Clinical, haematological and biochemical findings in tigers infected by Leishmania infantum

Abstract

Background A large number of animal species are susceptible to Leishmania infantum (Kinetoplastida, Trypanosomatidae) in endemic areas, including domestic and wild felids such as tigers (Panthera tigris). Knowledge on the infection of this endangered species is still at its infancy, and therefore this study aims to identify clinical presentation and clinicopathological findings of tigers naturally infected by L. infantum. Results Tigers either L. infantum-positive (group A) or -negative (group B) were apparently healthy or presented visceral leishmaniasis unrelated conditions, except for one animal in which a large non-healing cutaneous lesion was observed. However, histological exam and immunohistochemistry carried out on the lesion excluded the presence of L. infantum amastigotes. Biochemical analysis showed that the average concentration of total proteins, globulins and haptoglobin were significantly higher (p<0.01, p=0.01 and p=0.02, respectively), while the albumin/globulin ratio significantly lower (p=0.05) in group A compared with group B. The biochemical alterations were partially confirmed by the serum protein electrophoresis results revealing a significant increase in the total protein value (p=0.01) and hypergammaglobulinemia (p=0.03) but an unmodified albumin/globulin ratio in group A.Conclusions In this study tigers infected by L. infantum have shown to be mainly asymptomatic. The absence of clinical signs may lead veterinarians to overlook leishmaniasis in animals kept in captivity. Therefore, diagnostic and screening tests as serology should be part of routinely surveillance programs to be performed on tigers in zoological gardens located in endemic areas. Though only few protein-related laboratory abnormalities were recorded in infected animals, they could provide diagnostic clues for a first suspicion of L. infantum infection in tigers. Indeed, considering the high risk of zoonotic transmission in heavily frequented environment as zoos, a prompt diagnosis of L. infantum infection is of pivotal importance.

Serum amyloid A levels and alpha 2 and gamma globulins on serum protein electrophoresis in cats exposed to and infected with Leishmania infantum

“…SAA is substantially increased in cats with clinical signs of vector-borne infections, such as those caused by Hepatozoon felis and Babesia vogeli, compared to uninfected and subclinically infected cats [25]. Recently, protein-related laboratory abnormalities were reported in tigers naturally infected by L. infantum [26]. While information on serum APP levels in cats infected with vector-borne pathogens remains limited [25], these findings may suggest a useful diagnostic and prognostic role for SAA.…”

Serum Amyloid A levels and α2- and Gamma globulins on Serum Protein Electrophoresis in cats exposed to and infected with Leishmania infantum

“…SAA is substantially increased in cats with clinical signs of vector-borne infections such as Hepatozoon felis and Babesia vogeli, compared to uninfected and infected asymptomatic cats (Vilhena et al, 2017). Recently, protein-related laboratory abnormalities were reported in tigers naturally infected by L. infantum (Cavalera et al, 2020). Information on serum APP levels in cats infected with vector-borne pathogens remains limited (Vilhena et al, 2017), however these ndings may suggest a useful diagnostic and prognostic role for SAA.…”