Lyme borreliosis in dogs and cats: background, diagnosis, treatment and prevention of infections with Borrelia burgdorferi sensu stricto

Zoonoses and pet owners: A survey on risk perception in Northern Italy

Veterinary and human medicine are focused on the issue of emerging and re-emerging diseases, which are especially represented by zoonosis that could be a threat for public health. Zoonotic risk may come from pets: some canine and/or feline viral, bacterial, parasitic, protozoal or mycotic diseases can be transmitted directly to humans. There are several strategies to prevent the transmission of such zoonosis, and among them vaccination plays an important role. Through a survey carried out in Northern Italy aimed to collect information regarding owners' knowledge and perception of the zoonotic risks associated with three zoonoses (rabies, leptospirosis, and dermatophytosis), it was demonstrated that dog owners tend to adhere more consistently to their pets' vaccination schedules and are more receptive to changes in vaccination scheduling compared to cat owners. This study also suggests that cat owners predominantly visit veterinarians for vaccination purposes, whereas dog owners seek veterinary services for a variety of reasons. The survey highlighted the ongoing need to enhance owners' understanding of zoonoses affecting their pets and also the protective role of vaccines. Veterinarians should undertake the responsibility of educating, reassuring, and informing pet owners about the significance of vaccines for their pets and for public health.

[Overview on utility of in-house tests for detection of systemic infectious diseases in dogs]

For detection of infectious diseases, several point-of-care (POC) tests are on the market in addition to methods performed in commercial laboratories. These POC tests are based on enzyme-linked immunosorbent assay (ELISA) or other immunochromatographic technologies and present results within few minutes in veterinary practice. This article gives an overview of the utility of numerous POC tests of different manufacturers for detection of parvovirus antigen in feces, Dirofilaria (D.) immitis antigen in blood as well as antibodies against Borrelia (B.) burgdorferi, Anaplasma (A.) spp., Ehrlichia (E.) spp., Leptospira (L.) spp. and Leishmania (L.) infantum in blood (single or in different combinations). Sensitivity and specificity of these tests are important for their usefulness in veterinary practice. Furthermore, presence of antibodies or detection of antigen has to correlate with the presence of clinical signs. POC tests for detection of canine parvovirus antigen have a very high specificity, the sensitivity of all evaluated POC tests, however, is very low. POC tests for detection of D. immitis antigen have a very high sensitivity and specificity. As they detect antigen from the uterus of female adult parasites, test results are negative when only very few female or only male adults are present. POC tests for detection of antibodies against B. burgdorferi only indicate contact with Borrelia spp. and do not prove clinical Lyme disease, as the infection only extremely rarely causes clinical signs. POC tests for detection of antibodies against A. phagocytophilum are also not suitable for diagnosis of clinical anaplasmosis. Infections with A. phagocytophilum only lead to clinical disease in very rare cases and in these, clinical signs occur before the development of antibodies. POC tests for detection of antibodies against E. canis have a very high sensitivity as well as specificity. POC tests for detection of antibodies against L. infantum and Leptospira species (spp.) show a very high specificity and a high sensitivity. However, Leptospira spp. antibody-positive results may occur following vaccination, as the POC tests cannot distinguish between field and vaccination strains.

First molecular confirmation of multiple zoonotic vector-borne diseases in pet dogs and cats of Hong Kong SAR

In recent years, the incidence of vector-borne diseases (VBDs) has increased throughout the globe. In particular, tick-borne diseases (e.g., caused by Ehrlichia canis, E. ewingii, Anaplasma phagocytophilum, A. platys, Borrelia burgdorferi sensu stricto (s.s.) and Babesia gibsoni) and mosquito-borne diseases (e.g., caused by Dirofilaria immitis) diseases pose a burden on animal health. Nevertheless, there have been no studies undertaken on the occurrence of VBDs in pet dogs and cats in Hong Kong SAR. This study fills this gap, and is the first to determine the seroprevalence of major VBDs, such as those caused by D. immitis, E. canis, E. ewingii, A. phagocytophilum, A. platys and B. burgdorferi s.s, in dogs and cats through commercially available SNAP 4Dx plus testing. Infection by all these pathogens and Babesia sp. was further assessed through PCR and DNA sequencing. A total of 224 blood samples were collected from domestic dogs (n = 159) and cats (n = 65) in Hong Kong SAR during summer 2022. Hematocrit and platelet counts were determined in each blood sample and other hematological parameters were assessed using an automatic hematology analyzer and vortex the specimen for one to two minutes at or near the highest setting to minimize the clumping. All cat sera samples were negative for tested pathogens, but antibodies against some of the pathogens were detected in dog sera samples. Here, the highest figures were recorded for seroprevalence of E. canis/E. ewingii (10.7%), followed by D. immitis (5.7%), and A. phagocytophilum/A. platys (2.5%). No B. burgdorferi s.s. antibodies were detected in any of the dogs tested. Through molecular diagnostics, we detected the presence of B. gibsoni (3.7%), E. canis (3.1%), D. immitis (5.7%), and A. phagocytophilum (1.3%). Neighbor-Joining phylogenetic trees for vector-borne pathogens (i.e., genus Anaplasma sp.) showed 100% clustering to Japan, the USA and Germany, whereas genus Ehrlichia sp. showed 100% clustering to China, Turkey, Cuba, and Greece. Similarly, genus Babesia sp. clustered 100% to India, Sri Lanka and Austria, while D. immitis clustered in Iraq, South Korea, Portugal, France, the USA and Italy. This study provides the first evidence on the occurrence of tick-borne pathogens in pet dogs in Hong Kong SAR. Based on these findings, it is recommended that appropriate screening should be undertaken in domestic dogs to evaluate the prevalence of these pathogens and promote the timely control of VBDs.

Seroexposure to Zoonotic Anaplasma and Borrelia in Dogs and Horses That Are in Contact with Vulnerable People in Italy

Equine and canine anaplasmosis and borreliosis are major tick-borne zoonotic diseases caused by Anaplasma phagocytophilum and various species of Borrelia (the most important being Borrelia burgdorferi s.l.), respectively. This study evaluated the seroexposure to Anaplasma and Borrelia in dogs and horses used in Animal-Assisted Interventions or living in contact with children, elderly people or immunocompromised persons. A total of 150 horses and 150 dogs living in Italy were equally divided into clinically healthy animals and animals with at least one clinical sign compatible with borreliosis and/or anaplasmosis (present at clinical examination or reported in the medical history). Serum samples were tested with ELISA and immunoblot for the presence of antibodies against A. phagocytophilum and B. burgdorferi s.l., and the association between seropositivity and possible risk factors was analyzed using multivariate and univariate tests. Overall, 13 dogs (8.7%) and 19 horses (12.7%) were positive for at least one of the two pathogens. In addition, 1 dog (0.7%) and 12 horses (8%) were positive for antibodies against A. phagocytophilum, while 12 dogs (8.0%) and 10 horses (6.7%) had antibodies against B. burgdorferi s.l. Tick infestation in the medical history of the dogs was significantly associated with seropositivity to at least one pathogen (p = 0.027; OR 7.398). These results indicate that, in Italy, ticks infected with A. phagocytophilum and/or B. burgdorferi circulate in places where horses and dogs are in contact with people at risk of developing severe diseases. Awareness should be increased, and adequate control plans need to be developed to protect human and animal health, especially where vulnerable, at-risk individuals are concerned.

