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At least 73 records · Page 4Linked to original sources
PubMed1992

Exposure to Psoroptes sp. mites is common among bighorn sheep (Ovis canadensis) populations in California.

Sera (n = 806) from 50 populations of bighorn sheep (Ovis canadensis) in California (USA) were evaluated for antibodies to Psoroptes sp. mites using a kinetic enzyme-linked immunosorbent assay (ELISA). Test values for each sample were determined to be either positive or negative at each of two ELISA cutoff values that provided either 100% sensitivity (low cutoff) or 100% specificity (high cutoff), respectively. One hundred sixty-eight (20.8%) sera were seropositive at the low cutoff value, and 87 (10.8%) of these sera also were seropositive at the high cutoff value. Eleven populations were designated as scabies-suspect and 25 populations were designated as scabies-positive because they had at least one seropositive animal at the low and the high cutoff values, respectively. Based on these results, exposure to Psoroptes sp. mites appeared to be widely distributed among bighorn sheep populations from 1980 to 1990 and infested animals may have been present prior to 1980.

Animals↗
PubMed1993

Efficacy of in-feed formulation ivermectin against Psoroptes sp. in bighorn sheep.

Four Rocky Mountain bighorn sheep (Ovis canadensis canadensis) were experimentally inoculated with Psoroptes sp. of bighorn sheep origin by placing approximately 50 mites into each ear. Two sheep developed reproducing mite colonies and lesions consisting of alopecia, and exudative dermatitis with scabs on ears, face and neck. Three months after inoculation, all four sheep were treated with an in-feed formulation of ivermectin at a dosage of 1 mg/kg of body weight in a pelleted ration daily for seven consecutive days. Mites could not be detected on any of the sheep 1, 2, or 3 mo after treatment, and lesions on the affected sheep resolved within 6 to 8 wk after treatment. Thus, under these conditions, ivermectin was completely effective in eliminating the mites; it also was palatable and nontoxic. Use of ivermectin in pelleted feed for field treatment of psoroptic mange is encouraged.

Administration, Oral↗
PubMed1996

Seroprevalence of Psoroptes sp. mites in free-ranging elk (Cervus elaphus) as determined by kinetic ELISA.

Western blots and a kinetic enzyme-linked immunosorbent assay (ELISA) were used to characterize and quantify the prevalence of antibodies to Psoroptes sp. mites in elk (Cervus elaphus) from nine herds in North America. Sera from infested (n = 18) and non-infested (n = 22) elk were used to optimize test methodology and to define cut-off values for negative, suspect, and positive samples. Among 357 samples, 35 (9.8%) of the animals were seropositive, 259 (73%) were negative, and 63 (18%) were suspect. Six of nine herds (67%) contained positive animals and two additional herds (22%) had suspect animals. Sex was not associated with prevalence of antibodies, but adults greater than 2 yr old were approximately five times more likely (95% confidence interval = 2.6-15.4) to be seropositive than calves. Based on these results, we propose that exposure to Psoroptes sp. mites may be widespread in free-ranging elk of North America.

Animals↗
PubMed1992

Psoroptes sp. in two llamas (Lama glama) in Washington.

Psoroptes sp. mites were isolated from two llamas (Lama glama), a 4-mo-old male and its dam, in Washington. Mites were restricted to the ears and were responsible for head-shaking and incoordination. Infestations were treated successfully with a subcutaneous injection of ivermectin at 0.2 mg/kg of body weight and with 2 drops of ivermectin diluted in saline given topically in each ear. This is the first known report of Psoroptes sp. in llamas in the United States.

Animals↗
PubMed1991

Antigenic characterization of Psoroptes spp. (Acari: Psoroptidae) mites from different hosts.

