Mange (Mites: Sarcoptes, Demodex, Psoroptes)
Introduction
Mange is a group of highly contagious or non-contagious parasitic skin diseases caused by different species of mites. It is characterized by pruritus, alopecia, dermatitis, and varying degrees of skin thickening. Mange is economically important in livestock and a major dermatological condition in companion animals.
Etiology
Causative Mites
- Sarcoptes scabiei (sarcoptic mange / scabies)
- Demodex spp. (demodectic mange / follicular mange)
- Psoroptes spp. (psoroptic mange / non-burrowing surface mites)
Mite Characteristics
- Small arthropods living on or in the skin
- Feed on skin debris, sebum, or tissue fluids
- Some species are burrowing (Sarcoptes), others are surface or follicular (Psoroptes, Demodex)
Epidemiology
Species Affected
- Dogs (Sarcoptes, Demodex)
- Cattle (Psoroptes, Sarcoptes)
- Sheep (Psoroptes – sheep scab)
- Goats (Sarcoptes)
- Horses (Chorioptes/Psoroptes-like infestations in some regions)
Transmission
- Sarcoptes: Highly contagious via direct contact and fomites
- Psoroptes: Direct contact and environmental contamination (sheep scab spreads rapidly)
- Demodex: Usually non-contagious; transmission occurs from dam to neonates
Risk Factors
- Overcrowding and poor hygiene
- Stress, malnutrition, and immunosuppression (especially Demodex)
- Youth (juvenile demodicosis)
- Cold seasons in some ectoparasitic outbreaks
Pathogenesis
Sarcoptic Mange
- Mites burrow into superficial skin layers
- Cause intense hypersensitivity reaction
- Severe pruritus leads to self-trauma
Demodectic Mange
- Mites inhabit hair follicles and sebaceous glands
- Overgrowth occurs when immune control fails
- Leads to folliculitis and secondary bacterial infection
Psoroptic Mange
- Mites live on skin surface and feed on exudates
- Cause severe inflammation and exudation
- Thick crust formation and skin irritation
Clinical Signs
General Signs
- Pruritus (variable intensity depending on mite species)
- Alopecia
- Crusting and scaling
- Thickened skin (lichenification)
Sarcoptic Mange
- Severe itching
- Red papules and crusts
- Alopecia starting on ears, elbows, abdomen
Demodectic Mange
- Patchy alopecia (localized form)
- Generalized form with secondary bacterial infections
- Usually minimal pruritus unless infected
Psoroptic Mange
- Intense irritation
- Thick crusts and scabs
- Exudative dermatitis (especially sheep scab)
Summary for Practitioners
Sarcoptic mange is typically intensely pruritic, demodectic mange is often associated with immune dysfunction, and psoroptic mange causes severe crusting dermatitis in livestock.
Diagnosis
Clinical Diagnosis
Based on lesion distribution, pruritus severity, and species affected.
Laboratory Diagnosis
- Skin scrapings (deep for Demodex, superficial for Sarcoptes/Psoroptes)
- Mite identification under microscope
- Adhesive tape tests (supportive)
- Skin biopsy (in difficult cases)
Differential Diagnosis
- Dermatophytosis (ringworm)
- Bacterial dermatitis
- Allergic skin disease (fleas, food allergy)
- Other ectoparasites (lice, fleas)
Summary for Practitioners
Deep skin scrapings are essential for diagnosing Demodex, while superficial scrapings are more useful for Sarcoptes and Psoroptes.
Treatment
Antiparasitic Therapy
- Ivermectin
- Macrocyclic lactones (moxidectin, doramectin)
- Amitraz (especially for Demodex in dogs)
- Isoxazolines (fluralaner, afoxolaner in small animals)
Supportive Therapy
- Antibiotics for secondary bacterial infections
- Anti-inflammatory drugs for pruritus control
- Skin care and antiseptic washes
Summary for Practitioners
Successful treatment requires both mite elimination and management of secondary infections and inflammation.
Control and Prevention
Management Practices
- Improve hygiene and reduce overcrowding
- Quarantine infected animals
Environmental Control
- Disinfection of housing and equipment (especially for Sarcoptes/Psoroptes)
Herd/Flock Management
- Whole-group treatment in outbreaks (especially sheep scab)
- Regular ectoparasite monitoring
Summary for Practitioners
Control is most effective when entire groups are treated simultaneously and environmental sources are addressed.
Zoonotic Importance
Sarcoptes scabiei can cause transient dermatitis in humans through close contact with infected animals. Demodex is not considered zoonotic, while Psoroptes has limited zoonotic relevance.
Economic Importance
Mange causes significant economic losses due to reduced weight gain, poor wool/hide quality, decreased milk production, and treatment costs in livestock systems.
Summary
Mange is a group of mite infestations affecting the skin of animals, caused by Sarcoptes, Demodex, and Psoroptes. It presents with pruritus, alopecia, and dermatitis, and requires accurate diagnosis and targeted acaricidal treatment combined with good herd management.
Home