Field efficacy of moxidectin in dogs and rabbits naturally infested with Sarcoptes spp., Demodex spp. and Psoroptes spp. mites

The efficacy of moxidectin 1% injectable for cattle was evaluated in dogs and rabbits with naturally acquired sarcoptic, demodectic or psoroptic mites. Twenty-two dogs with generalised demodicosis were orally treated with 0.4mg/kg moxidectin daily. Forty-one dogs suffering from sarcoptic mange were treated with 0.2-0.25mg/kg moxidectin either orally or subcutaneously every week for three to six times. Seven rabbits were treated orally with 0.2mg/kg moxidectin twice 10 days apart. Of the 22 dogs with demodicosis, 14% were stopped treatment because of side effects, 14% were lost and of the remaining 72% all were cured (mean therapy duration 2.4 months). Thirty-seven of the sarcoptic mange-infected dogs finished treatment and were cured. In 17% of dogs, side effects were noted. All seven rabbits treated for psoroptic mange were cured and did not show any side effect. Our results indicate that moxidectin is effective and a good alternative for the treatment of demodicosis and scabies in dogs and psoroptic mange in rabbits. Side effects seem to occur more frequently if applied subcutaneously, therefore the oral route should be preferred.     

A review of the use of a controlled-release formulation of ivermectin in the treatment and prophylaxis of Psoroptes ovis infestations in sheep.

The options for the treatment and control of sheep scab (psoroptic mange) have been increased in recent years through the introduction of the endectocides ivermectin, doramectin and moxidectin. Whilst therapeutic efficacy is good, the current injectable formulations offer limited protection against re-infestation with Psoroptes ovis. An intraruminal controlled-release formulation of ivermectin has been developed to provide therapeutic and prophylactic activity against a range of sensitive endo- and ecto-parasites of sheep for 100 days after administration. These ivermectin boluses are designed to release ivermectin at 20-40 microg/kg/day over 100 days and were developed for use in sheep of 20-90 kg bodyweight. Several controlled therapeutic and prophylactic trials against sheep scab have been conducted under a variety of protocols with such boluses in Europe and South America. The results of these studies indicate that the bolus provides 100% therapeutic efficacy against established P. ovis infestations and equivalent prophylactic efficacy against challenge infestations administered during the active life of the bolus.     

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.     

Control of cattle mange in southern africa using ivermectin

Seven trials including 768 cattle were conducted in South Africa and Namibia to evaluate the efficacy of the systemic parasiticide ivermectin when administered subcutaneously at a dose rate of 200 micrograms/kg against sarcoptic (Sarcoptes scabiei var. bovis), chorioptic (Chorioptes bovis) and psoroptic (Psoroptes ovis var. bovis) mange mites. The efficacy of a single treatment against Psoroptes and Sarcoptes was greater than against Chorioptes. There was marked clinical cure in all treated cases with loss of crusts and hair regrowth. The number of cases of psoroptic mange in two large herds, of which 42.4% of 724 animals were clinically affected prior to mass treatment, was reduced by 99.3% following a single subcutaneous treatment with ivermectin; a single animal from which mites were recovered may not have been treated. The apparent prevalence and prospects for control and eradication of cattle mange in South Africa and Namibia are discussed.     

Use of doramectin for treatment of sarcoptic mange in five Angora rabbits

The efficacy of administering doramectin after moxidectin treatment, which has previously proved only partially effective, was evaluated in five Angora rabbits naturally infested with Sarcoptes scabiei mange. Evaluations included physical examination for clinical signs of sarcoptic mange and collection of skin scrapings for determination of mites. The rabbits first received two subcutaneous injections, 10 days apart, of moxidectin 1% injectable solution at a dosage of 0.2 mg kg(-1) of bodyweight. Although moxidectin treatment resulted in clinical improvement within 10 days post initial injection, on days 10 and 35 post initial treatment live mites were present in skin scrapings. Administration of doramectin 1% injectable solution using the same route and dosage and at similar intervals to moxidectin led to complete disappearance of signs of scabies and parasitological cure in all rabbits.     

