An Update on the Serodiagnosis of Canine Lyme Borreliosis

The first report of canine Lyme borreliosis was published in 1984, and since that time there have been numerous reports. Clinical manifestations have varied, and serology is often used to make the diagnosis. This review is designed to inform veterinary clinicians about the current serologic tests and their limitations. In endemic areas, the fact that up to 50% of the canine population can be asymptomatic, yet seropositive, suggests that positive antibody titers do not necessarily indicate the presence of disease. Instead, the presence of a positive antibody titer should be considered evidence of exposure to the agent. Many dogs apparently are exposed to the agent of Lyme borreliosis but do not come down with the disease. Immunoblots are not able to distinguish between infection versus exposure. Newer diagnostic tests, such as antigen assays, are being evaluated. However, the fact that spirochetes have been isolated from 8% of asymptomatic dogs living in an endemic area is evidence that these tests will also need to be cautiously interpreted. Our inability to characterize the relationship between clinical signs and serology has hampered our understanding of canine Lyme disease. Presently, the diagnosis should be one of exclusion. A diagnosis of Lyme borreliosis should be considered confirmed only when other diseases are completely ruled out.     

ACVIM small animal consensus statement on Lyme disease in dogs: diagnosis, treatment, and prevention

The purpose of this report is to offer a consensus opinion of ACVIM diplomates on the diagnosis, treatment, and prevention of Borrelia burgdorferi infections in dogs (canine Lyme disease). Clinical syndromes known to commonly be associated with canine Lyme disease include polyarthritis and glomerulopathy. Serological test results can be used to document exposure to B. burgdorferi but not prove illness. Although serum enzyme-linked immunosorbent assay/indirect fluorescent antibody assay titers can stay positive for months to years after treatment, quantitative C6 peptide antibody paired tests need more study. Serological screening of healthy dogs is controversial because it can lead to overdiagnosis or overtreatment of normal dogs, most of which never develop Lyme disease. However, serological screening can provide seroprevalence and sentinel data and stimulate owner education about tick infections and control. Although it is unknown whether treatment of seropositive healthy dogs is beneficial, the consensus is that seropositive dogs should be evaluated for proteinuria and other coinfections and tick control prescribed. Tick control can include a product that repels or protects against tick attachment, thereby helping to prevent transmission of coinfections as well as Borrelia spp. Seropositive dogs with clinical abnormalities thought to arise from Lyme disease generally are treated with doxycycline (10 mg/kg q24h for 1 month). Proteinuric dogs might need longer treatment as well as medications and diets for protein-losing nephropathy. The ACVIM diplomates believe the use of Lyme vaccines still is controversial and most do not administer them. It is the consensus opinion that additional research is needed to study predictors of illness, "Lyme nephropathy," and coinfections in Lyme endemic areas.     

Canine haemobartonellosis, canine hepatozoonosis, and feline cytauxzoonosis

Although Lyme borreliosis (Lyme disease), ehrlichiosis, Rocky Mountain spotted fever, and babesiosis occur more frequently in dogs or cats, from a clinical standpoint, other tick-borne diseases such as canine haemobartonellosis, canine hepatozoonosis, and feline cytauxzoonosis are just as important to recognize. Information concerning these less common tick-borne diseases are discussed, including their causative agents and their relationship to disease pathogenesis, diagnosis, treatment, and prevention.     

