Open Access
Research Article
Issue
Parasite
Volume 23, 2016
Article Number 25
Number of page(s) 5
DOI https://doi.org/10.1051/parasite/2016025
Published online 17 June 2016

© S. Wang et al., published by EDP Sciences, 2016

Licence Creative CommonsThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Introduction

Neospora caninum is an intracellular protozoan parasite that causes the disease neosporosis. It has a worldwide distribution and is known to cause neuromuscular disorders in dogs and abortion in cattle, the latter leading to substantial economic losses in the dairy industry [15, 17, 24, 33]. Canids such as dogs, dingoes, gray wolves, and coyotes (but not foxes) are its definitive hosts and a variety of animals ranging from birds to mammals can act as its intermediate hosts [11, 14, 20, 27].

Dogs are important in the epidemiology of N. caninum because they act as definitive hosts, shedding oocysts into the environment [20, 23], which is a major risk factor for the occurrence of miscarriages and stillbirths associated with N. caninum in cattle and other intermediate hosts [2, 3, 9]. Moreover, the parasite can be transmitted transplacentally in dogs for several generations [6, 7]. Neosporosis can cause severe neuromuscular disorders such as ascending paralysis with hyperextension of the hind limbs, especially in congenitally infected dogs [17].

Antibodies to N. caninum have been reported in dogs worldwide [21, 28, 29]. There have also been some surveys of N. caninum infections in dogs in some provinces or cities of China in recent years (Table 1, [1, 16, 18, 19, 26, 30, 32, 35]). However, little information is available on the epidemiology of N. caninum infections in dogs in central China. In 2014, Yang et al reported the infection rate of N. caninum in dogs from Henan province to be 0.0% (0/31) [35]. But only 31 serum samples of dogs from Henan province were tested for antibodies to N. caninum in Yang et al.’s study [35]. The number of serum samples tested was too small to objectively reflect the overall infection status of N. caninum in dogs in Henan province. Therefore, the objective of the present survey was to determine the seroprevalence of N. caninum in domestic dogs in Henan province, central China.

Table 1.

The prevalence of Neospora caninum infection in dogs in the People’s Republic of China.

Materials and methods

Ethics statement

The study was reviewed and approved by the Ethics Review Committee of the Xinxiang Medical University (Reference No. 2015018).

The study site

The study was conducted in Henan province, located in the central part of mainland China, covering an area of 167,000 km2, with a population of approximately 106.01 million. Its geographical position is at east longitude 110°21′–116°39′ and at north latitude 31°23′–36°22′. The Yellow River passes through central Henan. The area has a continental monsoon climate, with four distinctive seasons. There are 17 provincial cities distributed across Henan province, with the city of Zhengzhou as its capital. Five cities including Anyang (35°13′–36°22′ N, 113°37′–114°58′ E), Sanmenxia (33°31′–35°05′ N, 110°21′–112°01′ E), Zhengzhou (34°16′–34°58′ N, 112°42′–114°13′ E), Xinyang (31°46′–31°52′ N, 114°01′–114°06′ E), and Shangqiu (33°43′–34°52′ N, 114°49′–116°39′ E), located in the northern, western, central, southern, and eastern parts of Henan province, were selected for sample collections.

Sample collection

A total of 1176 blood samples from domestic dogs were collected in these five cities in Henan province between March 2015 and February 2016. Dog owners were asked for details on the animal’s age, sex, source, breed, rearing conditions, and medical history, using a structured questionnaire. Blood samples were centrifuged and sera were recovered and transferred to 1.5 mL Eppendorf tubes. All sera were then stored at −80 °C until testing for the anti-N. caninum antibodies.

