Veterinary Parasitology Arthropod Parasites - Review

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1 Veterinary Parasitology Arthropod Parasites - Review Melanie Buote DVM, DACVP, PhD Candidate Office: 3319 North Annex, Office phone # Cell phone # mabuote@upei.ca

Cytauxzoon III. Malarias 1. Plasmodium 2. Leucocytozoon Arthropods (5 lectures) I.

2 Outline Protozoan parasites transmitted by arthropods (1 lecture) I. Hemoflagellates 1. Trypanosomes 2. Leishmania II. Piroplasms 1. Babesia 2. Cytauxzoon III. Malarias 1. Plasmodium 2. Leucocytozoon Arthropods (5 lectures) I. Arachnids (2 lectures) 1. Ticks 2. Mites II. Insects (3 lectures) 1. Lice 2. Fleas 3. Flies 4. Myiasis

3 Protozoan parasites transmitted by arthropods Hemoflagellates Trypanosoma Piroplasms Babesia Malarias Plasmodium Trypomastigotes in blood Merozoites in RBCs Merozoites in RBCs Leishmania Cytauxzoon Leucocytozoon Amastigotes in macrophages Merozoites in RBCs (& mø) Merozoites in RBCs, round & elongate gametocytes in blood

4 Protozoan parasites transmitted by arthropods Hemoflagellates Piroplasms Trypanosoma Babesia* Plasmodium* *RBCs are infected Anemia! Malarias Nagana Chronic ill thrift Leishmania Chagas CHF Anemia > cerebral congestion Cytauxzoon* Anemia, fatal in naive species Leucocytozoon* Cutaneous & Visceral Granulomatous inflam Pancytopenia, histiocytic inflam Anemia, hepatosplenomegaly

5 Protozoan parasites transmitted by arthropods Protozoan Vector Host Disease Trypanosoma congolense Tse tse fly (Glossina sp.) African cattle Bovine trypanosomiasis Trypanosoma brucei brucei Tse tse fly (Glossina sp.) African cattle Nagana Trypanosoma cruzi Triatomine (kissing) bug (Triatoma sp.) Dogs Chagas Disease Leishmania donovani complex Phlebotomus sandfly Lutzomyia sandfly Dogs Leishmaniasis Babesia bovis Ixodid tick (Rhipicephalus appendiculatus) Cattle Bovine babesiosis Babesia gibsonii Ixodid tick (Rhipicephalus sanguinensis) Dogs Canine babesiosis Cytauxzoon felis Ixodid tick (Dermacentor variabilis) Cats (bobcats) Cytauxzoonosis Plasmodium relictum Culicine mosquito (Culex spp.) Birds Avian malaria Leucocytozoon simondi Simulium black fly (Simulium spp.) Ducks & geese Turkeys Chickens Leucocytozoonosis

6 Ticks Important Genera Ixodid (Hard) Ticks 1. Ixodes 2. Rhipicephalus (Boophilus) 3. Dermacentor 4. Amblyomma Argasid (Soft) Ticks 1. Argas 2. Ornithodoros 3. Otobius

7 Ixodid Tick Identification 1. Scutum (shield) pattern Each species has a unique pattern or color. 2. Festoons Small areas separated by short grooves on the back margin of the tick Helps distinguish all other ticks from Ixodes ticks, which lack festoons 3. Location and time of year Based on your location in North America and the time of year, only certain ticks will be active

8 Tick Identification 1. Scutum (shield) pattern Each species has a unique pattern or color. Ixodes ticks often have a black/brown solid colored scutum. Dermacentor and Amblyomma ticks each have a patterned scutum.

10 Tick Identification 2. Festoons Ixodes spp. Lack Festoons Anal groove in front of anus Dermacentor spp., Amblyomma spp., and Rhipicephalus spp. Prominent festoons* Anal groove behind anus

11 Tick Identification 3. Location & time of year Based on your location in North America and the time of year, only certain ticks will be active org/current_tick_activi ty

Rhipicephalus (Boophilus) Inornate Anal groove in behind anus Hexagonal basis capitulum 3.

