Microalbuminuria and comparison of serologic testing for exposure to Borrelia burgdorferi in nonclinical Labrador and Golden Retrievers

Human and Veterinary Vaccines for Lyme Disease

Lyme disease (LD) is an emerging zoonotic infection that is increasing in incidence in North America, Europe, and Asia. With the development of safe and efficacious vaccines, LD can potentially be prevented. Vaccination offers a cost-effective and safe approach for decreasing the risk of infection. While LD vaccines have been widely used in veterinary medicine, they are not available as a preventive tool for humans. Central to the development of effective vaccines is an understanding of the enzootic cycle of LD, differential gene expression of Borrelia burgdorferi in response to environmental variables, and the genetic and antigenic diversity of the unique bacteria that cause this debilitating disease. Here we review these areas as they pertain to past and present efforts to develop human, veterinary, and reservoir targeting LD vaccines. In addition, we offer a brief overview of additional preventative measures that should employed in conjunction with vaccination.

Changes in renal parameters and their association with subclinical vector-borne infections in Bernese Mountain dogs

Background

An increased risk for glomerulonephritis and a higher prevalence of antibodies to Borrelia (B.) burgdorferi sensu lato have been reported in Bernese mountain dogs (BMDs). The aim of the study was to determine the prevalence of laboratory abnormalities suggestive of kidney disease in clinically healthy BMDs compared to a control population and to investigate if there is a correlation with the occurrence of antibodies to B. burgdorferi sensu lato, Ehrlichia canis, and Anaplasma (A.) spp. and with the occurrence of Dirofilaria (D.) immitis antigen.

A total of 197 BMDs and 57 control dogs were included in the study. Laboratory evidence of kidney disease was defined as renal azotemia and/or proteinuria with a urine protein creatinine ration of more than 0.5 in an inactive urine sediment. A SNAP®4Dx® ELISA (IDEXX, Laboratories, Inc., Westbrook, ME, USA) was used to detect antibodies to B. burgdorferi sensu lato, E. canis and Anaplasma spp. and antigen of D. immitis.

Results

Laboratory evidence of kidney disease was significantly more common in BMDs than in control dogs (17.8% versus 1.8%) (p = 0.005). The proportion of BMDs with anti-B. burgdorferi sensu latu antibodies and anti-A. phagocytophilum antibodies was significantly higher in BMDs (p <  0.001). However, an association between these findings could not be identified.

Conclusion

BMDs are more often affected by kidney disease and have a higher prevalence of antibodies to bacterial pathogens transmitted by Ixodes ticks than control dogs. However, a causal relationship between these two variables could not be established due to a lack of association between these two findings.

Differences in clinicopathologic variables between Borrelia C6 antigen seroreactive and Borrelia C6 seronegative glomerulopathy in dogs

Background

Rapidly progressive glomerulonephritis has been described in dogs that seroreact to Borrelia burgdorferi, but no studies have compared clinicopathologic differences in Lyme‐seroreactive dogs with protein‐losing nephropathy (PLN) versus dogs with Borrelia‐seronegative PLN.

Hypothesis/Objectives

Dogs with Borrelia C6 antigen‐seroreactive PLN have distinct clinicopathologic findings when compared to dogs with Borrelia seronegative PLN.

Animals

Forty dogs with PLN and Borrelia C6 antigen seroreactivity and 78 C6‐seronegative temporally matched dogs with PLN.

Methods

Retrospective prevalence case‐control study. Clinical information was retrieved from records of dogs examined at the University of California, Davis, Veterinary Medical Teaching Hospital. Histopathologic findings in renal tissue procured by biopsy or necropsy of dogs with PLN were reviewed.

Results

Retrievers and retriever mixes were overrepresented in seroreactive dogs (P < .001). Seroreactive dogs were more likely to have thrombocytopenia (P < .001), azotemia (P = .002), hyperphosphatemia (P < .001), anemia (P < .001), and neutrophilia (P = .003). Hematuria, glucosuria, and pyuria despite negative urine culture were more likely in seroreactive dogs (all P ≤ .002). Histopathologic findings were consistent with immune‐complex glomerulonephritis in 16 of 16 case dogs and 7 of 23 control dogs (P = 006). Prevalence of polyarthritis was not different between groups (P = .17).

