Performance of a point-of-care test for the detection of anti-Leishmania infantum antibodies is associated with immunofluorescent antibody titer and clinical stage of leishmaniosis in dogs from endemic regions

Canine leishmaniosis (CanL) is caused by the protozoal parasite Leishmania infantum, which is transmitted by sand flies in warm climates across the world. Because dogs are considered a primary domestic reservoir for the parasite that causes leishmaniosis in humans, it is important from a One Health perspective that CanL be properly managed. In endemic regions, CanL is a common differential diagnosis in sick dogs because the clinical signs and clinicopathological disorders of the disease are non-specific, variable, and may overlap those of other common conditions. Diagnosis is based on the presence of compatible clinical signs, laboratory abnormalities, and confirmation by serological and parasitological evidence of infection. Here, we describe the performance of a point-of-care (POC) immunoassay that uses recombinant antigens to detect canine anti- L. infantum antibodies in a convenience sample set from a diagnostic laboratory, a group of canine patients with clinical staging, and in apparently healthy dogs from endemic areas. An immunofluorescence antibody test (IFAT) was used as the semiquantitative reference method. In the convenience sample set with high IFAT titers (≥ 1:800), the POC immunoassay demonstrated perfect agreement with IFAT (100%; 90/90). Using samples from dogs staged as either LeishVet Stage 2 or 3 or LeishVet Stage 1, positive agreement of the POC immunoassay with the IFAT was 98.8% (82/83) and 83.8% (31/37), respectively. The negative agreement with IFAT was 98.9% (272/275) in apparently healthy dogs from endemic areas of Greece and Italy. Since the performance of the POC immunoassay was associated with IFAT titer and clinical stage of CanL, the test may help veterinarians when determining if CanL is likely responsible for a patient's clinical picture or when evaluating an apparently healthy patient prior to vaccination.

Genotyping USA laboratory-maintained isolates and European clinical isolates of Dirofilaria immitis to assess macrocyclic lactone susceptibility or resistance at predictive SNP sites using droplet digital PCR

Dirofilaria immitis is a parasitic nematode that causes cardiovascular dirofilariosis ("heartworm disease") primarily in canids. The principal approach for mitigating heartworm infection involves the use of macrocyclic lactone (ML) for prophylaxis. Recent research has substantiated the emergence of D. immitis displaying resistance to MLs in the USA. Numerous factors, such as the mobility of companion animals and competent vectors could impact the spread of drug resistance. Genomic analysis has unveiled that isolates resistant to ML exhibit unique genetic profiles when compared to their wild-type (susceptible) counterparts. Out of the ten single nucleotide polymorphism (SNP) markers validated in clinical samples of D. immitis from the USA, four have demonstrated their effectiveness in distinguishing between isolates with varying ML efficacy phenotypes. This study explores the potential of these confirmed SNPs for conducting surveillance studies. Genotypic analysis using SNP markers emerges as a valuable tool for carrying out surveys and evaluating individual clinical isolates. Two USA laboratory-maintained isolates (Berkeley, WildCat) and twenty-five random European clinical samples of either adult worms or microfilariae (mf) pools isolated from domestic dogs, were tested by droplet digital PCR (ddPCR)-based duplex assay. This approach elucidates genetic evidence pertaining to the development of drug resistance and provides baseline data on resistance related genotypes in Europe. The data on these clinical samples suggests genotypes consistent with the continued efficacy of ML treatment regimens in Europe. In addition, this assay can be significant in discriminating cases of drug-resistance from those possibly due to non-compliance to the recommended preventive protocols.

First case of macrocyclic lactone-resistant Dirofilaria immitis in Europe - Cause for concern

Heartworm disease caused by the nematode Dirofilaria immitis is one of the most important parasitoses of dogs. The treatment of the infection is long, complicated, risky and expensive. Conversely, prevention is easy, safe, and effective and it is achieved by the administration of macrocyclic lactones (MLs). In recent years, D. immitis strains resistant to MLs have been described in Southern USA, raising concerns for possible emergence, or spreading in other areas of the world. The present study describes the first case of ML-resistant D. immitis in a dog in Europe. The dog arrived in Rome, Italy, from USA in 2023. Less than 6 months after its arrival in Italy, the dog tested positive for D. immitis circulating antigen and microfilariae, despite it having received monthly the ML milbemycin oxime (plus an isoxazoline) after arrival. The microfilariae suppression test suggested a resistant strain. Microfilariae DNA was examined by droplet digital PCR-based duplex assays targeting four marker positions at single nucleotide polymorphisms (SNP1, SNP2, SNP3, SNP7) which differentiate resistant from susceptible isolates. The genetic analysis showed that microfilariae had a ML-resistant genotype at SNP1 and SNP7 positions, compatible with a resistant strain. It is unlikely that the dog acquired the infection after its arrival in Europe, while it is biologically and epidemiologically plausible that the dog was already infected when imported from USA to Europe. The present report highlights the realistic risk of ML-resistant D. immitis strains being imported and possibly transmitted in Europe and other areas of the world. Monitoring dogs travelling from one area to another, especially if they originate from regions where ML-resistance is well-documented, is imperative. Scientists, practitioners, and pet owners should be aware of the risk and remain vigilant against ML-resistance, in order to monitor and reduce the spreading of resistant D. immitis.