Determination of antibodies against N. caninum

An indirect fluorescent antibody test (IFAT) was performed to detect anti-N. caninum antibodies in dog sera. The test procedures were performed using a Neospora caninum FA Substrate Slide according to the manufacturer’s instructions (Catalog No. SLD-IFA-NC, VMRD Inc, Washington, USA). Teflon-masked slides were coupled with N. caninum NC-1 tachyzoites maintained in Vero cells. Anti-Canine IgG FITC Conjugate (Catalog No. 035-10, VMRD Inc, Washington, USA) was used as secondary antibody. On each slide, sera from canines positive for N. caninum and from canines negative for N. caninum (Catalog No. 211-P-NC-CAN and 211-N-NC-CAN, VMRD Inc, Washington, USA) were included as a control. Dog sera were screened at a titer of 1:50 cut-off value [28, 34].

Statistical analysis

Differences in N. caninum prevalence for certain variables such as age, breed, and sex were analyzed using a chi square test. Statistical analysis was performed using SPSS 20 software for Windows (SPSS Inc, Chicago, Illinois, USA). The differences were considered statistically significant if p < 0.05.

Results

In the present study, 1176 dogs were tested for the presence of antibodies against N. caninum using the IFAT. As shown in Table 2, the overall recorded seroprevalence of N. caninum in dogs in Henan province, central China was 14.63% (172/1176). Seropositive dogs from different cities were: 16.07% of 224 from Anyang, 20.43% of 235 from Sanmenxia, 14.84% of 256 from Zhengzhou, 9.50% of 242 from Xinyang, and 12.33% of 219 from Shangqiu.

Table 2.

Seroprevalence of Neospora caninum infection in dogs in Henan province, central China.

The seroprevalence of N. caninum in males was 15.72% (97/617) and in females 13.42% (75/559) (Table 2). Although the seroprevalence in males was higher than the females, the difference was not significant (p > 0.05).

The seroprevalence of N. caninum infection was 13.61% (101/742) in purebred dogs and 16.36% (71/434) in cross-breed dogs, showing no significant difference by breed (p > 0.05). The prevalence of N. caninum infection in rural dogs (18.17%) was significantly higher compared to that of dogs raised in urban areas (11.33%) (p < 0.01).

The prevalence of N. caninum infection in dogs increased significantly (p < 0.05) with increasing age. The highest prevalence of infection (18.60%) was detected in six-year-old or older dogs, followed by intermediate prevalence (15.18%) in the 3–6 year age group, while the prevalence found in dogs in the ≤3 year age group was 10.06% (Table 2).

Discussion

The detection of antibodies against N. caninum has been undertaken worldwide in dogs [25, 28, 29, 34]. The reference method for this detection is the IFAT [5, 8, 28]. A 1:50 cut-off in IFAT has been recommended and commonly used for canine sera [25, 28, 34]. Hence, in the present study, we used the IFAT to determine the seroprevalence of N. caninum in dogs and used a titer of 1:50 as the positive threshold titer.

Out of the 1176 dog serum samples tested in this study, 172 were classified as seropositive for N. caninum, giving a seroprevalence of 14.63%. The prevalence of 14.63% was lower than the prevalence of 21.7% in central Poland [12], 32.0% in Italy [28], and 19.4%–33.0% in Iran [10, 12, 13, 22], but higher than the reported prevalence of 3.6% in Korea [25], 7.9% in Portugal [21], and 12.4% in Brazil [31]. These differences, as previously commented, may be explained by the use of different serological tests, survey periods, sample sizes, and type of dog population.

In the present study, a higher prevalence rate of N. caninum was found in males than in females, but the difference was not significant (p > 0.05). These findings are consistent with the observations made by others [21, 25]. However, some researchers found female dogs to be affected more than males [12, 31].

Most of the reports find no specific breed susceptibility or a higher seroprevalence of N. caninum in mixed breed dogs [21, 23]. In the present study, although the seroprevalence in cross-breed dogs was higher than in purebred dogs, the difference was not significant (p > 0.05). However, Robbe et al. have suggested higher seropositivity in purebred dogs [28]. The role of breeds in the epidemiology of canine neosporosis is not well established and requires further research.

The present survey also showed that N. caninum seroprevalence was higher in rural dogs than in urban dogs (p < 0.01). This interesting finding may be attributed to feeding habits (like eating raw meat containing parasite cysts), differences in welfare, and different living environments.

