An evaluation of ivermectin in the treatment of sarcoptic mange in dogs

A colony of mixed-breed dogs (n = 298) naturally infested with Sarcoptes scabiei was treated, twice, with 200 micrograms of ivermectin/kg of body weight subcutaneously at 14-day intervals. After the initial injection, positive skin scrapings from 20 treated dogs decreased from 7 to 1 and the degree of pruritus decreased. In contrast, positive skin scrapings from 22 nontreated dogs increased from 10 to 14, and there was an additional deterioration in the condition of the skin and an increase in the degree of pruritus. Complete control was noticed in all treated dogs by posttreatment day 28 (14 days after a 2nd injection) based on negative skin scrapings.     

Topical (pour-on) ivermectin in the treatment of canine scabies.

The efficacy of a pour-on formulation of ivermectin at 500 micrograms/kg body weight applied on the dorsum on days 1 and 15 was evaluated in 90 dogs from a shelter, naturally infested with Sarcoptes scabiei. This very practical form of treatment was successful in eradicating scabies from this shelter.     

Ivermectin for the control of swine scabies: relative values of prefarrowing treatment of sows and weaning treatment of pigs

Ivermectin given in a single subcutaneous dose (300 micrograms/kg of body weight) was tested for activity against swine scabies (Sarcoptes scabiei). Efficacy was determined by recoveries of mites from ear scrapings and by observations of clinical signs. Treatment of infected sows 8 to 37 days before farrowing eliminated scabies from the sows and prevented its transmission to their offspring. Pigs farrowed by ivermectin-treated sows remained noninfected throughout the study regardless of whether they were treated with ivermectin at weaning. Placebo-treated sows remained infected and transmitted scabies to their offspring. Ivermectin treatment of pigs at weaning eliminated the infection, whereas placebo treatment did not. The placebo-treated pigs remained infected while in the nursery, but ivermectin treatment eliminated the infection when they were moved to the growing and finishing floor at 12 weeks of age. It appears that an effective control program for swine scabies using ivermectin could be based on a single treatment of the sows before farrowing. Any infection (epizootic) appearing in growing pigs could be controlled by a single treatment of all in-contact pigs.     

Value of the pinnal-pedal reflex in the diagnosis of canine scabies

The potential value of the pinnal-pedal scratch reflex as an aid to diagnosing canine scabies was assessed in 588 dogs with skin disease. The reflex was assessed by vigorously rubbing the tip of one earflap on to the base of the ear for five seconds, and it was considered positive if the ipsilateral hind leg made a scratching movement. A diagnosis of scabies was based on the dog's history, a physical examination and either positive skin scrapings or the complete resolution of pruritus and dermatitis after treatment with ivermectin or milbemycin, with no relapse for at least 12 months. Scabies was diagnosed in 55 of the dogs, allergic skin disease in 463, and 70 had other miscellaneous skin diseases. There was a positive pinnal-pedal scratch reflex in 45 (82 per cent) of the 55 dogs with scabies. Forty (73 per cent) of the dogs with scabies had pinnal dermatitis, and 36 (90 per cent) of these had a positive pinnal-pedal scratch reflex. There was a positive pinnal-pedal scratch reflex in 33 (6.2 per cent) of the other 533 dogs. On the basis of these results, the specificity of testing for scabies by the pinnal-pedal scratch reflex was 93.8 per cent, and the sensitivity was 81.8 per cent The test's positive predictive value was 0.57 and its negative predictive value was 0.98.     

P-23 Clinical and epidemiological characteristics of 153 cases of Sarcoptic acariosis in dogs

A randomized and controlled field study was performed in canine patients to evaluate the efficacy of selamectin in the treatment of naturally occurring Sarcoptes scabiei and Otodectes cynotis infestations in dogs. A total of 227 dogs from six veterinary practices in South Korea were included. Dogs were randomly assigned to treatment with selamectin or a positive-control product. Selamectin was administered as a unit dose providing a minimum of 6 mg/kg in a topical preparation applied to the skin in a single spot on days 0 and 30 [ S. scabiei ( n =  113) and O. cynotis ( n =  114)]. The presence of parasites was assessed before treatment and at 14, 30 and 60 days after the initiation of treatment. The animals were evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis , selamectin eliminated mites in 100% of dogs by day 60. However, clinical signs of pruritus, erythema, scale, and crusted papules did not diminish concomittantly with resolution of S. scabiei in skin scrapings. The positive-control products achieved similar results. Therefore, selamectin was safe and effective against sarcoptic mange and ear mites in dogs.
Funding: Pfizer Animal Health.     

