Abstract：
Toxoplasma gondii and Neospora caninum infections may be associated with neuromuscular disorders in dogs. The aim of this study was to assess the seroprevalence to these protozoan parasites in dogs with neuromuscular disease from urban areas of Buenos Aires province, Argentina, over a period of 20 years, and to evaluate the association of seropositivity and antibody titres with different variables such as sex, breed and age. For this, a total of 7238 serum samples from urban owned dogs were analysed by the indirect fluorescence antibody test (IFAT) for specific IgG antibodies. The observed seropositivity rates were 35.7 % for T. gondii and 25.7 % for N. caninum. Crossbred dogs had a significantly higher seroprevalence for T. gondii than purebred dogs (41 % vs. 29.3 %), while a trend towards significance was observed for N. caninum, which was slightly higher in purebred dogs (26 % vs. 23.6 %). Seroprevalence for both parasites increased with age and was higher in older animals. Regarding the distribution of specific antibody titres, the most frequent IFAT T. gondii titre found was 100 and for N. caninum it was ≥800. For toxoplasmosis, there was no association with age group, and low titres (50, 100 and 200) predominated in all groups. However, for neosporosis, age and titres were significantly associated for one age group, with dogs under 12 months of age having a higher proportion of high titres (400 and 800). The trend in the seroprevalence for T. gondii is increasing over the years and lower antibody titres predominate in the dogs studied, which may be more related to the presence of chronic infections and not necessarily to the clinical signs of the animals. Despite the generally low titres observed for toxoplasmosis in this study, it is important to highlight the high seroprevalence found in our region, as dogs can act as sentinels of environmental contamination and as indicators of possible human infection. In the case of neosporosis, although the trend in seroprevalence in dogs with signs appears to be decreasing over the years, our work shows that higher antibody titres predominate, and are probably related to the clinical signs presented by the dogs. This study provides the most recent epidemiological data and serological profiles of T. gondii and N. caninum infections in a large number of canine sera from urban areas in Argentina, providing relevant information for clinical veterinarians and epidemiologists in order to understand the circulation of the parasites.
摘要：
弓形虫和犬新孢子虫感染可能与狗的神经肌肉疾病有关。这项研究的目的是评估来自布宜诺斯艾利斯省城市地区患有神经肌肉疾病的狗对这些原生动物寄生虫的血清阳性率。阿根廷,在20年的时间里，并评估血清阳性和抗体滴度与不同变量如性别的关联，品种和年龄。为此，通过间接荧光抗体测试(IFAT)分析了来自城市犬的7238份血清样本中的特异性IgG抗体.观察到的弓形虫血清阳性率为35.7%，犬奈瑟菌为25.7%。杂交狗对弓形虫的血清阳性率明显高于纯种狗（41％vs.29.3%），虽然观察到了一种具有显著性的趋势，这在纯种狗中稍高(26%vs.23.6%）。两种寄生虫的血清阳性率随着年龄的增长而增加，并且在老年动物中更高。关于特异性抗体滴度的分布，发现的最常见的IFAT弓形虫滴度为100，而犬奈米则≥800。对于弓形虫病，与年龄组没有关联，低滴度（50，100和200）在所有组中占主导地位。然而,对于新孢子虫病，一个年龄组的年龄和滴度显著相关，12月龄以下的狗具有较高的高滴度比例（400和800）。弓形虫血清阳性率的趋势多年来呈上升趋势，在所研究的狗中，较低的抗体滴度占主导地位。这可能与慢性感染的存在有关，而不一定与动物的临床症状有关。尽管在这项研究中观察到弓形虫病的滴度普遍较低，重要的是要强调在我们地区发现的高血清阳性率，因为狗可以充当环境污染的哨兵和可能的人类感染的指标。在新孢子虫病的情况下，尽管有体征的狗血清阳性率的趋势多年来似乎在下降，我们的工作表明，较高的抗体滴度占主导地位，可能与狗的临床症状有关。这项研究提供了阿根廷城市地区大量犬血清中弓形虫和犬奈瑟菌感染的最新流行病学数据和血清学概况，为临床兽医和流行病学家提供相关信息，以了解寄生虫的循环。