Hepatozoon spp. in stray cats from the metropolitan area of Rio de Janeiro, Brazil

In the last few years, the number of studies on feline hepatozoonosis has increased, but our knowledge on the actual species of Hepatozoon and/or different genotypes affecting felines is still incipient. At least three species, namely Hepatozoon felis, H. canis, and H. silvestris, have been isolated from domestic cats in various countries. Additionally, there are indications that other species and genotypes may affect felines in given geographic areas. This study was carried out to investigate the occurrence of Hepatozoon spp. in cats from Niterói, a municipality within the metropolitan area of Rio de Janeiro, Brazil. Individual blood samples were collected from 28 cats enrolled in a spaying/castration program. DNA was extracted from all samples and subjected to sequencing specific for Hepatozoon spp. DNA of H. felis was found in 21/28 cats (75%), and four genetic polymorphisms never described thus far were detected. This is the first report of H. felis in cats living in the State of Rio de Janeiro, and the present data confirm that H. felis is a species complex encompassing different genotypes circulating within cat populations. Further studies are warranted to investigate whether different genotypes have different biology or pathogenicity for felids.

Efficacy of Bravecto® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) in the prevention of feline Aelurostrongylus abstrusus infection evaluated in a multi-diagnostic approach

BACKGROUND

Aelurostrongylus abstrusus is one of the most important respiratory nematodes of felines. Infections may lead to respiratory clinical signs with varying severity or even death, emphasizing the need for preventive treatment of cats with outdoor access to circumvent patent infections.

METHODS

Therefore, the preventive efficacy of a spot-on formulation of 280 mg/ml fluralaner and 14 mg/ml moxidectin (Bravecto® Plus spot-on solution for cats, MSD) against A. abstrusus was evaluated in a negative controlled, randomized and partially blinded efficacy study with 28 purpose-bred cats in a non-terminal design. In three different treatment regimes, the minimum recommended dose of 40 mg fluralaner and 2.0 mg moxidectin/kg bodyweight (BW) was administered once at 12, 8 or 4 weeks (study group G1, G2 and G3, respectively) prior to experimental infection with 300 third-stage A. abstrusus larvae, while G4 served as placebo-treated control.

RESULTS

From 30 to 46 days post infection (dpi; SD 114 to 130), faeces were sampled to monitor first-stage larvae (L1) excretion for efficacy determination. Secondary efficacy criteria, including respiratory parameters, serological antibody levels and computed tomography (CT) findings, were assessed once before enrolment (SD -7 to -1) and before infection (SD 75 to 83). After infection, CT evaluation was performed once at 47-50 dpi (SD 131 to 134), and respiratory parameters and antibody levels were regularly assessed twice or once a week, respectively (1 up to 78 dpi, SD 85 up to 162). All animals in the control group excreted L1 by 33-37 dpi and remained positive throughout the study period from 41 to 46 dpi (SD 125 to 130). In the treatment groups, only one animal each of G1 and G2 excreted L1 at two consecutive days, and four cats of G1, two of G2 and three of G3 were positive on single occasions. While the geometric mean (GM) of the maximum number of excreted L1 per 5 g of faeces was 7380.89 in the control group (G4), GMs were significantly lower in the treatment groups with 1.63 in G1, 1.37 in G2 and 0.79 in G3. Thus, based on GMs, the reduction in excreted L1 exceeded 99.9% in all three treatment groups. Based on CT severity scores, all lungs of the animals of the control group showed severe pulmonary changes post infection, whereas lungs of the cats of the treatment groups were either unaltered (4 animals), mildly (11 animals), or moderately altered (5 animals). Moreover, seroconversion was observed in all cats of the control group, but not in those of the treatment groups.

CONCLUSIONS

The combination of diagnostic methods used in this non-terminal study yielded coherent and reliable results. A single administration of Bravecto® Plus spot-on solution for cats was well tolerated and effective in the prevention of aelurostrongylosis for at least 12 weeks.

