Canine Host Research Articles

In vitro assessment of assembly and sex pheromones in the control of larval stages of brown dog ticks

The increasing incidence of tick-borne diseases and the growing resistance to conventional acaricides underscore the urgent need for innovative and sustainable tick management strategies. This study investigates the potential of assembly and sex pheromones for the control of larval stages of Rhipicephalus sanguineus, the brown dog tick, which poses significant health risks to dogs. The ticks were collected from various canine hosts in Thrissur, Kerala and subjected to Petri-dish bioassays using vapour patches impregnated with synthetic assembly pheromone (AP) and sex pheromone (SP), both individually and in combination. The efficacy of these semiochemicals was assessed based on the attraction and clustering behaviour of unfed larvae and partially fed adult ticks over a 24-hour period. Results demonstrated a significantly higher attraction to AP-impregnated patches, with notable efficacy observed in causing tick aggregation, particularly beyond 30 min of exposure. While SP also showed potential in attracting ticks, the combination of SP and AP did not result in a synergistic effect. The study highlights the potential of using semiochemicals as an environmentally sustainable alternative to traditional acaricides, highlighting their role in integrated pest management strategies Keywords: Rhipicephalus sanguineus, adenine, guanine, xanthine, 2,6-DCP, Petri-dish bioassay

'Transmission Tracker - Dirofilaria'- a public dashboard to assess in real-time the temperature-bounded transmissibility of canine heartworm across Australia.

The causative agent of canine heartworm disease, Dirofilaria immitis, requires specific temperature conditions to mature within its mosquito vector, and therefore (re-)infect a canid host. Suitable temperature conditions are not continuously met for locations where most (>97%) Australians and their pet dogs live. The length of the disruption in the transmissibility of D. immitis varies greatly across Australia, and to some degree, between years. We developed an online dashboard 'Transmission Tracker - Dirofilaria' that processes near real-time temperature records across Australia and allows users to enquire about historical and current weather suitability for canine heartworm transmission at any Australian postcode of their interest. This information allows veterinarians to access when, and for how long, heartworm may be transmitted at a specific location, assess the associated risk of infection and advise on a patient-dependent dirofilariosis prevention plan for their canine patients and guardians. Our dashboard is publicly accessible at: https://heartworm-mapping.adelaide.edu.au/shiny/.

Saurian-associated Leishmania tarentolae in dogs: Infectivity and immunogenicity evaluation in the canine model.

In canine leishmaniosis endemic areas, Leishmania infantum may occur in sympatry with the non-pathogenic Leishmania tarentolae, which is associated to reptiles. The potential infectivity of L. tarentolae for mammals raises questions about the interactions between the two Leishmania species, and the potential cross-immune protection in dogs. This study aimed to assess the outcome of experimental L. tarentolae infection in dogs, determining: i) the anti-L. tarentolae antibody production, ii) the duration of the immunity and cytokine expression, and iii) the possible pathogenic effect in the canine host. Twelve purpose-bred beagle dogs were randomly allocated to three groups (intravenous inoculation, G1; intradermal inoculation, G2; negative control, G3). G1 and G2 dogs were inoculated twice (day 0, day 28) with 108 promastigotes of L. tarentolae strain (RTAR/IT/21/RI-325) isolated from a Tarentola mauritanica gecko. The animals were followed until day 206. Blood, serum, conjunctival swabs and lymph node aspirate samples were collected monthly and bone marrow, liver and spleen biopsies on day 91. Hematological and biochemical parameters were assessed monthly, as well as serology (IFAT and ELISA) and molecular identification of L. tarentolae. Mononuclear cells (PBMC) were obtained to assess the cytokine expression through in vitro stimulation or (re-) infection. Data from this study demonstrated that DNA from L. tarentolae is detectable up to 3 months post-infection, with seroconversion after day 28. Moreover, the non-pathogenic nature of L. tarentolae was confirmed, with a neutral Th1/Th2 polarization, and a possible shift to Th1 phenotype after derived macrophages (re-) infection, as demonstrated by the expression of IFN-gamma. Therefore, L. tarentolae demonstrated a great potential as a surrogate pathogen and/or immune-prophylaxis/immune-therapy against Leishmania infections in dogs and humans.

