selamectin and Rodent-Diseases

In the present study, the persistent efficacy of selamectin (SEL) in Angora rabbits infested with Haemaphysalis concinna was observed. SEL (6 mg/kg) was administered to rabbits with a single topical application. Eighteen Angora rabbits were randomly allocated to three groups of six rabbits each. At days 1, 8, 15, 22, and 29 following SEL administration, rabbits were inoculated with larval, nymphal, and adult ticks and were then observed for a period of 7 days. The cumulative reduction rates at days 1, 8, 15, 22, and 29 for dead ticks were 100%, 100%, 100%, 95.0%, and 76.7%, respectively, for larvae; 100%, 100%, 100%, 85.0%, and 65.0%, respectively, for nymphs; and 100%, 95.0%, 85.0%, 60.0%, and 45.0%, respectively, for adults. The cumulative reduction rates for larvae in untreated Angora rabbits (controls) were 3.3%, 1.7%, 3.3%, 5.0%, and 5.0%, respectively. There was no reduction of nymphs and adults in untreated Angora rabbits (controls). The reduction rates for larvae, nymphs, and adults were significantly higher for Angora rabbits inoculated with SEL than the controls (P < 0.001).

Topics: Acari; Animals; Antiparasitic Agents; Ivermectin; Ixodidae; Rabbits; Rodent Diseases; Tick Infestations; Ticks; Treatment Outcome

Efficacy of selamectin was studied in naturally acquired S. muris infections in rats. Fourty-eight S. muris-positive rats were divided into six treated and two control groups. Selamectin (6 mg/kg) was applied topically to the skin in a single spot at the base of the neck in the treatment group. The rats of treated and control groups were necropsied on the 24th day after the treatment. Topical selamectin was found to be 40.7-63.3% effective (based on egg per gram method) in eliminating S. muris infection in rats. The efficacy of the treatment against S. muris (based on adult worm counts) in male and female rats was 35.14-58.88%, respectively (mean 48.39%).

Topics: Animals; Animals, Laboratory; Anthelmintics; Ivermectin; Nematode Infections; Oxyuroidea; Parasite Egg Count; Rats; Rats, Sprague-Dawley; Rodent Diseases

We evaluated the efficacy and safety of topical selamectin, a novel avermectin, in eliminating naturally acquired Syphacia muris infections in rats and S. obvelata infections in mice. S. muris-positive rats were assigned randomly to 4 groups: selamectin (0.6 mg/kg), selamectin (6.0 mg/kg), fenbendazole-medicated (150 ppm) chow, and untreated. S. obvelata-positive mice were allocated into 4 groups similar to those for rats. Animals not exposed to pinworm-contaminated bedding were designated as negative controls. Treatment success was assessed weekly by anal tape impressions and by necropsy examinations at the end of week 9. Evaluations of intestinal contents at necropsy revealed that, although safe, topical selamectin was 100% ineffective in eliminating Syphacia spp. infections in rats and mice. Treatment with fenbendazole-medicated chow resulted in negative anal tape impressions beginning at week 2 in rats and week 1 in mice. Negative anal tape impressions in fenbendazole-treated animals were confirmed by negative intestinal content evaluations. Of the 2 treatments evaluated, fenbendazole-medicated chow remains an effective and practical method to eliminate pinworm infections in mice and rats.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Ivermectin; Male; Mice; Oxyuriasis; Oxyuroidea; Rats; Rodent Diseases

Ectoparasite infestations are not common in degus. Two cases are presented here where use of Stronghold® Plus/Revolution® Plus (selamectin and sarolaner topical solution) was successfully administered to a degu (Octodon degus) for treatment of naturally-occurring mite infesations. Selamectin (Stronghold®/Revolution®) has been demonstrated to be effective against naturally-occurring mite infections in dogs and selamectin is approved for use in dogs for the treatment of sarcoptic mange (caused by Sarcoptes scabiei) at a dose of 6 mg/kg. In the first case, a 2.6-years-old female degu housed in a group with four other degus was presented with pruritic skin reactions, restlessness and hairloss. Mites morphologically similar to Demodex sp. were detected in the deep skin scrapings. All four degus were treated with Stronghold® Plus/Revolution® Plus (30 mg/kg selamectin and 5 mg/kg sarolaner) once a week for a total of six treatments. The spot-on was administered topically on the dorsal cervical region. Following treatment the degu presenting with clinical signs showed a rapid improvement with the pruritus and overall dermatitis resolving within 2 weeks of treatment. Skin scrapes and microscopic examination of epidermal debris collected from the affected degu were negative for mites from day 14 onwards. In the second case, a group of four 4-6.5-years-old female and male degus that were housed together were infested with Ornithonyssus bacoti. All animals were treated with 30 mg/kg selamectin and 5 mg/kg sarolaner in four total weekly doses. One week later no living mites were found on the patients or in their environment. The four degus improved visibly, and within three weeks of treatment the skin lesions associated with the infestation subsided. The antiparasiticides showed a satisfactory efficacy and were well tolerated (n = 9 animals treated in a total).