Lyme Borreliosis in Dogs: Background, Epidemiology, Diagnostics, Treatment and Prevention

Lyme borreliosis (LB) is a multisystemic tick-borne disease that can affect many organs and have various clinical manifestations in dogs. We attempted to summarise various aspects of Lyme disease: i. e., pathogenesis, epidemiology, benefits and risks of diagnostic approaches, treatment options, and prevention in dogs. Several diagnostic bottlenecks for LB in dogs and humans are compared. Because the occurrence of LB in both humans and dogs is closely related, monitoring its prevalence in dogs as sentinel animals is an excellent aid in assessing the risk of Lyme disease in a given geographic area. Although clinical symptoms in humans help clinicians diagnose LB, they are ineffective in dogs because canines rarely exhibit LB symptoms. Despite significant differences in sensitivity and specificity, sero-logical two-step detection of antibodies against Borrelia spp. (ELISA and Western blot) is the most commonly used method in humans and dogs. The limitations of the assay highlight the need for further research to develop new clinical markers and more accurate diagnostic tests. Due to the lack of a specific all-encompassing LB test, a definitive diagnosis of LB remains a difficult and time-consuming process in human and veterinary medicine. Understanding the disease prevalence and diagnostics, as well as preventing its spread with effective and timely treatment, are fundamental principles of good disease management.

Advanced approaches for the diagnosis and chemoprevention of canine vector-borne pathogens and parasites-Implications for the Asia-Pacific region and beyond

Vector-borne pathogens (VBPs) of canines are a diverse range of infectious agents, including viruses, bacteria, protozoa and multicellular parasites, that are pernicious and potentially lethal to their hosts. Dogs across the globe are afflicted by canine VBPs, but the range of different ectoparasites and the VBPs that they transmit predominate in tropical regions. Countries within the Asia-Pacific have had limited prior research dedicated to exploring the epidemiology of canine VBPs, whilst the few studies that have been conducted show VBP prevalence to be high, with significant impacts on dog health. Moreover, such impacts are not restricted to dogs, as some canine VBPs are zoonotic. We reviewed the status of canine VBPs in the Asia-Pacific, with particular focus on nations in the tropics, whilst also investigating the history of VBP diagnosis and examining recent progress in the field, including advanced molecular methods, such as next-generation sequencing (NGS). These tools are rapidly changing the way parasites are detected and discovered, demonstrating a sensitivity equal to, or exceeding that of, conventional molecular diagnostics. We also provide a background to the armoury of chemopreventive products available for protecting dogs from VBP. Here, field-based research within high VBP pressure environments has underscored the importance of ectoparasiticide mode of action on their overall efficacy. The future of canine VBP diagnosis and prevention at a global level is also explored, highlighting how evolving portable sequencing technologies may permit diagnosis at point-of-care, whilst further research into chemopreventives will be essential if VBP transmission is to be effectively controlled.

A Retrospective Study with a Commercial Vaccine against Lyme Borreliosis in Dogs Using Two Different Vaccination Schedules: Characterization of the Humoral Immune Response

Lyme borreliosis, a multisystemic disease caused by spirochetes of the genus Borrelia, is the most common tick-borne disease in the northern hemisphere. Differently from human medicine, several vaccines are available for dogs. To provide the best protection possible, vaccination schemes should be adapted regularly to meet the needs resulting from an increased tick exposure risk due to an inescapable climate change. In this retrospective study, a total of 183 vaccinations were performed with a commercial, multivalent vaccine against Lyme borreliosis, and vaccinated dogs were monitored over an observation period of 13 months. Dogs were either vaccinated on days 0 and 21 and a booster on day 365 (standard vaccination schedule), or with an additional booster vaccination on day 180. Canine serum samples were then tested for their borrelia-specific antibody levels using a two-tiered test system consisting of a kinetic ELISA followed by a line immunoassay. Dogs vaccinated with the standard vaccination schedule displayed decreasing antibody levels between days 120 and 360, which is probably insufficient to prevent an infection with borreliae. In contrast, the additional booster vaccination received on day 180 intercepts this decline in antibody levels between days 225 and 360, providing a sufficient immunity to prevent infection. The results from this retrospective study allow us to recommend a basic vaccination schedule with an additional booster vaccination on day 180 to ensure the best possible protection for dogs against Lyme borreliosis.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

Ticks and their epidemiological role in Slovakia: from the past till present

In Slovakia, 22 tick species have been found to occur to date. Among them, Ixodes ricinus, Dermacentor reticulatus, D. marginatus and marginally Haemaphysalis concinna, H. inermis and H. punctata have been identified as the species of public health relevance. Ticks in Slovakia were found to harbour and transmit zoonotic and/or potentially zoonotic agents such as tick-borne encephalitis virus (TBEV), spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex, the relapsing fever sprirochaete Borrelia miyamotoi, bacteria belonging to the orders Rickettsiales (Rickettsia spp., Anaplasma phagocytophilum, Neoehrlichia mikurensis), Legionellales (Coxiella burnetii), and Thiotrichales (Francisella tularensis), and Babesia spp. parasites (order Piroplasmida). Ixodes ricinus is the principal vector of the largest variety of microorganisms including viruses, bacteria and piroplasms. TBEV, B. burgdorferi s.l., rickettsiae of the spotted fever group, C. burnetii and F. tularensis have been found to cause serious diseases in humans, whereas B. miyamotoi, A. phagocytophilum, N. mikurensis, Babesia microti, and B. venatorum pose lower or potential risk to humans. Distribution of TBEV has a focal character. During the last few decades, new tick-borne encephalitis (TBE) foci and their spread to new areas have been registered and TBE incidence rates have increased. Moreover, Slovakia reports the highest rates of alimentary TBE infections among the European countries. Lyme borreliosis (LB) spirochaetes are spread throughout the distribution range of I. ricinus. Incidence rates of LB have shown a slightly increasing trend since 2010. Only a few sporadic cases of human rickettsiosis, anaplasmosis and babesiosis have been confirmed thus far in Slovakia. The latest large outbreaks of Q fever and tularaemia were recorded in 1993 and 1967, respectively. Since then, a few human cases of Q fever have been reported almost each year. Changes in the epidemiological characteristics and clinical forms of tularaemia have been observed during the last few decades. Global changes and development of modern molecular tools led to the discovery and identification of emerging or new tick-borne microorganisms and symbionts with unknown zoonotic potential. In this review, we provide a historical overview of research on ticks and tick-borne pathogens in Slovakia with the most important milestones and recent findings, and outline future directions in the investigation of ticks as ectoparasites and vectors of zoonotic agents and in the study of tick-borne diseases.

