Marie-Christine Cadiergues

First Bloodmeal of Ctenocephalides felis felis (Siphonaptera: Pulicidae) on Cats: Time to Initiation and Duration of Feeding

Abstract Three experiments were conducted on cats to evaluate precocity and duration of the first blood meal ofCtenocephalides felis felis(Bouché). Percentage of engorged fleas was calculated for fleas held on cats for 5, 15, 30, and 60 min. Duration of first blood meal was also measured for individual fleas confined on cats. When fleas are free in the hair coat, 24.9% are engorged after 5 min and 97.2% are engorged after 1 h. Fleas confined to a vial on the cats fed significantly sooner; 60% of females were engorged within 5 min. The mean delay between deposition and biting for fleas, which began feeding within 15 min, was 24 s ± 31 s for females and 23 s ± 44 s for males. The mean duration of meals was 25 ± 18 min for females and 11 ± 8 min for males.

A comparison of jump performances of the dog flea, Ctenocephalides canis (Curtis, 1826) and the cat flea, Ctenocephalides felis felis (Bouché, 1835).

Jump performances of Ctenocephalides canis and Ctenocephalides felis felis have been measured and compared on unfed young imagos. The mean length of the C. felis felis jump was 19.9+/-9.1cm; minimum jump was 2cm, and the maximum was one 48cm. The C. canis jump was significantly longer (30.4+/-9.1cm; from 3 to 50cm). For height jump evaluation, grey plastic cylindric tubes measuring 9cm in diameter were used. Their height was increasing from 1 to 30cm by 1cm. Groups of 10 fleas of the same species were deposited on the base of the tube. The number of fleas which succeeded in jumping above the tube was recorded. The mean height jump carried out by 50% of fleas was calculated after linearisation of the curves: it was 15.5 and 13.2cm for C. canis and C. felis, respectively. The highest jump was 25 for C. canis and 17cm for C. felis.

Activity of a deltamethrin shampoo against Ctenocephalides felis and Rhipicephalus sanguineus in dogs

A controlled clinical trial was undertaken to assess the efficacy of an application of a 0.07% deltamethrin shampoo against fleas and ticks in dogs. Twenty beagles, housed in separate cages, were randomly allocated into two groups of 10. The dogs were infested with 50 Ctenocephalides felis and 50 Rhipicephalus sanguineus each, and parasites were counted 24 h (fleas) and 72 h (ticks) later (Day 0). Dogs, when state, were then treated with 25 ml of a shampoo containing 0.07% deltamethrin (Group 1). Dogs in Group 2 were the controls. Fleas and ticks were counted 24 h (Day 1) and 48 h (Day 2) after the shampoo was applied, and the parasites were then removed. All the dogs were reinfested with fleas and ticks on Days 2, 7, 9, 14, 16 and 20. Parasites were counted 24 and 48 h after each reinfestation. Effectiveness against fleas was calculated 24 h after infestation, and against ticks 48 h after infestation. This study showed that the application of 25 ml of shampoo containing 0.07% deltamethrin to beagle dogs weighing between 10.2 and 12 kg was very well tolerated. It controlled the parasites present on the animals at the time of application: with an efficacy of 100% against fleas 24 h after treatment and an efficacy of 95% against ticks 48 h after treatment. The treatment protected against flea reinfestations with an efficacy of 100% during the first week, >98% in the second week and >95% in the third week. It also gave >99% protection against tick reinfestations in the first week and >96% in the second week.

Efficacy of spinosad tablets administered to a colony of 15 indoor cats naturally infested with fleas.

The aims of the study were (i) to describe adult fleas distribution in a strictly indoor cat colony composed of cats with flea allergy dermatitis (FAD) and non-FAD cats and (ii) to evaluate the efficacy of spinosad used alone. Skin lesions were scored according to the SCORing Feline Allergic Dermatitis lesion severity scale (SCORFAD) on days 0, 15, 30, 45, 60, and 90. Cats were combed prior to the treatment (days 0, 30, and 60) and on days 15, 45, and 90; collected fleas were replaced on the animals. All cats received flavored spinosad tablets (Comfortis) at a dosage of 50–75 mg/kg on days 0, 30, and 60. Cats were fed immediately afterwards. On day 0, a total of 60 fleas were collected (mean: 4 ± 4). Cats with FAD had a SCORFAD of 6, 8, 12, and 13 and harbored 0, 2, 1, and 0 fleas, respectively. Tablets were taken voluntarily by 8, 11, and 12 cats on days 0, 30, and 60, respectively. No adverse event was recorded. From day 15 to day 90, no fleas could be collected. SCORFAD was reduced by 40%, 71%, 80%, 89%, and 98% on days 15, 30, 45, 60, and 90, respectively.