Persistent efficacy of doramectin and ivermectin against experimental infestations of Sarcoptes scabiei var. suis in swine

Two studies were performed to compare the persistent efficacy of doramectin and ivermectin in swine experimentally infested with Sarcoptes scabiei var. suis. In the Study 1, 84 pigs were treated with doramectin, ivermectin, or saline solution on Day 0. Pigs were then challenged with mites on Days 0, 7, 14, 21, 28, 35, or 42. Weekly evaluations were performed for 5 weeks following challenge with mites. Weekly evaluations included physical examination for clinical signs of sarcoptic mange and collection of skin scrapings for determination of mite counts. In the Study 2, 80 pigs were treated with doramectin, ivermectin, or saline solution on Day 0, and challenged with mites on Days 3, 6, 9, 12, 15, 18, 21, 24, or 27. Weekly evaluations were performed for 6 weeks after challenge exposure. All negative-control (saline-treated) animals in both studies developed evidence of mite infestation. In the Study 1, doramectin prevented mite infestations 7 days longer than ivermectin. Results from the Study 2 indicated that the persistent efficacy of doramectin was 18 days on the basis of mite recovery. This was twice as long as the persistent efficacy of ivermectin, which was 9 days on the basis of mite recovery.     

Huizache (<Emphasis Type="Italic">Acacia farnesiana</Emphasis>) whole pods (flesh and seeds) as an alternative feed for sheep in Mexico

Two experiments were undertaken to evaluate the use of pods from Huizache (Acacia farnesiana), common in the arid and semiarid regions of Mexico, on the perfromance and apparent digestibility in Pelibuey Mexican hair growing ewe lambs. Twenty-four Pelibuey ewe lambs were used in the animal performance experiment, with a mean live weight of 14.91 ± 1.48 kg, randomnly allocated to three groups which received ad libitum for 77 days (11 weeks) experimental whole rations T0 with 0%, T12 with 12% or T24 with 24% inclusión of dried and ground Huizache pods. Dry matter intakes (g/kg ^0.75 daily) were 83, 95, 90 for T0, T12, and T24 respectively (P > 0.05). Mean daily live-weight gain was 90, 75, and 63 g/day for T0, T12, and T24 (P < 0.001). Nine Pelibuey ewe lambs were used to determine apparent digestibility in vivo of the experimental diets using a 3 × 3 latin square design repeated three times. There were differences in the digestibility of dry matter (P < 0.001), organic matter (P < 0.001), nitrogen (P < 0.031), neutral detergent fibre (P < 0.002), and acid detergent fibre (P < 0.001) being lower in T24. Huizache pods may be an alternative feed when included up to 12% of dry matter in the diets for sheep growing moderately.     

Risk factors of infestation by Psoroptes spp. mites in buffalo (Bubalus bubalis) at smallholder farms in the Nile Delta region, Egypt

The aim of the present study was to explore the prevalence and potential risk factors associated with infestation by Psoroptes spp. mites in buffalo at smallholder farms in the Nile Delta region, Egypt. A total of 318 out of 1234 buffalo in 77 small scale herds were examined. The age of buffalo varied from three months to seven years. In all, 53 (16.66%) buffalo were recorded to be infested; 51 (16.35%) with Psoroptes spp. mites and two cases (0.31%) with Chorioptes spp. mites. Multivariate logistic regression was performed for significant risk factors at univariate analysis on both animal and herd level. The results of multivariate analysis showed that, on the animal level, the prevalence was affected by animal age (P?<?0.01; OR: 0.71; CI 95%: 0.441–1.11), season (P?<?0.01; OR: 1.20; CI 95%:0.541–1.15), indoor management (P?<?0.001; OR: 6.625; CI 95%:2.489 –17.631) and rearing with other animals (P?<?0.01; OR: 2.22; CI 95%:1.340 –7.132). However, on the herd level, the prevalence was affected by indoor rearing (P?<?0.05; OR: 22.4; CI 95%:2.75–16.431), mixed rearing with other animal species (P?<?0.05; OR: 4.5; CI 95%:1.66–7.941), and season (P?<?0.01; OR: 2.3; CI 95%:0.575–2.426). Clinically, mild skin lesions with mild pruritis were significantly prevalent in buffalo with the infestation by Psoroptes spp. mites (P?<?0.001), where 33/51 cases showed mild lesions. Also, psoroptic mites had significant association with inappitence (P?<?0.001). The result of the present study indicates that Psoroptes spp. mites are the most prevalent in buffalo in the Nile Delta Region, Egypt. Moreover, recognition of risk factors associated with mange mites in buffalo may enable the practitioner to establish the most appropriate control measures.     