In the present study, there appears to be a strong tendency for elevated risk of pathogen contact with increasing age, suggesting postnatal exposure to N. caninum. Similar observations from Brazil [4], Poland [12], and Iran [10] confirm this finding.

In conclusion, a high prevalence of N. caninum infection was found in domestic dogs in Henan, central China. Sanitary conditions and animal health must be improved to prevent the transmission risk of N. caninum by dogs.

Conflict of interest

The authors declare no conflict of interest in relation with this paper.

Acknowledgments

This study was supported by the Doctoral Scientific Research Activation Foundation of Xinxiang Medical University (No. XYBSKYZZ201504), the National Natural Science Foundation of China (No. 81502313), and the Key Scientific and Technological Project of Xinxiang City (No. ZG15014).

References

  1. Abdushukur S, Chen L, Yang F, Memet Y, Bayin C. 2010. Survey on the epidemiological features of neosporosis in dogs in Urumchi. Xinjiang Animal Husbandry, 11, 33–35 (in Chinese). [Google Scholar]
  2. Arunvipas P, Inpankaew T, Jittapalapong S. 2012. Risk factors of Neospora caninum infection in dogs and cats in dairy farms in Western Thailand. Tropical Animal Health and Production, 44(5), 1117–1121. [CrossRef] [PubMed] [Google Scholar]
  3. Asadpour R, Jafari-Joozani R, Salehi N. 2013. Detection of Neospora caninum in ovine abortion in Iran. Journal of Parasitic Diseases, 37(1), 105–109. [Google Scholar]
  4. Azevedo SS, Batista CS, Vasconcellos SA, Aguiar DM, Ragozo AM, Rodrigues AA, Alves CJ, Gennari SM. 2005. Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraiba, Northeast region of Brazil. Research in Veterinary Science, 79(1), 51–56. [CrossRef] [PubMed] [Google Scholar]
  5. Dubey JP. 2003. Review of Neospora caninum and neosporosis in animals. Korean Journal of Parasitology, 41(1), 1–16. [CrossRef] [Google Scholar]
  6. Dubey JP, Koestner A, Piper RC. 1990. Repeated transplacental transmission of Neospora caninum in dogs. Journal of the American Veterinary Medical Association, 197(7), 857–860. [PubMed] [Google Scholar]
  7. Dubey JP, Lindsay DS. 1989. Transplacental Neospora caninum infection in dogs. American Journal of Veterinary Research, 50(9), 1578–1579. [PubMed] [Google Scholar]
  8. Ghalmi F, China B, Jenkins M, Azzag N, Losson B. 2014. Comparison of different serological methods to detect antibodies specific to Neospora caninum in bovine and canine sera. Journal of Veterinary Diagnostic Investigation, 26(1), 136–140. [CrossRef] [Google Scholar]
  9. Ghalmi F, China B, Kaidi R, Losson B. 2011. Neospora caninum is associated with abortion in Algerian cattle. Journal of Parasitology, 97(6), 1121–1124. [CrossRef] [Google Scholar]
  10. Gharekhani J, Tavoosidana G, Akbarein H. 2014. Serological study of Neospora caninum infection in dogs and cattle from west of Iran. Comparative Clinical Pathology, 23(5), 1203–1207. [CrossRef] [Google Scholar]
  11. Gondim LF, McAllister MM, Pitt WC, Zemlicka DE. 2004. Coyotes (Canis latrans) are definitive hosts of Neospora caninum. International Journal for Parasitology, 34(2), 159–161. [CrossRef] [PubMed] [Google Scholar]