Immunoblotting with defined antigens and antisera revealed extensive and nearly complete antigenic cross-reactivity between Psoroptes spp. mites from a bighorn sheep, a mule deer, a cow, and a rabbit. Antigenic differences were not detected between mites from the sympatric bighorn sheep and mule deer. However, minor antigenic differences between mites from the cow and rabbit suggested that these mites were distinct from each other, as well as from the mites from the bighorn sheep and mule deer. These results are consistent with earlier morphologic studies of these populations of mites and provide additional support for the hypothesis that putative populations and/or species of Psoroptes mites may not be reproductively or ecologically isolated, particularly when their hosts are sympatric.

Animals↗
PubMed1989

Pathogenesis of psoroptic scabies in Hereford heifer calves.

Hereford heifer calves were experimentally infested with Psoroptes ovis. Histologic examination of skin specimens was conducted at weekly intervals before and after treatment with ivermectin on postinfestation week 7. Electron microscopy revealed numerous degranulating mast cells in the skin of infested but not in control calves. many active, as well as degenerate, neutrophils were in the scab on infested calves. Microscopic epidermal ulcers developed on infested calves when live mites were present but not after treatment. Numbers of dermal neutrophils and plasma cells decreased and numbers of circulating neutrophils increased 1 week after treatment. Numbers of dermal eosinophils and mast cells in calves with eosinophilia increased for several weeks after treatment. Statistical analysis indicated significant correlations (P less than 0.05) among numbers of dermal inflammatory cells, hemogram values, and changes in dermal thickness. Seemingly, mite-induced epidermal damage was the key pathogenic event in psoroptic scabies in calves. Mast cell degranulation contributed to the pathogenesis of the dermatitis, and neutropenia was caused by sustained, poorly compensated efflux of neutrophils into the scab through mite-induced breaks in the epidermis.

Animals↗
PubMed1988

Haematological and immunological response of unrestrained cattle to Psoroptes ovis, the sheep scab mite.

Cows were infected twice with 600 and 500 nymphs and adults of a bovine strain of Psoroptes ovis with a nine-week interval. The haematological response and the non-specific mitogen- and antigen-induced responsiveness of the peripheral blood lymphocytes of the animals was followed. Dermal reactivity to P ovis antigen injection was studied five weeks after reinfection. After the first infection with 600 mites none of the infected animals developed clinical psoroptic mange but a leucocytosis developed, contributed to primarily by an eosinophilia and by a slight lymphocytosis. Antigen-induced lymphocyte blastogenesis was used to measure the antigen-sensitive cell population in peripheral blood and this population showed a maximum increase 10 days after infection; however, antigen-sensitive cells remained above normal levels until reinfection. Upon challenge infection with 500 mites the infected animals showed an immediate hypersensitivity type reaction with a marked pruritus, scratching and exudation. Thereafter the lesions healed rapidly and none of the animals developed clinical mange. This clinical reaction was accompanied by a secondary eosinophilia but no change was apparent in the other blood elements. A marked increase in the blastogenic response of the peripheral blood lymphocytes was also apparent and this peaked three weeks after challenge. Following the intradermal injection of P ovis antigen there was an immediate swelling of the injection site in all infected and control animals and skin thickness was maximal one hour after injection. Thereafter there was a clear distinction in dermal reactions between P ovis infected and control animals; after 48 hours reactions were not seen in the control animals while marked dermal reactions were still present in the P ovis infected group.

Animals↗
PubMed1987

Infestivity of Psoroptes ovis on ivermectin-treated cattle.

Psoroptes ovis was not transmitted by natural contact to susceptible cattle which were exposed to infested, ivermectin-treated cattle 6, 12, 14, 16, and 18 days after treatment was given. However, clinical scabies did develop in 2 calves naturally exposed to P ovis-infested, ivermectin-treated calves at 10 days after treatment was given subcutaneously (200 micrograms/kg). Psoroptes ovis was transmitted to stanchioned cattle manually exposed to 200 to 300 ml of hair and skin scrapings from infested, ivermectin-treated cattle at 6, 10, 12, 14, and 16 days after treatment was given subcutaneously (200 micrograms/kg). Scabies did not develop in cattle exposed to skin scrapings obtained from infested, treated cattle at 18 and 20 days after they were treated with ivermectin. The 14-day isolation of P ovis-infested, ivermectin-treated cattle from susceptible cattle recommended by the US Department of Agriculture, although marginal, is adequate under natural conditions to prevent transmission of scabies from treated to noninfested cattle.