A new canid host for subcutaneous ticks: A report from Algeria in an African golden wolf (Canis lupaster)

BackgroundTicks are hematophagous ectoparasites that feed on the skin surface of their host. Subcutaneous localizations of ticks have predominantly been associated with red foxes, documenting new cases still brings new and potentially valuable data for tackling this unusual situation. The objective of this study is to report the presence of subcutaneous ticks in a new host and on a new continent. MethodsBetween February 2022 and September 2023, 47 road-killed animal carcasses belonging mostly to carnivorous species were subjected to a comprehensive parasitological necropsy. Upon detection of subcutaneous tick, the protuberance was excised, dissected, and preserved in labeled vials containing ethanol. Identification of the subcutaneous tick was carried out at the species level. ResultsA single nodule of subcutaneous ticks was found in an African golden wolf (Canis lupaster) collected from Northern Algeria; no other cases of unusual tick locations were observed. Based on morphological criteria the tick was identified as Ixodes ricinus / I. inopinatus. ConclusionThis study represents the first documentation of subcutaneous tick in an African golden wolf (Canis lupaster), thereby broadening the host spectrum for this atypical location. Furthermore, it underscores North Africa as a new geographical area where this phenomenon occurs.

Long-Term Protective Immunity against Ehrlichia chaffeensis Infection Induced by a Genetically Modified Live Vaccine.

Human monocytic ehrlichiosis, an emerging tick-borne disease, is caused by Ehrlichia chaffeensis. Infections with the pathogen are also common in the canine host. Our previous studies demonstrated that functional disruption within the E. chaffeensis phage head-to-tail connector protein gene results in bacterial attenuation, creating a modified live attenuated vaccine (MLAV). The MLAV confers protective immunity against intravenous and tick transmission challenges one month following vaccination. In this study, we evaluated the duration of MLAV protection. Dogs vaccinated with the MLAV were challenged with wild-type E. chaffeensis via intravenous infection at 4-, 8-, and 12-months post-vaccination. Immunized dogs rapidly cleared the wild-type pathogen infection and tested positive for bacteremia less frequently than unvaccinated controls. While immune responses varied among dogs, vaccinees consistently mounted IgG and CD4+ T-cell responses specific to E. chaffeensis throughout the assessment period. Our findings demonstrate that MLAV-mediated immune protection persists for at least one year against wild-type bacterial infection, marking a major advancement in combating this serious tick-borne disease. The data presented here serve as the foundation for further studies, elucidating the molecular mechanisms underlying virulence and vaccine development and aiding in preventing the diseases caused by E. chaffeensis and other tick-borne rickettsial pathogens.

Sparganosis in the Indian Sub-continent and the Middle East.

Sparganosis is one of the common zoonotic diseases caused by infection with the larval plerocercoids (spargana) of the cestode genus Spirometra. While this parasite distributes globally in canine and feline hosts, human infection is predominantly reported in East Asia, especially China, Korea, Japan, and Thailand. Maybe related to the behavior and food culture, this zoonotic disease is rather rare in South Asia to the Middle East. In these areas, sporadic case reports have been appeared mostly in the local medical journals. To draw a solid picture of sparganosis in these non-endemic areas of Asia, we made an extensive literature survey to gather sparganosis cases in the Indian subcontinent and the Middle East.

Serosurvey of canine leishmaniasis in five departments near an identified human clinical case in Marseille (France)

Leishmania infantum is a protozoan parasite of the family Trypanosomatidae, transmitted by the bite of phlebotomine sand flies (Diptera: Psychodidae). It is responsible for human and canine leishmaniasis in countries bordering the Mediterranean basin. Here we describe a clinical case of human cutaneous leishmaniasis in a 76-year-old female patient living in Marseille. Upon interrogation, the patient had no history of recent travel or contact with animals. The study involved clinical, serological, and molecular investigation of the occurrence of Leishmania infection in 718 dogs from five departments within a 130 km radius perimeter around Marseille. Five dogs showed signs of moderate leishmaniasis. Additionally, the serological survey of dogs revealed a global seroprevalence of 5.1%, with a significantly different prevalence in the Vaucluse department. Molecular analysis and phylogenetic studies highlighted the close relatedness of Leishmania strains between human and canine hosts with 99.6% of identity, indicating local transmission. The findings underscore the importance of serological surveillance in dogs and human. In a One Health approach, it is necessary to continue investigating Leishmania infection in all potential reservoirs, especially for zoonotic L. infantum in wildlife (red foxes, leporids, rodents, etc.) but also in dogs, cats, and equids.