12 Ixodid (Hard) Ticks Important Genera 1. Ixodes Inornate Anal groove in front of anus Long mouthparts (relatively) 2. Rhipicephalus (Boophilus) Inornate Anal groove in behind anus Hexagonal basis capitulum 3. Dermacentor Ornate Anal groove behind anus (not prominent) Rectangular basis capitulum 4. Amblyomma Ornate Anal groove behind anus Mouthparts longer than basis capitulum

13 Tick Identification 2. Festoons Ixodes spp. Lack Festoons Anal groove in front of anus Dermacentor spp., Amblyomma spp., and Rhipicephalus spp. Prominent festoons* Anal groove behind anus Small areas separated by short grooves on the back margin of the tick

14 Argasid (Soft) Ticks 1. Argas persicus Ectoparasite of poultry Feeds at night, Hides in cracks & crevices during the day 2. Ornithodoros moubata Infects domestic pigs Vector of African Swine Fever Virus (asfivirus) 3. Otobius megnini Common parasites of livestock Larval & nymphal stages Found in the ear canal

15 Species Common Names 1 Host Tick 3 Host Tick Ixodes scapularis Blacklegged Tick Deer Tick Ixodes pacificus Western blacklegged tick Rhipicephalus sanguineus Brown dog tick Rhipicephalus (Boophilus) annulatus Rhipicephalus (Boophilus) microplus Blue cattle tick Texas cattle fever tick Cattle Tick Southern cattle tick Dermacentor variabilis American Dog Tick Dermacentor andersoni Rocky Mountain Wood Tick Dermacentor albipictus Moose tick Amblyomma americanum Lone star Tick Argas persicus Fowl Tick Chicken Tick Multihost Ornithodoros moubata Eyeless tampan Multihost Otobius megnini Spinose ear tick

wounds, secondary infections & absorption of toxins 3.

16 1. Anemia Blood loss in heavy infestations 2. Tick worry Ill thrift caused by the loss of blood, pain & swelling from the bite wounds, secondary infections & absorption of toxins 3. Dermatosis Inflammation, swelling, ulceration & itching Induced by components of tick s saliva & mouthparts that remain in the wound Pathogenesis

17 5. Vectors Ticks transmit a number of bacterial, viral & protozoal pathogens Pathogens may be passed 1. Transstadially = from larva to nymph & nymph to adult 2. Transovarially = from female to next generation Pathogenesis 4. Paralysis (Tick Toxicosis) Some species of ticks saliva contain neurotoxins disrupts motor nerve synapses in the spinal cord & blocks neuromuscular junctions ascending paralysis a single tick can produce paralysis in dogs (and humans) heavy infections are required to produce paralysis in cattle Clinical signs do not appear unless the tick has been feeding for approximately four (4) days Removing the tick(s) often result in dramatic recovery

18 Lyme Disease

19 Mites Important Genera Genera of Mange Mites 1. Sarcoptes 2. Notoedres 3. Knemidocoptes 4. Psoroptes 5. Chorioptes 6. Otodectes 7. Cheyletiella 8. Demodex Ectoparasites Pruritus!

20 Mites Important Genera Genera of Mange Mites Dogs & Cats 1. Sarcoptes & Notoedres (cats only) 2. Otodectes 3. Cheyletiella 4. Demodex Rabbits 1. Sarcoptes 2. Psoroptes 3. Cheyletiella 4. (Demodex)

21 Mites Important Genera Genera of Mange Mites Cattle, Sheep & Goats, & Horses 1. Sarcoptes 2. Psoroptes 3. Chorioptes 4. (Demodex) Pigs 1. Sarcoptes 2. (Demodex)

22 Mange Mites Pruritic Dermatitis Dogs Cats Rabbits Cattle Sheep & Goats Horses Pigs Avian Sarcoptes Notoedres Knemidocoptes Psoroptes Chorioptes Otodectes Cheyletiella Demodex Pneumonyssoides caninum Dermanyssus gallinae Ornithonyssus sylviarum

23 Ruminant mange mites Sarcoptic mites burrow into the skin. Short Legs Psorptic and Chorioptic mites are non-burrowing. Long legs At the end of the legs of all three types are thin structures called pedicels which have a sucker at the end. The appearance of these pedicels is used to identify the type of mite. The pedicels of the Psoroptes type of mite are long and jointed. Sarcoptic mites also have long pedicels but they are not jointed. The pedicels of Chorioptic mites are short. Psoroptes pedicels are segmented: P is for parts

24 8. Demodex spp. 1 Sarcoptes mite = Sarcoptic Mange 1 Demodex mite = Normal Flora Numerous Demodex mites = Demodectic mange Most Demodex spp. are considered normal mammalian fauna Are acquired at birth by direct contact Considered normal inhabitants of the skin (usually non-pathogenic) Overgrowth of normal mite fauna development of patchy hair loss +/- mild to severe dermatitis in dogs and (less commonly) in cats Exceptions (FYI): Demodex sp. cornei (dogs) & D. gatoi (cats) Small, blunt-ended demodectic mites Disease is thought to be caused by the infestation itself rather than an overgrowth of mites Can be associated with pruritus in the absence of pyoderma Contagious (vs. overgrowth)