Conclusions and Clinical Importance

C6 seroreactivity in dogs with PLN is associated with a clinicopathologically distinct syndrome when compared with other types of PLN. Early recognition of this syndrome has the potential to improve outcomes through specific aggressive and early treatment.

ACVIM consensus update on Lyme borreliosis in dogs and cats

An update of the 2006 American College of Veterinary Internal Medicine (ACVIM) Small Animal Consensus Statement on Lyme Disease in Dogs: Diagnosis, Treatment, and Prevention was presented at the 2016 ACVIM Forum in Denver, CO, followed by panel and audience discussion and a drafted consensus statement distributed online to diplomates for comment. The updated consensus statement is presented below. The consensus statement aims to provide guidance on the diagnosis, treatment, and prevention of Lyme borreliosis in dogs and cats.

Tick-borne Diseases (Borreliosis, Anaplasmosis, Babesiosis) in German and Austrian Dogs: Status quo and Review of Distribution, Transmission, Clinical Findings, Diagnostics and Prophylaxis

Tick-borne diseases (TBD) in dogs have gained in significance in German and Austrian veterinary practices. The widespread European tick species Ixodes ricinus represents an important vector for spirochaetes of the Borrelia burgdorferi sensu lato group and Rickettsiales such as Anaplasma phagocytophilum. The meadow or ornate dog tick (Dermacentor reticulatus) is an important vector for Babesia canis, as is the brown dog tick (Rhipicephalus sanguineus) for Babesia vogeli in the Mediterranean region. The present work covers pathogen transmission by tick vectors, including the mechanisms and the minimum intervals required, in conjunction with possible non-vector-borne transmission routes. It also addresses the incubation periods, pathogenicity and clinical findings associated with each pathogen and genospecies and presents case examples. Current data on prevalence, annual fluctuations and distribution in various pre-selected dog populations (symptomatic versus asymptomatic) in both countries are depicted in maps. Reasons for changes in prevalence (especially of Borrelia) are discussed. Criteria and algorithms for clinical diagnosis and monitoring in dogs, including case history, direct detection (blood smears, molecular detection by species-specific PCR and sequencing) and indirect methods (whole-cell and peptide-based antibody tests), are presented, together with laboratory abnormalities (haematology, clinical chemistry, urine). The role of anti-C6 antibody concentration (ACAC) and its correlation with proteinuria and Lyme nephritis are assessed on the basis of new data. Consideration is also given to the importance of blood smears, PCR and serology in the case of anaplasmosis and babesiosis, and the diagnostic value of combining these methods. The relevance of molecular differentiation of Anaplasma species (A. phagocytophilum versus A. platys) and Babesia spp. (large versus small forms) in cases of serological cross-reaction is emphasized. A summary is given of methods for prophylaxis using acaricide products (collars, spot-on solutions and oral treatments in both countries), vaccination (Borrelia and Babesia vaccines) and imidocarb-based chemoprophylaxis for large Babesia.

Recent study on canine vector-borne zoonoses in southern Slovakia - serologic survey

Over the last decade a significant spread of Canine Vector Borne Diseases has been recorded in Central Europe. The aim of the study described here, was to collect current data on the occurrence and distribution of three major canine vector-borne pathogens in the veterinary clinical practice by a newly-developed commercial ELISA test for the detection of Dirofilaria immitis antigen as well as specific circulating antibodies to Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato. Circulating D. immitis antigen was detected in five of 180 investigated sera samples. Two of D. immitis seropositive dogs revealed also microfilariae of D. repens in the blood and three of them were negative for the presence of microfilariae in the Knott's test. From the practical point of view, the finding of D. immitis occult infections might influence existing knowledge about distribution of this species among dogs in Central European countries. In 11.7% of the tested dogs the presence of specific antibodies against A. phagocytophilum was confirmed. Antibodies against B. burgdorferi s.l. were detected in 2.8% of tested sera samples. Coinfection with A. phagocytophilum and B. burgdorferi s.l. was observed in two dogs from Košice district in south-eastern Slovakia. Our data point toward the presence of Canine Vector Borne Diseases in the studied area. Therefore, veterinarians should include these diseases in their differential diagnosis and higher awareness should be focused also on prophylactic measures to prevent the pathogens transmission by arthropod vectors.

Lyme nephritis

OBJECTIVE

To review what is known and highlight knowledge gaps regarding Lyme nephritis (LN).