Exposure to Tick-Borne Pathogens in Cats and Dogs Infested With Ixodes scapularis in Quebec: An 8-Year Surveillance Study

Cats that spend time outdoors and dogs are particularly at risk of exposure to ticks and the pathogens they transmit. A retrospective study on data collected through passive tick surveillance was conducted to estimate the risk of exposure to tick-borne pathogens in cats and dogs bitten by blacklegged ticks (Ixodes scapularis) in the province of Quebec, Canada, from 2010 to 2017. Blacklegged ticks collected from these host animals were tested by PCR for Borrelia burgdorferi sensu stricto, Borrelia miyamotoi, Anaplasma phagocytophilum, and Babesia microti. A total of 13,733 blacklegged ticks were collected from 12,547 animals. Most ticks were adult females and partially engorged. In total, 1,774 cats were infested with ticks and 22.6 and 2.7% of these animals were bitten by at least one tick infected with B. burgdorferi and A. phagocytophilum, respectively. For the 10,773 tick infested dogs, 18.4% were exposed to B. burgdorferi positive ticks while 1.9% of infested dogs were exposed to ticks infected with A. phagocytophilum. The risk of exposure of both cats and dogs to B. miyamotoi and B. microti was lower since only 1.2 and 0.1% of ticks removed were infected with these pathogens, respectively. Traveling outside of the province of Quebec prior to tick collection was significantly associated with exposure to at least one positive tick for B. burgdorferi, A. phagocytophilum and B. microti. Animals exposed to B. burgdorferi or B. miyamotoi positive tick(s) were at higher risk of being concurrently exposed to A. phagocytophilum; higher risk of exposure to B. microti was also observed in animals concurrently exposed to B. burgdorferi. The odds of dogs having B. burgdorferi antibodies were higher when multiple ticks were collected on an animal. The testing and treatment strategies used on dogs bitten by infected ticks were diverse, and misconceptions among veterinarians regarding the treatment of asymptomatic but B. burgdorferi-seropositive dogs were noted. In conclusion, our study demonstrates that cats and dogs throughout Quebec are exposed to blacklegged ticks infected with B. burgdorferi and A. phagocytophilum, and veterinarians across the province need to be aware of this potential threat to the health of pets and their owners.

Comparative analysis of antibody responses to outer surface protein (Osp)A and OspC in dogs vaccinated with Lyme disease vaccines

Lyme disease (LD), the most common tick-borne disease of canines and humans in N. America, is caused by the spirochete Borreliella burgdorferi. Subunit and bacterin vaccines are available for the prevention of LD in dogs. LD bacterin vaccines, which are comprised of cell lysates of two strains of B. burgdorferi, contain over 1000 different proteins and cellular constituents. In contrast, subunit vaccines are defined in composition and consist of either outer surface protein (Osp)A or OspA and an OspC chimeritope. In this study, we comparatively assessed antibody responses to OspA and OspC induced by vaccination with all canine bacterin and subunit LD vaccines that are commercially available in North America. Dogs were administered a two-dose series of the vaccine to which they were assigned (3 weeks apart): Subunit-AC, Subunit-A, Bacterin-1, and Bacterin-2. Antibody titers to OspA and OspC were determined by ELISA and the ability of each vaccine to elicit antibodies that recognize diverse OspC proteins (referred to as OspC types) assessed by immunoblot. While all of the vaccines elicited similar OspA antibody responses, only Subunit-AC triggered a robust and broadly cross-reactive antibody response to divergent OspC proteins. The data presented within provide new information regarding vaccination-induced antibody responses to key tick and mammalian phase antigens by both subunit and bacterin LD canine vaccine formulations.

VANGUARD®crLyme: A next generation Lyme disease vaccine that prevents B. burgdorferi infection in dogs

Lyme disease, a public health threat of significance to both veterinary and human medicine, is caused by the tick (Ixodes) transmitted spirochete, Borreliella burgdorferi. Here we report on the immunogenicity and efficacy of VANGUARD®crLyme (Zoetis), the most recent canine Lyme disease vaccine to be approved by the United States Department of Agriculture. VANGUARD®crLyme is a subunit vaccine consisting of outer surface protein A (OspA) and a recombinant outer surface protein C (OspC) based-chimeric epitope protein (chimeritope) that consists of at least 14 different linear epitopes derived from diverse OspC proteins. The combination of OspA and the OspC chimeritope (Ch14) in the vaccine formulation allows for the development of humoral immune responses that work synergistically to target spirochetes in both ticks and in mammals. Immunogenicity was assessed in purpose-bred dogs. A two-dose vaccination protocol resulted in high antibody titers to OspA and Ch14 and vaccinal antibody reacted with 25 different recombinant OspC variants. Efficacy was demonstrated using an Ixodes scapularis -purpose bred dog challenge model. Vaccination with VANGUARD®crLyme provided protection against infection and prevented the development of clinical manifestations and histopathological changes associated with Lyme disease.

Serosurvey of arthropod-borne diseases among shelter dogs in the Cumberland Gap Region of the United States

Background

The Cumberland Gap Region (CGR) of the United States is a natural corridor between the southeastern, northeastern, and midwestern regions of the country. CGR has also many species of ticks and mosquitos that serve as competent vectors for important animal and human pathogens. In this study, we tested dogs from six different animal shelters in the CGR for Rocky Mountain spotted fever (RMSF), anaplasmosis, Lyme disease, canine ehrlichiosis and canine heartworm disease.

Results

Sera from 157 shelter dogs were tested for antibodies to RMSF agent, Rickettsia rickettsii, using an indirect immunofluorescence assay. Sixty-six dogs (42.0%) were positive for either IgM or IgG, or both IgM and IgG antibodies to R. rickettsii. Moreover, the same set of sera (n = 157) plus an and additional sera (n = 75) from resident dogs at the same shelters were tested using the SNAP 4Dx Plus. Of 232 dogs tested, two (0.9%) were positive for antibodies to Anaplasma phagocytophilum/A. platys, nine (3.9%) were positive for antibodies to Borrelia burgdorferi, 23 (9.9%) for positive for antibodies to Ehrlichia canis/E. ewingii, and 13 (5.6%) were positive for Dirofilaria immitis antigen. Co-infection with two or more etiologic agents was detected in five animals. Three dogs had antibodies to both B. burgdorferi and E. canis/E. ewingii, and two dogs were positive for D. immitis antigen and antibodies to B. burgdorferi and E. canis/E. ewingii.

Conclusions

Shelter dogs in the CGR are exposed to a number of important vector-borne pathogens. Further studies are required to ascertain the roles these animals play in maintenance and transmission of these pathogens.

A Host-Specific Blocking Primer Combined with Optimal DNA Extraction Improves the Detection Capability of a Metabarcoding Protocol for Canine Vector-Borne Bacteria

Bacterial canine vector-borne diseases are responsible for some of the most life-threatening conditions of dogs in the tropics and are typically poorly researched with some presenting a zoonotic risk to cohabiting people. Next-generation sequencing based methodologies have been demonstrated to accurately characterise a diverse range of vector-borne bacteria in dogs, whilst also proving to be more sensitive than conventional PCR techniques. We report two improvements to a previously developed metabarcoding tool that increased the sensitivity and diversity of vector-borne bacteria detected from canine blood. Firstly, we developed and tested a canine-specific blocking primer that prevents cross-reactivity of bacterial primer amplification on abundant canine mitochondrial sequences. Use of our blocking primer increased the number of canine vector-borne infections detected (five more Ehrlichia canis and three more Anaplasma platys infections) and increased the diversity of bacterial sequences found. Secondly, the DNA extraction kit employed can have a significant effect on the bacterial community characterised. Therefore, we compared four different DNA extraction kits finding the Qiagen DNeasy Blood and Tissue Kit to be superior for detection of blood-borne bacteria, identifying nine more A. platys, two more E. canis, one more Mycoplasma haemocanis infection and more putative bacterial pathogens than the lowest performing kit.

Novel targets and strategies to combat borreliosis

Lyme borreliosis is a bacterial infection that can be spread to humans by infected ticks and may severely affect many organs and tissues. Nearly four decades have elapsed since the discovery of the disease agent called Borrelia burgdorferi. Although there is a plethora of knowledge on the infectious agent and thousands of scientific publications, an effective way on how to combat and prevent Lyme borreliosis has not been found yet. There is no vaccine for humans available, and only one active vaccine program in clinical development is currently running. A spirited search for possible disease interventions is of high public interest as surveillance data indicates that the number of cases of Lyme borreliosis is steadily increasing in Europe and North America. This review provides a condensed digest of the history of vaccine development up to new promising vaccine candidates and strategies that are targeted against Lyme borreliosis, including elements of the tick vector, the reservoir hosts, and the Borrelia pathogen itself.