Animals↗
PubMed1995

[Psoroptic scab control in sheep herds--experiences in use of medications].

Due to an uncontrolled trade in sheep, the importance of sheep scab has increased recently. Alone in Thuringia six outbreaks occurred in 1993. Now psoroptic mange is endemic in Germany. Mutual infections between sheep and cattle seem to be extremely rare in the field. Outbreaks of sheep scab entails heavy economic losses. Therefore, control has to be successful and to aim at eradication. The survivability of the psoroptic mites aside from the host until 48 days has to be considered. Eradication can be achieved, as proved by own field trials for a period of 10 months only either by two repeated dipping using Phoxim or HCH drugs or by subcutaneous Ivermectin injections (0.2 mg/kg bodyweight) seven days apart. The success of treatment has to be checked carefully.

Animal Husbandry↗
PubMed1997

[Allergenicity and specific protein profiles of mange mites Chorioptes bovis, Psoroptes ovis (Acari: Psoroptidae), Saroptes suis and Notoedres cati (Acari: Sarcoptidae) using SDS-PAGE and immunoblotting].

A main point of immunoparasitological research in regard to pest arthropod-infestation is biochemical and immunological characterization of antigens. Precondition of own examinations to the specific protein pattern of mange mites were in quality and amount sufficient antigen preparations in mite extract solutions. For mite separation and antigen refinement field strains of Chorioptes bovis, Psoroptes ovis, Sarcoptes suis and Notoedres cati from definitive host animals cattle, sheep, pig and cat have been used. Parasites were isolated in a migration procedure. After having applicated subepidermally a low dose of mite extract solutions in sensitized animals allergic skin changes (Immediate reaction type 1) became apparent. SDS-PAGE exhibited specific protein patterns of 4 pathogen mite species. For Chorioptes bovis 16, Psoroptes ovis 15, Sarcoptes suis 27, and Notoedres cati 36 fractions have been detected. Proteins are antigens or allergen structures to be found in saliva, faecal output or moulting products of developmental stages and other metabolites of the parasites. Protein components were transferred onto nitrocellulosis. Immunoblotting made fractions with antigen activity visible.

Allergens↗
PubMed1998

Humoral and cell-mediated immune responses of beef and dairy cattle experimentally infested with Psoroptes ovis.

OBJECTIVE: To compare cellular and humoral immune responses of beef (Belgian White and Blue [BWB]) and dairy (Friesian-Holstein [FH]) cattle to Psoroptes ovis infestation and to determine whether P ovis infestation impaired immune responses to infectious bovine rhinotracheitis virus (IBR) vaccine or an immunogenic protein (keyhole-limpet hemocyanin [KLH]). ANIMALS: 19 BWB and 6 FH 1-year-old calves. PROCEDURE: 2 trials were performed. In each trial, 7 (trial 1) or 6 (trial 2) BWB calves and 3 FH calves were experimentally infested with P ovis and 3 BWB calves were maintained as uninfested controls. Animals were inoculated with KLH and IBR virus vaccine twice; 3 BWB calves in each trial were treated with ivermectin. Serum antibody responses to KLH, IBR virus, and P ovis were measured by use of ELISA. A lymphocyte transformation assay was used to determine nonspecific responses to 3 mitogens and specific lymphocyte reactivity to P ovis antigen. RESULTS: In each trial, 3 BWB and 3 FH calves developed clinical signs of psoroptic mange and mites could be recovered. Infested and control animals developed similar antibody titers to KLH and IBR virus. Antibodies to P ovis were detected early in some infested calves, and this was correlated with a marked cell-mediated immune response. Lymphocyte responsiveness to the 3 mitogens was not significantly different among groups. CONCLUSIONS: In these calves, infestation with P ovis induced a marked humoral and cell-mediated immune response. Immunosuppression was not evident.

