Newไรที่มีความสำคัญทางสัตวแพทย์18-10-62

Mites of medical and veterinary importance By Asst.Prof. Khampee Pattanatanang

Classification

Classification • Phylum : Arthropoda • Subphylum : Chelicerata • Class : Arachnida • Subclass : Acari (Ticks and Mites) • Superorder : Parasitiformes • Order : Mesostigmata • Superorder : Acariformes • Order : Sarcoptiformes • Order : Trombidiformes

Classification • Order Ixodida (Metastigmata Ticks) • Order Mesostigmata • Suborder Monogynaspida- Gamasid mites • Order Sarcoptiformes • Suborder Oribatida – Oribatid mites • Suborder Astigmata -Mange mites • Order Trombidiformes • Suborder Prostigmata – Chigger mites, Follicle mites

Ticks vs Mites • Class Arachnida • Subclass Acari (Ticks & Mites) • Characteristics • Sac-like, unsegmented body • Highly specialized mouthparts, capitulum with hypostome • Phytophagous, Predatory, Parasitic (Med & Vet Importance) • Complete metamorphosis • Larvae 6 legs, nymph & adult 8 legs • 4-stage life cycle, egg  larva  nymph  adult

TICKS MITES 6

Mites Respiratory organs(stigmata) that characterize 1 order and 2 suborders of mites • Actenedida =Prostigmata • Acaridida =Astigmata • Gamasida =Mesostigmata

Why should Veterinarians concern about Mites? • Medical and Veterinary Importance • Vectors transmitting diseases • Bacteria, Virus, Protozoa, Helminth • Human and Animal Health problems • Itching, Dermatitis, Mange, Asthma • Animal production and Industry • Economic and production losses

Overview • Mites • Large group of arthropods • Worldwide distribution • Tiny creatures Mostly microscopic in size • A small dot parasite . (~0.5-2 mm.) • A microscopic parasite micron



General Life cycle of Mite • 4 stages egg larva  protonymph  deutonymph  adult Northern fowl mite

Habitats group • Two groups of mites (Habitats) • Free-living group • Parasitic group

Free-living group • Oribatid mites ( beatle mites) • Usually the most abundant and diverse arthropods in soil • Vary in relation to various environmental factors (Hansen & Coleman, 1998) • Temperature • Moisture • Organic matter and Nutrient • The density of soil mites considered as indicator of soil condition and quality (Usher, 1971)

Free-living group • Oribatid mites( beatle mites) • Economic importance • Intermediate host of tapeworm

Free-living group • Oribatid mites • Tapeworm (Transmission by ingestion of infected free-living mites ) • Anoplocephala spp. (horse) • Moniezia spp. (ruminants) • Avitellina spp. (ruminants)

Oribatid mites Anoplocephala magna

Parasitic group • Mange mites • Burrowing mites • Non-burrowing mites • Gamasid mites • Dermatitis • Vector transmitting disease

Mange mites • Burrowing mites • Tunnel into the skin • Tend to have short legs with terminal suckers on the end of legs • Smaller than the non-burrowing mites • Generally have a circular shape • Non-burrowing • Live on the skin surface and hair

Medical and Veterinary Importance • Mange mites (Burrowing mites) • Family Sarcoptidae (Astigmata) • Sarcoptes scabiei var canis • Notoedres cati

Medical and Veterinary Importance • Mange mites (Burrowing mites) • Family Knemidokoptidae (Astigmata) • Knemidocoptes spp.

Medical and Veterinary Importance • Mange mites (Non-burrowing mites) • Family Psoroptidae (Astigmata) • Psoroptes ovis, Psoroptes cuniculi • Chorioptes ovis, Chorioptes cuniculi

Medical and Veterinary Importance • Mange mites • Family Demodicidae (Prostigmata) • Demodex canis • Demodex folliculorum

Mange mites • Sarcoptes scabiei var canis • Notoedres cati • Knemidocoptes mutans • Psoroptes ovis • Chorioptes bovis • Otodectes cynotis • Demodex canis (Prostigmata) • Demodicosis is not considered mange, but it is also caused by mites

Mite Infestation in Dogs • There are two types of mites that affect dogs • Canine scabies (sarcoptic mite) • Canine demodicosis (demodex mite)

Saecoptes scabiei var canis Photo by Louis De Vos.

