Elsevier

Veterinary Parasitology

Volume 74, Issues 2–4, 31 January 1998, Pages 133-142
Veterinary Parasitology

A survey of tick-borne bacteria and protozoa in naturally exposed dogs from Israel

https://doi.org/10.1016/S0304-4017(97)00149-0Get rights and content

Abstract

Antibody reactivity against seven bacterial or protozoal pathogens was measured in sera derived from 40 dogs suspected of a tick-borne disease. Sera from 73% (29/40) of the dogs reacted with three or more test antigens. Seroreactivity was most prevalent to Babesia canis antigen (90%) followed by Babesia gibsoni (75%), Ehrlichia canis (63%), Rickettsia conorii—Moroccan strain (58%), Rickettsia conorii—Israeli strain no. 2 (28%), Borrelia burgdorferi (10%) or Bartonella vinsonii (berkhoffii) (10%). Seroconversion documented in seven dogs, supported an acute phase diagnosis of ehrlichiosis in four dogs, R. conorii infection in three dogs and babesiosis in one dog. In the remaining dogs, correlation of clinical abnormalities with increased seroreactivity was not established through the design of this study. Although Lyme borreliosis has not been reported in people in Israel, Western blot analysis for antibodies reactive to B. burgdorferi identified genus-specific antiflagellin antibodies indicating that dogs in Israel are exposed to a Borrelia species. Identification of species-specific seroreactivity was not possible and infection with a Borrelia species other than B. burgdorferi is likely. Seroreactivity to B. vinsonii (berkhoffii) in dogs outside the USA is reported here for the first time.

Introduction

Tick-borne pathogens are a major cause of disease in many regions of the world including Israel. Lyme disease, granulocytic ehrlichiosis and Rocky Mountain spotted fever are diseases of comparative medical importance since both dogs and humans contract illness through tick infestation. Other tick-borne infectious organisms such as Ehrlichia canis, Babesia canis and Babesia gibsoni are pathogenic to canids but not to humans. Dogs which spend much of their time outdoors and often are allowed to roam freely are exposed extensively to ticks during the tick season which varies in length depending on climatic conditions. Ticks can survive for long periods of time off a vertebrate host, and may then find a new host. Many tick species that infest dogs may feed on other hosts including domestic livestock, wildlife carnivores, rodents, and man. Acaricidal treatment of dogs by their owners is often ineffective or completely lacking.

Tick-borne pathogens may cause an acute or chronic disease in susceptible hosts. Other hosts recover spontaneously by elimination of the infective organisms, or may develop a carrier state. Exposure to a pathogen, regardless of whether it results in elimination of the causative agent, or in a state of subclinical infection, produces in most instances an antibody response that can be measured in the animal's serum.

This report describes antibody prevalence to six tick-borne pathogens in dogs from Israel, in which a tick-borne disease was suspected based on clinical history, physical examination and blood tests results. E. canis is a rickettsia that is known to cause a severe disease in dogs (Troy and Dru Forrester, 1990). Canine ehrlichiosis was first described in dogs from Israel in 1972 (Klopfer and Nobel, 1972). Recently, an Israeli strain of E. canis (Keysari et al., 1995) and the prevalence of antibodies against this pathogen in dogs from Israel have been reported (Baneth et al., 1996). B. canis and B. gibsoni are two piroplasm parasites of the red blood cells (RBC) of dogs (Breitschwerdt, 1990). Although B. canis is recognized as a pathogen of dogs in Israel, B. gibsoni has not been reported from this country. B. gibsoni infection has been described in dogs from many regions including: Egypt, the Far East (Purnell, 1981), southern Africa (Matthewman et al., 1993), and North America (Conrad et al., 1991). Rickettsia conorii, the causative agent of Mediterranean spotted fever in humans, is transmitted by the tick Rhipicephalus sangineus and antibody reactivity against this spotted-fever group rickettsial organism has been reported also in dogs (Keysari et al., 1988). Unlike Rickettsia rickettsii which causes Rocky Mountain spotted fever in both dogs and humans, it is not known whether R. conorii can cause disease in dogs. Two strains of R. conorii, one from Morocco and another from Israel (Israel 2) were used in this study. Borrelia burgdorferi is the causative agent of Lyme disease in humans and dogs. Antibody reactivity against a Borrelia sp. in one dog in Israel has been reported previously (Harrus and Bark, 1994) but little evidence concerning the identity of the actual Borrelia was presented and it is not clear whether the reported dog was infected by B. burgdorferi, a different Borrelia species or a serologically cross-reacting organism. Bartonella vinsonii berkhoffii is a gram-negative bacteria that has been isolated from the blood of dogs in North America and is associated with endocarditis (Breitschwerdt et al., 1995). Seroepidemiologic evidence of the transmission of B. vinsonii berkhoffii by ticks has been reported (Pappalardo et al., 1997).