25 8. Demodex spp. Dogs Demodex canis* (180 to 210 µm) Demodex injai (330 to 370 µm) Demodex sp. cornei (90 to 140 µm) Cats Demodex cati* (181 to 219 µm) Demodex gatoi (81 to 115 µm) Demodex sp. ( µm) D. canis vs. D. injai D. cati vs. D. gatoi *Prevalence is virtually 100%

crusting Severe cases are accompanied by a foul smelling putrid odor & are difficult to cure 8. Demodex spp. Two forms of canine demodecosis: 1.

26 2. Generalized demodecosis (the other 10%) Onset in dogs due to some underlying factor Lesions spread from head to rest of body Generalized erythema, alopecia, crusting & scaling Secondary infections can occur (i.e., pyoderma) resulting in oozing exudative lesions with severe crusting Severe cases are accompanied by a foul smelling putrid odor & are difficult to cure 8. Demodex spp. Two forms of canine demodecosis: 1. Localized demodecosis (90% of cases) Focal areas of erythema & alopecia Head, neck, & forelegs No secondary problems Most (90%) will resolve spontaneously

27 Mites Important Genera Genera of Mange Mites Avian 1. Knemidocoptes 1. Knemidocoptes mutans * 2. Knemidocoptes gallinae* 3. Knemidocoptes jamaicensis 4. Knemidocoptes pilae 2. Dermanyssus gallinae* 3. Ornithonyssus sylviarum* *Fowl Mites

28 3. Knemidocoptes spp. Clinical Signs 3.1 Knemidocoptes mutans Scaly leg and face in domestic fowl Chickens, turkeys, pheasants, and other gallinaceous birds Several raptor species Mite burrows beneath leg scales and causes them to loosen and rise hyperkeratosis FYI: 3.2 Knemidocoptes gallinae 3.3 Knemidocoptes jamaicensis 3.4 Knemidocoptes pilae

Dermanyssus gallinae & Ornithonyssus sylviarum Dermanyssus gallinae - Chicken Mite (= Red Mite) A blood-sucking mite of poultry in wood-framed houses Mites are found on birds only when feeding (at

29 Dermanyssus gallinae & Ornithonyssus sylviarum Dermanyssus gallinae - Chicken Mite (= Red Mite) A blood-sucking mite of poultry in wood-framed houses Mites are found on birds only when feeding (at night) otherwise hide in nests, roosts & crevices Ornithonyssus sylviarum - Northern Fowl Mite The most important & common ectoparasite of the poultry industry Is also a blood-sucking mite, and is reddish-brown after a bloodmeal Remains on bird throughout life

30 Fowl ticks (Argas persicus) Argasid (soft) ticks live in the cracks and crevices of a poultry house. Ticks in various stages of development will feed on a host. nal-parasites-of-poultry#.uqt43sdocyk

Linognathus Dogs, Cattle, Sheep (and Goats) II. Mallophaga (chewing/biting lice) 1.

31 Ectoparasites Pruritus Lice Pruritic Dermatitis I. Anoplura (sucking lice - mammals) 1. Haematopinus Horses, Cattle, Pigs 2. Linognathus Dogs, Cattle, Sheep (and Goats) II. Mallophaga (chewing/biting lice) 1. Trichodectes Dogs 2. Felicola Cats 3. Bovicola Horses = Bovicola equi Cattle = Bovicola bovis Sheep = Bovicola ovis 4. Menopon Poultry

Sucking Lice (Anoplura) Head is narrower than thorax & elongated Adults 0.

fine cutting structures Hosts are placental mammals Crab-like claws on the tarsus Cling to

shaft host specificity Chewing Lice (Mallophaga) Heads are large, wider than thorax &

Feed on feathers, hair, and skin Some feed on blood Hosts are birds and mammals The species

32 Sucking Lice (Anoplura) Head is narrower than thorax & elongated Adults mm in length Mouth parts are highly modified Composed of 3 stylets which form a set of fine cutting structures Hosts are placental mammals Crab-like claws on the tarsus Cling to hairs of the host, The diameter of the claw is related to the diameter of the host s hair shaft host specificity Chewing Lice (Mallophaga) Heads are large, wider than thorax & rounded Usually 2-3 mm in length Have mandibulate mouthparts typical of chewing insects Feed on feathers, hair, and skin Some feed on blood Hosts are birds and mammals The species that feed on birds typically have 2 claws on the end of each tarsus; those that feed on mammals typically have just 1 claw

