a proliferative glomerulopathy. Degenerative lesions were severe in peripheral nerves, dorsal and ventral spinal nerve roots, and less marked in dorsal fasciculi of the spinal cord. Cell bodies of spinal ganglia were minimally diseased; ventral horn neurons occasionally had central chromatolysis and nuclear displacement. Glomerular lesions ranged from mild mesangial hypercellularity to glomerulosclerosis. Pedigree analysis of affected animals from one herd indicated a strong familial relationship and probable hereditary basis for the syndrome.

Spinal dysmyelination in new-born brown Swiss x Braunvieh calves

In four new-born Braunvieh calves suffering from connate recumbency and body tremor, a hitherto not described myelination disorder of the spinal cord was examined. Bilateral symmetric hypo- as well as demyelination in several spinal tracts were the most conspicuous findings, affecting the ascending gracile funiculus, the ascending dorsolateral spinocerebellar tract, and the mainly descending sulcomarginal tract. Deficient myelin production, loss of myelin, consecutive axonal degenerations, and prominent astrogliosis within these tracts were the histological hallmarks of the disease. This possibly inherited primary myelination disorder of the spinal cord differs markedly from known hereditary neurological diseases in Brown Swiss and Braunvieh cattle, respectively, i.e. the weaver-syndrome and the spinal muscular atrophy.

Congenital defects of the bovine central nervous system

What should you do if you observe a defective calf in a herd? Our suggestion is to seek qualified help to examine and diagnose the condition. Parentage should be verified by blood typing. But, most important, you can keep cattle genetically clean by having your clients report all defects in calves to their breed association and artificial insemination centers.

Congenital tremor in Holstein Friesian-cattle

In a female family line of Holstein-Friesian cattle a series of trembling calves was born within a period of ten years. All trembling animals were male; female calves appeared normal. At necropsy of one calf severe degenerative lesions of spinal cord and brain white matter were observed. Both myelin and axons were lost and some macrophages occurred within digestion chambers. Obviously degenerated neurones were not found. The lesion was interpreted as a single recessive sex-linked hereditary trait.

Congenital defects of the bovine central nervous system

Congenital brain defects in cattle are usually obvious at birth, but detection may depend on the nature and extent of the defect. The cause may be genetic or environmental, or the cause may be unknown. Many central nervous system defects are inherited as a simple autosomal recessive trait and may have a significant economic impact on purebred and commercial cattle operations. A common structural defect of genetic nature is internal hydrocephalus. A functional defect of simple autosomal recessive inheritance is bovine progressive degenerative myeloencephalopathy. The most significant teratogenic agents causing central nervous system defects are prenatal viral infections such as bovine virus diarrhea and bluetongue viruses. Many other defects of the central nervous system are reviewed.