Efficacy of a spot-on formulation containing 280 mg/ml fluralaner and 14 mg/ml moxidectin (Bravecto® Plus) in the prevention of cat aelurostrongylosis under field conditions

Aelurostrongylus abstrusus is the most important respiratory nematode of domestic cats. Effective control options are crucial to protect health and welfare of cats and to reduce the spread of aelurostrongylosis in both enzootic and free regions. The present study evaluated the efficacy of a spot-on formulation containing 280 mg/ml fluralaner and 14 mg/ml moxidectin (Bravecto® Plus, MSD) in the prevention of aelurostrongylosis in cats under field conditions. One hundred and fifty-two cats from Italy, Hungary and Bulgaria, were randomly divided in two groups, one treated with Bravecto® Plus on Study Days (SDs) 0 and 84 (74 cats, IVP Group) and one left untreated (78 cats, control group). Faecal samples were collected from all animals on SDs 42 ± 4, 84, 126 ± 4 and 168 ± 4 and subjected to the Baermann's technique and species-specific PCR for A. abstrusus. Each cat was subjected to a clinical examination on SDs 0, 84 and 168 ± 4 to check health condition and possible adverse events. The results of the faecal analysis were statistically analyzed for treatment group differences in the percentage of cats negative to the Baermann's test and PCR and percentage of reduction of fecal larvae counts as the primary and secondary efficacy criteria, respectively. The percentage of negative cats was higher in the IVP group compared to the control group and the percentage of reduction of fecal larvae counts in the IVP group compared to the control group was 100%. These results show that two administrations of Bravecto Plus® spot-on 12 weeks apart were safe and effective in the prevention of aelurostrongylosis for a period of almost 6 months.

Efficacy of a combination of esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) against Thelazia callipaeda in naturally infected cats

This clinical study assessed the efficacy of a topical combination of esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) in treating cats naturally infected with the eyeworm Thelazia callipaeda (Nematoda, Thelaziidae). On Study Day (SD) 0, sixteen client-owned cats with eyeworm infection were allocated to an untreated control group (G1, 8 cats) or to a NexGard® Combo treated group (G2, 8 cats) and subjected to ocular examination. Cats in G2 received the treatment as per label recommendations. On SD 7 and 14 (±1), cats were examined for the presence of eyeworms and clinical signs. On SD 14, eyeworms were collected and counted. On SD 7 and 14, all cats in G1 were still infected with eyeworms, while G2 cats were free from eyeworms on SD 7 and 14, demonstrating 100% efficacy (p < 0.0001). All collected eyeworms were morphologically and molecularly confirmed to be T. callipaeda. On SD 0, fifteen out of the sixteen cats (7 in G1 and 8 in G2) displayed inflammatory ocular signs. On SD 7, all eight untreated cats and seven treated cats displayed inflammatory ocular signs. On SD 14, five out of eight G2 treated cats had recovered, while the eight untreated cats still displayed inflammatory ocular signs. The treatment significantly reduced lacrimation and conjunctivitis (p = 0.0001). No adverse reactions occurred. This clinical study provides evidence that NexGard® Combo is highly safe and effective for the treatment of T. callipaeda infection in cats under field conditions.

Efficacy of a topical formulation containing eprinomectin, esafoxolaner and praziquantel (NexGard® Combo) in the treatment of natural respiratory capillariosis of cats

Feline pulmonary capillariosis is a significant disorder due to its distribution and clinical impact. This study evaluated the safety and efficacy of two administrations 28 days apart of a topical solution containing esafoxolaner, eprinomectin and praziquantel (NexGard® Combo) in treating Eucoleus aerophilus (syn. Capillaria aerophila) infection in naturally infected cats. Cats were allocated to two groups: G1 cats (n = 23) received two treatments at study days (SDs) 0 and 28 (±2) and were evaluated for 6 weeks, and G2 cats (n = 17) served as a negative control for 6 weeks and were then treated twice on SDs 42 (±2) and 70 (±2), allowing for an additional 6-week assessment of efficacy. Each cat was subjected to McMaster coproscopy at SDs -7/0, 28 (±2) and 42 (±2) for both groups, 70 (±2) and 84 (±2) only for G2. Clinical examination and chest radiographic images were performed at SDs 0, 28 (±2) and 42 (±2) for G1 and G2, 70 (±2) and 84 (±2) only for G2. The comparison of EPG (eggs per gram of feces), clinical (CS), and radiographic scores (RS) at each time-point was used as a criterion. The efficacy based on the EPG reduction was 99.5% (G1) and 100% (G2) after two administrations of NexGard® Combo 2 weeks apart. At SD 0, no significant differences for CS and RS were recorded between G1 and G2, while a significant reduction (p < 0.05) was observed post-treatment for CS, RS, oculo-nasal discharge, auscultation noises, and cough. Two doses of NexGard® Combo 28 days apart stopped egg shedding and significantly improved clinical alterations in cats infected by E. aerophilus.