Saecoptes scabiei var canis

Saecoptes scabiei var canis

Sarcoptes scabiei var canis • Highly contagious parasite is found on dogs worldwide • Humans and other animals that come in contact with an infected dog may also become infected

Sarcoptes scabiei var canis • Life cycle (17 to 21 days) of these mites is spent on the infested dog • Mites live in keratin of skin’s surface • Females burrow tunnels in the skin to lay eggs

Sarcoptes scabei var canis Life-cycle of the scabies mite. Only the female mite creates a burrow in the skin. Larvae hatch from the eggs, exit the burrows and continue their life on the skin surface. They develop to the nymph stages and then to adulthood. Male mites remain on the skin surface.

Clinical signs • Not all dogs have signs when they are infested with sarcoptic mange mites • Usually, the animal will have intense itching that comes on suddenly

Clinical signs • Skin irritation • Itching, hair loss, and inflammation • The itching is probably caused by sensitivity to the mites' droppings • Initially, infested skin will erupt with small, solid bumps

Clinical signs • Because the dog scratches or bites itself to relieve the itch, these bumps and the surrounding skin are often damaged, causing thick, crusted sores • Secondary yeast or bacterial infections can develop in the damaged skin

Clinical signs • Usually, the sores appear first on the abdomen, chest, ears, elbows, and legs • If the mange is not diagnosed and treated, the sores can spread over the entire body

Clinical signs • Dogs with long term, recurring mange develop oily dandruff (seborrhea), severe thickening of the skin with wrinkling and crust build-up, and oozing, weeping sores • Dogs affected this severely can become emaciated and may even die

Diagnosis • History taking and Physical examination • Clinical signs • Lesions • Skin scraping • Morphology Identification

Diagnosis

Diagnosis Canine scabies is caused by the Sarcoptes scabiei var canis

Diagnosis

Diagnosis

Diagnosis • Skin scraping

Diagnosis(female)

External Anatomy (Astigmata) • Gnathosoma (False head or Capitulum) • Basis capituli • Pedipalps or Palps • Chelicerae • Hypostome (no teeth)

External Anatomy • Idiosoma (body) Female • Transverse ridge or striation • Epimeres Skeletal enlargement for legs attactment • Stigmata rudimentary structure

External Anatomy • Spines, Cones, Scales • Copulatory papilla(bursa copulatrix) or Vagi • Anus • Terminal (eg. Sarcoptic group and others) • Dorsal (Notoedric group)

External Anatomy • Idiosoma (Male) • Epimeres • Genital apparatus • Epiandrium • Medial rod • Genital apron • Copulatory tubercles and adanal suckersPsoroptes

External Anatomy • The legs • General mites • Pedicel or stalk and terminal cup-shaped (sucker)

External Anatomy • Male • Spines < • Scales < • Ridges >

Genus Egg-laying Female Male Anus terminal Sarcoptes Short leg Short leg dorsal S1 , S2 S1 , S2 , S4 terminal on long-unjointed pedicel terminal on long-unjointed pedicel terminal Short leg Notoedres Short leg S1 , S2 , S4 terminal S1 , S2 on long-unjointed pedicel on long-unjointed pedicel short leg S1 , S2 , S3 ,S4 Knemidocoptes short leg on long-unjointed pedicel No suckers Long leg Psoroptes Long leg S1 , S2 , S3 Chorioptes S1 , S2 , S4 on long-jointed pedicel on long-jointed pedicel Long leg, Leg 4 reduced Long leg S1 , S2 , S3 ,S4 S1 , S2 , S4 on short-unjointed pedicel on short-unjointed pedicel Otodectes Long leg, Leg 4 reduced or Long leg rudimentary S1 , S2 , S3 ,S4 S1 , S2 on short-unjointed pedicel on short-unjointed pedicel

Diagnosis (female)