COVID-19 restrictions limit the circulation of H3N2 canine influenza virus in China

Canine health is consistently affected by the circulation of the H3N2 strain of canine influenza virus (CIV). Prior research has indicated that the isolation rate of H3N2 CIVs in dogs has gradually increased in China, and these viruses have progressively adapted to humans over the course of their evolution within canine hosts, posing a significant public health threat. However, the key factors influencing the spread of CIVs remain elusive. From January 2020 to December 2022, during the COVID-19 pandemic, strict epidemic prevention policies were implemented in China. Thus, this measure provides an ideal model for studying factors influencing the prevalence of CIVs. In this study, we continuously monitored the prevalence of CIVs in China before and after the COVID-19 pandemic. We found that the pathogen detection rate and seropositivity rate of domestic CIVs significantly declined after the implementation of epidemic control measures. However, after restrictions on human movement were lifted in 2023, the circulation of CIVs gradually increased. Our results demonstrate that restricting human activity directly impacts the epidemic caused by CIVs and provide a theoretical basis for the implementation of control measures during outbreaks of zoonotic diseases in human companion animals.

Echinococcus multilocularis infection affects risk-taking behaviour in Microtus arvalis: adaptive manipulation?

Manipulation of host behaviour by parasites to enhance transmission to the next host is a fascinating phenomenon that has interested scientists since the 1970s. It has been proposed that infection with the cestode Echinococcus multilocularis produces an impairment of the antipredatory behaviour in the rodent intermediate host common vole, Microtus arvalis, which may facilitate transmission of the tapeworm to the canid final host. In this study, we observed the behaviour of infected common voles at 12 weeks post-infection, when protoscoleces production and maturation commonly occurs, in order to assess behavioural changes compared to uninfected controls, that might ease predation in the wild. Infected and uninfected voles were monitored for 24 h to observe their spontaneous activity. In addition, the next day, both infected and uninfected voles were subjected to 4 different behavioural tests: open field test, barrier test, platform test and air-puff test in a running wheel. No significant difference between uninfected and infected voles emerged during the behavioural tests. However, observation of spontaneous activity revealed that infected voles increased their feeding frequency and spent significantly more time above bedding even when not eating, compared to the uninfected controls. In the wild, these behavioural changes increase the animals exposure to predators, raising their chance of becoming prey. These findings are the first direct evidence consistent with behavioural manipulation by E. multilocularis on common voles.

Proteomic change in the upper lobe of the left lung of Beagle dogs at the lung migration stage of Toxocara canis infection

BackgroundToxocara canis is considered one of the most neglected parasitic zoonoses and threatens the health of millions of people worldwide with a predilection for pediatric and adolescent populations in impoverished communities. Exploring the invasion and developmental mechanisms associated with T. canis infection in its definitive canine hosts will help to better control zoonotic toxocariasis.MethodsProteomic changes in samples from the upper lobe of the left lung of Beagle puppies were systematically analyzed by quantitative proteomic technology of data-independent acquisition (DIA) at 96 h post-infection (hpi) with T. canis. Proteins with P-values < 0.05 and fold change > 1.5 or < 0.67 were considered proteins with differential abundance (PDAs).ResultsA total of 28 downregulated PDAs and 407 upregulated PDAs were identified at 96 hpi, including RhoC, TM4SFs and LPCAT1, which could be associated with the maintenance and repair of lung homeostasis. GO annotation and KEGG pathway enrichment analyses of all identified proteins and PDAs revealed that many lung proteins have correlation to signal transduction, lipid metabolism and immune system.ConclusionsThe present study revealed lung proteomic alterations in Beagle dogs at the lung migration stage of T. canis infection and identified many PDAs of Beagle dog lung, which may play important roles in the pathogenesis of toxocariasis, warranting further experimental validation.Graphical

Ticks analysis for molecular detection and phylogenetic evaluation of stray dogs infecting protozoa from Alborz, Iran