The efficacy of selamectin in the treatment of naturally acquired infestations of sarcoptes scabiei on dogs

Selamectin, a novel avermectin, was evaluated for its effect on naturally occurring infestations of Sarcoptes scabiei in 42 dogs. In two controlled and masked laboratory studies conducted in the USA and Italy, infested dogs received treatment with either selamectin (6mgkg(-1); range: 6-12mgkg(-1)) or the vehicle only (negative control). Treatments were administered topically to the skin on each animal's back at the base of the neck in front of the scapulae. Study day 0 was defined as the first day of treatment administration. Dogs were treated on days 0 and 30, and efficacy was assessed by counting viable mites recovered from skin scrapings performed on each dog on days 14, 29 or 30, 44, and 60, and by categorising the clinical signs of canine scabies on the same days. Percentage reductions in geometric mean mite counts for selamectin, compared with vehicle, on days 14, 29 or 30, 44, and 60 were > or =98.1, > or =93.5, 100, and 100%, respectively. Analysis of variance, confirmed by Savage Scores, showed that ln(mite counts+1) values for selamectin-treated dogs were significantly lower (P< or =0.0391) than those for vehicle-treated dogs on all post-treatment assessment days. Clinical signs of scabies were markedly reduced in selamectin-treated dogs, compared with vehicle-treated dogs. Topical administration to the skin in a single spot of a single unit dose of selamectin, or of two unit doses given 1 month apart, each providing at least the recommended minimum dosage of 6mgkg(-1), was highly effective against naturally acquired infestations of S. scabiei in dogs, reducing mite counts by >93% (single dose) and 100% (two doses).     

Diagnostic challenge: Generalized erythema and pruritus in a miniature pot-bellied pig (Sus scrofa)

A 10-week-old, intact male miniature potbellied pig (Sus scrofa) presented for intense pruritus that had started approximately 2 weeks earlier. Following microscopic identification of multiple stages of the Sarcoptes scabiei, var. suis from its skin,the pig was treated with ivermectin (300-400 μg/kg subcutaneously), three times at 10-day intervals.     

Cheyletiellosis and scabies

Cheyletiellosis and scabies can cause pruritus in dogs and cats. Cheyletiellosis is variably pruritic, whereas scabies is usually intensely pruritic. Hypersensitivity reactions are described in both of these parasitic dermatoses and probably contribute to the development of lesions and pruritus. Both parasites are readily eradicated with insecticides.     

Efficacy and safety of selamectin against Sarcoptes scabiei on dogs and Otodectes cynotis on dogs and cats presented as veterinary patients

A series of randomized, controlled and masked field studies was conducted in veterinary patients to evaluate the efficacy of selamectin, a novel avermectin, in the treatment of naturally occurring Sarcoptes scabiei infestations on dogs and Otodectes cynotis infestations on dogs and cats. A total of 342 dogs and 237 cats participated in these studies, which were conducted at 40 veterinary practices in the USA and Europe. Animals were randomly assigned to treatment with selamectin or a positive-control product (existing approved products). Selamectin was administered as a unit dose providing a minimum of 6mgkg(-1) (range: 6-12mgkg(-1)) in a topical preparation applied to the skin in a single spot on day 0 (O. cynotis in cats, n=144), or on days 0 and 30 (O. cynotis and S. scabiei in dogs, n=83 and n=122, respectively). The presence of parasites was assessed before treatment and at 30 days (for all studies) and 60 days (for O. cynotis and S. scabiei dog studies) after first treatment. The animals were also evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis, selamectin eliminated mites in 94-100% of cats by day 30, and in 90% of dogs by day 60. The positive-control products achieved similar results. Thus, selamectin was safe and effective against ear mites in dogs and cats and sarcoptic mange in dogs when used in field (veterinary patient) studies in dogs and cats of a wide variety of ages and breeds.     