33 The Fleas Common species 1. Ctenocephalides felis - cat flea - most dog and cat fleas in NA 2. Ctenocephalides canis - dog flea 3. Pulex irritans - human flea 4. Xenopsylla cheopis - Oriental rat flea 5. Echidnophaga gallinacea - poultry sticktight flea 6. Ceratophyllus niger - Western chicken flea

34 The Fleas Order Siphonaptera I. Order Siphonaptera = Fleas Ctenocephalides felis - "cat" flea Ctenocephalides canis - "dog" flea

35 The Fleas 1. Ctenocephalides felis - the cat flea The most important species on dogs & cats 93% of fleas on dogs 99.8% of fleas on cats The major cause of flea allergy dermatitis (FAD) Ubiquitous & parasitizes a wide range of hosts cats, dogs, cattle & humans Sloping elongated front of head Genal & pronotal comb About 2.5 mm long Life cycle completed in days days depending on conditions Only a few fleas required to cause great misery to host One bite can cause allergic reaction in sensitized host (FAD)

The Fleas Pruritic Dermatitis Pathology Flea bite dermatitis Low numbers = an annoyance # of fleas dermatitis Heavy infestation Anemia and death Flea allergy dermatitis Hapten in fleas saliva

36 The Fleas Pruritic Dermatitis Pathology Flea bite dermatitis Low numbers = an annoyance # of fleas dermatitis Heavy infestation Anemia and death Flea allergy dermatitis Hapten in fleas saliva Antigenic when fixed to host protein Increased scratching or itchiness (pruritus) pruritus-induced self trauma Loss of hair, hairs that appear broken, Crusts and erosions, and pimple-like bumps. Thickened skin with darkened areas can be seen in severe cases. Hot spots sometimes can be seen along the dog's back and tail base. Circular, red, oozing, painful sores Can be perpetuated by a single flea!

Clean up host s environment This step begins by laundering and steam cleaning/vacuuming: Wash pet bedding in hot water to kill flea larvae.

37 Flea Control Host has: Adults on body + eggs in hair or feathers Environment: Eggs + Larvae + Pupae + Adults Majority of fleas usually in environment! Integrated control program: Includes the host AND the environment. 1. Control on host Dips, sprays, powders, shampoos, flea collars, and systemics 2. Clean up host s environment This step begins by laundering and steam cleaning/vacuuming: Wash pet bedding in hot water to kill flea larvae. If animals sleep with family members, all bedding must be washed. Steam clean or vacuum carpets thoroughly everywhere the infested pet is allowed to roam. Use chemicals to treat environment Residuals or knockdown, Insect growth regulators Focus on locations where pets go in and out of the house, sleep and rest, jump off beds, sofas and chairs, and spend time with family members.

38 The Fleas Pathology Intermediate hosts Dipylidium caninum Dipetalonema reconditum Vectors Plague (Yersinia pestis) Typhus (Rickettsia typhi)

39 The Fleas 4. Xenopsylla cheopis - the Oreintal rat flea Genus of rodent fleas that attacks humans Lacks combs Has smoothly rounded head A bristle in front of the eye A vertical rod on the mesothorax (Pulex does not) Vector Yersinia pestis (Bubonic Plague) Rickettsia typhi (Typhus )

40 The Flies Adult Flies of Veterinary Importance 1. Culicidae - Mosquitoes 2. Simuliidae - Black Flies 3. Ceratopogonidae - Gnats & biting midges 4. Psychodidae (Phlebotominae) - Sand Flies 5. Tabanidae - Horse Flies & Deer Flies 6. Muscidae - House flies, Stable Flies & Horn Flies 7. Hippoboscidae Sheep Keds (wingless flies) 8. Glossinidae Tse tse flies FYI: Descriptive features of Dipteran Familes: &class=17&subclass=&order=7&couplet=0

41 The Flies Ways to control flies: Regardless of the species of fly, an integrated approach that incorporates sanitation, mechanical control, and the use of insecticides is the best strategy for fly control. 1. Sanitation: Since manure and organic matter are common breeding grounds for flies, regular removal of manure & organic matter will deter fly populations by reducing the number of eggs laid. 2. Mechanical control Preventing accumulation of water and wet areas reduces fly breeding. Mechanical control of flies in buildings through the use of screens. 3. Insecticides Can be delivered by ear tags, dust bags, oilers, sprays, pour-ons, and feed additives.

