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Background: In Argentina, only very few reports are available for canine tick-borne diseases where most are related to parasitic diseases. The objective of this survey was to investigate the prevalence of tick-borne pathogens in 70 dogs from Santa Fé and Córdoba, Argentina., Methods: Microscopic blood smear examination as well as polymerase chain reaction (PCR) amplification using species-specific markers of Anaplasma, Babesia, Bartonella, Borrelia, Ehrlichia, Francisella, Mycoplasma (hemotropic group) and Rickettsia, followed by DNA sequencing were used to establish the prevalence of each infecting pathogen., Results: Blood smear analysis showed 81% (57/70) prevalence of structures morphologically compatible with hemotropic mycoplasmas. No structures resembling either piroplasms or Anaplasma/Ehrlichia were detected. Hemotropic mycoplasma species (Mycoplasma haematoparvum, Mycoplasma haemocanis and Mycoplasma suis) were the most prevalent pathogens detected with an overall prevalence of 77.1%. Anaplasma platys was detected and identified in 11 of the 70 dogs (15.7%), meanwhile two Bartonella spp. (B. clarridgeiae and an uncharacterized Bartonella sp.) and Babesia vogeli were detected at 3 and 7% prevalence, respectively., Conclusions: The work presented here describes a high molecular prevalence for hemotropic mycoplasma species in each of the five locations selected. Three Mycoplasma spp., including Mycoplasma suis, reported for the first time in dogs have been identified by DNA amplification and sequencing. This study highlights the risk that these bacterial pathogens represent for companion animals and, due to their potential zoonotic nature, also for people.

Mycoplasma suis is a swine erythrocyte obligatory parasite. Its presence may result in chronic or acute anaemia in different pig categories. It is considered that the postweaning multisystemic wasting syndrome (PMWS) is caused by porcine circovirus type 2, but some aspects of the pathogenesis remain unknown. PMWS signs are impaired weight gain, anaemia and jaundice in 5 to 12 week-old pigs that suffer from immunosuppression and bacterial co-infections. The pigs with signs of these diseases on three porcine farms were studied. Compatible M. suis forms in blood smears and typical PMWS lesions in tissue cuts were seen. This is the first communication of the clinical association between these two entities.

In Argentina pseudorabies is an endemic disease. Routine diagnosis is made by virus isolation. It is a very long procedure to carry out and gives variable results depending on the quality of sample, hence the need for effective techniques, which are rapid and not dependent on the isolation of infectious virus. The polymerase chain reaction (PCR) technique has provided a sensitive, specific and rapid mean to detect DNA sequences. This study describes a PCR method for detection of pseudorabies virus sequences in swine tissues. In order to determine the presence of suid herpesvirus-1 DNA and antigens, 36 tissue samples collected from 19 dead pigs, with signs of pseudorabies infection, were examined by PCR, virus isolation and indirect immunofluorescence, respectively. Fifteen out of 19 pigs were positive at least for one tissue by PCR (15/19) while only three pseudorabies virus strains were isolated (3/19). All the amplified products were identified by digestion with Sa/l and hybridization. The method described herein circumvents tedious viral isolation and DNA purification and would be a valuable tool for rapid diagnosis, since it would take less than 5 h to reach an accurate result even in poorly preserved tissue samples.

Various methods have been employed for the diagnosis of pseudorabies in Argentina. A large serological survey was carried out by means of enzyme-linked immunosorbent assay (blocking ELISA) and virus neutralisation (VN). An outbreak was studied by virological and immunohistochemical methods and in situ nucleic acid hybridisation.