Evidence for Clinical Anaplasmosis and Borreliosis in Cats in Maine

Lyme disease in companion animals: an updated state-of-art and current situation in Portugal

Lyme disease (LD) is a globally distributed zoonotic multisystemic condition caused by gram-negative spirochete bacteria of the Borrelia burgdorferi complex, transmitted through tick bites. Research on LD in domestic animals in Portugal is limited, potentially leading to underestimating its prevalence. This disease affects many species, including humans, making it a critical public health issue. In domestic animals, LD often presents subclinically or with non-specific clinical signs, complicating its diagnosis. Nevertheless, veterinarians should always consider LD in cases with a history of tick exposure and compatible clinical signs. Diagnostic confirmation can be achieved through serological and other complementary tests. Treatment involves eradicating the bacterial infection and managing clinical signs using a combination of antibiotics, analgesics, anti-inflammatories, and other medications. Effective prevention primarily relies on tick control measures. This review aims to provide an up-to-date state-of-the-art LD, particularly in Portugal.

Assessing the spatial and temporal patterns and risk factors for acquisition of Ixodes spp. by companion animals across Canada

Climatic and land use changes have contributed to substantial changes in the abundance, distribution, and activity patterns of ticks in Canada, which have led to an increased risk of tick bites and tick-borne pathogen exposure for companion animals. The objectives of this study were to describe current spatial and temporal patterns of Ixodes spp. on companion animals in Canada and explore the association between tick bites and dog and cat demographic factors. Ticks were collected for one year (April 2019 - March 2020) from 94 veterinary clinics. Included with each submission was a short questionnaire containing owner-reported information on travel history, date of removal and suspected location of tick acquisition, and animal-specific demographic factors. Ticks were identified morphologically using a stereomicroscope, standard keys, and through PCR analyses. Mixed effect multivariable logistic regression models were built to explore the association between an Ixodes scapularis bite and animal demographic factors; veterinary clinic was included as a random effect. Approximately 2300 submissions were received from clinics across Canada, totalling 4425 ticks. The most common Ixodes spp. was I. scapularis (n = 2168), followed by Ixodes pacificus (n = 172) and Ixodes cookei (n = 155). Ixodes scapularis were well distributed in regions across central and eastern Canada. Ixodes cookei was found in eastern Canada, with the greatest numbers from Quebec and New Brunswick. Ixodes pacificus submissions were restricted to British Columbia. Across eastern Canada, dogs of the herding, mixed breed (large and small), sporting, working, terrier, and toy breed groups, and spayed cats were all found to have higher odds of acquiring I. scapularis, compared to other tick species. For the dog model, significant interactions were found between predictor variables age and sex. Regional information on tick distribution, seasonality, and risk factors for acquisition contribute to evidence-based veterinary practices for tick and tick-borne disease control in Canada.

Influence of ecological and climatic conditions on the spread of Borrelia burgdorferi in domestic dogs in Ukraine