First report of Lyme borreliosis leading to cardiac bradydysrhythmia in two cats

Case series summary

Two cats were presented for investigation of bradyarrhythmia detected by their referring veterinarians during routine examination. Both cats had extensive investigations, including haematology, serum biochemistry with electrolytes and thyroxine concentrations, systolic blood pressure measurement, echocardiography, electrocardiography and infectious disease testing. Infectious disease testing included serology for Toxoplasma gondii, Ehrlichia canis, Anaplasma phagocytophilum and Borrelia burgdorferi, and PCR for B burgdorferi antigen in both cats. Case 1 was also assessed by PCR for Bartonella henselae antigen and case 2 was assessed for Dirofilaria immitis by serology. All infectious disease tests, other than for B burgdorferi, were negative. Case 1 was diagnosed with Lyme carditis based on marked bradydysrhythmia, positive B burgdorferi serology, a structurally normal heart and clinical resolution with appropriate treatment with a 4-year follow-up. Case 2 was diagnosed with Lyme carditis based on marked bradydysrhythmia and positive B burgdorferi PCR; however, this cat had structural heart disease that did not resolve with treatment.

Relevance and novel information

This small case series describes two B burgdorferi positive cats presenting with newly diagnosed cardiac abnormalities consistent with those found in humans and dogs with Lyme carditis. Both cats were asymptomatic as perceived by their owners; the arrhythmia was detected by their veterinarians.

[Ecology of Lyme disease]

Diseases spread by ticks are complex and typically come under the One Health approach because the implications for human, animal and environmental health are so intricately interconnected. In Europe and North America, these diseases, particularly the emblematic case of Lyme disease, are constantly on the rise. They are associated with a very strong emotional element in Western societies, where citizens are preoccupied by this upsurge and call on governments and health services to act. There is no vaccine against Lyme disease. This is the backdrop against which scientists are looking for alternative solutions based on the identification of ecological factors that are liable to better control tick populations and the movements of pathogens within ecosystems. This article describes the main knowledge already acquired about the ecology of Lyme disease and then provides a list of a number of instruments that can be leveraged to limit the risks and improve control.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Seroprevalence of vector-borne pathogens in dogs from Croatia

Canine vector-borne pathogens (VBPs) are a group of globally distributed and rapidly spreading microorganisms transmitted by arthropods. In the present survey, we investigated Anaplasma spp., Ehrlichia canis, Dirofilaria immitis and Borrelia burgdorferi sensu lato seroprevalence between three groups of dogs (asymptomatic, suspected and deceased) from continental and coastal regions of Croatia with the commercial point-of-care SNAP®4Dx®Plus for VBPs. The overall prevalence for tested pathogens in dogs was 6.1% with the highest prevalence detected for Anaplasma spp. (4.5%), while the remaining pathogens were found at a prevalence of less than 1% (E. canis 0.6%, B. burgdorferi s.l. 0.4%, D. immitis 0.6%). No statistically significant differences in VBP detection between dog cohorts could be found with the exception of D. immitis in the deceased group. Interestingly, no evidence of D. immitis could be found in the hearts of dogs in this group at necropsy, however. This study provides the first data on the seroprevalence of selected VBPs between dogs of different health statuses in Croatia. The results demonstrate that serological evidence of VBPs alone or in combination with co-infections were found just as frequently in asymptomatic dogs as those with suspected or confirmed evidence of VBP disease, raising questions about the pathogenic potential of these organisms in domesticated dogs.

Borreliosis in Sport Horse Practice

Given the variable clinical signs attributed to Borrelia burgdorferi, including infectious arthritis, neurologic disease, and behavioral changes, B burgdorferi is an important differential for decreased performance in sport horses. The primary vectors (Ixodes tick species) are expanding their range and thus Borrelia species are located in a wider area, making exposure more likely. Due to regionally high seroprevalence and vague clinical signs, diagnosis of Lyme disease in the horse is believed overestimated. Antibiotics are first-line treatment of confirmed Lyme disease. A single positive serologic test, by itself, is not conformation of Lyme disease but is evidence of current or past infection.

Detection of tick-borne pathogens in ticks from dogs and cats in different European countries

Ticks are known to transmit pathogens which threaten the health and welfare of companion animals and man globally. In the present study, mainly adult ticks were collected from dogs and cats presented at their local veterinary practice in Hungary, France, Italy, Belgium (dogs only) and Germany (cats only), and identified based on tick morphology. If more than one tick was collected from a host animal, ticks were pooled by tick species for DNA extraction and subsequent PCR examination for the presence of tick-borne pathogens. Out of 448 tick samples, 247 (95 from dogs and 152 from cats) were Ixodes ricinus, 26 (12 from dogs and 14 from cats) were I. hexagonus, 59 (43 from dogs and 16 from cats) were Dermacentor reticulatus and 116 (74 from dogs and 42 from cats) were Rhipicephalus sanguineus sensu lato (s.l.). In 17% of the I. ricinus samples Anaplasma phagocytophilum was found. Borrelia spp. were mainly identified in I. ricinus collected from cats (18%) and to a lesser extent in dog-sourced ticks (1%), with Borrelia afzelii (n = 11), B. garinii (n = 7), B. valaisiana (n = 5), B. lusitaniae (n = 3) and B. burgdorferi sensu stricto (n = 3) being identified. One I. hexagonus sample collected from a cat in France tested positive for B. afzelii. Babesia canis was detected in 20% of the D. reticulatus samples, mainly from Hungary. Rhipicephalus sanguineus s.l. was found positive for Hepatozoon canis (3%), A. platys (5%) and three Rickettsia species (7%; R. massiliae; R. raoultii and R. rhipicephali). Furthermore, a total of 66 R. sanguineus s.l. ticks were subjected to molecular analysis and were identified as R. sanguineus sp. II-temperate lineage, with seven haplotypes recorded. Amongst them, the most prevalent sequence types were haplotype XIII (n = 24; 69%) and haplotype XIV (n = 16; 52%) in France and in Italy, respectively, found both in cats and dogs. Although differences related to both country and host, were observed, the results of this study indicate that cats and dogs are exposed to tick-borne pathogen infected ticks, which may represent a medical risk to these host animals.

Ticks and Tick-Borne Infections: Complex Ecology, Agents, and Host Interactions

Ticks transmit the most diverse array of infectious agents of any arthropod vector. Both ticks and the microbes they transmit are recognized as significant threats to human and veterinary public health. This article examines the potential impacts of climate change on the distribution of ticks and the infections they transmit; the emergence of novel tick-borne pathogens, increasing geographic range and incidence of tick-borne infections; and advances in the characterization of tick saliva mediated modulation of host defenses and the implications of those interactions for transmission, establishment, and control of tick infestation and tick-borne infectious agents.