In addition to describing the association between clinical findings in dogs suspected of tick-borne disease and seroreactivity to selected tick-borne pathogens, our aims were to determine the seroprevalence of tick-transmitted pathogens among dogs suspected of tick-borne infection in Israel, and to provide serologic data suggesting the presence of tick-transmitted pathogens that have not previously been described in Israel.

Section snippets

Dogs sampled

Paired, acute and convalescent, (n=20) or single (n=20) serum samples were obtained from dogs suspected of tick-borne illness that were admitted for examination at the Hebrew University Veterinary Teaching Hospital in Israel during the spring and summer of 1994. Initial examination of the dogs consisted of a comprehensive physical examination which included palpation of the prescapular and popliteal lymph nodes, abdominal palpation for an observation of the spleen size, and an inspection of the

Results

Of the 40 dogs in this study, 45% (18/40) were males and 55% (22/40) females. Thirty percent of the dogs were of mixed breeding and the remaining 70% were of various breeds with no particular breed represented by more than six dogs. The age distribution, clinical and hematological abnormalities are presented in Table 1.

Two dogs (in youngest age group) reacted with no antigens (Table 2) and no dog reacted with all of the antigens. Seventy three percent (29/40) reacted with three or more antigens

Discussion

Our findings demonstrate that most of the dogs in this study had antibody titers to several tick-borne pathogens and were therefore presumably exposed to a variety of vector-transmitted organisms. The demonstration of antibodies reactive with a certain antigen in the serum of a dog may be due to a past exposure which resolved, a current subclinical infection, or recent `active' infection. As clinical signs of several tick-borne diseases of dogs, including ehrlichiosis, babesiosis and Rocky

Acknowledgements

We thank Robin Gager, Dr. Michael Levy and Dr. Jay F. Levine from the North Carolina State University for their technical assistance. We also thank Dr. Tom Schwan, National Institutes of Health, for donating the anti-p39 monoclonal antibodies and Dr. David H. Walker from the University of Texas, Medical Branch, Galveston, TX for providing the R. conorii strains used in this study.

References (18)

  • G Baneth et al.

    Survey of Ehrlichia canis antibodies among dogs in Israel

    Vet. Rec.

    (1996)
  • Breitschwerdt, E.B., 1990. Babesiosis. In: Greene, C.E. (Ed.), Clinical Microbiology and Infectious Diseases of the Dog...
  • E.B Breitschwerdt et al.

    Natural infection with Borrelia spirochetes in two dogs from Florida

    J. Clin. Microbiol.

    (1994)
  • E.B Breitschwerdt et al.

    Endocarditis in a dog due to infection with a novel Bartonella subspecies

    J. Clin. Microbiol.

    (1995)
  • P Conrad et al.

    Hemolytic anemia by Babesia gibsoni infection in dogs

    J. Am. Vet. Med. Assoc.

    (1991)
  • S Harrus et al.

    Canine Lyme borreliosis in Israel

    Isr. J. Med. Sci.

    (1994)
  • A Keysari et al.

