Neurological Manifestation of Canine Distemper Virus: Increased Risk in Young Shih Tzu and Lhasa Apso with Seasonal Prevalence in Autumn

Canine distemper virus (CDV) is a highly contagious disease with high morbidity and mortality rates in veterinary medicine. This retrospective study aimed to identify epidemiological characteristics and potential risk factors associated with CDV infection in dogs exhibiting neurological manifestations. The diagnosis was confirmed through immunochromatographic antigen testing, RT-PCR, or <i>Lentz corpuscles</i> identification. Dogs diagnosed with central nervous system (CNS) disorders unrelated to CDV served as the control group. Age, breed, weight, sex, and neuter status were compared between groups using logistic regression (<i>p</i> < 0.05), the log-likelihood method, and log odds ratio (LOR) calculations. Clinical signs, seasonality, and vaccination protocols were documented. Prevalence, mortality, lethality, and survival rates were determined. Younger dogs (<i>p</i> = 0.00690; LOR = -0.01438) and Shih Tzu (<i>p</i> = 0.00007; LOR = 1.53774) and Lhasa Apso (<i>p</i> = 0.000264; LOR = 1.76084) showed a significantly increased likelihood of developing neurological signs due to CDV infection. Most CDV-infected dogs exhibited multifocal CNS involvement and accompanying extra-neural signs. The highest occurrence of CDV-related neurological signs was recorded in autumn. Many infected dogs had an updated vaccination protocol. The prevalence of dogs with CDV was 4.72%. Mortality and lethality rates were 1.94% and 47.06%, respectively. The median survival time was 754 days. The identified epidemiological characteristics and risk factors provide essential insights for improving preventive strategies against CDV infection.