Lyme-borreliosis is a zoonotic, infectious disease that has a complex chain of transmission of the pathogen Borrelia burgdorferi sensu lato and includes the relationship between ixodid ticks, vertebrate hosts, humans and companion animals in the environment. The article shows general trends in the prevalence of canine Lyme-borreliosis in Ukraine depending on environmental, climatic and physiographic factors. The results of a comparative cartographic analysis of the prevalence of Lyme borreliosis among domestic dogs in Ukraine are presented by systematizing, mathematical and statistical processing of the data obtained by surveying veterinarians engaged in clinical veterinary practice. The paper includes generalized data on the clinical manifestations, methods of diagnosis and treatment of Lyme borreliosis in dogs. We determined the dependence of the prevalence of Lyme borreliosis in dogs on the types of physical and geographical territories – natural zones of Ukraine. Each of the natural zones differs in types of relief, climatic conditions, soil types, composition of fauna and flora, which affect the epizootic chain of Lyme disease. There is a clear correlation between the incidence of Lyme borreliosis in dogs and the types of natural areas. The highest incidence of Lyme borreliosis in dogs was observed in the forest-steppe zone and the zone of broad-leaved forests. A sharp decrease in the incidence of dogs was recorded in areas of mixed forests, the Ukrainian Carpathians and in the South of Ukraine in the steppe zone. The study also confirmed that the prevalence of Lyme disease among domestic dogs was influenced by the climatic factors, in particular: gross moisture of territories, average annual air temperature and soil temperature. In Ukraine, veterinarians in the vast majority of cases use serological diagnostic methods: immunochromatographic analysis, immunoenzymatic assay, and western blot, which are insufficient, since the presence of antibodies to the Lyme borreliosis pathogen is only a confirmation of the animal's contact with the antigen and may not indicate the presence of the disease in the clinical form. The generalized data on the use of antimicrobial drugs in the treatment of Lyme borreliosis in dogs indicate the predominant use of tetracycline antibiotics and cephalosporins. The majority of veterinarians reported symptoms of Lyme arthritis, somewhat fewer reported Lyme nephritis, neuroborreliosis, Lyme carditis and in rare cases, veterinarians observed erythema at the site of tick bite. About half of the veterinarians in Ukraine observed an increase in the incidence of Lyme disease in dogs, indicating a probable deterioration of the epizootic and epidemiological situation regarding Lyme borreliosis, especially in areas with favourable conditions for the circulation of Lyme borreliosis pathogens in natural and urban ecotopes. The results substantiate the need for the further study of the circulation of Borrelia burgdorferi sensu lato and their ability to cause disease in humans and animals, as well as the need to implement the principles of the One Health concept for the control and management of Lyme borreliosis.

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.

Evaluation of the role of Babesia species and Cytauxzoon felis in feline anemia cases in Colorado, USA

Objectives

The aim of this study was to evaluate the blood of cats in Colorado, USA, with suspected infectious causes of anemia for the presence of Babesia species and Cytauxzoon felis DNA. Results of PCR testing for other common vector-borne diseases potentially associated with anemia are also reported.

Methods

Samples from 101 cats were tested using a PCR assay that coamplified the DNA of C felis and Babesia species mitochondrial DNA. PCR testing for DNA of hemoplasmas, Bartonella species, Ehrlichia species, Anaplasma species, Neorickettsia risticii and Wolbachia genera was also performed if not carried out previously.

Results

Twenty-two cats (21.8%) were positive for DNA of an infectious agent. DNA from hemoplasma species were amplified from 14 cats (13.9%). Bartonella species DNA was amplified from four cats (4%) and Ehrlichia canis, Anaplasma platys, Anaplasma phagocytophilum and Wolbachia genera DNA were amplified from one cat each. Babesia species and C felis mitochondrial DNA were not amplified from any sample.

Conclusions and relevance

Based on the results of this study, it does not appear that Babesia species or C felis are clinically relevant in anemic cats in Colorado, USA. For C felis, this suggests that the vector Amblyomma americanum is still uncommon in this geographic area.

Efficacy of a novel topical combination of esafoxolaner, eprinomectin and praziquantel against Ixodes ricinus and Ixodes scapularis in cats

Esafoxolaner is a purified enantiomer of afoxolaner with insecticidal and acaricidal properties. It is combined with eprinomectin and praziquantel in a novel topical endectoparasiticide formulation for cats. The efficacy of this novel formulation was evaluated in three Ixodes ricinus and two Ixodes scapularis experimental studies, with comparable designs. In each study, cats were randomly allocated, based on a pre-treatment tick infestation and count, to a placebo control group or a group treated with the minimum recommended dose of the novel formulation. Cats were infested two days before treatment and weekly thereafter. Immediate efficacy was evaluated 48 h after treatment; persistent efficacy was evaluated 48 h after new weekly infestations for at least one month after the treatment (in one of the studies, the first two weeks of persistent efficacy against I. ricinus were not tested). Efficacy was calculated at each timepoint by comparison of arithmetic means of live ticks found in the control and the treated groups. In the three studies targeting I. ricinus, immediate and persistent efficacies ranged between 91% and 100% for five weeks. In the two studies targeting I. scapularis, immediate and persistent efficacies ranged between 95% and 100%, and 98% and 100% for one month, respectively. These studies provide robust evidence of efficacy of the novel topical formulation of esafoxolaner, eprinomectin and praziquantel against experimental I. ricinus and I. scapularis infestations for at least one month in cats.