Use of In-Clinic Diagnostic Kits for the Detection of Seropositivity to Leishmania infantum and Other Major Vector-Borne Pathogens in Healthy Dogs

Canine Vector-Borne Diseases (CVBDs) are widespread in Europe and enzootic in many other countries. Though severe illnesses may occur, dogs living in enzootic areas often show vague or no clinical signs of CVBDs. Undiagnosed infections/co-infections in subclinically infected animals favor the spread of CVBDs and increase the risk of transmission to other animals and, in some cases, humans. This study has evaluated the exposure of dogs living in key enzootic countries, i.e., Italy and Greece, to major CVBDs via the use of in-clinic diagnostic kits. Overall, 300 privately owned dogs without/with single mild clinical signs living in different regions of Italy (n. 150) and Greece (n. 150) were included in the study. As part of a clinical examination, a blood sample was collected from each dog and subjected to two serological rapid tests, i.e., the SNAP^® 4Dx^®Plus (IDEXX Laboratories Inc.) for the detection of antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi s.l. and Dirofilaria immitis antigen and the SNAP^®Leishmania (IDEXX Laboratories Inc.) for the detection of antibodies against Leishmania infantum. In all, 51 dogs (17%; 95% CI 12.9-21.7) were seropositive to at least 1 pathogen, i.e., 4 in Italy (2.7%; 95% CI 1.4-13.1) and 47 in Greece (31.3%; 95% CI 24-39.4). Dirofilaria immitis antigens were found in 39 dogs (13%; 95% CI 9.4-17.3), while antibodies against Ehrlichia, Anaplasma and Leishmania were detected in 25 (8.3%; 95% CI 5.5-12.1), 8 (2.7%; 95% CI 1.2-5.2) and 5 (1.7%; 95% CI 0.5-3.8) dogs, respectively. None of the dogs tested seropositive for B. burgdorferi s.l. Statistical analyses were performed to evaluate associations between exposure to CVBDs and possible risk factors. The present results indicate that dogs living in enzootic areas may be seropositive for one or more CVBDs in absence of clinical signs. Rapid kits are among first line tools for the detection of CVBDs in clinical settings, as they are cost-effective, straightforward and quick to use. Also, in-clinic tests used herein allowed detection of co-exposure to CVBDs investigated.

An Uncommon and Severe Clinical Case of Sarcoptes scabiei Infestation in a Cat

The burrowing mite Sarcoptes scabiei causes sarcoptic mange in dogs and other mammals, including humans. Despite S. scabiei infests several animals, little is known about the epidemiology, clinical features, and treatment of sarcoptic mange in cats. A few reports have shown that clinical signs of S. scabiei infestation in cats may vary from non-pruritic crusted lesions to itchy and mild lesions, while severe signs are very infrequent. The present report describes a severe case of S. scabiei infestation in a stray cat from Italy, characterized by bilateral alopecia, diffuse and multifocal hyperpigmented, crusted, erythematous, scaled, and exfoliated lesions. The cat was FIV-positive and also infected by the cestode Dipylidium caninum. After treatment with a broad-spectrum parasiticide and an antibiotic, the cat showed an almost complete clinical recovery in 4 weeks. Unfortunately, no further clinical examinations were performed due to the lack of compliance of the owner and to the death of the cat for causes unrelated to sarcoptic mange. This clinical case indicates that under certain circumstances, S. scabiei can reproduce and cause severe clinical signs in cats which are usually considered non-permissive hosts for this mite, and in which the disease is usually self-limiting. Clinic-pathological, epidemiological, and zoonotic implications are discussed.