    Prevalence of antibodies to Rickettsia conorii in dogs in Israel and its relation to outbreaks in man

    Refuah Vet.

    (1988)
  • A Keysari et al.

    The first isolation, in vitro propagation, and genetic characterization of Ehrlichia canis in Israel

    Vet. Parasitol.

    (1995)
  • U Klopfer et al.

    Canine ehrlichiosis (canine tropical pancytopenia) in Israel

    Refuah Vet.

    (1972)
There are more references available in the full text version of this article.

Cited by (74)

  • Simultaneous differential detection of canine blood parasites: Multiplex high-resolution melting analysis (mHRM)

    2020, Ticks and Tick-borne Diseases
    Citation Excerpt :

    Tick-borne diseases are among the most significant health problems for dogs and humans and result in significant incidences of morbidity and mortality (Chomel, 2011). Common tick-borne pathogens for dogs include Babesia spp., Hepatozoon canis, Ehrlichia canis, and Anaplasma platys, leading to diseases identified as babesiosis, hepatozoonosis, ehrlichiosis, and anaplasmosis, respectively (Baneth et al., 1998; Yabsley et al., 2008; Chomel, 2011). These pathogens comprise of two major taxa of haemoparasite: (i) protozoans (Babesia spp. and H. canis), and (ii) Rickettsia (E. canis and A. platys) (Baneth et al., 1998; Chomel, 2011), and infect domestic dogs through the parasitic feeding of the brown dog tick, Rhipicephalus sanguineus sensu lato (Lewis et al., 1977; Nava et al., 2015).

  • The risk of vector-borne infections in sled dogs associated with existing and new endemic areas in Poland. Part 1: A population study on sled dogs during the racing season.

    2014, Veterinary Parasitology
    Citation Excerpt :

    Interestingly, the influence of host age was very similar to the results of our previous study, with the number of positive dogs increasing with age, despite applied anti-tick treatment (Welc-Faleciak et al., 2009). Although B. canis infections are reported worldwide (Adaszek and Winiarczyk, 2008a,b; Beck et al., 2009; Baneth et al., 1998; Bourdoiseau, 2006; Cacciò et al., 2002) comparison of the prevalence of this parasite between countries is difficult, because of (1) the lack of population studies in dogs, (2) the endemic distribution of the disease and its vector D. reticulatus, and (3) due to the use of different detection methods. In Europe, a relatively high prevalence of B. canis infections, similar to that found in our study, was reported locally in France, which is also an ‘old’ endemic region (Halos et al., 2013).

  • First detection of Ixodes ricinus on beef cattle in Israel

    2013, Veterinary Parasitology
    Citation Excerpt :

    Among the diseases that are transmitted by I. ricinus, babesiosis – which was described in Europe in cattle, rodents and humans – and is caused by B. divergens, B. microti, B. odocoilei and B. venatorum (Gigandet et al., 2011; Gray et al., 2002; Hunfeld and Brade, 2004; L’Hostis and Seegers, 2002) – was not previously found in Israel. Lyme disease, caused by Borellia burgdorferi and transmitted by I. ricinus, has not been diagnosed in Israel, but serological assays of dogs revealed the presence of antibodies to Borrelia species other than B. burgdorferi (Baneth et al., 1998). Occurrence in humans and domestic animals of Q fever – another disease transmitted by I. ricinus – was also reported in Israel (Amitai et al., 2010; Oren et al., 2005).

  • Four promising antigens, BgP32, BgP45, BgP47, and BgP50, for serodiagnosis of Babesia gibsoni infection were classified as B. gibsoni merozoite surface protein family

    2012, Parasitology International
    Citation Excerpt :

    In some cases, fatalities have been reported in infected dogs. Transmission route of this disease is mainly by tick-bites [1,2]. B. gibsoni infection is an emerging disease and has been reported in Asia, Africa, the United States, Europe, and Australia [3–5].

View all citing articles on Scopus
View full text