Evidence for Clinical Anaplasmosis and Borreliosis in Cats in Maine

The objectives of this study were to use data from client-owned cats in an Ixodes scapularis endemic area to evaluate for clinical associations with diagnostic test results for Anaplasma phagocytophilum and Borrelia burgdorferi and to provide information from a group of cats with possible borreliosis as the cause of clinical manifestations of disease. All cases were evaluated at one clinic, medical records were evaluated, and sera from all cats were tested using one of two commercially available assays labeled for the use with dog sera (SNAP 4Dx or SNAP 4Dx Plus; IDEXX Laboratories, Westbrook, ME). Of the 159 cats evaluated, 42 cats (26.4%) had clinical signs consistent with A. phagocytophilum or B. burgdorferi infection and 117 cats (73.6%) were apparently healthy. Antibodies against B. burgdorferi or A. phagocytophilum were detected in sera of 18.2% and 6.3% of the 159 cats, respectively. Cats with clinical signs of disease were 4 times more likely to have antibodies against one or both agents than healthy cats (95% confidence interval [CI] 1.7928-8.9246; P = .0007), cats allowed outdoors were 5 times more likely to have antibodies against one or both agents than cats housed exclusively indoors (95% CI 2.0196-12.4497; P = .0005), and cats of owners who purchased acaricides were more likely (odds ratio = .3977) to have antibodies against one or both agents than cats of owners who did not purchase acaricides (95% CI .1659-.9534; P = .0387). The cats in the case series were believed to have B. burgdorferi infection as the most likely cause of illness based on serological testing, select clinical information, and apparent response to administration of doxycycline. The results suggest that both A. phagocytophilum and B. burgdorferi are associated with clinical illness in cats. Owners of cats allowed outdoors should be diligent in the use of acaricides.

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.

Identification of Borrelia protein candidates in mouse skin for potential diagnosis of disseminated Lyme borreliosis

In vector-borne diseases, the skin plays an essential role in the transmission of vector-borne pathogens between the vertebrate host and blood-feeding arthropods and in pathogen persistence. Borrelia burgdorferi sensu lato is a tick-borne bacterium that causes Lyme borreliosis (LB) in humans. This pathogen may establish a long-lasting infection in its natural vertebrate host where it can persist in the skin and some other organs. Using a mouse model, we demonstrate that Borrelia targets the skin regardless of the route of inoculation, and can persist there at low densities that are difficult to detect via qPCR, but that were infective for blood-feeding ticks. Application of immunosuppressive dermocorticoids at 40 days post-infection (PI) significantly enhanced the Borrelia population size in the mouse skin. We used non-targeted (Ge-LC-MS/MS) and targeted (SRM-MS) proteomics to detect several Borrelia-specific proteins in the mouse skin at 40 days PI. Detected Borrelia proteins included flagellin, VlsE and GAPDH. An important problem in LB is the lack of diagnosis methods capable of detecting active infection in humans suffering from disseminated LB. The identification of Borrelia proteins in skin biopsies may provide new approaches for assessing active infection in disseminated manifestations.

[Heterogeneity of canine immune responses to Borrelia burgdorferi in a line immunoassay comprising recombinant VlsE and C6 peptide]

OBJECTIVE

The study aimed to investigate the distribution of specific immune responses (IgG) to Borrelia burgdorferi using a line immunoassay with recombinant VlsE (variable major protein-like sequence, expressed) protein and synthetic C peptide among other antigens. We compared the immune responses to VlsE protein and C₆ peptide, because both antigens have been considered specific for a Borrelia infection.

MATERIALS AND METHODS

A total of 1355 blood samples from dogs suspected of Borrelia infection were analysed. The line immunoassay employed nine antigens.

RESULTS

A total of 64.4% of all samples tested negative, 16.4% were positive for an infection and 17.4% were positive for vaccination. Band patterns specific for both infection and vaccination were observed in 1.2% of the dogs. The bands that most frequently tested positive were p100 (24.3%), p31/OspA (18.5%), C₆ (16.3%) and VlsE (13.9%). A total of 236 dogs (17.4% of the population) had antibodies to VlsE and/or C₆ peptide. In 73.3% of these dogs, results for VlsE and C₆ peptide were consistent, whereas this was not the case for 26.7% of these animals.

CONCLUSION AND CLINICAL RELEVANCE

Testing using a line immunoassay allows for qualitative analyses of different immune responses to various antigens used as probes. In our study, >  26% of the dogs displayed discrepant results with regard to VlsE and C₆, the two antigens considered specific for Borrelia burgdorferi infection. To confirm or rule out infection, the results of several band patterns, thought to be specific for infection, need to be taken into consideration.

Vector-borne diseases in cats in Germany

Vector-borne diseases (VBDs) are caused by a wide range of pathogens, which are transmitted by a variety of vectors, such as ticks and fleas. As a result of climate changes, more vector-borne diseases are becoming endemic in Germany, not only in dogs, but also in cats. For some of the pathogens prevalence data still need to be investigated in Germany. However, natural infections with Bartonella, Anaplasma, haemotropic Mycoplasma and Borrelia species have already been described in German cats. Clinical relevance of these pathogens is not fully understood, and it is still unknown, why most infected cats stay asymptomatic and which predisposing factors contribute to the development of clinical signs in cats. Moreover, there is a risk of zoonotic transmission for some of the pathogens, e.  g., for some Bartonella spp. infections that are associated with cat scratch disease in humans. Due to the increasing number of VBDs in cats in Germany, preventive measures, such as the use of acaricides and insecticides, should be performed on a regular base in order to reduce the risk of these infections.

Diagnosing Borreliosis

Borrelia species fall into two groups, the Borrelia burgdorferi sensu lato (Bbsl) complex, the cause of Lyme borreliosis (also known as Lyme disease), and the relapsing fever group. Both groups exhibit inter- and intraspecies diversity and thus have variations in both clinical presentation and diagnostic approaches. A further layer of complexity is derived from the fact that ticks may carry multiple infectious agents and are able to transmit them to the host during blood feeding, with potential overlapping clinical manifestations. Besides this, pathogens like Borrelia have developed strategies to evade the host immune system, which allows them to persist within the host, including humans. Diagnostics can be applied at different times during the clinical course and utilize sample types, each with their own advantages and limitations. These differing methods should always be considered in conjunction with potential exposure and compatible clinical features. Throughout this review, we aim to explore different approaches providing the reader with an overview of methods appropriate for various situations. This review will cover human pathogenic members of Bbsl and relapsing fever borreliae, including newly recognized Borrelia miyamotoi spirochetes.

Serologic responses to peptides of Anaplasma phagocytophilum and Borrelia burgdorferi in dogs infested with wild-caught Ixodes scapularis

Anaplasma phagocytophilum and Borrelia burgdorferi are both transmitted by Ixodes spp. and are associated with clinical illness in some infected dogs. This study evaluated canine antibody responses to the A. phagocytophilum p44 peptides APH-1 and APH-4 as well as the B. burgdorferi C6 peptide before and after doxycycline treatment. A total of eight dogs were infested with wild-caught I. scapularis for 1 week. Blood was collected prior to tick attachment and from Days 3-77 to 218-302 with doxycycline treatment beginning on Day 218. Blood was assayed for A. phagocytophilum DNA by PCR assay. Sera was assessed for antibodies by immunofluorescent antibody (IFA) test and ELISA. Anaplasma phagocytophilum DNA was amplified from blood of all dogs by Day 7. Antibodies to APH-4 were detected in serum as early as 14days after tick exposure and six dogs had APH-4 antibodies detected 3-7 days before antibodies against APH-1. All dogs were seropositive for A. phagocytophilum from Days 218 to 302. Antibodies to B. burgdorferi were detected in 6/8 dogs beginning 21days after I. scapularis infestation. Among the five dogs that remained seropositive at Day 218, C6 antibody levels declined on average 81% within 84days of initiating treatment. The results suggest that the APH-4 peptide may be more useful than APH-1 for detecting antibodies earlier in the course of an A. phagocytophilum infection. After doxycycline administration, C6 antibody levels but not APH-1 or APH-4 antibody levels decreased, suggesting a treatment effect on C6 antibody production.