Ticks, Fleas, and Harboured Pathogens from Dogs and Cats in Cyprus

Ticks and fleas are blood-sucking ectoparasites that cause irritation and anaemia to their hosts and act as vectors of pathogens (vector-borne pathogens, VBPs) of relevance for animal and human health. In the present study, tick and flea species in dogs and cats from Cyprus were recorded and VBPs were detected in the collected specimens. Ectoparasites were collected from 220 animals (161 dogs and 59 cats), and a questionnaire including demographic, clinical, and other information was filled out for each animal. The ectoparasites were morphologically identified and the detection of VBPs was performed by PCR-coupled sequencing. Rhipicephalus sanguineus sensu lato was found on 108 dogs and 13 cats, and Ixodes gibbosus on 2 dogs. Ctenocephalides felis was the predominant flea species (on 62 dogs and 45 cats), while one dog and one cat were infested by Ctenocephalides canis and Echidnophaga gallinacea, respectively. The VBPs in ticks were Anaplasma platys, Rickettsia massiliae, Rickettsia conorii, Rickettsia felis, Hepatozoon felis and Hepatozoon canis, while Rickettsia felis, Rickettsia sp., Bartonella koehlerae, Bartonella clarridgeiae, and Bartonella henselae were recorded in fleas. Statistical analysis (chi-square test and multiple univariate generalized linear model) showed that animals up to 6 months of age were less likely to be infested with ticks than older animals, but more likely to be infested with fleas. Ticks were more prevalent in sheltered than in owned animals, while the odds ratio of flea presence was higher in owned animals than those living in shelters. The present study is the first investigation on the occurrence of ticks and fleas in dogs and cats from Cyprus, showing the presence of different VBPs in these important ectoparasites. The results point out the importance of systematic ectoparasite control in dogs and cats.

Zoonotic intestinal helminthes diagnosed in a 6-year period (2015-2020) in privately owned dogs of sub-urban and urban areas of Italy

Intestinal helminthes of dogs have a relevant role for health and welfare of canine populations and many of them are zoonotic. Thus, a constant surveillance is pivotal to safeguard companion dogs and human health. Data from faecal examinations of pet dogs obtained in the last six years during the routine activity of the laboratory of Parasitology and Parasitic diseases of the University Teaching Veterinary Hospital of the University of Teramo, Italy, are here reported. From 2015 to 2020 a total of 1083 individual faecal samples from privately owned dogs were examined using conventional copro-microscopic techniques. Endoparasite elements were found in 278 (25.7%) dogs, and among them, eggs of intestinal zoonotic helminthes were detected in 184 (17%) samples. The most common zoonotic parasites were Toxocara canis and hookworms (8.9% positivity rate for both). Most dogs (88%) were positive for a single zoonotic parasite while 12% of the positive animals harbored two or more zoonotic helminthes. A statistical analysis showed a significant association between dogs with less than one year of age and positivity to at least one intestinal zoonotic helminth, and that infections by T. canis are significantly more prevalent in dogs under one year of age. Despite being well known in canine clinical practice, these results indicate that zoonotic helminthes are still frequent in owned dogs. Thus, increased awareness of veterinary practitioners and pet owners is necessary to implement current diagnostic and control strategies to minimize the risk of zoonotic transmission of intestinal helminthes.

Efficacy of a spot-on combination containing 10% w/v imidacloprid and 1% w/v moxidectin for the treatment of troglostrongylosis in experimentally infected cats

Background

Parasitic bronchopneumonia in domestic cats in Europe, which can manifest with moderate to severe clinical signs, is frequently caused by Troglostrongylus brevior. Data on epizootiological and clinical relevance of cat troglostrongylosis have been published in the last decade but treatment options are still limited. Promising effectiveness data have been generated from clinical cases and field trials for a spot-on formulation containing 1% w/v moxidectin and 10% w/v imidacloprid (Advocate^®, Elanco Animal Health). Therefore, two studies have been conducted to confirm under experimental conditions the efficacy of moxidectin 1% contained in Advocate^® for the treatment of cat troglostrongylosis.

Methods

Sixteen and 20 cats experimentally infected with T. brevior were included in two separate studies, i.e., Study 1 and 2, respectively. Cats were infected with T. brevior third-stage larvae via gastric tube. In both studies cats were randomized to untreated (control, Group 1) and treatment (Group 2) groups. In Study 1 and Study 2, the two groups comprised eight and 10 cats each. Treated cats received Advocate^® spot-on twice at a 4-week interval. The primary efficacy criterion was the number of viable adult T. brevior counted at necropsy. Throughout the trial, the fecal shedding of first-stage larvae (L1) was assessed in treated and untreated control cats.

Results

The experimental model was successful in both studies, as all cats started shedding T. brevior L1 within 25 days post-infection. At necropsy, T. brevior adults were found in 4/8 and 4/10 cats of the control groups in Study 1 and 2, respectively, while none of the treated cats harbored adult worms. The necropsy worm counts in controls did not meet relevant guideline requirements for adequacy of infection, with fewer than six infected cats in the control groups, thus limiting conclusions on treatment efficacy. The fact that 6/8 and 8/10 control cats in Study 1 and 2, respectively, shed L1 up to necropsy while larval shedding ceased in all treated animals after the first treatment provides supporting evidence on the level of efficacy. No remarkable adverse events were recorded in the two studies.

Conclusion

These results indicate that Advocate^® spot-on is a safe and effective option for treating cats infected by T. brevior.