Detection of Borrelia burgdorferi DNA in tissues from dogs with presumptive Lyme borreliosis

OBJECTIVE: To develop a quantitative PCR assay for detection of Borrelia burgdorferi DNA in formalin-fixed, paraffin-embedded tissues; compare results of this assay with results of immunohistochemical staining of tissues from seropositive dogs; and determine whether B burgdorferi DNA could be detected in renal tissues from dogs with presumptive Lyme nephritis. DESIGN: Cohort study. SAMPLE POPULATION: Archived tissue samples from 58 dogs. PROCEDURES: A quantitative PCR assay was performed on formalin-fixed, paraffin-embedded tissue sections from the dogs. Results were compared with results of immunohistochemical staining, B burgdorferi serostatus, clinical signs, and necropsy findings. RESULTS: 38 dogs were classified as having positive or equivocal results for Lyme borreliosis, and 20 were classified as having negative results on the basis of clinical signs, serologic findings, and pathologic abnormalities. Borrelia burgdorferi DNA was amplified from tissue samples from only 4 (7%) dogs, all of which had been classified as having positive or equivocal results for Lyme borreliosis and had signs of presumptive Lyme nephritis. Results of PCR assays of renal tissue were positive for only 1 dog, and there was no agreement between results of immunohistochemical staining (ie, detection of B burgdorferi antigen) and results of the PCR assay (ie, detection of B burgdorferi DNA) for renal tissues. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that detection of B burgdorferi DNA in formalin-fixed, paraffin-embedded tissues is feasible, but that intact B burgdorferi DNA is rarely found in tissues from naturally infected dogs, even tissues from dogs with presumptive Lyme borreliosis. Further, findings support the contention that Lyme nephritis may be a sterile, immune complex disease.     

Serodiagnosis of Lyme disease in UK dogs

Lyme disease is a chronic, multisystemic, inflammatory disorder of man and animals associated with infection by the tick-borne spirochaete, Borrelia burgdorferi. Lyme disease was recently reported for the first time in a dog in the UK (May and others 1990). Using an enzyme-linked immunosorbent assay (ELISA), we have performed a serological survey to investigate the prevalence of antibodies to B burgdorferi in UK dogs. The survey has shown that dogs from many areas in the UK have serum antibodies to B burgdorferi, that the presence of serum antibodies is associated with known exposure to ticks and that some dogs seropositive for B burgdorferi have clinical signs consistent with Lyme disease. High levels of serum anti-Borrelia antibodies are not diagnostic for canine Lyme disease, but, in association with appropriate clinical signs, they help to confirm the diagnosis in suspected cases.     

Canine borreliosis: a laboratory diagnostic trial

The aim of this study was to investigate samples from dogs suggestive of active canine borreliosis (group A) by culture and PCR and the detection of antibodies against Borrelia burgdorferi sensu lato in order to confirm a presumptive clinical diagnosis of canine borreliosis by laboratory results. Criteria for such a diagnosis were: history of tick exposure, lameness, neurological signs, nephropathy, lethargy, anorexia, and fever. A total of 302 samples comprising EDTA blood, urine, synovial fluid, cerebrospinal fluid, and tissue (skin, synovial membrane, kidney) from 98 dogs (26 with arthritis, 46 with neurological signs, 21 with nephropathy, 5 with non-specific symptoms) were collected and examined. Moreover, 55 healthy dogs (group B) and 236 dogs with symptoms or injuries unlikely to be associated with borreliosis (group C) were included in this study. Blood serum samples collected from all individuals (n=389) were analysed by ELISA. Twenty-one (21%) out of 98 dogs from group A, 4 (7%) out of 55 from group B and 15 (6%) out of 236 dogs from group C were positive for antibodies against B. burgdorferi sensu lato. The seroprevalences between groups A, B and C differed significantly. None of the corresponding samples investigated by PCR and culture were positive for spirochetal DNA or viable spirochetes. Borrelia afzelii was grown from one EDTA-blood sample but the corresponding blood serum sample remained antibody-negative. Consequently, the etiologic role of B. afzelii in this case is unclear. In approximately 40% of the presumptive canine borreliosis cases, other lesions have been found to be responsible for clinical signs. This study affirms that a definitive diagnosis of canine borreliosis cannot be made by clinical symptoms and serology based on a single consultation. Moreover, this study clearly revealed that the diagnostic sensitivity is enhanced by a thorough consideration and exclusion of other diseases.     