Topics: Administration, Topical; Animals; Antiparasitic Agents; Azetidines; Female; Ivermectin; Male; Mite Infestations; Mites; Octodon; Rodent Diseases; Spiro Compounds; Treatment Outcome

  Staff at a university laboratory responsible for management of a captive insurance colony of endangered Amargosa voles ( Microtus californicus scirpensis) discovered an outbreak of tropical rat mites ( Ornithonyssus bacoti) infesting 106 voles. This bloodsucking mesostigmatid mite typically occurs in laboratory settings and can cause weight loss, wounds, or other negative impacts on health. The source of the infestation was likely feral rodents, and the route was suspected to be straw bedding. Twenty-nine of the 106 (27.4%) infested voles developed ulcerated dorsal skin lesions that resolved when treated with topical selamectin. A triad approach was implemented to eradicate the mites, consisting of environmental management, individual animal treatment, and training. Voles were moved individually into a clean room containing only autoclaved materials (including straw), cages were treated with permethrin-impregnated cotton, treatment order was instituted to avoid transferring mites, and voles coming from outside were quarantined. All animals in an infested room were treated with topical selamectin, and personnel were trained on risks and new procedures. No adverse effects from the use of selamectin were identified, and this efficient protocol does not require the long-term use of acaricides. This report documents infestation of an endangered rodent with an exotic parasite, safe use of permethrin and selamectin in this species, and comprehensive management to manage a large infestation.

Topics: Acaricides; Animals; Animals, Zoo; Arvicolinae; California; Disease Eradication; Endangered Species; Ivermectin; Mite Infestations; Permethrin; Rodent Diseases

Detecting and controlling murine fur mites continues to be challenging. Here we compared the efficacy of fur-pluck, cage PCR, and fur PCR testing of mice naturally infested with Myocoptes musculinus and make recommendations regarding the application of these diagnostic strategies in aged or treated mice. We compared all 3 diagnostic methods in groups of infested and noninfested control mice over time. For fur plucks, we used a scoring system to quantitatively compare mite infestations across ages. Mice that were 4 wk old had higher egg and mite scores than did older mice, with average scores at 4 wk corresponding to 40 to 100 individual fur mites and eggs per sample. Furthermore, 15% and 20% of samples from infested mice at 24 and 28 wk of age, respectively, lacked all fur mites and eggs. Cage PCR results varied as mice grew older. Fur PCR testing was the most sensitive and specific assay in untreated infested mice, particularly when mite densities were low. In addition, we compared fur-pluck and fur PCR tests for evaluating the efficacy of selamectin treatment. Two treatments with selamectin eliminated Myocoptes fur-mite infestations. At 8 wk after treatment, all fur-pluck samples were negative, but one-third of treated infested cages remained positive by fur PCR assay; at 16 wk after treatment, all cages were negative by fur PCR assay. Because offspring of infested mice were invariably heavily infested, breeding of suspected infested mice with subsequent testing of offspring was the definitive testing strategy when fur-pluck and PCR results conflicted.

Topics: Animals; Antiparasitic Agents; Female; Ivermectin; Male; Mice; Mite Infestations; Mites; Polymerase Chain Reaction; Rodent Diseases; Sensitivity and Specificity

In June 2009, 27 guinea pigs kept at an animal petting facility at a zoo in Kanagawa Prefecture, Japan, were observed to scratch intensely, weaken, and develop lesions. Three sarcoptiform mites were found in skin scrapings taken from affected areas of 2 guinea pigs, and they were identified as Trixacarus caviae by morphological examination. This result confirmed the presence of T. caviae in Japan. For treatment, doses of 13.6-18.75 mg/head of selamectin were administered in a topical preparation applied to a single spot on the skin on the back of the neck, and no side effects were observed. In April 2010, a second outbreak of mange occurred at the zoo, and, following investigation, 2 mite eggs were observed. It was, therefore, thought probable that the mites had survived during the winter within nonclinical carriers. Accordingly, doses of 5.0-7.5 mg/head of selamectin were applied on days 0 and 28, after which clinical symptoms disappeared and general condition improved. This dose of selamectin was thus shown to be a suitable and economical treatment for guinea pigs infested with the mites. Because the mite is not always easily observed in infested guinea pigs and the potential for human infestation exists, clinicians should not hesitate to treat when the clinical presentation suggests infestation, particularly in a setting such as an animal petting facility, where large numbers of children and adults have direct contact with the animals.

Topics: Animals; Animals, Zoo; Antiparasitic Agents; Disease Outbreaks; Female; Guinea Pigs; Ivermectin; Japan; Male; Mite Infestations; Mites; Rodent Diseases; Skin

This study was designed to determine the acute effects of a single-dose of orally administered doramectin, eprinomectin and selamectin on Syphacia muris infection in rats. Rats, naturally infected with S. muris, were divided into four groups: three different treatment groups (n=7) and one positive control (n=7). Cellophane tape preparations were obtained from the treated rats on day 0 pre-treatment and on days 2, 4 and 6 post-treatment. Syphacia sp. eggs were counted. Eprinomectin was found to be 100% effective in eliminating eggs on two post-treatment. However when egg counts on day 6 post-treatment were compared with pre-treatment egg counts, doramectin and selamectin were found to be 99.32 and 98.77% effective in eliminating eggs, respectively. On day 7 post-treatment, blood samples were obtained from all groups, and then the rats were necropsied. Doramectin, eprinomectin and selamectin were found to be 100% effective in eliminating adult S. muris, when compared with the positive control group.

Topics: Administration, Oral; Animals; Animals, Laboratory; Anthelmintics; Hematologic Tests; Ivermectin; Male; Oxyuriasis; Oxyuroidea; Parasite Egg Count; Rats; Rats, Sprague-Dawley; Rodent Diseases

The present study investigated the efficacy of topical selamectin for elimination of naturally acquired Trichosomoides crassicauda infection in rats. Twelve T. crassicauda-positive rats were assigned to the treatment group and six rats were assigned to the control group. Selamectin (6 mg/kg) was applied topically to the skin in a single spot at the base of the neck in front of the scapulae in the treatment group. To assess the efficacy of the treatment, animal faeces were investigated with the use of the flotation technique on days 0, 4, 14 and 24 after selamectin application. The rats of the treatment and control groups were necropsied on the day 24. In the treatment group, 7 of 12 infected rats were cured completely. Topical selamectin was found to be effective in eliminating T. crassicauda infection in rats.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Enoplida Infections; Feces; Ivermectin; Random Allocation; Rats; Rodent Diseases; Time Factors; Treatment Outcome; Trichuroidea

A breeding colony consisting of 250 different strains of mice was treated with the topical acaricide selamectin for the mouse fur mite Myocoptes musculinus, with no apparent ill effect, suggesting that this drug is safe for use in mice. To further evaluate their efficacy in treating Myocoptes spp., we compared selamectin with another acaricide, moxidectin, in a controlled manner. Infested mice were treated with selamectin or moxidectin at the time of cage change, and a subset of mice was retreated 10 d later. Mice underwent routine cellophane tape examination of the pelage for 1 y. Although no adult mites were found in any group at 1 mo after treatment, egg casings were found in the selamectin treatment group as late as 6 mo after treatment, prompting concern about its effectiveness. Moxidectin used in combination with cage changing was effective in eradicating mites, with mice negative for traces of mites on cellophane tape examination of the pelage from months 2 through 12 after treatment.

Topics: Animal Husbandry; Animals; Female; Insecticides; Ivermectin; Macrolides; Mice; Mice, Inbred Strains; Mite Infestations; Rodent Diseases; Treatment Outcome

The effects of selamectin were studied in mice naturally infected with the mites Myobia musculi, Myoceptes musculinus and Radfordia ensifera and with the oxyurid nematodes Aspiculuris tetraptera and Syphacia obvelata. The mice were divided into three treated and three control groups (n=9). Selamectin in the range 10-12.4 mg/kg was applied topically to the skin in a single spot at the base of the neck in front of the scapulae. The mice of treated and control groups were necropsied on the 4th, 7th and 21st day after the treatment. While selamectin was 100% effective in removing M. musculi, M. musculinus and R. ensifera by the seventh day, its effect against S. obvelata and A. tetraptera was 36.7% and 49.2%, respectively on the 21st day.

Topics: Administration, Topical; Animals; Animals, Laboratory; Antiparasitic Agents; Female; Gastrointestinal Diseases; Ivermectin; Male; Mice; Mite Infestations; Mites; Nematoda; Nematode Infections; Rodent Diseases

Ectoparasites pose numerous research, health, and management problems for researchers and institutions. Our facility management experience was complicated by recurrence of murine fur mite (Radfordia affinis) infestation after several rounds of single-mode fur mite treatment with dichlorvos in the cage bedding. Subsequently, we successfully eradicated the fur mites using a multidrug therapeutic protocol. Over an 8-wk treatment period, 2 applications of topical selamectin were administered in conjunction with amitraz- and fipronil-treated nestlets changed weekly. Mice tolerated the therapy well with no side effects noted, and to date there has been no recrudescence. To our knowledge, this report is the first to describe combined use of these specific therapeutic agents to control fur mite infestation in laboratory mice.

Topics: Animals; Drug Therapy, Combination; Hair; Insecticides; Ivermectin; Laboratory Animal Science; Mice; Mite Infestations; Mites; Pyrazoles; Rodent Diseases; Toluidines

Topics: Administration, Topical; Animals; Antiparasitic Agents; Ivermectin; Mice; Oxyuriasis; Rats; Rodent Diseases; Treatment Failure; Treatment Outcome