Animals↗
PubMed2026

An improved chromosome-level genome resource for the sheep scab mite, Psoroptes ovis.

Sheep scab, caused by infestation with the ectoparasitic mite, Psoroptes ovis, represents a major welfare and economic challenge for the livestock industry. We present an updated 62.7 Mb genome assembly containing 10 chromosome-level scaffolds with 10,516 annotated protein-coding genes, which provides a useful resource for studies into resistance and control.

Psoroptes ovis↗
PubMed1986

Development and decline of serum antibody activity to Psoroptes ovis antigens in infested cattle in an endemic and nonendemic scabies area of Texas.

The serum antibody activity to Psoroptes ovis antigens, as determined by enzyme-linked immunosorbent assay (ELISA), was monitored during the development and decline phase of scabies in cattle herds under feedlot conditions in an endemic (Bushland) and a nonendemic (Kerrville) scabies area of Texas. The infestations were initiated by exposing six calves in each of the herds to P. ovis and allowing the infestations to spread to other members of the herd. The cattle in the endemic area developed more lesions and a higher incidence of the disease than did the cattle in the nonendemic area; also, there were more cattle with specific serum antibody activity in the Bushland herd than in the Kerrville herd at the peak of the infestations (late January--early February). As infestations declined because of summer latency, the number of calves with specific serum antibody activity declined in both herds. Specific serum antibody activity disappeared in the Kerrville cattle when P. ovis was no longer detected. However, specific serum antibody activity was still detected in some of the Bushland cattle in late summer (August) and fall (October) examinations, when low numbers of P. ovis were detected. These results indicate that the ELISA would be very useful in detection of specific serum antibody activity in lightly infested calves, especially during the developmental and decline phases of the disease.

Animals↗
PubMed1994

Examination of possible transmission of sheep scab mite Psoroptes ovis between host species.

Examination of possible transmission of the Irish strain of the sheep scab mite (Psoroptes ovis) of ovine origin between host species involved calves and goats being placed with infected sheep and also directly challenged with live mites. Although mites remained on recipient species for up to a week, they failed to produce disease in either of these species. Calves and goats that had live mites placed on them likewise failed to infect sheep with which they were housed.

Animals↗
PubMed1995

Haematology and blood biochemistry during the course of psoroptic scabies in sheep.

Haematology and blood biochemistry were monitored during the development and regression of psoroptic scabies in sheep. There were rises in numbers of neutrophils and eosinophils and in the fibrinogen concentrations, with lowered haemoglobin concentrations any lymphocyte numbers. The only biochemical parameters that were affected were the estimated serum globulin concentration, which rose during the disease process, and the serum albumin concentration, which fell. All of these changes reverted to normal soon after treatment.

Animals↗
PubMed1994

Survival and retention of infectivity of the mite Psoroptes ovis off the host.

Psoroptes ovis mites were removed from infected sheep and placed in positions where wool and mites normally accumulate during sheep scab outbreaks. The ambient temperature and humidity were monitored over a 3-week period and the survival and infectivity times were examined. The procedure was carried out during each of the seasons. The hatchability of mite eggs was also examined. It was found that little variation occurred between seasons, with mites regularly retaining viability and infectivity for 15 days during all seasons. Mites that survived for more than 16 days failed to infect sheep. Mite eggs retained hatchability for up to 7 days.

Animals↗
PubMed1980

Psoroptic mange in goats in Fiji.

Mange caused by Psoroptes cuniculi was first recognised in goats in Fiji in 1977. Of 33 widely separated herds examined 16 were infested 4 herds having the "extensive" type lesions in older goats. Treatment of the skin and superficial ear lesions with malathion or gamma-BHC was successful but mites survived in the proximal parts of the ear canal. Re-appearance of the mites following treatment was a common problem.

Animals↗