First Report of Acanthocheilonema reconditum Outbreak in Canines with Clinical Signs of Anemia from Southwestern Colombia

Different nematodes affect canines, however Acanthocheilonema reconditum was considered mostly a non-pathogenic parasite. Climate change, animal migration, and other factors transformed the dynamics of vector-borne diseases, including filariasis. Since 2016, a sudden increase in the number of dogs with microfilaremia was reported by different veterinary centers in Cali, southwest Colombia. The objective of this study was to molecularly identify the etiologic agent of this filariasis outbreak detected in this city, using PCR−RFLP and evaluating dogs’ clinical signs. From 2018−2019, canine filariasis cases were prospectively evaluated after a microscopic test, recruiting 82 cases and 43 healthy controls from 2971 samples. Acanthocheilonema reconditum (Nematoda, Onchocercidae) was identified in 61.3% of the cases (49/82) by PCR−RFLP. Sanger sequencing of the 5.8S ribosomal RNA gene and internal transcribed spacer-2 fragment was additionally performed on seven cases, confirming A. reconditum in all of them. The filariasis cases are statistically associated with male dogs who have clinical signs of anemia, low levels of hemoglobin and hematocrit (p < 0.0001), and high levels of plasma proteins (p < 0.001). This emerging canine disease constitutes an important public health concern among veterinarians and active surveillance is advised to explore its zoonotic potential.

Epizootiological observations on canine microfilaremia in Gujarat state, India

Aim

The present investigation was conducted to study the prevalence of microfilaremia in dogs in Gujarat.

Materials and Methods

A total of 418 adult dogs aged between 2 and 14 years with signs of weakness and non-specified complaints, presented at TVCC, Deesa (North Gujarat), Nandini Veterinary Hospital, Surat (South Gujarat), and Private Clinics, Ahmedabad (Central Gujarat), were included in the present investigation for studying the prevalence of microfilaremia from July 2016 to May 2017.

Results

A total of 418 dogs were screened, of which 33 were found positive for circulating microfilariae with the prevalence rate of 7.89% in the population. Among microfilaremic dogs, the finding of microfilariae of Dipetalonema (Acanthocheilonema) reconditum was more common (23 cases; 69.69%) than Dirofilaria immitis (10 cases; 30.30%) making their prevalence in the population of 418 dogs as 5.50% and 2.39%, respectively. Breed-wise distribution of microfilaremic dogs revealed that 12 (36.36%), 8 (24.24%), 5 (15.15%), 4 (12.12%), 2 (6.06%), 1 (3.03%), and 1 (3.03%) cases were observed in Pomeranian, non-descript, German Shepherd, Labrador, Great Dane, Lhasa Apso, and Pug dogs, respectively. Of 10 cases of D. immitis, 5, 2, 2, and 1 were observed in Pomeranian, Labrador, non-descript, and Great Dane dogs, respectively. Cases of Dipetalonema reconditum were highest in Pomeranian (7), followed by non-descript (6), German Shepherd (5), Labrador (2), Great Dane (1), Lhasa Apso (1), and Pug (1). Age-wise distribution recorded significantly (p≤0.01) higher number of cases in adult dogs (4-14 years) for D. immitis (30.30%) and D. reconditum (39.39%). Sex-wise distribution of microfilaremic dogs showed that male (22/33, 66.66%) was more predisposed to microfilaremia rather than females (11/33, 33.34%). It is apparent from the study that the number of dogs with microfilaremia due to D. reconditum was significantly (p≤0.01) higher than that of D. immitis.

Conclusion

The present study revealed that microfilaremia due to D. immitis and D. reconditum is prevalent in the state of Gujarat. The infection with D. immitis was associated with severe lung and cardiac pathological manifestations.

Epidemiological aspects of canine dirofilariasis in the north of iran

BACKGROUND

Dirofilaria immitis is an important parasite in dog and other carnivores. Our objective was study on incidence and periodicity of heartworm in north of Iran and using other methods for its diagnosis in addition to Parasitology exam.

METHODS

This survey spanned two years, between 2006 and 2008. Blood samples were collected from 431 stray dogs distributed along north of Iran, the coastal areas of the Caspian Sea. The Knott's modified test was used for diagnosis of D. immitis and other filariae. Meanwhile, the periodicity of microfilaria in peripheral blood circulation was calculated and the imaging diagnosis techniques of four dogs that had positive results were done.

RESULTS

Diagnostic parasitology results indicated that 16.01% of stray dogs were microfilaremic. Two different microfilariae were diagnosed: D. immitis in 13.69%, Dipetalonema reconditum in 1.86% and in 0.46% both of them. There was no statistically significant between infection to fiariae with sex and age of dogs. Also study on the periodicity of the presence of microfilaria in peripheral circulation showed that the highest rate of those was at 1 am and the lowest rate at 12 pm. Radiographic study showed distinctive signs with varied degrees of severity included: Tortuous and enlargement of main and lobar pulmonary artery, pulmonary parenchymal lesions and Right side heart enlargement that confirmed in electrocardiography. Also in echocardiographic images observed short parallel-sided images with the appearance of equal signs that indicated the presence of the heartworm.

CONCLUSION

These results showed that to obtain a reliable diagnosis of heartworm infection, imaging tests could support parasitological exams.