Veterinary session

The NVSD (neuronal vacuolation and spinocerebellar degeneration) – also known as JLPP (juvenile laryngeal paralysis and polyneuropathy) – is a rare, but lethal neurodegenerative disease which mostly affects purebred Rottweiler dogs. It is caused by a mutation in the RAB3GAP1 gene, resulting in disrupted function of proteins essential for intracellular membrane transport.

Previous publications have focused on the detailed analysis of central nervous system lesions, while a significant portion of the peripheral nervous system and musculature have been examined by only a few studies. Thus, in our study, in the light of the generalized symptoms we were interested in whether the peripheral nervous system and the muscles innervated by them were involved in degenerative processes.

We examined and presented the case of a registered purebred male Rottweiler dog. The symptoms first appeared at four months of age. Coughing, anorexia, hindlimb weakness, and ataxia had been unresponsive to empirical treatment. Within four weeks, the dog’s condition deteriorated rapidly. Due to increasing dyspnea, severe ataxia, and dysphagia the owner opted for humane euthanasia.

Histopathological examination revealed no abnormalities in the following segments of the peripheral nervous system: ggl. cervicale medii, ggl. cervicothoracicum, ggl. distale, n. vagus, tr. vagosymphaticus, n.laryngeus recurrens, n. medianus, n. radialis, n. phrenicus, n. ischiadicus and n. tibialis. In the analysis of skeletal muscle samples, severe dystrophy was observed in the intrinsic laryngeal muscles, with interstitial fibrosis appearing in the m. vocalis, and m. cricoarythenoideus dorsalis, as well as in the m. ventricularis and m.cricoarythenoideus lateralis with a lesser extent. In contrast, histophatological samples of the m. hyopharyngeus, m. extensor carpi radialis, m. flexor carpi radialis, m. phrenicus, m. rectus femoris and m. gastrocnemius showed a fully physiological picture.

In summary, the absence of peripheral lesions suggests that ataxia is occuring due to involvement of the cerebellum and spinal cord branches, and tetraparesis is not the result of regressive changes in the peripheral nerves and their associated muscles. NVSD is a serious, fatal disease that has appeared in the Rottweiler population of Hungary. Not only is the early detection of the disease important, but the exclusion of heterozygotes carrying the mutant gene from breeding using genetic testing is also necessary to eradicate NVSD.