Changes in colostrum of Murrah buffaloes after calving

Colostrum samples were collected from 8 Murrah buffaloes on days 1, 2, 3, 4 and 5 after calving. Levels of IgG averaged 54.0 mg/ml at calving, then decreased significantly (P < 0.01). IgA and IgM on day 1 were 3.22 mg/ml and 5.22 mg/ml, respectively; both decreased during the first five days after calving. Values of IgA and IgM were higher than those reported in cows. SCC values, which were high at calving (500 000 per ml), reduced significantly (P < 0.01) on day 2, then decreased slightly until day 5 (180 000 per ml). At calving, macrophages were the most prominent cells in buffalo colostrum, followed by lymphocytes and neutrophils. Phagocytic activity was 23% at calving and reduced significantly (P < 0.01) to 14% on day 5. Phagocytic index was highest in the first colostrum, and then decreased non-significantly.     

Acaricide treatment prevents adrenocortical hyperplasia as a long-term stress reaction to psoroptic mange in cattle

In cattle, infestation with Psoroptes ovis mites may cause severe dermatitis (psoroptic mange) which compromises the health and welfare of the animals and may lead to significant economic losses. To investigate yet undocumented effects of psoroptic mange mite infestations and how successful therapy promotes animal health, the present study examined alterations of the skin, lymph nodes and adrenal glands of P. ovis infested Fleckvieh (Simmental) bulls treated with either ivermectin long-acting injection (IVM LAI; IVOMEC^® GOLD, Merial; 3.15% ivermectin w/v) or saline (n = 16 each). Approximately 8 weeks subsequent to experimental infestation with P. ovis, the bulls had developed mange and were administered either IVM LAI or saline once at 1 mL/50 kg body weight by subcutaneous injection. Mite counts were conducted in weekly intervals for determination of efficacy of treatment, and following humane euthanasia of the animals 8 weeks after treatment, skin samples from affected (mangy or previously mangy) and unaffected areas, prescapular lymph nodes and adrenal glands were collected for gross and pathohistological examination. In addition, four age-matching, uninfested Simmental bulls were sampled as controls for comparison.No P. ovis mites were detected on any IVM LAI-treated bull after 28 days following treatment whereas saline-treated bulls maintained infestation throughout the study. At sampling (approximately 16 weeks after experimental infestation and 8 weeks following saline or IVM LAI treatment), saline-treated bulls displayed a severe, exsudative dermatitis with significantly increased skin thickness and inflammatory cell infiltration, significantly enlarged, hyperplastic prescapular lymph nodes, as well as significantly increased adrenal gland weights and volumes as compared to P. ovis-infested, IVM LAI-treated bulls and uninfested controls. Quantitative stereological analysis revealed that the adrenal gland enlargement in P. ovis-infested, saline-treated bulls was due to a selective increase of the volume of the zona fasciculata in the adrenal cortex. Compared to uninfested controls and P. ovis-infested, IVM LAI-treated bulls, the number of epithelial cells in the zona fasciculata was significantly increased in P. ovis-infested, saline-treated bulls, while the zona fasciculata cell volumes did not differ between the three groups of cattle. While the single point determination of serum cortisol concentrations did not reveal significant differences between the three groups of cattle at tissue sampling, the hyperplastic growth of the adrenal cortex in the P. ovis-infested, saline-treated bulls provides morphologic evidence that a chronic stress reaction is one consequence of mange mite infestations that can be prevented by efficacious acaricidal treatment.     

Efficacy of a long-acting formulation of ivermectin against Psoroptes ovis (Hering, 1838) on cattle

A study was conducted in cattle experimentally infested with Psoroptes ovis to compare the prophylactic control against P. ovis provided by a long-acting injectable formulation of ivermectin to that of a commercially available injectable formulation of doramectin. Thirty Holstein steers were used. Animals were allocated by restricted randomization based on Day 0 body weight, forming six replicates of five animals each. Within each replicate, one animal was randomly allocated to one of the following treatment groups, with ivermectin and doramectin administered subcutaneously where indicated: (1) untreated controls; (2) ivermectin long-acting injectable (LAI) 630 mcg/kg, 56 days before challenge; (3) ivermectin LAI 630 mcg/kg, 42 days before challenge; (4) ivermectin LAI 630 mcg/kg, 35 days before challenge; or (5) doramectin 200 mcg/kg, 35 days before challenge. Animals were housed in individual pens 1 week prior to treatment. All animals were experimentally infested with P. ovis mites in the area between the shoulders, on the same day. Live mites were counted in scrapings from mange lesions at 2 sites on each animal 14, 21 and 28 days after challenge. Live mites were found in 33, 67 and 83% of the untreated controls on each respective evaluation. No P. ovis mites were found in steers treated with ivermectin LAI. Those animals showed lower (P < 0.05) mite counts than untreated controls on evaluations conducted 21 and 28 days after challenge. These results indicate that the ivermectin long-acting injectable formulation prevents induced infestations by P. ovis for at least 56 days after treatment. Doramectin injectable formulation, used at 200 mcg/kg, did not have a prophylactic effect 35 days after treatment.     