药物治疗犬疥螨病比较试验

为了评估对犬疥螨病的治疗效果,将80只确诊为犬疥螨病的病犬随机分为4组,每组20只.第1组用阿维菌素加杀螨灵治疗；第2组用阿维菌素加双甲脒治疗；第3组用伊维菌素加杀螨灵治疗；第4组用伊维菌素加双甲脒治疗.结果表明,第1组治愈率为85％,第2组治愈率为80％,第3组治愈率为90％,第4组治愈率为95％.结果表明第4组的治...     

The curative and antioxidative efficiency of ivermectin and ivermectin + vitamin E-selenium treatment on canine <Emphasis Type="Italic">Sarcoptes scabiei</Emphasis> infestation

The objective of the present study was to investigate the curative and antioxidative efficacy of ivermectin and ivermectin + vitamin E-selenium, and the influence of these agents on oxidative stress parameters in canines infested by Sarcoptes scabiei. Twenty two sarcoptic mites infested dogs and nine healthy dogs of 6 months to 2 years of age were divided into three groups. Group I comprised of healthy dogs (n = 9) whereas animals in group II (n = 11) and III (n = 11) were positive for scabies. Group II animals were treated with only 1% ivermectin @ 0.2 mg/kg SC whereas group III were additionally treated with Vitamin E and selenium (tocopherol 50 mg + Se 1.5 mg/ml) @0.5 ml/20 kg IM at weekly intervals for three times. Blood samples were collected on day 0 and 28 post therapy. The values for hemato-biochemical parameters and activities of antioxidant enzymes were significantly decreased (P < 0.05) whereas level of lipid peroxidation was significantly increased in all the infested dogs in comparison to the healthy dogs on day 0 which approached normalcy by day 28 post therapy. The dogs of group III showed better clinical recovery in comparison to group II at the end of therapy. Thus, administration of vitamin E and selenium in addition to standard therapy can alleviate these alterations hastening the clinical recovery of diseased dogs and can be recommended as an adjunct therapy with miticides for canine sarcoptic mange.     

Treatment with ivermectin of sarcoptic mange in pigs

Ivermectin injectable solution (1% w/v) was highly effective against Sarcoptes scabiei var suis when administered subcutaneously once to swine at 300 mcg/kg body weight. There were significantly (P < 0.05) fewer Sarcoptes mange mites counted on pigs treated with ivermectin than on untreated pigs at each count up to day 56 after treatment. The results indicate ivermectin should provide an efficient, practical means of control of sarcoptic mange in intensive piggeries.     

Efficacy of topically administered ivermectin against chorioptic and sarcoptic mange of cattle

The efficacy of topically administered ivermectin against Chorioptes bovis and Sarcoptes scabiei var bovis on cattle was evaluated in five studies involving a total of 68 cattle. Treatment with ivermectin solution at a dose rate of 500 micrograms/kg bodyweight topically once was fully effective against C bovis and S scabiei when applied to healthy skin. Efficacy against S scabiei was impaired when the formulation was applied over areas of severe lesions caused by this parasite, presumably due to reduced absorption of ivermectin.     

米尔贝肟对自然感染疥螨病犬的治疗效果

为了评价米尔贝肟对临床自然感染疥螨犬的治疗效果,选用自然感染疥螨犬65例,随机选择5条服用伊维菌素,另外60条随机分为3组,分别服用高剂量(2g/kg体重)、中剂量(1g/kg体重)、低剂量(0.5g/kg体重)的米尔贝肟。给药后2、14、28、42d和56d,刮取皮屑,检查螨虫和虫卵,同时观察临床症状。试验结束时米尔贝肟高剂量组、伊维菌素组的无螨虫犬的比例和螨虫的下降率均为100%,临床症状如红疹、结痂、过度角化等现象均消失,所有动物毛发都开始大范围重生;米尔贝肟中、低剂量组结果稍差。米尔贝肟按2g/kg体重剂量,每周1次,连续用药3周,给药对自然感染疥螨病犬有很好的治疗效果。     

Biotin-avidin amplified ELISA for detection of antibodies to Sarcoptes scabiei in chamois (Rupicapra spp.)