Ticks play an important role in the transmission of parasitic diseases, especially pathogenic protozoa in canine hosts, and it is very important to determine the role and extent of their infection with these pathogens in order to determine important control strategies. This study assessed the molecular prevalence of three protozoan pathogens including Hepatozoon canis, Leishmania spp. and Babesia spp., in ticks using PCR. A total 300 stray dogs were investigated and 691 ticks (171 male, 377 female and 143 nymph) were detected directly from 45 infested dogs. Species, stage of growth, and gender were determined for each tick. DNA extracted from 224 ticks (26 male, 165 female and 33 nymph). The molecular presence of three protozoan pathogens including Hepatozoon spp. (18S rRNA gene), Leishmania infantum (kinetoplastid minicircle DNA) and Babesia spp. (ssrRNA gene) were investigated using PCR method. One species of ticks, Rhipicephalus sanguineus was identified. Two of the target pathogens, Hepatozoon spp. (7/83; 8.43 %) and Babesia spp. (1/83; 1.2 %), were detected by PCR method. Sequence analysis of the ssrRNA gene of detected Babesia spp. showed a close relationship to the deposited strains of Babesia vulpis in the gene bank. To the best of our knowledge, this is the first study to undertake a phylogenetic analysis of H. canis and Babesia spp. in stray dogs in Alborz province, Iran and the first report about molecular detection of Babesia vulpis from tick infesting dogs in Iran. According to the above results, it seems necessary to implement tick control programs in dogs.

Genetic diversity in Leishmania infantum and Leishmania tropica isolates from human and canine hosts in northern Morocco

This study investigated nine provinces in northern Morocco and collected 275 skin scraping, 22 bone marrow aspirates, and 89 fine needle aspirations from suspected cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) patients and potentially infected dogs. Molecular analysis using ITS1 RFLP PCR and RT-PCR revealed a higher prevalence of L. infantum (66.18 %; χ2 = 28.804; df = 1; P-value = 8.01e−08) than L. tropica in skin scraping, with L. infantum being the sole causative agent for both VL and canine leishmaniasis. L. infantum was predominantly found in most provinces, while L. tropica was relatively more dominant in Taza Province. Discriminant Analysis of Principal Components (DAPC) revealed distinct clustering between L. tropica and the other three species. However, no small subset of SNPs could clearly differentiate between Infantum_CL, Infantum_VL, and CanL, as they likely share a significant genetic background. The high rate of L. infantum could be attributed to the abundance of sand fly species transmitting VL. In Taza Province, Phlebotomus sergenti, responsible for anthroponotic CL, is the most abundant species. DNA sequencing demonstrated sequence heterogeneity in L. infantum (variants 1-9) and L. tropica (variants 1-7). Phylogenetic analysis showed a distinct separation between L. tropica and L. infantum strains, with an overlap among L. infantum strains isolated from cutaneous, visceral, and canine cases, and dogs serving as the central population for L. infantum.

Development of adult Dirofilaria immitis worms in the Rag2/Il-2rγ-/- mouse model

Dirofilaria immitis is the causative agent for one of the major parasitic infections in dogs. It is currently not possible to reliably diagnose the infection before the development of fertile adult female worms and the presence of microfilariae which takes six to 7 months. However, at this point adult worms already reside in the pulmonary arteries and can cause significant damage. Novel in vivo models may facilitate the development of new diagnostic tools and improve treatment options for both the early and late stages of D. immitis infections. In this paper, we aimed to increase the capabilities of recently published mouse models in which severely immune-deficient mice were shown to be susceptible to D. immitis. Our data shows that D. immitis may grow into fully developed mature male and female worms in C57BL/6 Rag2/Il-2rγ-/- mice with comparable growth rates to the natural canine host. The adult worms of D. immitis were shown to migrate into body cavities as well as the heart in this model. However, the presence of adult worms inside the heart of infected mice led to the development of caval syndrome in 36% of infected mice after five to 6 months. Overall, the current study complements recently published efforts to establish a D. immitis mouse model by extending the development of D. immitis into mature adult stages and will facilitate further preclinical research.

