Hаematologic indices in clinically healthy outdoor dogs exposed to vector-borne pathogens

Abstract

Haematologic abnormalities possibly associated with exposure to vector-borne pathogens are rarely reported in clinically healthy outdoor dogs. Therefore, we analysed changes in the complete blood count (CBC) of clinically healthy outdoor dogs seroreactive to Anaplasma spp. and Babesia spp., with or without microfilariosis. Stray, shelter and hunting dogs, 81 in total, that were polymerase chain reaction negative for Anaplasma spp. and Babesia spp. were divided into groups according to their seroreactive status and results of a modified Knott’s test: seronegative to both Anaplasma spp. and Babesia spp. SN (N=26); seroreactive to A. phagocythophilum SR-A (N=12); seroreactive to B. canis, B. gibsoni and/or B. vogeli SR-B (N=25); and seroreactive to both of the pathogens SR-AB (N=8). These four groups were negative to microfilariosis, unlike the fifth group, seroreactive to either or to both of the pathogens and with microfilariosis SR-M (N=10). The frequencies of CBC alterations among all analysed dogs were: 0.35 – leucocytosis, 0.44 – granulocytosis, 0.28 – anaemia, 0.74 – microcytosis, 0.37 – increased mean cell haemoglobin concentration (MCHC) and 0.33 – thrombocytopenia. The frequency of alterations did not differ across the groups. An exception was the SR-M group wherein increased MCHC peaked with a frequency of 0.80, while in the other four groups, the frequency ranged between 0.10 and 0.50. Clinically healthy outdoor dogs have multiple CBC abnormalities, consistent with stress and low-level chronic inflammation, but not associated with a previous exposure to Anaplasma spp. or Babesia spp. The presence of microfilaria increases haemolysis in vitro.

Klinički zdravi psi koji borave na otvorenom i koji su izloženi patogenima koje prenose vektori mogu imati hematološke premećaje vezane za dejstvo tih patogena. Ipak, hematološke pretrage se retko izvode na toj populaciji pasa. Stoga je cilj našeg rada bio da utvrdimo promene u krvnoj slici zdravih pasa lutalica, pasa smeštenih u azilima i lovačkih pasa, seroreaktivnih na uzročnike bolesti iz rodova Anaplasma i Babesia, sa ili bez mikrofilarioze. U ovom radu je ispitana krvna slika 81 psa. U studiju su uključeni psi kod kojih lančanom reakcijom polimerizacije nije pokazano prisustvo DNK Anaplasma spp. i Babesia spp. Psi su prema serološkom statusu raspoređeni u sledeće grupe: seronegativni na Anaplasma spp. i Babesia spp. SN (N=26), seroreaktivni na A. phagocytophilum SR-A (N=12), seroreaktivni na B. canis, B. gibsoni i/ili B. vogeli SR-B (N=25) i seroreaktivni na oba navedena patogena SR-AB (N=8). Ove četiri grupe su bile negativne na mikrofilariozu, dok je peta grupa, seroreaktivna na neki ili oba patogena imala i mikrofilarije SR-M (N=10). Učestalost promena kompletne krvne slike među svim ispitivanim psima je bila sledeća: 0,35 za leukocitozu, 0,44 za granulocitozu, 0,28 za anemiju, 0,74 za mikrocitozu, 0,37 za povećanu prosečnu koncentraciju hemoglobina u eritrocitima i 0,33 za trombocitopeniju. Grupe se nisu razlikovale u pogledu učestalosti navedenih promena. Izuzetak je grupa SR-M u kojoj je učestalost povećanja vrednosti za prosečnu koncentraciju hemoglobina u eritrocitima iznosila 0,80. U ostale četiri grupe ta učestalost je iznosila između 0,10 i 0,50. Zaključak je da ispitivani psi imaju višestruke poremećaje krvne slike koji najverovatnije odražavaju stres i nizak stepen hronične inflamacije, ali ne i vezu sa prethodnim kontaktom sa Anaplasma spp. i Babesia spp. Prisustvo mikrofilarija izaziva hemolizu in vitro.