Ticks infesting dogs and cats in North America: Biology, geographic distribution, and pathogen transmission

A diverse array of ixodid and argasid ticks infest dogs and cats in North America, resulting in skin lesions, blood loss, and disease. The ticks most commonly found on pets in this region are hard ticks of the genera Amblyomma, Dermacentor, Ixodes, and Rhipicephalus, as well as the more recently established Haemaphysalis longicornis. Soft tick genera, especially Otobius and Ornithodoros, are also reported from pets in some regions. In this review, we provide a summary of the complex and diverse life histories, distinct morphologies, and questing and feeding behaviors of the more common ticks of dogs and cats in North America with a focus on recent changes in geographic distribution. We also review pathogens of dogs and cats associated with the different tick species, some of which can cause serious, potentially fatal disease, and describe the zoonotic risk posed by ticks of pets. Understanding the natural history of ticks and the maintenance cycles responsible for providing an ongoing source of tick-borne infections is critical to effectively combatting the challenges ticks pose to the health of pets and people.

Zoonotic Tick-Borne Pathogens in Temperate and Cold Regions of Europe-A Review on the Prevalence in Domestic Animals

Ticks transmit a variety of pathogens affecting both human and animal health. In temperate and cold regions of Europe (Western, Central, Eastern, and Northern Europe), the most relevant zoonotic tick-borne pathogens are tick-borne encephalitis virus (TBEV), Borrelia spp. and Anaplasma phagocytophilum. More rarely, Rickettsia spp., Neoehrlichia mikurensis, and zoonotic Babesia spp. are identified as a cause of human disease. Domestic animals may also be clinically affected by these pathogens, and, furthermore, can be regarded as sentinel hosts for their occurrence in a certain area, or even play a role as reservoirs or amplifying hosts. For example, viraemic ruminants may transmit TBEV to humans via raw milk products. This review summarizes the role of domestic animals, including ruminants, horses, dogs, and cats, in the ecology of TBEV, Borrelia spp., A. phagocytophilum, Rickettsia spp., N. mikurensis, and zoonotic Babesia species. It gives an overview on the (sero-)prevalence of these infectious agents in domestic animals in temperate/cold regions of Europe, based on 148 individual prevalence studies. Meta-analyses of seroprevalence in asymptomatic animals estimated an overall seroprevalence of 2.7% for TBEV, 12.9% for Borrelia burgdorferi sensu lato (s.l.), 16.2% for A. phagocytophilum and 7.4% for Babesia divergens, with a high level of heterogeneity. Subgroup analyses with regard to animal species, diagnostic test, geographical region and decade of sampling were mostly non-significant, with the exception of significantly lower B. burgdorferi s.l. seroprevalences in dogs than in horses and cattle. More surveillance studies employing highly sensitive and specific test methods and including hitherto non-investigated regions are needed to determine if and how global changes in terms of climate, land use, agricultural practices and human behavior impact the frequency of zoonotic tick-borne pathogens in domestic animals.

Ixodes spp. from Dogs and Cats in the United States: Diversity, Seasonality, and Prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum

Ixodes spp. are commonly found on dogs and cats throughout the world. In the eastern United States, 16S rDNA sequence of Ixodes scapularis, the predominant species, reveals two clades-American and Southern. To confirm the species and clades of Ixodes spp. ticks submitted from pets, we examined ticks morphologically and evaluated 16S rDNA sequence from 500 ticks submitted from 253 dogs, 99 cats, 1 rabbit, and 1 ferret from 41 states. To estimate pathogen prevalence, flaB of Borrelia burgdorferi (Bb) sensu stricto and 16S rDNA of Anaplasma phagocytophilum (Ap) were amplified and sequenced. Most Ixodes spp. from the Northeast (n = 115/115; 100%) and the Midwest (n = 77/80; 96.3%) were I. scapularis, American clade. Borrelia spp. were identified in 34 of 192 (17.8%) and Ap in 5 of 192 (2.6%) I. scapularis. Two Ixodes cookei and one Ixodes texanus were identified from Ohio, Illinois, and Michigan. In contrast, 156 of 261 (59.8%) Ixodes spp. from the Southeast were I. scapularis, American clade; 86 of 261 (33.0%) were I. scapularis, Southern clade; 9 of 261 (3.4%) were Ixodes affinis; and 10 of 261 (3.8%) were I. cookei. Southern clade was significantly more common in Florida and less common in the upper South (p < 0.0001). One I. scapularis (1/242; 0.4%) from the Southeast (Kentucky) tested positive for Bb and 6 of 242 (2.5%) were positive for Ap. In the West, most (34/44; 77.3%) Ixodes spp. were Ixodes pacificus, with Ixodes angustus (n = 6) submitted from dogs in Alaska, Washington, and Oregon and Ixodes haerlei (n = 4) preliminarily identified from a dog in Montana. Pathogens were not detected in any ticks from the West. Although I. scapularis, American clade, predominated in the Northeast and Midwest, additional Ixodes spp. were found on dogs and cats in other regions and pathogens were less commonly detected. The role of less common Ixodes spp. as disease vectors, if any, warrants continued investigation.

Anaplasma phagocytophilum infection in cats: A literature review to raise clinical awareness

PRACTICAL RELEVANCE

Granulocytic anaplasmosis is a disease in humans and animals caused by the Gram-negative bacterium Anaplasma phagocytophilum within the family Anaplasmataceae. The pathogen is transmitted by ticks of the Ixodes species. Infections with A phagocytophilum have often been described in dogs but reports on natural infections in cats are rare. An infection with A phagocytophilum should be considered as a differential diagnosis in cats if the history reveals tick infestation and/or outdoor access in combination with the relevant clinical signs.

GLOBAL IMPORTANCE

A phagocytophilum is also important in human medicine because of its zoonotic potential. Due to the risk of vector-borne infections for both feline and public health, cats should be protected with ectoparasiticides, especially in endemic areas.

AIM

The aim of this review is to give an overview of the published data and summarise the epidemiology, pathogenesis, diagnosis, clinical signs and therapy of feline granulocytic anaplasmosis. As clinical signs are vague and non-specific, this review aims to raise awareness of A phagocytophilum infection, both among clinicians, so that they consider testing potentially exposed cats, and scientists, in order to prompt further research.

EVIDENCE BASE

Sixteen publications describing 55 cats have been reviewed. Thirty-four cats were well diagnosed based on guidelines of the European Advisory Board on Cat Diseases and blood analyses were performed to varying extents for these cats. Because of the limited number of studies and a lack of knowledge in cats, clinical signs and blood analyses are compared with available data in dogs.

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.

Role of vector-borne pathogens in the development of fever in cats: 2. Tick- and sandfly-associated diseases

PRACTICAL RELEVANCE

There has been increasing identification of vector-borne pathogens in cats presented to veterinary clinics around the world for evaluation of fever and the associated secondary effects, such as signs of depression and loss of appetite.

AIM

The aim of this article is to summarize the clinically relevant information concerning fever in cats that is associated with pathogens vectored by ticks or sandflies, with an emphasis on presenting clinical abnormalities and optimal diagnostic, treatment and prevention strategies. Fever in cats associated with pathogens known or suspected to be vectored by fleas was discussed within Part 1 of this two-part article series.

Detection and Transstadial Passage of Babesia Species and Borrelia burgdorferi Sensu Lato in Ticks Collected from Avian and Mammalian Hosts in Canada