Effect of eucalyptus wood vinegar on reproductive performance of Rhipicephalus sanguineus (Acari: Ixodidae) ticks

ABSTRACT Alternative treatments to control ticks are being increasingly investigated, including natural products to decrease parasitic resistance and environmental impact. The present study investigated the chemical profile of eucalyptus wood vinegar and evaluated its effect on the reproduction of Rhipicephalus sanguineus. Eucalyptus wood vinegar (WV) was tested at several concentrations. For the experiment, 500 engorged females were collected from canine hosts. The female ticks were distributed by weight in groups of ten per WV concentration, with five replicates per treatment. For all tests, the ticks were immersed for 5 min in a solution with each WV concentration. The positive control was amitraz and negative was water. The major components of the WV’s organic fraction were furfural and phenolic compounds. A significant decrease in egg hatching was observed in the WV concentration range from 65 to 1,000 mg mL−1. When parameters such as the percentage of hatching, female weight, and egg mass were evaluated, the efficiency of the product was verified as being between 84.97% and 99.38% in the concentration range of 65 to 1,000 mg mL–1, respectively. There is a real potential for using eucalyptus WV to control dog ticks since it negatively affects the reproductive cycle of the parasites.

In sickness and in health: the intestinal microbiome of dogs

Studies on the interactions between the intestinal microbiome and its host have strengthened in the last decade. However, publications on this topic in dogs still need to be made available, reinforcing the need for new studies and literary data for consultation. Given this, this review aims to describe the intestinal microbiome and its interactions with the canine host, which can contribute to both health and morbid conditions in these animals. The definition of microbiome encompasses the collective genome of all microorganisms that live in a defined habitat (intestine). It is known that the dog’s intestinal microbiota is varied, composed of bacteria, archaea, viruses, fungi, and protozoa. Under normal conditions, there is commensalism between some of these microorganisms and the host, which promotes critical physiological relationships and interactions that contribute to homeostasis and the consequent health of the animal. With this in mind, it is expected that the disturbances associated with the microbiome will result in imbalances in this commensal relationship and thus precipitate the development of diseases and aggravation of other diseases, thus characterizing intestinal dysbiosis.

Genomic and phylogenetic profiling of RNA of tick-borne arboviruses in Hainan Island, China

Ticks act as vectors and hosts of numerous arboviruses. Examples of medically important arboviruses include the tick-borne encephalitis virus, Crimean Congo hemorrhagic fever, and severe fever with thrombocytopenia syndrome. Recently, some novel arboviruses have been identified in blood specimens of patients with unexplained fever and a history of tick bites in Inner Mongolia. Consequently, tick-borne viruses are a major focus of infectious disease research. However, the spectrum of tick-borne viruses in subtropical areas of China has yet to be sufficiently characterized. In this study, we collected 855 ticks from canine and bovine hosts in four locations in Hainan Province. The ticks were combined into 18 pools according to genus and location. Viral RNA-sequence libraries were subjected to transcriptome sequencing analysis. Molecular clues from metagenomic analyses were used to classify sequence reads into virus species, genera, or families. The diverse viral reads closely associated with mammals were assigned to 12 viral families and important tick-borne viruses, such as Jingmen, Beiji nairovirus, and Colorado tick fever. Our virome and phylogenetic analyses of the arbovirus strains provide basic data for preventing and controlling human infectious diseases caused by tick-borne viruses in the subtropical areas of China.

Multiple Ehrlichia chaffeensis genes critical for persistent infection in a vertebrate host are identified as nonessential for its growth in the tick vector; Amblyomma americanum.

Ehrlichia chaffeensis is a tick-transmitted monocytic ehrlichiosis agent primarily causing the disease in people and dogs. We recently described the development and characterization of 55 random mutations in E. chaffeensis, which aided in defining the critical nature of many bacterial genes for its growth in a physiologically relevant canine infection model. In the current study, we tested 45 of the mutants for their infectivity ability to the pathogen's tick vector; Amblyomma americanum. Four mutations resulted in the pathogen's replication deficiency in the tick, similar to the vertebrate host. Mutations causing growth defects in both vertebrate and tick hosts included in genes coding for a predicted alpha/beta hydrolase, a putative dicarboxylate amino acid:cation symporter, a T4SS protein, and predicted membrane-bound proteins. Three mutations caused the bacterial defective growth only in the tick vector, which represented putative membrane proteins. Ten mutations causing no growth defect in the canine host similarly grew well in the tick vector. Mutations in 28 genes/genomic locations causing E. chaffeensis growth attenuation in the canine host were recognized as non-essential for its growth in the tick vector. The tick non-essential genes included genes coding for many metabolic pathway- and outer membrane-associated proteins. This study documents novel vector- and host-specific differences in E. chaffeensis for its functional gene requirements.

Environmental risk assessment for fecal contamination sources in urban and peri-urban estuaries, in Escambia and Santa Rosa counties, FL, USA.