Diagnosis of Borrelia‐associated uveitis in two horses

Borrelia burgdorferi, the etiologic agent of Lyme disease is a tick born spirochetal infection. Clinical signs of Lyme borreliosis are uncommon in horses, but when present they are often vague and nonspecific. In horses, Lyme borreliosis has been implicated in musculoskeletal, neurological, reproductive, and ocular disorders, including uveitis, but definitive diagnosis can be challenging as the causative agent is rarely isolated and serologic tests can be unreliable and do not confirm active disease. Here, we report two cases of equine uveitis associated with B. burgdorferi based on the identification of spirochetes within ocular fluids and confirmed with PCR testing. The two cases illustrate some of the challenges encountered in the recognition and diagnosis of equine Lyme borreliosis. Although only one of many possible causes of equine uveitis, Lyme disease should be considered a differential diagnosis, especially in endemic areas. Given the possibility for false negative results of serum tests during uveitis associated with B. burgdorferi and the failure of such tests to confirm active infection, a combination of cytologic assessment, antibody, and/or PCR testing of ocular fluids may be worthwhile if the clinical suspicion for Lyme uveitis is high.     

Lyme borreliosis in cattle and horses: a review of the literature.

A complete search of the literature concerning Lyme borreliosis as it relates to horses and cattle was done. The epidemiology, pathogenesis, immunological response to the disease, diagnosis and treatment are discussed. A review of clinical cases in horses and cattle is presented. Clinical signs of Lyme borreliosis in horses include: chronic weight loss, sporadic lameness, laminitis, low grade fever, swollen joints, muscle tenderness, and anterior uveitis. In addition to those clinical signs, neurological signs such as depression, behavioral changes, dysphagia, head tilt and encephalitis can be seen in chronic cases. Borreliosis occurs in cattle, usually as a herd problem. In acute Lyme borreliosis, cattle often will show a fever, stiffness, swollen joints, and decreased milk production. Chronic weight loss, laminitis and abortion are also possible outcomes of borreliosis in cattle. Diagnosis of clinical Lyme borreliosis is difficult and depends upon recognition of clinical signs, a history of possible exposure, and identification of the spirochete in the affected animal. Since the spirochete is very difficult to culture, confirmation of B. burgdorferi infection often relies on serologic testing. Subclinical seropositive animals do occur, thus confusing the diagnosis. An approach to treatment of cattle and horses with Lyme borreliosis is outlined.     

Canines as sentinels for Lyme disease in San Diego County, California.

Prevalence of Lyme borreliosis in canine sentinels has been shown to correlate with infection in humans. One thousand canine sera (917 dogs, 83 coyotes) obtained from animal control authorities and area veterinarians were screened by ELISA for antibodies to Borrelia burgdorferi. Results were validated by Western blot and indirect fluorescent antibody (IFA) tests at referee laboratories. Criterion for a positive Western blot was presence of 5 of 10 of the most common antigen IgG bands; for IFA, >1:128 or the equivalent when correcting for interlaboratory variability. Twenty-two of 1,000 canines were confirmed serologically positive (21 dogs and 1 coyote; seroprevalence 2.3% and 1.2%, respectively). Lifestyle, breed size, gender, and age were not statistically predictive of seropositive status. No regional clustering of seropositive animals was detected. The low prevalence of seropositivity in sentinel canines suggests the Lyme borreliosis hazard in San Diego County is minimal.     

