ISRAEL JOURNAL OF
VETERINARY MEDICINE
Abstract of papers presented at the 31st Symposium of Veterinary Medicine in memory of
Prof. Amnon Pazi, March 2007.
Chairperson Prof. K. Perk
Founder and honorary director, Koret School of Veterinary Medicine.
CASE-CONTROL RETROSPECTIVE STUDY OF CANINE LEISHMANIASIS IN
ISRAEL*
Baneth G., Milner-Roterman A. and Klement E.
School of Veterinary Medicine, Hebrew University of Jerusalem, Israel
Visceral leishmaniasis (VL) is a zoonotic parasitic disease that infects humans and dogs and is
transmitted by sand flies .Leishmania infantum is the causative agent of visceral
leishmaniasis in Israel and the Mediterranean region. The aim of this study was to evaluate
the characteristic findings in dogs with VL as compared to dogs admitted with other
conditions to the Hebrew University Veterinary Teaching Hospital (HUVTH) .To our best
knowledge ,this is the first case-control study of canine leishmaniasis.
The medical records of 72 dogs diagnosed with VL at the HUVTH during 1995-2004 were
retrospectively reviewed and compared to a control group of sick dogs (n=134) diagnosed
with other diseases. For every dog diagnosed with VL, 2 dogs admitted on the same day
were selected as controls .Statistical analyses were performed using the X 2test or logistic
regression.
No significant difference was found between the mean ages of the VL group (66.57 months)
vs. the control group (65.72 months). However, the age distributions were significantly
different( p<0.001) with the VL group having a narrower age range that did not include
immature dogs. A significant difference was found in the gender distribution between the VL
and control groups (p=0.027). Males comprised 68% (49/72) of the dogs in the VL group
whereas only 51% (69/134) of the control dogs were males. Dogs with VL were heavier
(mean 25.8kg) than control dogs (22.02kg) (p<0.0001 .)The Rottweiler breed was
significantly over-represented (p=0.023) in the study group as compared to the controls. The
disease had a primarily rural pattern of distribution, with a significantly higher percentage
(p<0.0001) of dogs originating from rural areas versus cities, as compared to the control
group. Most infected dogs originated from the western slopes of the Judean and Samarian
mountains or the Galilee whereas the majority of the control dogs originated from the
Coastal Plain.
The main presenting clinical problem in the VL group was dermal abnormalities (90%). Other
presenting problems in dogs with no visible dermal disease included: ocular abnormalities
(4%), epsitaxis (3%) and renal failure (1.5%). The most common clinical signs were:
exfoliative dermatitis (84%), lymphadenomegaly (78.5%), weight loss (58.5%) , periorbital
alopecia (50%), diffuse alopecia (40%,) ocular abnormalities (38.5%), palpable splenomegaly
(37%), facial ulceration (31.5%), skin ulceration (27%), PU\PD (17%), epistaxis (17% ,)
arthropathies (13%) and onychogryphosis (11.5%). Renal disease was found among %21 of
the VL group versus 3.5% in the control group (p<0.0001 .)
Comparison of laboratory findings revealed that the albumin/globulin ratio was lower than
0.7 in 90% of the dogs with VL and only in 31.5% of the controls (p<0.0001).
Hyperglobulinemia and hypoalbuminemia were found in 73% and 78.5% of the VL group vs.
9% and 30% ,respectively in the control group (p< 0.0001). Eighty % of the VL dogs were
anemic vs. 35% of the controls (p.)0.0001< Anemia was mainly normocytic normochromic.
Thrombocytopenia was significantly more frequent in the VL group (p< 0.003). In addition,
Hepatozoon canis infection was diagnosed more frequently in the VL group (p=0.043).
Necropsy of dogs with VL (n=29) revealed pathologic abnormalities in the skin (66%), kidney
(59%), spleen ,)%45( liver (34%), heart (24%) and lungs (21%), with lymphadenomegaly
.)%55(
Serology by crude Leishmania antigen ELISA was positive in 99% of the VL cases. PCR
targeting the internal transcribed spacer1 (ITS1) region was positive in 97% of the cases
whereas culture was positive in 89%, and detection of the parasite by cytology in only 45% .
In conclusion, the case-control design of this study revealed significant differences between
dogs with symptomatic leishmanisis and dogs with other disease conditions admitted to the
HUVTH. The clinical presentation and characteristics of this infection and the data on the
efficiency of diagnostic methods will help clinicians and diagnosticians by highlighting the
features of this disease and raising the suspicion index when compatible clinical findings are
presented .