Lyme disease and human babesiosis are the most common tick-borne zoonoses in the Temperate Zone of North America. The number of infected patients has continued to rise globally, and these zoonoses pose a major healthcare threat. This tick-host-pathogen study was conducted to test for infectious microbes associated with Lyme disease and human babesiosis in Canada. Using the flagellin (flaB) gene, three members of the Borrelia burgdorferi sensu lato (Bbsl) complex were detected, namely a Borrelia lanei-like spirochete, Borrelia burgdorferi sensu stricto (Bbss), and a distinct strain that may represent a separate Bbsl genospecies. This novel Bbsl strain was detected in a mouse tick, Ixodes muris, collected from a House Wren, Troglodytes aedon, in Quebec during the southward fall migration. The presence of Bbsl in bird-feeding larvae of I. muris suggests reservoir competency in three passerines (i.e., Common Yellowthroat, House Wren, Magnolia Warbler). Based on the 18S ribosomal RNA (rRNA) gene, three Babesia species (i.e., Babesia divergens-like, Babesia microti, Babesia odocoilei) were detected in field-collected ticks. Not only was B. odocoilei found in songbird-derived ticks, this piroplasm was apparent in adult questing blacklegged ticks, Ixodes scapularis, in southern Canada. By allowing live, engorged ticks to molt, we confirm the transstadial passage of Bbsl in I. muris and B. odocoilei in I. scapularis. Bbss and Babesia microti were detected concurrently in a groundhog tick, Ixodes cookei, in Western Ontario. In Alberta, a winter tick, Dermacentor albipictus, which was collected from a moose, Alces alces, tested positive for Bbss. Notably, a B. divergens-like piroplasm was detected in a rabbit tick, Haemaphysalis leporispalustris, collected from an eastern cottontail in southern Manitoba; this Babesia species is a first-time discovery in Canada. This rabbit tick was also co-infected with Borrelia lanei-like spirochetes, which constitutes a first in Canada. Overall, five ticks were concurrently infected with Babesia and Bbsl pathogens and, after the molt, could potentially co-infect humans. Notably, we provide the first authentic report of I. scapularis ticks co-infected with Bbsl and B. odocoilei in Canada. The full extent of infectious microorganisms transmitted to humans by ticks is not fully elucidated, and clinicians need to be aware of the complexity of these tick-transmitted enzootic agents on human health. Diagnosis and treatment must be administered by those with accredited medical training in tick-borne zoonosis.

2019 AAFP Feline Zoonoses Guidelines

AIM

The overarching purpose of the 2019 AAFP Feline Zoonoses Guidelines (hereafter referred to as the 'Guidelines') is to provide accurate information about feline zoonotic diseases to owners, physicians and veterinarians to allow logical decisions to be made concerning cat ownership.

SCOPE AND ACCESSIBILITY

The Panelists are physicians and veterinarians who worked closely together in an attempt to make these Guidelines a document that can be used to support the International One Health movement. This version of the Guidelines builds upon the first feline zoonosis panel report, published in 2003 ( catvets.com/guidelines ), and provides an updated reference list and recommendations. Each of the recommendations received full support from every Panelist. Primary recommendations are highlighted in a series of 'Panelists' advice' boxes.

Comparative efficacy of topical treatments with Revolution® Plus (selamectin and sarolaner) and Bravecto® for Cats (fluralaner) against Ixodes scapularis ticks on cats

The efficacy of three consecutive monthly treatments with a novel topical product (Revolution^® Plus/Stronghold^® Plus, Zoetis) containing selamectin in combination with the isoxazoline, sarolaner, was compared with that of another topical isoxazoline, fluralaner [Bravecto^® (fluralaner topical solution) for Cats, Merck] against Ixodes scapularis ticks on cats. Twenty-four cats were ranked by pre-treatment tick counts to form groups of three and were randomly allocated to be treated with placebo, the minimum label dosage of Revolution^® Plus (6 mg/kg selamectin plus 1 mg/kg sarolaner) or the minimum label dosage of Bravecto^® for Cats (40 mg/kg fluralaner) within the groups. On Days 0, 30, and 60, each cat in the placebo and Revolution^® Plus-treated groups was treated topically, whereas cats in the Bravecto^® for Cats-treated group were treated topically once on Day 0 with fluralaner and, subsequently, these animals were treated with the placebo on Days 30 and 60 to maintain masking. Doses were calculated based on weight to provide the minimum label dosage for each product; the calculated volume of product to be administered was rounded off to the nearest 0.1 mL. The selamectin plus sarolaner-treated cats received effective dosages of 5.29-7.12 mg/kg selamectin and 0.88-1.19 mg/kg sarolaner, while the fluralaner cats received dosages of 35.21-43.16 mg/kg fluralaner. Cats were infested with approximately 50 unfed viable adult I. scapularis ticks on Days 5, 12, 26, 40, 54, 68, 82, and 88. Efficacy was assessed at 48 h after each infestation. There were no adverse reactions to any treatment during the study. The placebo-treated cats maintained adequate tick infestations throughout the study. Three monthly treatments with selamectin plus sarolaner (Revolution^® Plus) resulted in high and consistent efficacy against I. scapularis for up to 30 days after each treatment. Based on geometric means, efficacy was ≥99.1% at all time points assessed. Treatment with fluralaner (Bravecto^® for Cats) provided high and consistent efficacy of ≥99.3% up to Day 70. On Day 84, efficacy was 90.1%; however, cats from which ticks were recovered on Day 84 had received approximately 4%-12% less than the minimum dosage of 40 mg/kg fluralaner. Three consecutive monthly treatments with Revolution^® Plus or a single treatment with Bravecto^® for Cats provided >90% control of I. scapularis ticks over a 12-week time period.