Scabies is a major threat to the well being of mountain-dwelling Bovid hosts, Rupicapra rupicapra and Rupicapra pyrenaica. Severe outbreaks are in progress over a significant part of their distribution area and resource managers demand improved methods to monitor, analyse and possibly forecast the spread and effects of scabies at the population level. An amplified capture enzyme-linked immunosorbent assay was developed to detect antibodies to Sarcoptes scabiei in chamois (Rupicapra spp.) serum. The method used the biotin-avidin amplification system and was validated on a panel of 144 serum samples, of which 40 were obtained from scabietic and 104 from healthy unexposed individuals originating from a scabies-free area. The antigen, a whole body extract of the various developmental stages of S. scabiei, was prepared from mites actively leaving the skin lesions of naturally infested red foxes (Vulpes vulpes). The resulting LAB-ELISA was characterised by 93% sensitivity, 97% specificity and a high degree of repeatibility. A single seroreactor was found amongst 32 chamois affected with skin pathologies other than scabies, including infestations by other Acarina (Trombicula spp. and Ixodid ticks). Antibodies to S. scabiei were present in 26 out of 169 sera (15.4%) obtained by clinically healthy chamois within a scabies outbreak area, indicating that asymptomatic infestations by S. scabiei can be revealed by serological methods in the studied Caprinae hosts.     

The efficacy of simplified eradication strategies against sarcoptic mange mite infections in swine herds monitored by an ELISA

Eradication programmes directed against Sarcoptes scabiei var. suis, performed without any disinfection of the environment, were compared to an eradication programme including a simultaneous environmental disinfection. The performance of such programmes would be facilitated considerably if environmental disinfection could be avoided. The trial was conducted in four conventional piglet-producing herds designated A-D. All herds suffered from a subclinical but persistent infection with the sarcoptic mite. Herd A was treated with two injections of ivermectin and simultaneously disinfection of the environment was done. In the other herds, the animals were treated twice (B and C) or three times (D) with acaricides (ivermectin or phoxim) at intervals of 7-12 days without any simultaneous disinfection of the buildings or environment. The results were monitored by attempts to demonstrate the mite by skin scrapings, and by monitoring the levels of serum antibodies to Sarcoptes scabiei by an ELISA. Samples were taken from all adults and from 20% of the piglets aged 10-12 weeks, before initiating the control programmes, every third month during the first year and a final sampling 18 months after the treatments. After treatment, the levels of antibodies continuously decreased. Presumably dead S. scabiei were demonstrated in one sow from two of the herds 3 months after initiating acaricidal treatments. S. scabiei was not demonstrated later, nor from skin scrapings of the piglets. The results obtained demonstrate that it is possible to eradicate sarcoptic mange mites in swine herds with the use of simplified eradication programmes. The success of such programmes may efficiently be monitored by measuring the levels of serum antibodies to S. scabiei.     

Experimental infection of chamois (Rupicapra pyrenaica parva) with Sarcoptes scabiei derived from naturally infected goats

Two chamois (Rupicapra pyrenaica parva) out of a group of three were experimentally infected with Sarcoptes scabiei derived from a naturally infected domestic goat. One of the chamois presented the first clinical manifestations (papules and desquamation) at 7 days post-infection, after 22 days crusts and alopecia appeared and after 41 days pruritus. The other chamois presented desquamation after 15 days and papules after 21 days and crusts and alopecia after 31 days. All these clinical manifestations continued to spread and when the animals were treated at 84 days post-infection, pruritus, papules and crusts were first to disappear, there being no evidence of their presence at 99 days post-infection, when the second treatment dose was applied. The desquamation and alopecia disappeared at 114 days post-infection, by which stage both animals were considered to have been cured. The results of the skin scraping was negative in both chamois until 54 days post-infection and it became negative again after 84 days, when the first treatment dose was applied. Biopsies showed different levels of hyperkeratosis and a marked epidermic hyperplasia with formation of small crusts. Superficial epidermis presented marked vasodilatation and also infiltrated inflammation. None of the biopsies carried out showed the presence of parasites. The non-infected chamois, which was kept in the same compound as the other two, did not present any clinical manifestations compatible with infection by S. scabiei throughout the entire period of the experiment.     