  12. Gozdzik K, Wrzesien R, Wielgosz-Ostolska A, Bien J, Kozak-Ljunggren M, Cabaj W. 2011. Prevalence of antibodies against Neospora caninum in dogs from urban areas in Central Poland. Parasitology Research, 108(4), 991–996. [CrossRef] [PubMed] [Google Scholar]
  13. Haddadzadeh HR, Sadrebazzaz A, Malmasi A, Talei Ardakani H, Khazraii Nia P, Sadreshirazi N. 2007. Seroprevalence of Neospora caninum infection in dogs from rural and urban environments in Tehran, Iran. Parasitology Research, 101(6), 1563–1565. [CrossRef] [PubMed] [Google Scholar]
  14. King JS, Slapeta J, Jenkins DJ, Al-Qassab SE, Ellis JT, Windsor PA. 2010. Australian dingoes are definitive hosts of Neospora caninum. International Journal for Parasitology, 40(8), 945–950. [CrossRef] [PubMed] [Google Scholar]
  15. Klauck V, Machado G, Pazinato R, Radavelli WM, Santos DS, Berwaguer JC, Braunig P, Vogel FF, Da Silva AS. 2016. Relation between Neospora caninum and abortion in dairy cows: Risk factors and pathogenesis of disease. Microbial Pathogenesis, 92, 46–49. [CrossRef] [PubMed] [Google Scholar]
  16. Lai PA, Li MW, Zhai XJ, Tian HY. 2015. Epidemiological investigation of some zoonosis in pet dogs and cats in Beijing. Chinese Journal of Veterinary Medicine, 51(5), 69–70 (in Chinese). [Google Scholar]
  17. Langoni H, Matteucci G, Medici B, Camossi LG, Richini-Pereira VB, Silva RC. 2012. Detection and molecular analysis of Toxoplasma gondii and Neospora caninum from dogs with neurological disorders. Revista da Sociedade Brasileira de Medicina Tropical, 45(3), 365–368. [CrossRef] [PubMed] [Google Scholar]
  18. Li J, He P, Yu Y, Du L, Gong P, Zhang G, Zhang X. 2014. Detection of Neospora caninum-DNA in feces collected from dogs in Shenyang (China) and ITS1 phylogenetic analysis. Veterinary Parasitology, 205(1–2), 361–364. [CrossRef] [PubMed] [Google Scholar]
  19. Li WC, Liu DY, Zhou L, Cao JT, Mei N, Zhang H, Chen C, Chen T, Han MM, Zhang W, Fan ZL, Gu YF. 2015. Prevalence of Neospora caninum infection in the intestine of pet dogs in some areas of Anhui and Zhejiang. Chinese Journal of Parasitology & Parasitic diseases, 33(4), 283–286 (in Chinese). [Google Scholar]
  20. Lindsay DS, Dubey JP, Duncan RB. 1999. Confirmation that the dog is a definitive host for Neospora caninum. Veterinary Parasitology, 82(4), 327–333. [CrossRef] [PubMed] [Google Scholar]
  21. Maia C, Cortes H, Brancal H, Lopes AP, Pimenta P, Campino L, Cardoso L. 2014. Prevalence and correlates of antibodies to Neospora caninum in dogs in Portugal. Parasite, 21, 29. [CrossRef] [EDP Sciences] [PubMed] [Google Scholar]
  22. Malmasi A, Hosseininejad M, Haddadzadeh H, Badii A, Bahonar A. 2007. Serologic study of anti-Neospora caninum antibodies in household dogs and dogs living in dairy and beef cattle farms in Tehran, Iran. Parasitology Research, 100(5), 1143–1145. [CrossRef] [PubMed] [Google Scholar]
  23. Nazir MM, Maqbool A, Akhtar M, Ayaz M, Ahmad AN, Ashraf K, Ali A, Alam MA, Ali MA, Khalid AR, Lindsay DS. 2014. Neospora caninum prevalence in dogs raised under different living conditions. Veterinary Parasitology, 204(3–4), 364–368. [CrossRef] [PubMed] [Google Scholar]
  24. Nematollahi A, Moghaddam GH, Jaafari R, Helan JA, Norouzi M. 2013. Study on outbreak of Neospora caninum-associated abortion in dairy cows in Tabriz (Northwest Iran) by serological, molecular and histopathologic methods. Asian Pacific Journal of Tropical Medicine, 6(12), 942–946. [CrossRef] [PubMed] [Google Scholar]