Feline Vector-Borne Diseases in North America

"In North America, with the exceptions of Bartonella henselae and Cytauxzoon felis, feline vector-borne diseases (FVBDs) have been minimally studied in domestic cats. Cats can be infected with many of the same vector-borne pathogens that infect dogs. Nonspecific clinical signs linked to FVBDs and low prevalence of certain vector-borne pathogens contribute to a limited awareness of FVBDs in sick cats. As clinicians become informed about FVBDs and as vector-borne disease diagnostics are routinely applied to evaluate sick cats, we will gain a stronger understanding of vector-borne pathogens in cats. This article focuses on recent findings related to FVBDs."

Efficacy of a new topical formulation of selamectin plus sarolaner for the control of fleas and ticks infesting cats in Japan

The efficacy of a single application of a new topical formulation containing selamectin plus sarolaner (Revolution^® Plus / Stronghold^® Plus, Zoetis) was evaluated against fleas and ticks infesting cats enrolled as veterinary patients in two field studies conducted in Japan and against Haemaphysalis longicornis ticks on cats in a laboratory study. In the laboratory study, sixteen cats were ranked based on pre-treatment tick counts and allocated randomly to treatment on Day 0 with either selamectin plus sarolaner or placebo. Cats were infested with adult H. longicornis on Days -2, 5, 12, 19, 26 and 33. Efficacy relative to placebo was based on live attached tick counts conducted 48 h after treatment and subsequent re-infestations. Selamectin plus sarolaner reduced live, attached H. longicornis counts by 96.4% within 48 h of treatment, and by ≥91.7% within 48 h of weekly re-infestation for 35 days, based on arithmetic means. In the field studies, 67 client-owned cats harboring six or more live fleas and 63 cats harboring four or more live attached ticks were enrolled to evaluate selamectin plus sarolaner for efficacy and safety compared with a registered product. Cats were allocated randomly to treatment with selamectin plus sarolaner or fipronil plus (S)-methoprene based on order of presentation. Treatment was administered once on Day 0 and efficacy was assessed by parasite counts conducted on Days 14 and 30 compared to the pre-treatment count. In the flea field study, live flea counts on Days 14 and 30 were reduced by 99.5% and 99.9% in the selamectin plus sarolaner group, and by 97.6% and 98.6% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Clinical signs typically associated with flea allergy dermatitis improved following treatment. In the tick field study, live tick counts on Days 14 and 30 were reduced by 97.5% and 97.7% in the selamectin plus sarolaner group, and by 91.5% and 93.4% in the fipronil plus (S)-methoprene group, based on least squares mean percentage reductions. Selamectin plus sarolaner was determined to be non-inferior to fipronil plus (S)-methoprene in both field studies. There were no treatment-related adverse events in any study. A single topical dose of Revolution^® Plus / Stronghold^® Plus providing a minimum dosage of 6.0 mg/kg selamectin and 1.0 mg/kg sarolaner was confirmed to be effective against H. longicornis ticks on cats for one month and safe and effective in the treatment of fleas and ticks on cats enrolled as veterinary patients in Japan.