Dataset Information

Efficacy of Bravecto^® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) for the prevention of aelurostrongylosis in experimentally infected cats.

ABSTRACT:

Background

The feline lungworm Aelurostrongylus abstrusus affects the lower respiratory tract in cats worldwide. As infections may lead to chronic respiratory changes or even death, preventive treatment in cats with outdoor access is warranted.

Methods

The preventive efficacy of a spot-on solution (Bravecto® Plus spot-on solution for cats, MSD) against cat aelurostrongylosis was evaluated using three different preventive treatment regimes in a negative controlled, randomized and partially blinded laboratory efficacy study with 31 purposed-bred cats. The minimum recommended dose of 2.0 mg moxidectin + 40 mg fluralaner/kg bodyweight was applied once 12 (Group [G]1), 8 (G2) or 4 (G3) weeks before experimental infection with 300 third-stage larvae (L3) of A. abstrusus. Another group served as untreated control (G4). Individual faecal samples were analysed as of day 30 post infection (pi) to monitor larvae excretion. Necropsy was performed at days 47-50 pi. The lungs were examined macroscopically for pathological findings and (pre-)adult worms were counted to assess preventive efficacy.

Results

Beginning at day 32-40 pi, all cats of the control group were constantly shedding larvae of A. abstrusus, whereas only one animal of G1 excreted larvae at several consecutive days. In addition, two cats of G1 and G3 and three of G2 were positive on a single occasion. The geometric mean (GM) of the maximum number of excreted larvae was 7574.29 in the control group compared to 1.10 (G1), 1.19 (G2) and 0.53 (G3), resulting in a GM reduction of > 99.9% in all treatment groups. All lungs of the control animals showed severe or very severe alterations at necropsy, while in 94.44% of the treated cats lung pathology was rated as absent or mild. The GM number of (pre-)adult A. abstrusus retrieved from the lungs was 26.57 in the control group, 0.09 in G1 and 0.00 in G2 and G3. Thus, GM worm count reduction was 99.66% in G1 and 100% in G2 and G3.

Conclusions

A single application of Bravecto® Plus spot-on solution at a dose of 2.0 mg moxidectin + 40 mg fluralaner/kg bodyweight reliably prevents cat aelurostrongylosis for at least 12 weeks.

SUBMITTER: Raue K

PROVIDER: S-EPMC7885211 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundMosquitoes serve as the vector of canine heartworm (Dirofilaria immitis), which represents a significant and persistent threat to canine health. A reduction in the longevity and/or reproductive success of mosquitoes that take a blood meal from fluralaner-treated dogs may consequently reduce the local transmission of heartworm and prevent new infections. A novel secondary effect of an oral formulation of the ectoparasiticide fluralaner (Bravecto®) against a laboratory strain of the mosquito Aedes aegypti, a potential major vector of canine heartworm, was investigated in this study.MethodsSix dogs were administered a single dose of fluralaner orally in the form of Bravecto® Chews (at the labeled fluralaner dose of 25 mg/kg body weight), while six control dogs received no treatment. Mosquitoes were fed on blood that was collected from each dog prior to treatment and weekly for 15 weeks post-treatment to assess the continued effects of fluralaner as its serum level decreased. Mosquito fitness was assessed by three parameters: rate of successful blood-feeding, survival, and egg laying.ResultsSuccessful blood-feeding rate was similar between control and treatment groups. In the fluralaner treatment, mosquito survival was significantly reduced within the first 24 h after blood-feeding, for the first 12 weeks post-treatment of the dogs (efficacy range = 33.2-73.3%). Survival of mosquitoes up until a potentially heartworm-infective timepoint (14 days post-blood-feeding) was significantly reduced in the fluralaner-treated group at several timepoints (1, 2, 5, 11, 12, 13, 14, and 15 weeks post-treatment; efficacy range = 49.4-91.4%), but was less consistently reduced at the other timepoints. Egg laying by mosquitoes was almost completely suppressed for the first 13 weeks following treatment of the dogs with fluralaner (treatment efficacy ≥ 99.8%).ConclusionsMosquitoes fed blood from fluralaner-treated dogs experienced a significant reduction in survival and fecundity. These findings support the potential for a reduction in heartworm transmission directly by lethal effects on the vector and indirectly through a reduction of the local vector population when mosquitoes are exposed to animals treated with fluralaner.

Project description:BACKGROUND:The safety of ProHeart® 12 (PH 12; extended-release injectable suspension; 10% moxidectin in glyceryl tristearate microspheres) was evaluated in four studies using Beagle dogs and one study using ivermectin-sensitive Collies. The recommended dose is 0.5 mg/kg subcutaneously once yearly. METHODS:Study 1: safety margin was evaluated as 3 treatments of PH 12 (0× (control); 1× (recommended dose); 3× (3 times recommended dose) and 5× (5 times recommended dose) in 12 months via clinical observations, body weights, food consumption, injection site observations, physical examinations, moxidectin tissue assay, pharmacokinetics, and clinical and anatomic pathology. Study 2: safety in breeding-age males was demonstrated by semen testing at 14-day intervals from Day 7 to Day 91 post-treatment (0× or 3×). Study 3: reproductive safety in females was demonstrated by monitoring dams and litters following treatments (0× or 3×) administered during breeding, gestation, or lactation. Study 4: safety in dogs surgically implanted with adult heartworms was evaluated by clinical and laboratory monitoring following treatment with 0× or 3× administered 61 days post-implantation. Study 5: safety in ivermectin-sensitive dogs (120 µg/kg SC) was by clinical monitoring for 1 week after administering 1×, 3× or 5×. RESULTS:Study 1: slight swelling clinically detectable at some 3× and 5× injection sites was characterized microscopically as granulomatous inflammation, like tissue responses to medical implants, interpreted as non-adverse. Pharmacokinetics were dose-proportional and there was little or no systemic accumulation. Residual moxidectin mean (range) at 1× injection sites after 1 year was 16.0% (0.045-37.6%) of the administered mass. Studies 2 and 3: no effects were identified in reproductive indices (females) or semen quality characteristics (males). Study 4: PH 12 produced marked reductions in circulating microfilariae and lower numbers of adult heartworms, but no adverse clinical signs were identified. Study 5: there were no abnormal clinical signs at 1×, 3× or 5× overdoses of PH 12 in ivermectin-sensitive dogs. CONCLUSIONS:PH 12 has a > 5× safety margin in both normal and ivermectin-sensitive dogs, has no effects on canine reproduction, and is well tolerated in heartworm-positive dogs. The only treatment-related finding was non-adverse, granulomatous inflammation at the injection site.

Dataset Information

Efficacy of Bravecto^® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) for the prevention of aelurostrongylosis in experimentally infected cats.

Background

Methods

Results

Conclusions

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Dataset Information

Efficacy of Bravecto® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) for the prevention of aelurostrongylosis in experimentally infected cats.

Background

Methods

Results

Conclusions

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Efficacy of Bravecto^® Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) for the prevention of aelurostrongylosis in experimentally infected cats.