Graphical Abstract

Hemorrhagic Meningoencephalomyelitis Due to Ectopic Localization of Aelurostrongylus abstrusus in a Cat: First Case Report

Simple Summary

Aelurostrongylus abstrusus is the most important parasitic nematode affecting cat airways worldwide. The adult nematodes live in the lungs and cause pneumonia with typical respiratory clinical signs such as cough, nasal and ocular discharge, and difficulties in breathing. The localization of adult A. abstrusus in other organs than lungs is not common. This report describes, for the first time, an unusual and fatal localization of A. abstrusus within the central nervous system of a kitten displaying neurological signs.

Abstract

The lungworm Aelurostrongylus abstrusus is one of the main causes of respiratory diseases in cats worldwide. This report describes the unusual case of a kitten infected with A. abstrusus and presented to a veterinary clinic in Brazil with lethargy, dysphagia, non-ambulatory tetraplegia, and pelvic limbs bilateral myoclonus. The clinical picture of the kitten worsened with generalized flaccid tetraplegia and death a few days after hospitalization. At necropsy, hemorrhagic necrosis and subarachnoid hemorrhages were detected in several areas of the central nervous system. Nematode stages were found at post-mortem histological examinations in lungs, cerebellum, subarachnoid space of the brain and spinal cord. Microscopic and molecular (PCRs-coupled-sequencing protocols) examination showed the presence of A. abstrusus in histological samples. This study describes the first neurological aelurostrongylosis due to ectopic localization of adult worms in the central nervous system of a cat, causing acute hemorrhagic multifocal meningoencephalomyelitis. Further studies are necessary to elucidate whether unusual localizations and the migration of A. abstrusus are more frequent than expected.

Multicenter randomized, and blinded European field study evaluating the efficacy and safety of Felpreva®, a novel spot-on formulation containing tigolaner, emodepside and praziquantel, in treating cats with mixed infection with intestinal nematodes, cestodes and/or lungworms

This paper describes a multicentric field study which has evaluated the safety and efficacy of a novel spot on formulation containing emodepside 2.04% w/v, praziquantel 8.14% w/v and tigolaner 9.79% w/v (Felpreva®, Vetoquinol) when administered at the intended commercial dose of 0.15 ml/kg body weight to privately owned cats infected with major intestinal nematodes (Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Uncinaria stenocephala) and/or cestodes (Dipylidium caninum, Taenia taeniaeformis) and/or lungworms (Aelurostrongylus abstrusus, Troglostrongylus brevior). A total of 219 cats from 26 veterinary clinics located in Albania, Greece, Hungary, Italy and Portugal were included in the study. Feces from the cats were examined on a single occasion between Study Day −7 and Day 0 (baseline) and post-treatment (i) twice between Day 7 and Day 14 (± 2) (for intestinal helminths) or (ii) twice between Day 21 (± 2) and Day 28 (± 2) (for lungworms). Cats were allocated into two groups at a ratio of 2:1 (Felpreva®: Profender®, i.e. a commercial control product containing emodepside and praziquantel). Cats infected with intestinal helminths were treated once on Day 0 (i) with Felpreva® (Group 1) or (ii) with Profender® (Group 2). Animals infected with lungworms received a second treatment with Profender® on Day 14 (± 2) regardless of group allocation. Faecal egg or larval count reduction for Felpreva® was 97.47% for intestinal nematodes and 96.80% for lungworms. No cats infected with cestodes at baseline resulted positive after treatment with Felpreva®. However, the low number of cats (n = 10) did not allow for a statistical analysis to be performed. Non-inferiority of Felpreva® compared to Profender® was statistically demonstrated for all target intestinal and respiratory parasites. No adverse events nor application site reactions were observed. These results show that the new topical combination product Felpreva® is highly safe and efficacious in treating infections caused by major species of feline intestinal nematodes, cestodes and lungworms under field conditions.

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Felpreva®, containing tigolaner, emodepside and praziquantel, is a spot-on formulation.

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This study confirmed the safety and high efficacy of Felpreva®, Vetoquinol, against feline helminths.

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Faecal egg count (FEC) reduction for intestinal nematodes was 97.47%.

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Faecal larval count (FLC) reduction for lungworms was 96.80%.

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All cats infected with tapeworms at baseline were negative after treatment with Felpreva®.

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.