Retinopathy associated with ivermectin toxicosis in two dogs

CASE DESCRIPTION: 2 dogs (dogs 1 and 2) were examined for sudden onset of blindness. Both dogs had mild obtundation and mydriasis in both eyes. It was thought that dog 1 may have ingested ivermectin; dog 2 had been treated with ivermectin for demodectic mange. CLINICAL FINDINGS: On initial examination, both dogs had mydriasis and decreased pupillary light reflexes in both eyes. Dog 1 had an absent menace response bilaterally. Fundic examination of both eyes in both dogs revealed regions of multifocal retinal edema and folds with low-lying retinal separation. The electroretinogram was extinguished in dog 1 and attenuated in dog 2. Ivermectin was detected in serum samples from both dogs. TREATMENT AND OUTCOME: Both dogs made a complete clinical recovery following cessation of exposure to ivermectin; electroretinographic findings improved, and retinal edema resolved with some residual chorioretinal scarring. CLINICAL RELEVANCE: To our knowledge, this is the first report of resolution of retinal edema and electroretinographic changes associated with ivermectin toxicosis in dogs. In dogs that develop blindness suddenly, fundic examination, electroretinography, and assessment of serum ivermectin concentration are diagnostically useful, even if exposure to ivermectin is unknown.     

P‐24 Efficacy of selamectin in canine scabies and ear mite infestation in Korea

A randomized and controlled field study was performed in canine patients to evaluate the efficacy of selamectin in the treatment of naturally occurring Sarcoptes scabiei and Otodectes cynotis infestations in dogs. A total of 227 dogs from six veterinary practices in South Korea were included. Dogs were randomly assigned to treatment with selamectin or a positive‐control product. Selamectin was administered as a unit dose providing a minimum of 6 mg/kg in a topical preparation applied to the skin in a single spot on days 0 and 30 [S. scabiei (n = 113) and O. cynotis (n = 114)]. The presence of parasites was assessed before treatment and at 14, 30 and 60 days after the initiation of treatment. The animals were evaluated clinically at each assessment period. Based on skin scrapings, the efficacy of selamectin against S. scabiei infestations on dogs was >95% by day 30, and 100% by day 60. Against O. cynotis, selamectin eliminated mites in 100% of dogs by day 60. However, clinical signs of pruritus, erythema, scale, and crusted papules did not diminish concomittantly with resolution of S. scabiei in skin scrapings. The positive‐control products achieved similar results. Therefore, selamectin was safe and effective against sarcoptic mange and ear mites in dogs. Funding: Pfizer Animal Health.     

Clinical Picture and Antibody Response to Experimental Sarcoptes scabiei var. vulpes Infection in Red Foxes (Vulpes vulpes)

Three red foxes (Vulpes vulpes) were experimentally infected with Sarcoptes scabiei isolated from a naturally infected wild red fox. A fourth red fox served as a control. The first signs of sarcoptic mange became evident on the 31st day post infection (dpi). The signs gradually increased thereafter and between dpi 49 and 77 characteristic lesions of hyperkeratosis developed. Two of the infected foxes developed severe sarcoptic mange, and one of these animals died on dpi 121. The third fox developed a chronic hyperkeratotic lesion on its back, at the site where the mites had been applied. On dpi 127 the surviving foxes were treated systemically with ivermectin, and within 4 weeks the skin lesions had healed except on the pinnae of one animal.Antibodies to S. scabiei var. vulpes were demonstrated in the infected foxes by an ELISA with which seroconversion was seen around 4 weeks post infection (wpi). Western blot analysis of sequential sera of the infected animals demonstrated antibody activity consistently after the 2nd wpi.The fourth, non-infected, fox did not show any skin lesions throughout the experimental period nor any specific antibodies to S. scabiei var. vulpes. kw|Keywords|k]sarcoptic mange; k]red fox; k]serodiagnosis; k]ELISA