Campylobacteriosis in dogs and cats: a review

Campylobacter species are commonly isolated from faecal samples collected from dogs and cats, with the most prevalent species being C. upsaliensis, C. helveticus, and C. jejuni. Although the majority of dogs and cats are subclinically infected, some will develop mild to moderate enteritis. Immature animals, animals from intensive housing backgrounds, and animals with concurrent disease are especially predisposed to infection and the development of clinical signs. Bacterial culture methods applied in diagnostic laboratories remain biased to C. jejuni and C. coli detection, but molecular methods to diagnose Campylobacter spp. infections in dogs and cats have become widely available and can aid rapid and accurate diagnosis. Multilocus sequence typing has also been developed for subtyping different strains and has been used in epidemiological investigations. In the majority of cases, clinical signs are self-limiting and antimicrobial treatment is not warranted. Campylobacter spp. isolated from dogs and cats have shown resistance to commonly used antimicrobials, so antimicrobial therapy should only be administered where this is justified. Contact with dogs and cats is a recognised risk factor for human campylobacteriosis, thus people living or working in close contact with cats and dogs should be made aware of the zoonotic organisms these animals can shed.     

Diagnostic aspects of Borrelia-infections in dogs

This paper discusses the problem of diagnosing borreliosis (Lyme disease) in dogs. A prospective cohort study in the Kempen district, a known Borrelia focus in The Netherlands, showed that dogs with the presumptive symptoms of borreliosis, episodic malaise and lameness, had significantly higher and longer lasting anti-Borrelia IgG titers than asymptomatic dogs. A small part of these dogs also had antibodies directed against the IR6 (C6) antigen which indicates persistent active Borrelia infection. A few typical case histories are presented. Dogs with episodic malaise and lameness with persistent high IgG titers are suspect of suffering from borreliosis. IR6 antibodies make this diagnosis likely. Initially, such patients should be treated with doxycyclin (10 mg/kg 1dd) for 10 days. If the symptoms recurr within a few months, a longer treatment (eg 6 weeks) should be considered. Bernese mountain dogs were strongly over-represented among the borreliosis patients in the cohort study and most high titered samples among those submitted for--diagnostic--serology appear to come from this breed, which suggests that these dogs have difficulties with clearing this tick-borne infection.     

Canine borreliosis.

A guild of organisms carried by the same vector (Ixodes ticks) in Lyme-endemic areas may be confounding the understanding of Lyme disease in dogs. A new diagnostic method, the C6 peptide test for Lyme, and serology and PCR testing for Ehrlichia, Babesia, and Bartonella species will help to sort out seroprevalence and symptomatology caused by exposure to these agents or by coinfections. In addition, Rickettsia, Leptospira, Mycoplasma species, and more could be involved in dogs diagnosed with a "doxycycline-responsive" disease. The author does not recommend treating asymptomatic Borrelia carrier dogs, but does recommend screening them for proteinuria and for exposure to other agents. A positive Lyme titer is a marker of exposure to Ixodes ticks and the agents they carry. The risk/benefit of vaccination will be understood better as the symptomatology and immunopathogenesis of Lyme disease are defined. Meanwhile, tick control is highly recommended for all dogs in Lyme-endemic areas.     

Food hypersensitivity dermatitis in the dog: diagnostic possibilities

Dogs with food hypersensitivity usually develop chronic pruritic dermatoses virtually indistinguishable from atopic dermatitis. These reactions are often called food allergy but the pathogenesis is poorly characterized. Several studies have addressed the incidence of canine adverse reactions to food but the outcomes were conflicting. The gold standard for the diagnosis of such a condition is the restricted dietary trial and the subsequent provocation challenge. Some attempts have been made to develop serological tests but none of these tests accurately predicted canine food sensitivity. The aim of the present study was to determine the incidence of food hypersensitivity dermatitis and to evaluate a newly developed serological test for the diagnosis of food allergy in dogs. Only 9% of 55 dogs with dermatological signs compatible with food hypersensitivity or atopic dermatitis have been diagnosed as food hypersensitive dogs.The repeatability of the serological test has shown to be insufficient.     