Highly Variable Clinical Pictures in Dogs Naturally Infected with Angiostrongylus vasorum

Canine angiostrongylosis by Angiostrongylus vasorum is increasingly reported in both enzootic and previously free areas. The complex pathogenesis of the disease makes the clinical workup challenging. Infected dogs show highly variable clinical pictures, characterized by subclinical to life-threatening general, cardio-respiratory, neurological and/or gastrointestinal signs. The present study reports the high variability of clinical pictures from 36 dogs across central and southern Italy that were naturally infected by A. vasorum. Of them, 23 (63.9%) presented at least one clinical sign, while 13 (36.1%) were subclinically infected and apparently healthy. Overall, 19 dogs (52.8%) showed cardiorespiratory signs, 14 (38.9%) had non-specific abnormalities, 2 (5.6%) presented coagulation disorders and 1 (2.8%) had a severe neurological condition. Importantly, four dogs presenting with clinical signs had neither cough nor dyspnea. These results underline that angiostrongylosis should be included in the differential diagnosis, even when dogs display only non-specific clinical signs. The proportion of apparently healthy dogs highlights the relevance of routine copromicroscopic and/or antigenic tests in enzootic areas to avoid the sudden onset of potentially life-threatening signs.

Angiostrongylosis in Animals and Humans in Europe

Lungworms in the genus Angiostrongylus cause disease in animals and humans. The spread of Angiostrongylus vasorum within Europe and the recent establishment of Angiostrongylus cantonensis increase the relevance of these species to veterinary and medical practitioners, and to researchers in parasitology, epidemiology, veterinary science and ecology. This review introduces the key members of the genus present in Europe and their impacts on health, and updates the current epidemiological situation. Expansion of A. vasorum from localized pockets to wide distribution across the continent has been confirmed by a rising prevalence in foxes and increasing reports of infection and disease in dogs, while the list of carnivore and mustelid definitive hosts continues to grow. The tropically distributed rat lungworm A. cantonensis, meanwhile, has been recorded on islands south of Europe, previously the Canary Islands, and now also the Balearic Islands, although so far with limited evidence of zoonotic disease. Other members of the genus, namely, A. chabaudi, A. daskalovi and A. dujardini, are native to Europe and mainly infect wildlife, with unknown consequences for populations, although spill-over can occur into domestic animals and those in zoological collections. The epidemiology of angiostrongylosis is complex, and further research is needed on parasite maintenance in sylvatic hosts, and on the roles of ecology, behaviour and genetics in disease emergence. Improved surveillance in animals and humans is also required to support risk assessments and management.

Cytauxzoon sp. and Hepatozoon spp. in Domestic Cats: A Preliminary Study in North-Eastern Italy

Knowledge on the presence of Cytauxzoon sp. and Hepatozoon spp. in Italy is scant and mostly limited to a few areas of Northern and Southern regions, respectively. The present study updated the current epidemiological scenario by investigating the occurrence of these protozoa in domestic cats from three broad regions of North-Eastern Italy. Blood samples from cats at risk of vector-borne diseases were processed by PCR to detect Cytauxzoon and Hepatozoon DNA. Blood smears were observed for haemoparasite inclusions. The influence of cat individual data (e.g., provenance, management, indoor/outdoor lifestyle) on the prevalence of haemoprotozoan infections was statistically evaluated. Among 158 cats, Cytauxzoon and Hepatozoon DNA were detected in 6 (3.8%) and 26 (16.5%) animals, respectively. No Hepatozoon gamonts were detected in blood smears, whereas all Cytauxzoon PCR-positive samples were microscopically positive, though with low levels of parasitaemia. Two species of Hepatozoon were identified, Hepatozoon felis (n = 10) and Hepatozoon silvestris (n = 16). Hepatozoon silvestris prevalence values were significantly (p < 0.05) higher in the region Friuli Venezia Giulia and in stray cats. Cytauxzoon sp. was detected in 6/39 (15.4%) stray cats from Friuli Venezia Giulia (Trieste province). These data add new information on the occurrence of these neglected protozoa in domestic cats' populations.

Simultaneous Exposure to Angiostrongylus vasorum and Vector-Borne Pathogens in Dogs from Italy

Several drivers have recently fostered the expansion of Angiostrongylus vasorum throughout Europe, where Vector-Borne Pathogens (VBPs) are also spreading. However, the level of simultaneous risk of infection is still unknown in canine populations. This study evaluated the simultaneous exposure to A. vasorum and major canine VBPs in dogs of Italy. Sera of 294 dogs were subjected to two ELISAs, detecting A. vasorum circulating antigens and antibodies against the parasite, and to the following assays: (i) SNAP® 4DX (IDEXX Laboratories Inc.) detecting Dirofilaria immitis antigens, and antibodies vs. Borrelia burgdorferi, Anaplasma spp. and Ehrlichia spp. and (ii) IFAT for the detection of antibodies vs. Leishmania infantum, Babesia canis and Rickettsia conorii. Twenty-two (7.5%, CI: 4.8-11.1%) and six (2%, CI: 0.7-4.4%) dogs scored positive for circulating A. vasorum antibodies and antigens, respectively. Seventeen dogs (5.8%, CI: 3.4-9.1%) were positive for A. vasorum antibodies + at least one VBP, three (1%, CI: 0.2-3%) for A. vasorum antigen + at least one VBP, while one dog (0.3%, CI: 0.01-1.88%) was positive for A. vasorum antigen + A. vasorum antibodies + B. canis antibodies. These results show that dogs living in different regions of Italy are at risk of simultaneous infections with both A. vasorum and VBPs. Despite the same scenario being likely in other countries of Europe, the current knowledge is scant. Therefore, further studies are warranted to amplify current epizootiological information and to understand whether control programs should be improved.