Canine infection with Borrelia burgdorferi, Dirofilaria immitis, Anaplasma spp. and Ehrlichia spp. in Canada, 2013-2014

BACKGROUND

Canine test results generated by veterinarians throughout Canada from 2013-2014 were evaluated to assess the geographical distribution of canine infection with Borrelia burgdorferi, Dirofilaria immitis, Ehrlichia spp., and Anaplasma spp.

METHODS

The percent positive test results of 115,636 SNAP® 4Dx® Plus tests from dogs tested were collated by province and municipality to determine the distribution of these vector-borne infections in Canada.

RESULTS

A total of 2,844/115,636 (2.5%) dogs tested positive for antibody to B. burgdorferi. In contrast, positive test results for D. immitis antigen and antibodies to Ehrlichia spp. and Anaplasma spp. were low, with less than 0.5% of dogs testing positive for any one of these three agents nationwide. Provincial seroprevalence for antibodies to B. burgdorferi ranged from 0.5% (Saskatchewan)-15.7% (Nova Scotia); the areas of highest percent positive test results were in proximity to regions in the USA considered endemic for Lyme borreliosis, including Nova Scotia (15.7%) and Eastern Ontario (5.1%). These high endemic foci, which had significantly higher percent positive test results than the rest of the nation (P < 0.0001), were surrounded by areas of moderate to low seroprevalence in New Brunswick (3.7%), Quebec (2.8%), and the rest of Ontario (0.9%), as well as northward and westward through Manitoba (2.4%) and Saskatchewan (0.5%). Insufficient results were available from the westernmost provinces, including Alberta and British Columbia, to allow analysis.

CONCLUSION

Increased surveillance of these vector-borne disease agents, especially B. burgdorferi, is important as climate, vector range, and habitat continues to change throughout Canada. Using dogs as sentinels for these pathogens can aid in recognition of the public and veterinary health threat that each pose.

A Bayesian spatio-temporal model for forecasting the prevalence of antibodies to Borrelia burgdorferi, causative agent of Lyme disease, in domestic dogs within the contiguous United States

This paper models the prevalence of antibodies to Borrelia burgdorferi in domestic dogs in the United States using climate, geographic, and societal factors. We then use this model to forecast the prevalence of antibodies to B. burgdorferi in dogs for 2016. The data available for this study consists of 11,937,925 B. burgdorferi serologic test results collected at the county level within the 48 contiguous United States from 2011-2015. Using the serologic data, a baseline B. burgdorferi antibody prevalence map was constructed through the use of spatial smoothing techniques after temporal aggregation; i.e., head-banging and Kriging. In addition, several covariates purported to be associated with B. burgdorferi prevalence were collected on the same spatio-temporal granularity, and include forestation, elevation, water coverage, temperature, relative humidity, precipitation, population density, and median household income. A Bayesian spatio-temporal conditional autoregressive (CAR) model was used to analyze these data, for the purposes of identifying significant risk factors and for constructing disease forecasts. The fidelity of the forecasting technique was assessed using historical data, and a Lyme disease forecast for dogs in 2016 was constructed. The correlation between the county level model and baseline B. burgdorferi antibody prevalence estimates from 2011 to 2015 is 0.894, illustrating that the Bayesian spatio-temporal CAR model provides a good fit to these data. The fidelity of the forecasting technique was assessed in the usual fashion; i.e., the 2011-2014 data was used to forecast the 2015 county level prevalence, with comparisons between observed and predicted being made. The weighted (to acknowledge sample size) correlation between 2015 county level observed prevalence and 2015 forecasted prevalence is 0.978. A forecast for the prevalence of B. burgdorferi antibodies in domestic dogs in 2016 is also provided. The forecast presented from this model can be used to alert veterinarians in areas likely to see above average B. burgdorferi antibody prevalence in dogs in the upcoming year. In addition, because dogs and humans can be exposed to ticks in similar habitats, these data may ultimately prove useful in predicting areas where human Lyme disease risk may emerge.

Cats are not small dogs: is there an immunological explanation for why cats are less affected by arthropod-borne disease than dogs?

It is widely recognized that cats appear to be less frequently affected by arthropod-borne infectious diseases than dogs and share fewer zoonotic pathogens with man. This impression is supported by the relative lack of scientific publications related to feline vector-borne infections. This review explores the possible reasons for the difference between the two most common small companion animal species, including the hypothesis that cats might have a genetically-determined immunological resistance to arthropod vectors or the microparasites they transmit. A number of simple possibilities might account for the lower prevalence of these diseases in cats, including factors related to the lifestyle and behaviour of the cat, lesser spend on preventative healthcare for cats and reduced opportunities for research funding for these animals. The dog and cat have substantially similar immune system components, but differences in immune function might in part account for the markedly distinct prevalence and clinicopathological appearance of autoimmune, allergic, idiopathic inflammatory, immunodeficiency, neoplastic and infectious diseases in the two species. Cats have greater genetic diversity than dogs with much lower linkage disequilibrium in feline compared with canine breed groups. Immune function is intrinsically related to the nature of the intestinal microbiome and subtle differences between the canine and feline microbial populations might also impact on immune function and disease resistance. The reasons for the apparent lesser susceptibility of cats to arthropod-borne infectious diseases are likely to be complex, but warrant further investigation.

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.

A case of canine borreliosis in Iran caused by Borrelia persica

Tick-borne relapsing fever is an endemic disease in Iran, with most cases attributed to infection by Borrelia persica, which is transmitted by Ornithodoros tholozani soft ticks. Here, we report spirochetemia in blood of a puppy residing in Tehran, Iran. The causative species was identified by use of highly discriminative IGS sequencing; the 489 bp IGS sequence obtained in our study showed 99% identity (100% coverage) when compared with B. persica sequences derived from clinical cases or from O. tholozani ticks. Our IGS sequence also showed 99% similarity over 414 bp (85% coverage) with a strain from a domestic dog, and 96% over 328 bp (69% coverage) with a strain from a domestic cat. Pet-keeping in cosmopolitan cities like Tehran has become increasingly popular in recent years. Animals are often transported into the city in cages or cardboard boxes that might also harbor minute tick larvae and/or early stages of the nymphs bringing them into the urban environment. This may pose a threat to household members who buy and keep these puppies and as a result may come into close contact with infected ticks.

