Haematological parameters in stray dogs seropositive and seronegative to Ehrlichia canis in North Trinidad.

In view of the fact that stray dogs are a reservoir for many diseases, this study was undertaken to determine the prevalence of Ehrlichia canis in stray dogs in North Trinidad and to evaluate the diagnostic implications of haematological alterations associated with seropositivity. Overall, 41 (44.6%) of 92 stray dogs were seropositive to E. canis by the indirect immunofluorescent antibody test. Dogs, one year of age and older (59.7%) were more likely to be seropositive than dogs less than one year old (13.3%) (p<0.001). No significant differences in seropositivity between females and males were found. The odds ratios showed that seropositive dogs were 3.34 (CI 95%; 1.33-8.59) and 5.17 (CI 95%; 0.19-1.26) times more likely to have low platelet counts and elevated total serum protein concentrations (p=0.014 and p<0.001, respectively) than seronegative dogs. Lower mean platelet counts and a higher mean total protein concentration were associated with seropositivity (p<0.01). Mean eosinophil and segmented neutrophil counts were elevated in dogs that tested negative for E. canis antibodies (p=0.002 and p<0.005, respectively). Other haematological parameters were not different between the 2 groups. The high percentage of stray dogs infected with E. canis should alert veterinarians to the potential risk of transmission of the disease. A comprehensive study possibly using molecular methods such as nested PCR should be undertaken to determine how co-infection with other pathogens may alter haematological profiles. In general, control of ticks and stray dog populations may help to control the spread of tick-borne diseases.

The application of PCR and reverse line blot hybridization to detect arthropod-borne hemopathogens of dogs and cats in Trinidad.

Arthropod-borne diseases are important causes of morbidity and mortality of companion animals in Trinidad. As clinical signs are vague, more sensitive methods to diagnose these diseases based on the polymerase chain reaction (PCR) followed by reverse line blot hybridization (RLB) of amplified products are being developed. An RLB of 14 oligonucleotide probes coupled with polymerase chain-amplified regions of 16S rRNA or 18S rRNA genes of hemoparasites from cats and dogs detected Ehrlichia canis, Anaplasma platys, Babesia canis vogeli, feline mycoplasmas ("Candidatus Mycoplasma haemominutum,"Mycoplasma haemofelis), and some unknown species within the Babesia/Theileria group and the Anaplasma/Ehrlichia tribe. Amplified products were obtained from blood samples collected from 348 dogs and 15 cats. Overall, hemopathogen DNA was detected in 92 (26.4 per cent) dogs and six (40.0 per cent) cats. E. canis (49, 14.1 per cent) and feline mycoplasma (5, 33.3 per cent) DNA were most frequently identified in dogs and cats, respectively. B. canis vogeli (1, 6.7 per cent) and E. canis (1, 6.7 per cent) were also detected in cats. Mixed infections of Anaplasma/Ehrlichia sp. and Babesia sp. were present in five (1.4 per cent) dogs, while mixed infections of the feline mycoplasmas were present in two (13.3 per cent) cats, one of which was also positive for E. canis. Pyrexia was significantly associated with a positive RLB result in dogs (P= 0.00, chi(2), 1 df). This is the first reported application of macro-arraying techniques to detect arthropod-borne hemopathogens of companion animals in the Americas and the first detection of DNA of B. canis vogeli and E. canis in cats in Trinidad.

The application of PCR and reverse line blot hybridization to detect arthropod-borne hemopathogens of dogs and cats in Trinidad.

Arthropod-borne diseases are important causes of morbidity and mortality of companion animals in Trinidad. As clinical signs are vague, more sensitive methods to diagnose these diseases based on the polymerase chain reaction (PCR) followed by reverse line blot hybridization (RLB) of amplified products are being developed. An RLB of 14 oligonucleotide probes coupled with polymerase chain-amplified regions of 16S rRNA or 18S rRNA genes of hemoparasites from cats and dogs detected Ehrlichia canis, Anaplasma platys, Babesia canis vogeli, feline mycoplasmas ("Candidatus Mycoplasma haemominutum,"Mycoplasma haemofelis), and some unknown species within the Babesia/Theileria group and the Anaplasma/Ehrlichia tribe. Amplified products were obtained from blood samples collected from 348 dogs and 15 cats. Overall, hemopathogen DNA was detected in 92 (26.4%) dogs and six (40.0%) cats. E. canis (49, 14.1%) and feline mycoplasma (5, 33.3%) DNA were most frequently identified in dogs and cats, respectively. B. canis vogeli (1, 6.7%) and E. canis (1, 6.7%) were also detected in cats. Mixed infections of Anaplasma/Ehrlichia sp. and Babesia sp. were present in five (1.4%) dogs, while mixed infections of the feline mycoplasmas were present in two (13.3%) cats, one of which was also positive for E. canis. Pyrexia was significantly associated with a positive RLB result in dogs (P= 0.00, chi(2), 1 df). This is the first reported application of macro-arraying techniques to detect arthropod-borne hemopathogens of companion animals in the Americas and the first detection of DNA of B. canis vogeli and E. canis in cats in Trinidad.