Efficacy of fipronil/(S)-methoprene/eprinomectin/praziquantel (Broadline®) against Thelazia callipaeda in naturally infected cats

Background

The present clinical field trial was conducted to assess the efficacy of a broad-spectrum parasiticide spot-on formulation containing eprinomectin (Broadline^®) against Thelazia callipaeda eyeworm in naturally infected cats.

Methods

Fifteen privately owned cats harboring at least one live adult T. callipaeda were included in the study. Cats were randomly allocated to an untreated control group of seven cats or to a Broadline^®-treated group of eight cats. Cats were treated on Day 0; ocular examinations were performed at inclusion and on Days 7 and 14; eyeworms were recovered and counted on Day 14. The primary efficacy assessment was based on group comparison of number of T. callipaeda on Day 14.

Results

Seven days after treatment, six of eight treated cats were negative for eyeworm infection per visual examination, and on Day 14 no eyeworms were found in the treated cats while the seven untreated cats were still infected (geometric mean: 1.97). All cats had inflammatory ocular signs at inclusion; on Day 14, five of eight treated cats had recovered while all untreated control cats were still symptomatic. All collected parasites were confirmed to be T. callipaeda by morphology and molecular characterization.

Conclusions

A single treatment with Broadline^® provided 100% efficacy against feline thelaziosis and improved related ocular inflammation signs.

Graphical abstract

The Influence of Temperature on the Larval Development of Aelurostrongylus abstrusus in the Land Snail Cornu aspersum

The metastrongyloid Aelurostrongylus&nbsp;abstrusus has an indirect lifecycle involving gastropod intermediate hosts. The widespread snail Cornu&nbsp;aspersum is an efficient intermediate host of A. abstrusus. As the temperature may influence the developmental rate of metastrongyloids from first (L1) to the third infective larval stage (L3) inside molluscs, this study evaluated the effect of two controlled temperatures on the development of A. abstrusus in C. aspersum. Overall, 300 snails were infected with 500 L1 of A. abstrusus and kept at ∼25 °C. Fifteen days post infection (D15), the overall developmental rate to L3 (0.8%) was assessed in a subset of 20 snails. The remaining gastropods were divided in 2 groups, i.e., 180 still kept at ∼25 °C (G1) and 100 hibernated at ∼4 °C (G2). On D30, the larval development was evaluated in 20 snails from each group, while another batch of 80 snails was selected random from G1 and hibernated at ∼4 °C (G3). The larval developmental rate was determined digesting 20 snails from each of the three groups on D45, D60, and D75. The higher mean developmental rate was registered in G1 (3.8%) compared to G2 (1.9%) and G3 (2.3%), indicating that the development to L3 of A. abstrusus in C. aspersum is positively influenced by the increase of temperature.

Do All Roads Lead to Rome? The Potential of Different Approaches to Diagnose Aelurostrongylus abstrusus Infection in Cats

An infection with the cat lungworm, Aelurostrongylus abstrusus, can be subclinical, but it can also cause severe respiratory clinical signs. Larvae excretion, antibody levels, clinical assessment findings of the respiratory system and diagnostic imaging findings were recorded and compared for six cats with experimental aelurostrongylosis. In five cats, patency started 33-47 days post infection (pi), but two cats excreted larvae only in long intervals and low numbers. Positive ELISA results were observed in four cats with patent aelurostrongylosis, starting between five days before and 85 days after onset of patency. One seropositive cat remained copromicroscopically negative. Mild respiratory signs were observed in all cats examined. A computed tomographic (CT) examination of the lungs displayed distinct alterations, even in absence of evident clinical signs or when larvae excretion was low or negative. The thoracic radiograph evaluation correlated with the CT results, but CT was more distinctive. After anthelmintic treatment in the 25th week post infection, pulmonary imaging findings improved back to normal within 6-24 weeks. This study shows that a multifaceted approach, including diagnostic imaging, can provide a clearer diagnosis and monitoring of disease progression. Furthermore, a CT examination provides an alternative to post mortem examination and worm counts in anthelmintic efficacy studies.