Multiple antigen target approach using the Accuplex4 BioCD system to detect Borrelia burgdorferi antibodies in experimentally infected and vaccinated dogs

The primary objective of our study was to optimize detection of serum antibodies to Borrelia burgdorferi using a new commercial automated fluorescence system (Accuplex4 BioCD system, Antech Diagnostics, Lake Success, New York). The system used multiple natural and artificial peptides-outer surface proteins (OspA, OspC, OspF), an outer membrane protein (P39), and a proprietary synthetic peptide (small Lyme peptide [SLP])-and the results were compared with a commercially available enzyme-linked immunosorbent assay that uses a proprietary peptide (C6). Sera from 4 groups were evaluated: dogs vaccinated with 1 of 3 commercially available vaccines (n = 18); dogs infested with adult Ixodes scapularis (black-legged tick; n = 18); dogs previously vaccinated and then infested with I. scapularis (n = 18); and dogs with B. burgdorferi infection that were then vaccinated (n = 14). All of the vaccines evaluated induced OspA responses. However, antibodies against OspF or C6 were not induced in any of the vaccinated dogs. Additionally, the OspF antibodies had 100% sensitivity and specificity when compared to antibodies against C6 peptide. In B. burgdorferi-infected dogs, antibodies against OspC and SLP were detected in serum sooner than antibodies against the other targets. Low levels of antibodies against OspA developed in 6 of 14 B. burgdorferi-infected, unvaccinated dogs and had the shortest duration compared to the other antibodies. Detection of antibody responses to multiple B. burgdorferi targets with this system can be used to help differentiate vaccinated dogs from exposed dogs as well as acute infection from chronic infection.

Comparison of effectiveness of cefovecin, doxycycline, and amoxicillin for the treatment of experimentally induced early Lyme borreliosis in dogs

Background

While Koch’s postulates have been fulfilled for Lyme disease; causing transient fever, anorexia and arthritis in young dogs; treatment of sero-positive dogs, especially asymptomatic animals, remains a topic of debate. To complicate this matter the currently recommended antibiotic treatments of Lyme Disease in dogs caused by Borrelia burgdorferi require daily oral administrations for 31 days or longer, which makes non-compliance a concern. Additionally, there is no approved veterinary antimicrobial for the treatment of Lyme Disease in dogs in the USA and few recommended treatments have been robustly tested.

In vitro testing of cefovecin, a novel extended-spectrum cephalosporin, demonstrated inhibition of spirochete growth. A small pilot study in dogs indicated that two cefovecin injections two weeks apart would be as efficacious against B. burgdorferi sensu stricto as the recommended treatments using doxycycline or amoxicillin daily for 31 days.

This hypothesis was tested in 17–18 week old Beagle dogs, experimentally infected with B. burgdorferi sensu stricto, using wild caught ticks, 75 days prior to antimicrobial administration.

Results

Clinical observations for lameness were performed daily but were inconclusive as this characteristic sign of Lyme Disease rarely develops in the standard laboratory models of experimentally induced infection. However, each antibiotic tested was efficacious against B. burgdorferi as measured by a rapid elimination of spirochetes from the skin and reduced levels of circulating antibodies to B. burgdorferi. In addition, significantly less cefovecin treated animals had Lyme Disease associated histopathological changes compared to untreated dogs.

Conclusions

Convenia was efficacious against B. burgdorferi sensu stricto infection in dogs as determined by serological testing, PCR and histopathology results. Convenia provides an additional and effective treatment option for Lyme Disease in dogs.

Evidence of Anaplasma phagocytophilum and Borrelia burgdorferi infection in cats after exposure to wild-caught adult Ixodes scapularis

Cats are infected by Anaplasma phagocytophilum and Borrelia burgdorferi when exposed to infected Ixodes scapularis (black-legged ticks). The purpose of our study was to allow wild-caught I. scapularis to feed on healthy research cats (n = 4) and temporally evaluate for A. phagocytophilum DNA in blood by a polymerase chain reaction (PCR) assay as well as for antibody responses to the B. burgdorferi C6 peptide, to the A. phagocytophilum P44 peptide, and to a novel A. phagocytophilum peptide (P44-4). Prior to I. scapularis infestation, all cats were negative for antibodies against both organisms based on a kit optimized for dog serum, and negative for A. phagocytophilum DNA in blood using a conventional PCR assay. Using the pre-infestation samples, an enzyme-linked immunosorbent assay for detecting antibodies against the P44-4 peptide was optimized. Cats were infested with wild-caught I. scapularis for 7 days. Genomic DNA of A. phagocytophilum was amplified from the blood before antibodies were detected in all 4 cats. Antibodies against the C6 peptide, P44 peptide, and P44-4 peptide were detected in the sera of all 4 cats. Antibodies against P44-4 were detected prior to those against P44 in 3 out of 4 cats. The results suggest that a PCR assay should be considered in acutely ill cats with suspected anaplasmosis that are seronegative.

Wildlife reservoirs for vector-borne canine, feline and zoonotic infections in Austria

Austria's mammalian wildlife comprises a large variety of species, acting and interacting in different ways as reservoir and intermediate and definitive hosts for different pathogens that can be transmitted to pets and/or humans. Foxes and other wild canids are responsible for maintaining zoonotic agents, e.g. Echinococcus multilocularis, as well as pet-relevant pathogens, e.g. Hepatozoon canis. Together with the canids, and less commonly felids, rodents play a major role as intermediate and paratenic hosts. They carry viruses such as tick-borne encephalitis virus (TBEV), bacteria including Borrelia spp., protozoa such as Toxoplasma gondii, and helminths such as Toxocara canis. The role of wild ungulates, especially ruminants, as reservoirs for zoonotic disease on the other hand seems to be negligible, although the deer filaroid Onchocerca jakutensis has been described to infect humans. Deer may also harbour certain Anaplasma phagocytophilum strains with so far unclear potential to infect humans. The major role of deer as reservoirs is for ticks, mainly adults, thus maintaining the life cycle of these vectors and their distribution. Wild boar seem to be an exception among the ungulates as, in their interaction with the fox, they can introduce food-borne zoonotic agents such as Trichinella britovi and Alaria alata into the human food chain.

Canine vector-borne infections in Mauritius

Background

Canine vector-borne diseases have a worldwide distribution, but to the best of our knowledge, no research has been carried out to evaluate their presence on the Indian Ocean island of Mauritius. An investigation into canine vector-borne infections was conducted in dogs (n = 78) resident at an animal shelter in Port Louis, Mauritius using a combination of traditional microscopy and serological methods.

Methods

Ticks were manually collected from the stray dog population for identification as well as for quantifying tick burdens. Blood was also collected from each dog via either the jugular vein or the cephalic vein, and was stored in EDTA tubes. The stored blood was then used to measure PCV values, make blood smears for the identification of parasites, and used for serological testing of vector-borne disease.

Results

A total of 178 ticks were collected from 52 dogs and identified as Rhipicephalus sanguineus (175/178) or Amblyomma variegatum (3/178). Twenty-six (33%; 95% CI 23, 45) dogs were seropositive for Ehrlichia spp., and 12 (15%; 95% CI 8, 25) for Anaplasma spp., Dirofilaria antigen was detected in 14 (18%; 95% CI 10, 28), and nine (12%; 95% CI 5, 21) dogs had Hepatozoon canis gamonts observed in blood films during microscopic examination. Eleven (14%; 95% CI 7, 24) dogs were co-infected with two pathogens. Borrelia burgdorferi antibodies were not detected in any dogs.

Conclusions

Infection with these pathogens had no significant effect on the packed cell volume (PCV), but high tick burdens were significantly associated with the presence of a tick-borne pathogen. This is the first study of its kind on the dog population in Mauritius and demonstrates the presence of previously undocumented canine vector-borne infections on the island. The relatively high proportion of infected dogs within the study should alert clinicians to the presence of canine vector-borne diseases on the island of Mauritius.