  25. Nguyen TT, Choe SE, Byun JW, Koh HB, Lee HS, Kang SW. 2012. Seroprevalence of Toxoplasma gondii and Neospora caninum in dogs from Korea. Acta Parasitologica, 57(1), 7–12. [CrossRef] [PubMed] [Google Scholar]
  26. Niu XY, Ma LQ. 2008. Serodiagnosis of Neospora Caninum infection in shepherd dogs of Wulan County of Qinghai Province. China Animal Husbandry & Veterinary Medicine, 35(2), 124–125 (in Chinese). [Google Scholar]
  27. Prandini da Costa Reis R, Crisman R, Roser M, Malik R, Slapeta J. 2016. Neonatal neosporosis in a 2-week-old Bernese mountain dog infected with multiple Neospora caninum strains based on MS10 microsatellite analysis. Veterinary Parasitology, 221, 134–138. [CrossRef] [PubMed] [Google Scholar]
  28. Robbe D, Passarelli A, Gloria A, Di Cesare A, Capelli G, Iorio R, Traversa D. 2016. Neospora caninum seropositivity and reproductive risk factors in dogs. Experimental Parasitology, 164, 31–35. [CrossRef] [PubMed] [Google Scholar]
  29. Sharma R, Kimmitt T, Tiwari K, Chikweto A, Thomas D, Lanza Perea M, Bhaiyat MI. 2015. Serological evidence of antibodies to Neospora caninum in stray and owned Grenadian dogs. Tropical Biomedicine, 32(2), 286–290. [PubMed] [Google Scholar]
  30. Song H, Yu LZ, Sun JY, Wang JX, Qi HY, Li T, Jin CM. 2015. Seroprevalence of Neospora caninum infection in pet dogs in Yanbian of Jilin Province. Jilin Animal Husbandry and Veterinary Medicine, 36(12), 7–8 (in Chinese). [Google Scholar]
  31. Valadas S, Minervino AH, Lima VM, Soares RM, Ortolani EL, Gennari SM. 2010. Occurrence of antibodies anti-Neospora caninum, anti-Toxoplasma gondii, and anti-Leishmania chagasi in serum of dogs from Para State, Amazon, Brazil. Parasitology Research, 107(2), 453–457. [CrossRef] [PubMed] [Google Scholar]
  32. Wang CM, Liu ML, Chen QL, Xu ZM, Bayin C. 2015. Seroprevalence of Neospora caninum and Toxoplasma gondii in dogs from Kuerle. Xinjiang Animal Husbandry, 11, 36–40. [Google Scholar]
  33. Weston JF, Heuer C, Parkinson TJ, Williamson NB. 2012. Causes of abortion on New Zealand dairy farms with a history of abortion associated with Neospora caninum. New Zealand Veterinary Journal, 60(1), 27–34. [CrossRef] [PubMed] [Google Scholar]
  34. Yakhchali M, Javadi S, Morshedi A. 2010. Prevalence of antibodies to Neospora caninum in stray dogs of Urmia, Iran. Parasitology Research, 106(6), 1455–1458. [CrossRef] [PubMed] [Google Scholar]
  35. Yang Y, Zhang Q, Kong Y, Ying Y, Kwok OC, Liang H, Dubey JP. 2014. Low prevalence of Neospora caninum and Toxoplasma gondii antibodies in dogs in Jilin, Henan and Anhui Provinces of the People’s Republic of China. BMC Veterinary Research, 10, 295. [CrossRef] [PubMed] [Google Scholar]

Cite this article as: Wang S, Yao Z, Zhang N, Wang D, Ma J, Liu S, Zheng B, Zhang B, Liu K & Zhang H: Serological study of Neospora caninum infection in dogs in central China. Parasite, 2016, 23, 25.

All Tables

Table 1.

The prevalence of Neospora caninum infection in dogs in the People’s Republic of China.

Table 2.

Seroprevalence of Neospora caninum infection in dogs in Henan province, central China.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.