A Case of Atypical Psoroptic Mange in a Domestic Rabbit

A female checkered giant cross rabbit (Oryctolagus cuniculus) was presented with skin lesions on the perineal region. The cutaneous lesions extended 2 cm from the vulva and perineal glands. They were moist and erythematous, with abundant greasy yellowish scabs. Skin scrapings from the lesions were mounted in Amman’s chloral-lactophenol on microscope slides and examined at ×10 and ×40 magnification. Numerous mites were observed and identified as Psoroptes cuniculi, a common causal agent of otitis externa in rabbits. The rabbit was treated successfully with ivermectin. This case of psoroptic mange is atypical owing to the perineal location, apparent absence of auricular lesions, and the lack of contagion despite close contact with several other rabbits.     

Efficacy of moxidectin against sarcoptic mange and effects on milk yield of ewes and growth of lambs

Forty-eight dairy ewes and 45 lambs naturally infested with sarcoptic mange, were divided into three equal groups and treated with moxidectin 1% inj. sol. at a dose rate of 0.2 mg moxidectin kg(-1) bodyweight once or twice ten days apart. During the study, the skin lesions were scored and the number of mites recovered in facial skin scrapings from the animals were recorded. Moxidectin was found to be effective against ovine sarcoptic mange, when given twice; the percentage reduction of mites was 100% (p < 0.0001) and the skin lesions disappeared completely (p = 0.0001). In sheep treated once only, the percentage reduction of mites varied from 75% to 92%. Treated ewes produced up to 22.4% more milk than the infested ones (p = 0.0001). Treated lambs had up to 15% greater final weight and up to 23.7% more growth than infested controls (p = 0.0001). It is concluded that two injections of moxidectin 1% inj. sol. at a dose rate of 0.2 mg kg(-1) bodyweight, given ten days apart, were effective against ovine sarcoptic mange. Furthermore, it is considered that sarcoptic mange adversely affects the production of the infested animals.     

Comparative evaluation of two ivermectin injectable formulations against psoroptic mange in feedlot cattle

A study was carried out to compare the efficacy of two injectable formulations of ivermectin, Ivomec,(1) Merial (IVM reference) and Ivogell,(2) Intervet (IVM generic) in the treatment of psoroptic mange (Psoroptes ovis) in Charollais feedlot cattle. A total of 22 animals were ranked in order of the severity of mange and allocated to 11 replicates of 2 animals each. Within each replicate, one animal was randomly allocated to IVM reference product treatment (Group 1) and one to IVM generic (Group 2). Animals were treated on Day 0 and on Day 8 at the recommended dosage of 200 microg ivermectin/kg bodyweight. The pharmacokinetics profiles (pK) of both IVM formulations were evaluated in plasma samples taken from 6 cattle randomly chosen per group on Day 0, before treatment, and then at 6, 12, 24 hours and daily from Day 2 to Day 7 after the treatment on Day 0. Additionally, the severity of mange lesions was assessed and mites were counted in skin scrapings on Days 0, 8, 15 and 25. Animals were weighed on Day 0 and 25 and body weight and average daily gains (ADG) were evaluated. No statistical differences were found between the cattle of the two groups in any pK parameters, although the mean IVM plasma concentrations in cattle treated with the IVM reference product were consistently higher than those found in cattle treated with the generic compound. By Day 25, all animals in Group 1 had recovered clinically and parasitologically from psoroptic mange while cattle from Group 2 still had mange lesions and, in two animals, living mites were found in the skin scrapings; these differences were significant (P<0.001). The mean body weight of the two groups was significantly different on Day 25 (P<0.01) when animals in Group 1 weighed 20 kg more than those in Group 2. In conclusion, despite similarities in their pharmacokinetic profiles and formulations, the clinical efficacy of the two injectable formulations of IVM differed significantly in their therapeutic efficacy against psoroptic mange in feedlot cattle up to 25 days after treatment: this difference in response was reflected in an incomplete clinical and parasitological response in Group 2 and a slower growth rate.     