Clinical and serologic studies of canine borreliosis

During 1984 and 1985, blood samples were obtained from 271 dogs that were suspected of having borreliosis. The dogs lived in areas known to be infested with ticks and had been examined because of limb/joint disorders or for unknown illnesses marked by fever, anorexia, or fatigue. Lameness had been the most frequently reported clinical manifestation. Analyses of serum specimens, by an indirect fluorescent antibody (IFA) method or by an ELISA, detected antibodies to Borrelia burgdorferi, the etiologic agent of borreliosis in dogs and of Lyme disease in human beings. Antibody to B burgdorferi was detected in 76.3% of 114 specimens from dogs living in the lower Hudson Valley region of New York State (predominantly Westchester County), in 66.5% of 155 specimens from dogs from southern Connecticut, and in single specimens from dogs from Rhode Island and California. Geometric mean antibody titers peaked during the winter. Results of IFA tests and ELISA were in agreement, but the latter method yielded less variable results, had greater sensitivity, and was more easily standardized. Five dogs from New York State and Connecticut seropositive to B burgdorferi had developed kidney disorders during or after episodes of intermittent lameness. Application of murine monoclonal antibody in an IFA procedure verified the presence of B burgdorferi in renal cortical tissues from one dog.     

The prevalence of antibodies against B. burgdorferi, an indicator for Lyme borreliosis in dogs? A comparison of serological tests

Five serological tests for the detection of IgM and IgG antibodies to Borrelia burgdorferi, the causative microorganism of Lyme borreliosis (LB), were compared in 1177 sera from Dutch dogs: 401 healthy working hunting dogs, 100 healthy city pet dogs, 629 city dogs suspected of having LB with various clinical symptoms, and 47 hunting dogs with intermittent lameness. The results of the in-house species-independent enzyme immunoassay (i.e. an EIA which can be used to test serum samples from different animal species) showed a strong agreement (kappa: 0.78-0.81) with those of an experimental and a commercially available EIA (Genzyme Virotech, Rüsselsheim, Germany) for the detection of canine IgG antibodies to B. burgdorferi. Furthermore, the sensitivity of the in-house EIAs for the detection of antibodies to B. burgdorferi was independent of the antigenic heterogeneity, as demonstrated by the results of sera from dogs suspected of LB with various clinical symptoms: lameness (n = 60), and neurological (n = 60) and skin disorders (n = 52). Because of its high sensitivity for IgM antibodies, the indirect assay (Diagast, Pessac, France) proved to be an interesting tool for the detection of an acute Lyme infection in dogs. However, in this study a positive serological result could not be linked to any clinical symptom that has been related to LB in dogs. Results showed no difference in seroprevalence between dogs considered at high or at low risk of a B. burgdorferi infection. It was concluded that LB is an uncommon disease in the Dutch dog population despite the fact that many of Dutch dogs are infected with B. burgdorferi. Because of this low prevalence, the use of any immunoassay to support the clinical diagnosis of LB in dogs might be of limited value. Nevertheless, the species-independent EIA could be valuable in seroepidemiological studies when sera of several different animal species need to be tested.     

Western immunoblot analysis for distinguishing vaccination and infection status with Borrelia burgdorferi (Lyme disease) in dogs.

Serodiagnosis of Lyme borreliosis in dogs is complicated by the use of commercially available Lyme disease vaccines that may cross-react with certain diagnostic assays. Western immunoblotting may be used to distinguish between dogs naturally exposed and those vaccinated against Borrelia burgdorferi. Because current vaccines are not 100% efficacious and dogs may be vaccinated after natural exposure, certain dogs may show serum antibody responses against both natural and vaccine exposure (dual status). In this study, samples from 17 nonexposed, 17 B. burgdorferi-bacterin vaccinated, 13 naturally exposed, and 8 dual-status dogs were tested by western immunoblot to determine if dual-status dogs could be reliably differentiated from naturally infected or vaccinated dogs. Reaction to outer surface protein A antigen of B. burgdorferi (31 kD) was a consistent marker for vaccination, appearing in all samples from vaccinate and dual-status dogs and in no samples from single-status naturally exposed dogs. Antibodies to 4 bands, at 80, 39, 29, and 28 kD, were present in all naturally infected and dual-status dogs. No samples from vaccinated or nonexposed dogs were reactive to all 4 of these bands simultaneously. Thus, vaccine and natural exposure produce differing antibody responses, whereas dual-status dogs produced the full antibody response of both types of exposure.     