DATA SOURCES

Publications identified via PubMed using the keywords "Borrelia burgdorferi," "Borreliosis," "glomerulonephritis," "protein-losing nephropathy," "autoimmunity," and "retriever," and as generated by investigators working in the fields of Borreliosis and immune-mediated glomerulonephritis.

HUMAN DATA SYNTHESIS

Postborrelial immune-mediated glomerulonephritis was described recently in 6 people; 3 responded to antimicrobials/steroids, 1 to antimicrobials/angiotensin-converting enzyme inhibitor/warfarin, 1 required hemodialysis but became hemodialysis independent after 5 months and treatment with antimicrobials, steroids, plasmapheresis, immunoglobulin, and 1 did not respond to steroids and angiotensin-converting enzyme inhibitor and still requires hemodialysis.

VETERINARY DATA SYNTHESIS

Lyme nephritis is seen in <1-2% of Lyme seropositive dogs, with an average onset at 5-6 years. Labrador and Golden Retrievers are predisposed to this condition. Prior or concurrent lameness is described in 9-28% cases. Historical presentations include acute progressive protein-losing nephropathy with membranoproliferative glomerulonephritis, tubular necrosis/regeneration, and interstitial nephritis, but possibly milder forms exist. Complications include thromboembolic events, hypertension, effusive disease, and oliguric/anuric renal failure. Diagnostic tests help stage disease and rule out other causes. Renal biopsy is advocated early, when intervention may help, and to prove if immune-complex disease exists. Treatment includes standard therapy for protein-losing nephropathy, long-term antimicrobials, and perhaps immunosuppressive therapy.

CONCLUSIONS

There is no experimental model of LN to study predisposing factors, pathogenesis, onset, progression, treatment, or prevention. There are no predictive tests to identify the few individuals at highest risk, therefore all seropositive dogs should be screened and monitored for proteinuria. Lyme nephritis mimics other forms of protein-losing nephropathy and sometimes Leptospirosis. Renal biopsy helps show if immune-complex disease exists, but may not prove LN specifically. More studies are warranted on dogs with Lyme-specific immune-complex deposition to evaluate risk factors, understand pathogenesis, variability of expression, and to validate treatment and prevention protocols.

Follow-up of Bernese Mountain dogs and other dogs with serologically diagnosed Borrelia burgdorferi infection: what happens to seropositive animals?

Background

Data on the long-term outcome of B. burgdorferi infections in adult dogs are sparse. The aim of the present study was to investigate whether Bernese Mountain dogs with serological evidence of natural B. burgdorferi infection more often develop signs such as lameness, azotemia or proteinuria during a follow-up period of 2.5 to 3.0 years. Seropositive Bernese Mountain dogs were compared to seronegative Bernese Mountain dogs and to seropositive and seronegative control dogs of other breeds.

Dogs included in a previous study on the prevalence of antibodies against B. burgdorferi in Bernese Mountain dogs were re-evaluated. Antibodies against B. burgdorferi were determined using an ELISA with a whole-cell sonicate as antigen and results were confirmed using a Western blot assay.

Results

Fifty-three Bernese Mountain dogs and 30 control dogs were re-evaluated. Re-evaluation was performed between 2.5 and 3.0 years (median 2.7 years) after the first assessment.

The age of the dogs at the second evaluation ranged from 3 to 11 years (median 6 years). There were no significant differences with regard to poor general condition or lameness between the first and the second evaluation.

At the first evaluation 22 (42%) of the Bernese Mountain dogs and 11 (37%) of the control dogs were considered positive for antibodies against B. burgdorferi. At the second evaluation 25 (47%) of the Bernese Mountain dogs and 12 (40%) of the control dogs were considered positive; 69% of the dogs showed the same serological result at both examinations and 31% were seroconverted or seroreverted. During the first examination, azotemia was diagnosed in 6 Bernese Mountain dogs and during the second examination in 11 Bernese Mountain dogs. No control dogs had azotemia in this study. In seropositive dogs there was no increase in lameness or signs of renal disease over time.

Conclusion

It may be concluded that antibodies against B. burgdorferi determined by whole cell ELISA and confirmed by Western blot were neither associated with the development of lameness nor with signs of renal disease like azotemia or proteinuria in dogs observed over a period of 2.5 to 3.0 years.