Feed intake,digestibility and body weight change in Farta sheep fed hay supplemented with rice bran and/or noug seed (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>) meal

The study was conducted to determine the effect of supplementation with rice bran (RB) and /or noug seed (Guizotia abyssinica) meal (NSM) on feed intake, digestibility, and body weight (BW) change in hay based feeding of Farta sheep. Twenty five yearling Farta rams with a mean initial BW of 19.23 ± 0.28 kg were used in randomized complete block design arranged into five blocks of five animals. The five dietary treatments that consisted of hay alone (T₁), hay + RB (T₂), hay + mixture of RB and NSM at a ratio of 1:2 (T₃), hay + mixture of RB and NSM at a ratio of 2:1 (T₄) and hay + NSM (T₅) were randomly assigned to each sheep within a block. The supplements were daily offered at 300 g dry matter (DM) head⁻¹ in two equal parts at 800 and 1600 h. Supplementation improved the total DM and acid detergent fiber (ADF) intake (P < 0.05), organic matter (OM) intake (P < 0.01), crude protein (CP) intake (P < 0.001). The apparent digestibility of DM in T₅ was higher (P < 0.05) than in T₁ and T₂ and that of T₄ was also higher (P < 0.05) than in T₁. The apparent digestibility of CP in T₅ and T₄ were higher (P < 0.001) than in T₁ and T₂ and that of T₃ and T₂ were also higher (P < 0.001) than for T₁. The BW gain of experimental sheep was improved (P < 0.01) by supplementation with NSC (T₅) and/or its mixtures with RB (T₃ and T₄). The results of the study showed that supplementation with either of both mixtures of NSM and RB at 43% of total DM intake promoted better feed intake, digestibility and BW gain in Farta sheep.     

Effect of ruminally protected Methionine on the productive and reproductive performance of grazing <Emphasis Type="Italic">Bos indicus</Emphasis> heifers raised in the humid tropics of Costa Rica

With the objective of evaluating the effect of methionine supplementation prior to a breeding program, thirty one heifers (Bos taurus x Bos indicus) were used averaging 386  ±  29 days of age and a mean body weight of 402.6  ±  28 kg. Fifteen of the animals received a supplement (SG) during 45 days with molasses-urea mixture (2 kg molasses + 407 g urea/head/day), plus 10 g of ruminally protected methionine. The other sixteen heifers did not receive supplement (CG). Fecal and pastures samples were collected to assess dry herbage intake and digestibility. Serial ultrasound measurements from the ovary were performed in both groups to evaluate follicular dynamics. The heifers were categorized according to their follicular size and presence of a CL. Forage intake and dry matter digestibility were reduced (P  <  0.05) and body condition tended to improve (P  =  0.07) in the supplemented heifers, however, total intake, final weight, daily gain and dorsal back fat were not affected. After the supplementation period, the percentage of females in the categories < 3 mm and 3 to < 6 mm, was greater (P  <  0.05) in CG (25% and 43.7%) that in SG (0% and 26.6%) but in the follicle category of ≥  9 mm, the percentage of animals was 60% in SG and 18.8% in CG (P  <  0.05). The percentage of ovulation for the SG and CG was 86.7% and 62.5%, respectively (P  <  0.05). The combination of supplementation with methionine-urea and molasses at the end of the dry season and the anticipated onset of the rainy season favored the establishment of ovarian activity and follicular dynamics.     

A case of very serious Sarcoptes mange in alpacas (Lama pacos)

After the diagnosis sarcoptic mange in four alpaca's (Lama pacos) we have tried to control this infection. Despite three treatments with doramectin, three with ivermectin, four with amitraz and two with diazinon we were unable to get the animals free of Sarcoptes mites and their condition deteriorated. One animal died six month after the first treatment. The three remaining animals were euthanized one month thereafter.     

The effects of replacing <Emphasis Type="Italic">Dichantium</Emphasis> hay with banana (<Emphasis Type="Italic">Musa paradisiaca)</Emphasis> leaves and pseudo-stem on carcass traits of Ovin Martinik sheep