Canine parvoviral enteritis: a review of diagnosis, management, and prevention

Objective: To review and summarize current information regarding epidemiology, risk factors, and pathophysiology associated with canine parvoviral infection, and to outline diagnostic and treatment modalities for this disease. Preventative and vaccination strategies will also be discussed, as serologic documentation of immunocompetence and adoption of safe and effective vaccination protocols are crucial in limiting infection and spread of canine parvoviral enteritis. Etiology: Parvoviruses (Parvoviridae) are small, nonenveloped, single‐stranded DNA viruses that replicate in rapidly dividing cells. Canine parvovirus 2 (CPV‐2) remains a significant worldwide canine pathogen and the most common cause of viral enteritis in this species. Diagnosis: Classic presentation of CPV infection includes acute‐onset enteritis, fever, and leukopenia. Definitive diagnostic tests include detection of CPV in the feces of affected dogs, serology, and necropsy with histopathology. Therapy: Standard therapeutic practices for both mildly and severely affected puppies will be discussed. The ability of this virus to incite not only local gastrointestinal injury, but also a significant systemic inflammatory response has recently been reviewed in the literature, and novel innovative experimental and clinical therapeutic strategies, such as antagonism of proinflammatory cytokines and immunostimulation, are introduced in this article. Prognosis: CPV remains a significant worldwide canine pathogen. In experimentally affected dogs, mortality without treatment has been reported as high as 91%. However, with prompt recognition of dogs infected with CPV‐2, and aggressive in‐hospital supportive therapy of severely affected puppies, survival rates may approach 80–95%.     

Antinuclear antibodies: presence and specificity in autoimmune connective tissue disease in the dog.

Autoimmune connective tissue disease in both animals and humans present as multi-systemic disorders. Clinical signs referable to joints, musculoskeletal system and Dermatopathies are present. Autoantibody production is a regular feature of systemic autoimmune disease and these antibodies have diagnostic value in both human and veterinary medicine. In this study, we demonstrate that many of the commonly used diagnostic techniques developed for use with human patients may also be adapted for use in dogs. However, in some instances, 'canine specific' autoantibodies, distinct from analogous human antibodies may be detected in sera from dogs with a diagnosis of autoimmune disease. This finding indicates that dogs may develop 'dog-specific' autoimmune connective tissue disease.     

Borrelia burgdorferi infections with special reference to horses. A review

Summary This review discusses the literature on B. burgdorferi infections in view of the rising incidence of this infection in general and the increasing concerns of horse owners and equine practitioners. Lyme disease, the clinical expression of Borrelia infections in man is an important health problem. The geographic distribution of B. burgdorferi infections in equidae should resemble that of human cases because the vector tick involved, Ixodes ricinus, feeds on both species and, indeed, the infection has been established many times in horses. However, a definite diagnosis of the disease "Lyme borreliosis" in human beings as well as in horses and other animals is often difficult to accomplish. Although a broad spectrum of clinical signs has been attributed to B. burgdorferi infections in horses, indisputable cases of equine Lyme borreliosis are extremely rare so far, if they exist at all.     

Suspected Lyme borreliosis in sheep.

Two cases of suspected Lyme borreliosis in lambs are described. The clinical signs observed resemble those described for Lyme borreliosis in dogs and horses. The lambs were approximately six months old and came from two different flocks in a district heavily infested with Ixodes ricinus ticks. The lambs had pronounced lameness in one leg, generally bad condition and poor appetite. They had high serum levels of IgG antibodies to Borrelia burgdorferi when tested in an ELISA. The other lambs in the flocks were negative to B burgdorferi antibodies. Attempts were made to isolate spirochaetes from one of the lambs, but were unsuccessful.