Assay of two 10% (w/v) fipronil spot-on formulations against feline infestations with Ctenocephalides felis

A new fipronil-based spot-on formulation was evaluated against experimental flea infestations in cats in two studies. In both studies, eight cats served as negative controls (groups 1 and 4); on day 0, eight cats were treated with a 10% w/v fipronil-based spot-on solution (Effipro Spot-on, 0.5 ml per cat, groups 2 and 5) and eight cats served as positive controls (Frontline Spot-on, 0.5 ml per cat, groups 3 and 6). Each cat was infested on day − 1 with 50 fleas (study 1) and weekly (day 7–day 56) with 100 fleas (study 2). Geometric mean flea counts obtained 48 h after the treatment or each re-infestation were reduced by 99.0 and 98.3% in groups 2 and 3, respectively, on day 2, compared to the negative control group. Cats were protected from re-infestations with an efficacy >99% for 58 days in group 5 and for 37 days in group 6.

A Point Mutation in a lincRNA Upstream of GDNF Is Associated to a Canine Insensitivity to Pain: A Spontaneous Model for Human Sensory Neuropathies

Human Hereditary Sensory Autonomic Neuropathies (HSANs) are characterized by insensitivity to pain, sometimes combined with self-mutilation. Strikingly, several sporting dog breeds are particularly affected by such neuropathies. Clinical signs appear in young puppies and consist of acral analgesia, with or without sudden intense licking, biting and severe self-mutilation of the feet, whereas proprioception, motor abilities and spinal reflexes remain intact. Through a Genome Wide Association Study (GWAS) with 24 affected and 30 unaffected sporting dogs using the Canine HD 170K SNP array (Illumina), we identified a 1.8 Mb homozygous locus on canine chromosome 4 (adj. p-val = 2.5x10-6). Targeted high-throughput sequencing of this locus in 4 affected and 4 unaffected dogs identified 478 variants. Only one variant perfectly segregated with the expected recessive inheritance in 300 sporting dogs of known clinical status, while it was never present in 900 unaffected dogs from 130 other breeds. This variant, located 90 kb upstream of the GDNF gene, a highly relevant neurotrophic factor candidate gene, lies in a long intergenic non-coding RNAs (lincRNA), GDNF-AS. Using human comparative genomic analysis, we observed that the canine variant maps onto an enhancer element. Quantitative RT-PCR of dorsal root ganglia RNAs of affected dogs showed a significant decrease of both GDNF mRNA and GDNF-AS expression levels (respectively 60% and 80%), as compared to unaffected dogs. We thus performed gel shift assays (EMSA) that reveal that the canine variant significantly alters the binding of regulatory elements. Altogether, these results allowed the identification in dogs of GDNF as a relevant candidate for human HSAN and insensitivity to pain, but also shed light on the regulation of GDNF transcription. Finally, such results allow proposing these sporting dog breeds as natural models for clinical trials with a double benefit for human and veterinary medicine.

Comparison of Two Techniques for the Detection of Flea Faeces in Canine and Feline Coat Brushings

Flea infestation is diagnosed after the detection of either adult parasites or flea faeces in the fur. The latter is generally tested with the wet blotting paper technique (WBPT). However, microscopical examination (MT) of the coat brushing material is sometimes suggested as an alternative. This study aimed to compare the efficiency of the two techniques. In dogs, the entire body was hand-brushed and cats were combed. One half of the collected material was mounted in liquid paraffin on a glass slide and examined microscopically at low magnification. The second half was placed on a blotting paper and sterile water was added. After drying, reddish aureoles were counted. 255 animals (158 dogs and 97 cats) were included. 119 (47%) and 94 (37%) samples were revealed to be positive with WBPT and MT, respectively. 13 cases (5%) were positive with MT only and 38 cases (15%) were positive with WBPT only. 81 cases (32%) were positive and 123 (48%) were negative with both techniques. More positive cases were detected by WBPT than MT (P < 0.001). Amongst the 51 samples which were found positive with a sole technique, infestation was considered low in 43 cases and WBPT detected significantly more positive samples (31) than MT (12), P < 0.01.