A study was done to evaluate banana (Musa paradisiaca) as a forage (leaves and pseudo-stems) for feeding Ovin Martinik lambs (OMK), with the aim to test its impact on carcass quality. Forty four intact OMK male were used after weaning with an initial mean live weight of 14.4 (± 3.3) kg, reared in individual pens. Animals were offered either Dichantium hay (control diet, Dh) or cut chopped leaves and pseudo-stems of banana (experimental diet, Blps). They were fed 200—250 g.d⁻¹ of commercial concentrate. Lambs were slaughtered according to 3 classes of slaughter weight (SW): SW20, SW23 and SW26. Growth and carcass performances of both groups were not significantly different, 77 vs. 81 g.d⁻¹ and 42% vs. 43% hot carcass yield, for Dh vs. Blps, respectively. There was a significant (P < 0.05) decrease (31.0 vs. 29.7%) for the dry matter content of the shoulder for lambs fed the banana diet. However, there was no effect observed for the other chemical component (CP, lipid and mineral 585, 317 and 95 g.kg⁻¹DM, respectively). The shoulder (20% of the carcass whatever the SW) was precocious as demonstrated by the allometry coefficient relative to carcass weight (0.894) significantly (P < 0.01) less than 1. It was concluded that, the use of Blps had no significant effect on growth, carcass weights and yields of the OMK lambs, irrespective of the class of the slaughter weight. From these initial results, the use of banana foliages and pseudo-stems could be recommended as sources of forages.     

Treatment of psoroptic mange with reference to epidemiology and history.

Treatment methods in the last century involved the use of substances such as sulphur, mercury, hellebore, arsenic, nicotine and others, applied in various ways. The advent of dips in 1843 signalled an advance. However, the biology of the mite, Psoroptes ovis, the epidemiology of sheep scab and the lack of persistence of the acaricides necessitated repeated laborious treatments to ensure success. In 1947 this changed with the use of organo chlorines (OCs) which had up to 3 months residual activity. The use of OCs led to the eradication of psoroptic mange of sheep in USA. Organo phosphates (OPs) were introduced in the late fifties and synthetic pyrethroids (SPs) in the early seventies. In 1985, due to sheep tissue residues, lindane (OC) was withdrawn from the market and this greatly reduced the capacity for effective sheep scab control. Before the arrival of the endectocidal avermectin, ivermectin in 1978 and its successful use as an acaricide in 1992, control of psoroptic mange was limited to plunge dipping. In 1994 moxidectin, a milbemycin, was found to be effective and to have the added benefit of at least 4 weeks persistent activity. Another avermectin doramectin was shown, in 1995, to successfully treat scab and recently an ivermectin bolus has been introduced which has a 100 days' activity and is fully therapeutic and prophylactic. Strict attention to detail in the use of injectable products is essential in order to achieve satisfactory results. Work is progressing on the use insect growth regulators (IGRs) and also on naturally occurring substances such as linalool, neem and lavender oil. At the CVRL Dublin, promising results have been achieved with neem and some IGRs. Other areas of interest are allemones, synergists, microclimate manipulation, sheep breed resistance and vaccines. Successful control depends on epidemiological knowledge, accurate diagnostic techniques, intimate knowledge of the mite's life cycle, its behaviour on and off the host, its macro and molecular biology, the nature of the pathogenesis of the disease, sheep husbandry practices, nutritional and environmental factors; also farmer awareness and attitudes. The variable responses of sheep to the mite, the unpredictable incubation period, course, manifestations and outcome make this an intriguing and perplexing disease. Ways to overcome these problems and to achieve possible eradication are discussed.     

Efficacy of ivermectin against mange and gastrointestinal nematodes of buffalo (Bubalus bubalis)

The incidence of mange in dairy buffalo in India has increased significantly in recent years. The authors record an outbreak of mange affecting a dairy herd stocking about 30,000 buffalo and 1000 cows. The mange mites were either Sarcoptes scabiei or Psoroptes ovis, or a mixed infestation of both. The morbidity rate was 5-30% varying from group to group, with 100% in a severely affected group. Signs noticed were progressive dermatitis, alopecia, keratinization, skin thickened and wrinkled, intense itching and marked loss of condition often ending in death. Great losses of young animals from mange and gastrointestinal nematodes are very common in dairy herds in India. In view of their economic importance, the activity of ivermectin against naturally occurring mange and parasitic infections of adult buffalo and buffalo calves was determined. Ivermectin was administered by subcutaneous injection (IVOMEC 1% w/v - MSD AGVET) at a dose of 200 mcg kg-1 body weight. The efficacy was ascertained from the disappearance of mites from skin scrapings and the reduction in numbers of worm eggs in the faeces. The results of the treatment were dramatic: the mites disappeared within 2 weeks of the drug being administered in the majority of animals, with marked improvement in skin lesions. Four buffalo which had their entire body surface affected with mange needed a second dose on Day 28 for complete recovery. The effect on the nematodes was equally spectacular, with infections of Neoascaris vitulorum, Trichostrongylidae, Oesophagostomum spp. and Bunostomum being eliminated within 1 week of treatment.