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.     

A case of Trichophyton mentagrophytes infection in a fennec fox (Vulpes zerda)

A 2‐year‐old male fennec fox presented with a 4 month history of nonpruritic, crusty skin lesions on the forehead, the pinnae and the tail tip. Initial investigations, including routine haematology, biochemistry profile, multiple skin scrapings, trichoscopic examination, Wood’s lamp examination and fungal culture, failed to reveal any abnormalities. Histopathological examination of a first set of skin biopsies showed an interface dermatitis pattern, with lymphocyte infiltration in the basal layer, a significant lymphocytic exocytosis and occasional apoptotic basal epidermal keratinocytes; periodic acid Schiff stain did not reveal any fungal elements. On further biopsies, there was a pustular neutrophilic dermatitis, with numerous crusts containing high numbers of arthrospores and fungal hyphae. Trichophyton mentagrophytes infection was confirmed on fungal culture and PCR. The fennec fox received oral itraconazole (5 mg/kg once daily for 6 weeks) combined with a miconazole and chlorhexidine shampoo applied on affected areas once weekly, followed with an enilconazole dip. The fox improved dramatically, and a fungal culture performed at 6 weeks was negative. Unfortunately, a few days later the fennec fox developed anorexia, icterus and died. To the authors’ knowledge, this is the first report of Trichophyton infection in a fennec fox and, although a postmortem examination was not performed, this is possibly the first report of fatal acute liver failure associated with itraconazole in a canid.     

Pharmacokinetics of Selamectin in Dogs after Topical Application

Some pharmacokinetic parameters of selamectin were determined in male (n = 5) and female (n = 5) Beagle dogs following a topical application at a dose rate of 6 mg/kg. The plasma concentration versus time data for the drug were analysed using a one-compartment model. The maximum plasma concentrations of 12.72 +/- 5.13 ng/ml for males and 22.65 +/- 11.95 ng/ml for females occurred around 5 days after administration. The area under the concentration-time curve (AUC) was 192.08 +/- 63.85 ng.day/ml for males and 370.97 +/- 146.87 ng.day/ml for females. The mean residence time was the same in males and females (12.55 days). This study reveals a sex-influence on the disposition of selamectin in the plasma of dogs, which implies that further information will be needed for correlation with efficacy studies in dogs.     

Efficacy of an adulticide used alone or in combination with an insect growth regulator for flea infestations of dogs housed in simulated home environments.

OBJECTIVE: To determine the effect of an adulticide on flea populations of dogs and to evaluate efficacy of combined use of the adulticide and an insect growth regulator (IGR) in dogs with experimentally induced flea infestations. ANIMALS: 40 adult Beagles. PROCEDURE: Each group of 5 dogs was housed in a separate room. Each dog was infested 3 times with 50 fleas, and fleas were counted beginning on day -21. Groups of dogs and treatments (initiated on day 0) were as follows: 1, adulticide once; 2, adulticide on days 0 and 7; 3, adulticide on days 0, 3, and 7; 4, sham treatment; 5, IGR monthly; 6, IGR monthly plus adulticide once weekly for 6 weeks; 7, IGR monthly plus adulticide twice weekly for 6 weeks; 8, sham treatment. Flea counts were compared between treated and control dogs. RESULTS: By 24 hours after initial treatment, all adult fleas but 1 were dead in treated dogs. In groups 1 and 3, populations increased to 15 to 20 fleas/dog 2 months after treatment, compared with 48 fleas/dog in group 4. After treatment, mean flea counts were significantly lower for groups 1, 2, and 3, relative to group 4. Efficacy of treatment for group 5, relative to group 8, was > 94% after day 84. Efficacy of treatment for groups 6 and 7 was 99% after day 28. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with adulticide alone or in combination with an IGR had better efficacy, compared with sham treatment or IGR alone. Administration of adulticide twice weekly was not more efficacious than treatment once weekly.     

Determination of selamectin in dog plasma by high performance liquid chromatography with automated solid phase extraction and fluorescence detection

A method is described for the determination of selamectin in dog plasma, using High-Performance Liquid Chromatography (HPLC) with fluorescence detection (excitation and emission wavelengths fixed at 355 and 465 nm, respectively). The fluorescent derivative was obtained by condensation reaction with trifluoroacetic anhydride and N-methylimidazole. The method employs 1 mL plasma samples and gives linear calibration graphs (r = 0.999) over the concentration range studied (0.5-50 ng mL(-1)). Automatic solid phase extraction using the benchmate procedure was used for sample preparation. This method permits the determination of selamectin at levels as low as 0.1 ng mL(-1) and its suitability was demonstrated by a pharmacokinetic study on a dog receiving the therapeutic dose (Spot-on administration).