Fecal pollution of estuaries and adjacent creeks and streams is of significant concern along the Gulf of Mexico. The prospective threat to human life and water quality impairment via fecal pollution is a substantial danger to the strength and resistance of coastline areas. Pensacola, FL, has a prosperous coastal tourism industry that is utilized for numerous other uses, such as recreational watersports and boating, seafood, and shellfish harvesting. However, the frequency and severity of fecal contamination present possible socio-economic issues, specifically financial hardships. Therefore, understanding the source, abundance, and fate of fecal microbial pollutants in aquatic systems signifies an imperative initial stage for detecting the host sources and techniques to lessen their transport from the landscape. This research aimed to quantify the fecal indicator bacteria (FIB), Escherichia coli, and perform microbiological fecal source tracking to verify if the fecal inputs are of either animal or human host origin. Surface water samples were taken from urban and peri-urban creeks for two sampling periods (February 2021 and January 2022), and IDEXX Colilert-18 (USEPA Standard Method 9223) was used for E. coli enumeration. DNA extractions were obtained from each sample, and quantitative PCR was utilized for fecal microbial source tracking (MST) to detect human, dog, ruminant, and bird host-specific Bacteroides DNA. The result indicates elevated quantities of FIB, E. coli, that surpass the threshold considered safe regarding human health. E. coli at six sites over the two sampling periods exceeded the impairment threshold, reaching as high as 866.4 MPN/100ml. Fecal source tracking identified human host fecal contamination at four of nine sites, dogs at three of nine, and birds at one site. However, those sites with sources identified via MST all had E. coli levels below impairment thresholds. No sites were determined to be positive for ruminant as a source or for the pathogen Helicobacter pylori. No canine host fecal inputs were found in January 2022, and only one site with human sewage. Our results highlight the utility of MST in assessing bacterial inputs to water bodies and the challenges.

Blood meals from ‘dead-end’ vertebrate hosts enhance transmission potential of malaria-infected mosquitoes

Ingestion of an additional blood meal(s) by a hematophagic insect can accelerate development of several vector-borne parasites and pathogens. Most studies, however, offer blood from the same vertebrate host species as the original challenge (for e.g., human for primary and additional blood meals). Here, we show a second blood meal from bovine and canine hosts can also enhance sporozoite migration in Anopheles stephensi mosquitoes infected with the human- and rodent-restricted Plasmodium falciparum and P. berghei, respectively. The extrinsic incubation period (time to sporozoite appearance in salivary glands) showed more consistent reductions with blood from human and bovine donors than canine blood, although the latter's effect may be confounded by the toxicity, albeit non-specific, associated with the anticoagulant used to collect whole blood from donors. The complex patterns of enhancement highlight the limitations of a laboratory system but are nonetheless reminiscent of parasite host-specificity and mosquito adaptations, and the genetic predisposition of An. stephensi for bovine blood. We suggest that in natural settings, a blood meal from any vertebrate host could accentuate the risk of human infections by P. falciparum: targeting vectors that also feed on animals, via endectocides for instance, may reduce the number of malaria-infected mosquitoes and thus directly lower residual transmission. Since endectocides also benefit animal health, our results underscore the utility of the One Health framework, which postulates that human health and well-being is interconnected with that of animals. We posit this framework will be further validated if our observations also apply to other vector-borne diseases which together are responsible for some of the highest rates of morbidity and mortality in socio-economically disadvantaged populations.

Canine and feline papillomaviruses: an update.

Papillomaviruses are small viruses able to cause disease not only in mammalians, but also in birds and reptiles. In recent years, a rising number of papillomaviruses have been identified in dogs and cats, totaling 24 canine papillomavirus (CPV) and six feline papillomavirus (FcaPV). The canine and feline papillomaviruses (CPVs and FcaPVs, respectively) are responsible for multiple lesions in these domestic species but the potential pathological relevance of some recently identified types remains to be determined. CPVs are associated with oral papillomatosis, cutaneous papillomas and viral pigmented plaques, and have been rarely associated with the development of oral and cutaneous squamous cell carcinomas in their canine hosts. FcaPVs are associated with oral papillomas, viral plaques, and Bowenoid in situ carcinomas. The present review provides readers with the more recent advances on dog and cat papillomavirus research, bringing an update on this field to both veterinary practitioners and the virology community at large.