Temporal and Spatial Distribution of Tick-Borne Disease Cases among Humans and Canines in Illinois (2000-2009)

Four tick-borne diseases (TBDs), anaplasmosis, ehrlichiosis, Lyme disease (LD), and Rocky Mountain spotted fever (RMSF), are endemic in Illinois. The prevalence of human and canine cases of all four TBDs rose over the study period with significant differences in geographic distribution within the state. Among human cases, there were associations between cases of RMSF and LD and total forest cover, seasonal precipitation, average mean temperature, racial-ethnic groups, and gender. Estimated annual prevalence of three canine TBDs exceeded human TBD cases significantly in each region. There was concordance in the number of human and canine cases by county of residence, in annual prevalence trends, and in time of year at which they were diagnosed. To account for multiple environmental risk factors and to facilitate early diagnosis of cases, integrated surveillance systems must be developed and communication between veterinarians, physicians, and public health agencies must be improved.

Comparison of different diagnostic assays for the detection of Borrelia burgdorferi-specific antibodies in dogs

BACKGROUND

Antibody tests are frequently used in the diagnosis of canine Lyme borreliosis, including immunofluorescence assay (IFA) for immunoglobulin G (IgG) and M (IgM) antibodies, kinetic enzyme-linked immunosorbent assay (KELA), and Western blotting (WB). Recently, the SNAP4Dx, an in-house test using C6 technology has become available.

OBJECTIVES

The aim of this study was to compare IFA, KELA, and SNAP4Dx assay results, and to determine their sensitivity and specificity when compared with the WB, used as gold standard in this study.

METHODS

Two hundred canine sera were tested for the presence of specific antibodies against Borrelia spp. using the above-mentioned tests.

RESULTS

The sensitivity and specificity of IFA-IgG was 76.6% (95% confidence interval [CI] 46.87-86.72) and 87.1% (95% CI 80.06-91.90), and 26.3% (95% CI 11.81-48.79) and 81.0% (95% CI 73.64-86.71) for IFA-IgM, respectively. KELA was 100% (95% CI 83.18-100) sensitive and 75.4% (95% CI 67.02-82.09) specific, and the SNAP4Dx was 84.2% (95% CI 62.43-94.48) sensitive and 98.5% (95% CI 94.83-99.60) specific.

CONCLUSIONS

Both IFAs had very low sensitivity and specificity and cannot be recommended for screening purposes. In contrast, KELA showed excellent sensitivity, but positive results always need to be confirmed by WB to differentiate the source of antibody formation. The SNAP4Dx had a high sensitivity and specificity, and thus can potentially replace the more labor-intensive WB, at least in untreated dogs.

Inflammatory joint disease in cats: diagnostic approach and treatment

PRACTICAL RELEVANCE

Osteoarthritis, a degenerative non-inflammatory joint disease, is common in cats, usually causing gradual changes in behavior and lifestyle rather than severe lameness. Inflammatory arthritis occurs much less frequently and is nearly always associated with debilitating lameness. It may have an infectious or immune-mediated cause - but, unlike the canine disease, is much more likely to be infectious in origin.

CLINICAL CHALLENGES

Cats with inflammatory joint disease are presented for evaluation of lethargy, anorexia, reluctance to walk or fever. Synovial fluid collection and analysis is required to confirm joint inflammation, but this is a procedure many veterinarians are not comfortable performing in cats. Once inflammatory arthritis is confirmed, extensive testing is required to diagnose infectious causes and determine appropriate treatment. Immune-mediated polyarthritis can be treated with immunosuppressive drugs only after all infectious possibilities are eliminated. Radiographs are used to characterize the arthritis as erosive or nonerosive, but radiographic changes in cats are often subtle compared with those described in canine rheumatoid-like arthritis.

AUDIENCE

This review, aimed at all veterinarians who treat cats, describes the general clinical approach to feline joint disease, the collection and analysis of synovial fluid, and the diagnosis and management of inflammatory joint diseases affecting cats. The diagnostic approach to an unusual case of erosive polyarthritis is discussed in the Case Notes.

EVIDENCE BASE

To date, the veterinary literature on inflammatory joint disease in cats has been limited to older reviews of immune-mediated disorders and multiple single case reports or small case series describing infectious disorders. This article offers a current comprehensive review of these disorders.

Serological detection of Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Ehrlichia canis antibodies and Dirofilaria immitis antigen in a countrywide survey in dogs in Poland

Canine vector-borne diseases (CVBDs) have increasingly become a focus of attention in the past few years. Nevertheless, in many parts of Europe information on their occurrence is still scarce. In a large study in Poland 3,094 serum samples taken from dogs throughout all 16 Polish provinces were tested using a commercial kit for the detection of circulating antibodies against Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Ehrlichia canis and of Dirofilaria immitis antigen. A total of 12.31% (381/3,094; 95% confidence interval [CI]: 11.18-13.52%) and 3.75% (116/3,094; 95% CI: 3.11-4.48%) of the dogs were positive for A. phagocytophilum and B. burgdorferi s.l. antibodies, respectively. Furthermore, 0.26% (8/3,094; 95% CI: 0.11-0.51%) were positive for E. canis antibodies and 0.16% (5/3,094; 95% CI: 0.05-0.38%) for D. immitis antigen. The highest percentages of A. phagocytophilum-positive dogs were noted in Lesser Poland, Silesia and Łódź Provinces. For B. burgdorferi s.l., the highest prevalence was recorded in Łódź Province. Co-infections with A. phagocytophilum and B. burgdorferi s.l. were recorded in 1.71% of all examined dogs (53/3,094; 95% CI: 1.29-2.23%). One dog even had a triple infection, testing positive for E. canis too. Both A. phagocytophilum and B. burgdorferi s.l. have previously been reported in Poland and were confirmed in the present study by positive samples from all 16 provinces. Concerning E. canis and D. immitis travel history or importation cannot be excluded as factors which may have determined the occurrence of these pathogens in the relevant animals. Practitioners in Poland should be aware of the above mentioned CVBDs and of prophylactic measures to protect dogs and their owners.

Seroprevalence of some vector-borne infections of dogs in Hungary

The first comprehensive study on the prevalence of canine vector-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Ehrlichia canis, and Dirofilaria immitis) was carried in Hungary because, except for babesiosis and dirofilariosis caused by Dirofilaria repens, there were no data on their regional distribution and prevalence. In 2011 and 2012, 1305 blood samples were collected from randomly selected, apparently healthy pet dogs in 167 localities of 19 counties of Hungary. All sera samples from dogs were screened for simultaneous qualitative detection of circulating antibodies to E. canis and B. burgdorferi sensu lato and A. phagocytophilum and D. immitis antigen using SNAP(®) 4Dx (IDEXX Laboratories). Overall, 170 dogs (13.0%; 95% confidence interval [CI] 11-15) were serologically positive to one or more of the tested pathogens. A. phagocytophilum was the most prevalent pathogen detected in 102 dogs by antibody titers (7.9%, 95% CI 6.5-9.5), followed by D. immitis (2.4%, 95% CI 1.0-4.0, n=64) and B. burgdorferi (0.4%, 95% CI 0.0-1.1, n=11) out of 1305 tested dogs. The least prevalent infection was with E. canis, with only two positive dogs (0.16%, 95% CI 0.03-0.6). Co-infection was found in eight dogs (0.61%, 95% CI 0.29-1.21), of which seven were seropositive to two pathogens (five with A. phagocytophilum and D. immitis, two with A. phagocytophilum and B. burgdorferi). One dog was serologically positive to three pathogens (A. phagocytophilum, B. burgdorferi, and D. immitis). Purebred and crossbred animals did not show significantly different levels of seropositivity. There was no significant association between the gender and the results of diagnostic testing. Logistic regression analysis showed a higher chance of seropositivity in the older dogs.