42 Fly Vector Mosquitoes (Culex, Anopheles) Black flies (Simulium) Gnats (Culicoides) Sandflies (Phlebotomus = old world, Lutzomyia = new world) Horse & deer flies (Tabanid flies, such as Tabanus) House flies (Musca domestica) Horn flies (Haematobium) Tse tse flies (Glossina) Veterinary Disease Transmission Canine heartworm, avian malaria, West Nile virus, viral encephalitides Leukocytozoonosis (poultry), onchocerciasis (cattle) Bluetongue virus, onchocerciasis (cattle), viral encephalitides, African Horse sickness Leishmaniasis Bovine anaplasmosis, anthrax, tularemia, EIA virus, hog cholera virus, vesicular stomatitis E. coli, Salmonella, Shigella, Campylobacter, and Enterococcus; protozoan cysts; Habronemiass Stephanofilarial dermatitis (cattle) African trypanosomiasis (cattle)

43 Pruritus of the tail in horses 1. Culicoides hypersensitivity sweet itch 2. Simulium hypersensitivity 3. Haematopinus asini (sucking louse) 4. Psoroptic mange 5. Oxyuris equi (pinworms)

44 The Flies 8. Keds - Family Hippoboscidae Important Species Melophagus ovinus a wingless blood-sucking continuous ectoparasite of sheep & goats (a fly that doesn t fly) Morphology Tick-like in appearance 5-8 mm in length and brown Dorsoventrally flattened Wingless Strong claws Cling to wool or hair

45 Sheep Sheep Keds Melophagus ovinus (5-8 mm) X Pediculosis (Lice) Bovicola ovis Linognathus ovillus Linognathus pedalis (1-8 mm, most 2-3 mm) Mange Psoroptes & Chorioptes (~ um = <0.5 mm)

46 The Flies - Myiasis 2 important groups of blow flies I. Screwworms (cattle) 1. Cochliomyia (New World) Cochliomyia hominovorax ( 1 screw worm ) Cochliomyia macellaria (2 screw worm ) 2. Chrysomyia (Old World) II. Strike flies (fly strike in rabbits & sheep) 1-4. Lucilia, Phormia, Protophormia, Calliphora 4 Important Genera of bots and warbles: 1. Oestrus (sheep nasal bots) 2. Gasterophilus (horse bots) 3. Hypoderma (cattle grubs or warbles) 4. Cuterebra (rabbit bots)

forelegs invade via mouth (licking of legs) Bots Cardiac region of the

47 The Flies Myiasis 2. Bots & Warbles Family Oestridae Gasterophilus intestinalis Eggs Hairs of forelegs invade via mouth (licking of legs) Bots Cardiac region of the stomach Gasterophilus nasalis Eggs Hairs of the intermandibular skin invade via mouth Bots Pyloric region of the stomach >>> duodenum

48 The Flies Myiasis 2. Bots & Warbles Family Oestridae Bots attach to the gastric lining above the fluid line! Gastric bots: The two species we typically encounter are G. nasalis and G. intestinalis. G. nasalis is farthest from the nose, G. intestinalis is farthest from the intestine.

49 Hemimetabolous Incomplete development (egg, nymph, adult) Arachnida (ticks and mites) Phthiraptera (lice) Holometabolous Complete development (egg, larva, pupa, adult) Siphonaptera (fleas) Diptera (flies) F is for Full

50 1. Chelicera Cut & pierce the host s skin 2. Palps Sensory, stabilization 3. Hypostome Anchor 1. Mandibles (Jaws) Used for cutting, tearing & crushing 2. Maxillae Used in food handling 3. Labium Also used for food handling

51 Reminder! Final Lab Exam Content: CUMULATIVE Arthropod section: You only have to identify arthropod parasites to the level of GENUS Written Final Exam = 4 th Midterm Content: Protozoan parasites transmitted by arthropods and arthropod parasites (Dr. Buote s lectures) You will have to be able to RECOGNIZE (i.e., multiple choice & matching) and RECALL (i.e., fill in blanks, short answer questions, and long answer questions) arthropod parasites to the level of SPECIES

52 Questions?

Arthropod Parasites of Veterinary importance 2015

Arthropod Parasites of Veterinary importance 2015 VPM-122 Laboratory 6 Prepared by Spencer J. Greenwood PhD, DVM Dept. of Biomedical Sciences Room 2332N AVC North Annex sgreenwood@upei.ca Office phone: