38-57.pdf Veterinary Parasitology PDF

Sub Species Life Cycle Pathogenesis Tx, Px & Cx family Rhinoestrus Larvae deposited in nerves, Highly host specific (horses and (viviparous), dark...

Sub Species Life Cycle Pathogenesis Tx, Px & Cx family Rhinoestrus Larvae deposited in nerves, Highly host specific (horses and (viviparous), dark gray conjunctiva and occasionally mouth of large African mammals) flies; dorsal spots on animals dorsum of thorax and Larvae invades nasopharyngeal abdomen; R. purpurea – region of equine, less frequently Russian gadfly bovine. Occasionally causes “naso” and “optalmo” – myiasis in man Botflies – hairy, mouthparts reduced and functionless, 4th longitudinal vein straight and does not reach margin; bare arista; vestigial mouthparts; ovipositor elongate; posterior spiracle with 3 longitudinal slits Gasterophilus Female hovers about animal with Flies laying eggs annoy Tx: Carbon intestinalis ovipositor extended and darts at it to animals and cause panic. disulfide or Carbon glue an egg to hair. G. intestinalis Larva in pharynx, stomach, tetrachloride – kill G. hemorrhoidalis eggs laid around fetlocks of forelegs, duodenum incite inflammatory larva in the up the legs and scapular region. G. reaction - formation of ring-like stomach G. inermis nasalis - hairs of intermandibular thickening around larvae, Neguvon – 37 – 40 region. G. hemorrhoidalis /G. perforation possible. mg/kg in feed G. pecorum inermis - hairs around mouth and Interfere with action of Px: Frequent cheeks. G. pecorum - in. pastures. sphincter and food passage. grooming of G. nasalis (chin fly) Eggs hatch in 5-10 days or more. Larvae cause irritation due to horses, apply 2% Eggs of G. intestinalis / G. pecorum (+) spines in some species. carbolic dip weekly require to be licked or rubbed by the Clusters around pylorus (G. on sites where fly animal. Eggs around mouth hatch nasalis, G. pecorum, G. likely deposit eggs spontaneously. Larvae crawl into intestlnolls, G. Dx: examine sites mouth or transferred to tongue → hemorrhoidalis); (-) in G. where eggs are pharynx → esophagus → stomach inermis. possibly where they attach to epithelium → deposited; (+) of mature → pupa in the feces → adult larvae in the on the ground feed and live for a few pharynx days or week. Dermatobia hominis – When adult oviposits, captures Produces swelling which has a Tx: surgical adults do not feed, mosquito or other bloodsucking fly central opening through which it removal of nourishment derived from and glues and batch of eggs to breaths; swelling is painful parasite in food stored during larval abdomen of captive fly. Transport fly animal, dip with period alights on warm blooded host. Larva BHC, DDT, of D. hominis hatch from eggs and toxaphene penetrate skin of host often entering Dx: (=) of thru skin puncture made by superficial bloodsucking flies → 6 days hatching swelling with - occurs only when carrier fly settles central opening on a suitable animal. Man, usually infected when he is associated with domestic animals. Dev't in host requires 5-10 wks. larva escapes and pupates on the ground for an equally long period before fly emerges. Female gives birth to larvae which are ready to pupate, pupiparous Aberrant Dipteran which are adapted to parasitic life, permanent ectoparasites or tend to remain on their host for long periods Body broad and flattened dorsoventrally, abdomen indistinctly segmented. One-joint antenna, wall soft and leathery, feet provided with strong claws, wings may be present or absent 37 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Bloodsucking parasitic flies (male and female); pupiparous, larvae retained in the body nourished by special glands of the mother and extruded at time of pupation. Genus Hippobosca Forest flies, wings present. 1.0 cm in length Adult is pale reddish brown with pale yellow spots, veins crowded at anterior border of wings, with strong claws Species H. equina - equine H. rupifes - equine H. maculata - equine, bovine H. capensis - dog in Africa and Asia Life Cycle Female deposits one larva at a time in dark spots where it is dry or moist humus. Larva subglobular. Length of development depends on temperature. Ave - 35 days Habits Active in warm and sunny weather. Remain for long in host, not easily disturbed. Biting areas include perineal, pubic and abdominal regions. Transmission Trypanosoma theileri in bovine, anthrax, Haemoproteus anatis Genus Melophagus Melophagus ovinus Sheep ked, sheep tick (tick in appearance), sheep louse fly, wingles (no haltere), brown hairy and leathery body, common in temperate regions Life Cycle Larvae attached to walls of sheep → in minutes, turn into pupae (19-23 days during summer, 36 days during winter) → female flies live 4-5 months 011 sheep (entire life cycle). Pathogenesis Transmit Trypanosoma melophagium in sheep Feces of sheep ked stain wool, wool damage “cockle” formation in skin (vertical ridging of the skin) blood sucker - loss of condition/anemia in heavy infestation Control · BHC (lindane) and OP's Genus Pseudolynchia Pseudolynchia maura (P. canariensis) Pigeon louse fly Obligate parasite of pigeons and wild birds (tropics) Resembling ked but wings present (fast fliers), dark brown flies, wings transparent with reduced venation concentrated along anterior border Live on domestic pigeons, suck blood and cause painful wounds Life Cycle Female fly → 4-5 young ones of 43 days life span; copulation on host; larva laid on dark crevices of pigeon house → pupate in a matter of minutes. Pupal stage lasts 23-31 days. Pathogenesis Haemoproteus columbae – pigeon malaria H. lophortyx – quail (squabs) Young pigeons -painful bites/ blood sucking/ anemia 38 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Genus Lepopthena/ Lipoptena Lipoptena cervi Deer ked, have wings but break off when female finds a host They have halters (absent in Melophagus ovinus) Hippobosca Melophagus Pseudolynchia 2 pairs of wings: anterior (mesothoracic pair) thickened – acts as a cover called tegmina for hind pair; hind (metathoracic pair) - membranous; antennae, long, filamentous and many jointed mouthparts are adapted for chewing. e.g. grasshoppers, crickets, cockroaches, locusts, stick/leaf insects. Significance Melanoplus sp. (grasshoppers) intermediate host of spirururoid nematode like Tetromeres americana (proventricular worm) and Cheilospirura hamulosa Conocephalus maculatus and C. chinensis (grasshoppers) -2nd IH of Eurytrema pancreaticum and E. coelomaticum (pancreatic flukes) Oecanthus longicaudus (tree cricket) – 2nd IH of E. pancreaticum Blatella germanica – experimentally infected with spiruroid nematode Gonglynema pulchrum Pycnoscelus surinamensis – intermediate host of Oxyspirura parvorum in Australia Species of cockroaches (Order Blattodea; Family Blattidae) eggs laid in ootheca and carried about by ovipositors Common household cockroaches A) German cockroach Blatella germanica B) American cockroach croton bug C) Australian cockroach 15 mm long; light brown with 2 longitudinal dark stripes D & E) Oriental cockroach (♀ & ♂) over prothorax and wings; wings reach tip of abdomen in male and female Blattella orientalis 25 mm long; almost black; wings don't quite reach the tip of the abdomen in male and vestigial in female. Periplaneta australasia and P. americana Prefer warm places and roam in the dark; hide in cracks and crevices along baseboards of walls, water pipes; feed on starchy/sugary materials; Will eat almost anything if necessary - most frequently in kitchens, bakeries and storerooms where cereals are kept. Frequent pest in animal quarters; not parasitic but spread disease on account of habits; carry various fungi and protozoa; act as intermediate host of parasitic nematodes. Life Cycle Egg laid in egg cases (ootheca) → carried about for some time and seen protruding from abdomen of female → egg cases deposited in crevices and rate of development of egg and young cockroaches depends on temperature and food supply. 39 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Habits They are nocturnal, live preferably in dark, warm and humid places Omnivorous – eat almost anything if necessary, spoil food by importing their fetid odor on objects they are in contact with, it may bite Their filthy habits suggest the probability of spreading bacterial, viral and protozoal diseases e.g. typhoid and dysentery Dead roaches can trigger asthma and allergic reactions Pathogenesis IH of helminth parasites of mammals and birds: Oxyspirura mansoni (eyeworm of poultry), Tetrameres Americana, Physaloptera praeputialis neoplasticum, Gongylonema, G. pulchrum (experimental) Control Difficult due to habits and breeding potential CHC - lindane, dieldrin, 2.5% chlordane emulsion/solution, 0.5% dieldrin solution, 1% dieldrin dust, 2% chlordane use of OP's for strains resistant to CHC - 1.5% malathion, 1% Dipterex, 0.5% diazinon, 1.5% chlorthion regular cleaning, cracks and holes may require sealing beetles have two pairs of wings: front (elytra) – hard / horny; hind – membranous mouthparts for chewing holometabolous LC: egg → oligopod larvae → exarate pupae → adult FAMILIES Family Staphylinidae – rove beetles Family Silphidae – sexton beetle Family Scarabeidae – dung beetles Family Histeridae – black carrion beetle Family Meloidae – vesicating beetle (source of cantharidae) Examples Carrion beetles - feed on dead animal and plant o Necrophorus - burying beetle Darkling beetles o Tribolium confusum - Confused flour beetle o T. castaneum - Red flour beetle Scarabs, June beetles, lamellicorn - feed on dung, rotting bird or fungi, leaf o Macrodactylus subspinosus - Rose chafer Blister or oil beetles - contain an oil, cantharidin, which is a powerful skin irritant (vesicant) o Epicauta vittata - Striped blister beetle o E. pestifera - Margined blister beetle o Lytta vesicatoria - Spanish fly beetle o Sessinia collaris, Zonabris nubica, Oxycopis vittala Importance I.H. of the following helminth parasites o Cestodes: Rodentolepis = Hymenolepis / Vampyrolepsis nana, H. carioca, H. diminuta, R. cesticillus, Choanotaenia infundibulum o Nematodes: Ascarops strongylina, Physocephalus sexalatus, Gongylonema pulchrum, Spirocerca lupi, Physaloptera praeputialis, Cheilospirura hamulosa o Thorny-headed worms: Macracanthrohynchus hirudinaceus, Monilifomis moniliformis Some are poisonous to poultry when ingested, e.g. Macrodactylus subspinosus Some cause vesicating skin lesion when handled or if ingested → cantharidin toxicosis, e.g. Epicauta spp. Proboscis – piercing and sucking type; jointed and flexed under the head when not in use If wings are present, the anterior pair (hemelytra) has a harder consistency than the membranous posterior pair Have stink glands Hemimatabolous life cycle (egg, nymph adult) 40 VPARA 141 Lecture Handout_GG Calderon 2019-2020  FAMILY SPECIES COMMON NAME Cimex lectularius Common bedbug CIMICIDAE Cimex hemipterus Oriental bedbug Haemotosiphon inodorus Poultry bug Triatoma rubrofasciata Large kissing bug Triatoma sangisuga Mexican bedbug, Eastern blood-sucking conenose Triatoma protacta Western conenose REDUVIDAE Panstrongylus megistus Kissing bug Rhodnius prolixus Triatomid bug Reduvius personatus Masked hunter Elongate head, cone-shaped; well-developed wings Three segmented beaks Exclusively feeds on vertebrate blood Cause painless bite Nocturnal feeders Defecate on skin of host during feeding With connexival plate – prominent abdominal margin at the junction of the dorsal and ventral plates important in abdominal expansion Genus Triatoma Assassin bug/cone-nosed bug (pointed head) / kissing bugs / Barber’s bugs (bites the face) Species Triatoma proctata – China bedbug T. sanguisuga – Mexican bedbug T. rubrofasciata T. infestans Reduvius personatus – kissing bug (often bites the lips of sleeping persons) Life Cycle Eggs are white - yellowish and oval → singly/batch on ground, floors, walls, crevices → after 2-3 weeks moult to nymph, moult 5x → adult. Life span: 1-2 years. Pathogenesis blood suckers IH and transmission of Trypanosoma cruzi that causes CHAGAS disease in man (posterior station development / stercoraria) Control spray houses with BHC or dieldrin “bed bugs” Broad, dorsoventrally flat, reddish-brown bodies which are devoid of wings, except for a pair of bristly pads which represent the first pair of wings known as the hemelytra. The eyes project prominently at the sides of the head, the antennae are four-jointed, while the beak is 3- jointed. Prothorax is large, indented Infront of the head, and has a flat lateral expansion. Stink or scent glands – opens on the ventral side of the 3rd thoracic segments in adults The mesonutum is small and triangular, bearing he wings pads which nearly covers the mesonotum. The abdomen is flat with eight visible segments, the first two being fused. In males, the abdomen is pointed at the tip whereas in the females it is evenly rounded The greater part of the body is covered with bristles. It has incomplete metamorphosis. Genus Cimex bedbugs 41 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Species Cimex lectularius – common bedbug C. hemiptereus – Oriental or Indian bedbug Characteristics eight abdominal segments of the male is where the curve saber-like penis or aedaegus is located. In the female, the copulatory orifice, a slit located at the right side of the fifth (4th visible) abdominal segments, leading to a blind pouch - these are the outer Ribagas Organs and the inner Organ of Berlese. Life Cycle Egg laid singly, pearly white → 6-10 days after, becomes nymph → moult 5x in 8 days → adult Live 1 year without food. Habits Mainly nocturnal, but will also bite during daytime Can survive starvation (adults – at least 1 year, nymphs – 70 days) Pathogenesis annoying insects, blood sucking severe irritation and anemia in poultry cause allergy, asthma, insomnia, nervousness in man influenza like symptom Control dogs pheromones and alarm scent as attractants C. lectlarius – lateral expansions of the barrier or harborage mimicking devices pronotum are wide special high-technology devices (CO2, chemical lure - pyrethrin + heat) C. hemipterus – narrow lateral expansions fumigation of furniture with methyl bromide Difference Cimex hemipterus o less deeply indented anterior border o lesser antero-lateral extension of the dorsal convexity of the prothorax o Has shorter narrower head. o Les prolific o More resistant to higher temperature o Less resistant to low temperature o More resistant to DDT o Unadopted to living in temperate zones Cimex lectularius o can live both temperate and tropical zone o has an optimal temperature of 28 °C – 29 °C o will not breed at 36 °C ❖ Two species will cross breed, but the eggs are abnormal and infertile. SIMILARITIES PARAMETER CIMICIDAE REDUVIDAE Dorsoventrally flattened   Simple metamorphosis YES YES 3-segmented proboscis/ beak   Nymph molts 5x YES YES Synanthropic YES YES Blood-sucking nymphs YES YES DIFFERENCES PARAMETER CIMICIDAE REDUVIDAE size 5-7 mm 16 mm bite painful painless Presence of wings vestigial  Feeding habit nocturnal Nocturnal Stink gland   isobutyric acid Stridulating/ stridulation   Type of hypersensitivity Immediate / delayed Immediate CO2, ammonia, short chain amines, Attractants CO2, heat carboxylic acids, heat Possibly Hepatitis-B, Anthrax, Chagas disease, Equine Transmission of disease Tularemia, Bubonic plague encephalomyelitis 42 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Triatoma Cimex Wingless Bilaterally compressed, heavily chinitized Over 2,400 species and subspecies Greater than 95% found in mammals Do not occur in ruminants, horses and pigs although they may attack these animals Head broadly joined to the thorax which is relatively small. Laterally compressed bodies to facilitate gliding between hairs or feathers of their hosts. Compound eyes (-), large, simple eyes Abdomen has 10 segments, last 3 are modified for sexual purposes particularly the male. Sensilium/ pygidium – dorsal plate (+) on the 9th abdominal segment of both sexes which is covered with sensory setae Tergum of the 9th abdominal segment in male is modified to form claspers 7th tergum - one to four pairs of long antepygidial bristles. Penis (aedeagus) is chitinous and coiled 10th abdominal segment bears 2 hooked process called anal struts used for holding / locomotion Legs long and adapted for leaping Combs or ctenidia - thick heavy spines arranged in rows on the head and thorax In some species (+) of large spines in head and thorax “comb” or “ctenidia” – cheek genal comb, posterior border of 1st thoracic segment (pronotal comb) Short, clubbed antennae are suck in antennal grooves on sides of the head Fleas have no close relatives, but it is thought that they have evolved from a common ancestors of scorpion flies, the Mecoptera family Boreidae, which like fleas are wingless and capable of jumping. 43 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Mechanism of Jumping The posterior pair of legs of most species of flea is highly adapted for jumping. The energy is stored in the pleural arches which are pads of a rubbery protein called resilin. Resilin is found in the wing hinges of several species of flying insect including the mecopteran ancestors of fleas. The resilin wing hinges have moved from a dorsal to lateral position and form an inverted 'U'-shaped mass capping the pleural ridge. To jump, the femur of the 3rd pair of legs is first rotated to vertical position, bringing the trochanter and tibia of the 3rd pair of legs into contact with the ground. This movement results in the clamping of the 3 thoracic segments in position, engaging the cuticular catches. The resilin in the pleural arch is then compressed by the contraction of muscles and held in plea by the thoracic catches. In this "cocked" position the flea appears to be crouched with its back arched. On jumping, the femur rotates downwards simultaneously the muscles holding the catches in place relax, releasing the energy stored in the resilin. Because the tendon of the trochanteral depressor becomes wedged in its socket and forms an inextensible anchor force is transmitted down the vertical ridges of the notum, pleuron and coxa to the trochanter. The leverage for this movement is supplied by the point of attached at the base of the line of force. After the trochanter leaves the ground the trust is continued as the leg straightens and the descending femur exerts force through the tibia. A flea can jump about 7 inches vertically or 13 inches horizontally Life Cycle Fleas are holometabolous and go through four stages; egg, larva, pupa and adult. Under ideal conditions, the entire life cycle may take only 18 days to complete., although it can range from 6-12 mos. The rate life-cycle completion is dependent on ambient conditions, particularly temperature and humidity. Host availability also affects the time required to complete the lifecycle. Under ideal conditions, a female flea can produce up to several hundreds of eggs in its lifetime, with batches of 2-25 oviposited at intervals of 1-2 days. Eggs maybe laid on the ground, in the host nest or beddings or on the host itself. Eggs generally hatch within a few days of oviposition. Under ideal conditions, larvae emerge after 2-6 days. The flea embryo is equipped with a sharp spine on the head to help it burst through the eggshell. The flea larvae active and feed on proteinaceous organic debris, such as hair; feathers or adult flea feces. The larvae moult at least 2 times until fully grown and 3rd stage larvae spin a thin cocoon of silk. Particles of debris stick to the fleshy spun silk, serving to camouflage it. After several days of quiescence, the cocooned larvae transform into a pupa. After emerging from the pupal cuticle, the adult flea may remain within the cocoon until stimulated by a rise in temperature or another stimulus caused by a host returning to the nest. Both males and females are obligate blood feeders. Female require a blood meal before they can begin to mature their eggs and in males a blood meal is needed epithelial plug is opened in the testes. A female flea may ingest around 15 times her body weight in blood daily. Most species of flea are host- preferential rather than host specific and will try to feed on any available animal Generally, adult fleas do not actively search for hosts, rather awaiting the approach of a host. They remain motionless until vibrations or sudden rise in temperature or humidity signal the proximity of a host animal and trigger jumping. During feeding adults excrete feces which are rich in partially digested blood and which form an important food source for the larvae. Adult fleas can survive for long periods up to 6 mos. between feed. Lifespan: with food – 1 to 4 months, without food – 3 to 4 days. Most fleas feed before mating, in bird fleas, they copulate first before feeding. Egg production may begin within a few days of adult emergence. Copulation may last for an average of 13 hours. Ctenocephalides felis felis cat flea most common species affecting dog and cats. Occasionally man, mouse and rats genal ctenidium - 7-8 spines 1st and 2nd genal teeth are the same Pronotal - 16 spines On the dorsal border of the hind tibia (metathoracic) in both sexes there are only 6 notches bearing setae. IH Dipylidium caninum Flea allergy dermatitis – FAD Mouth parts (fascicle) fitted for piercing and biting 1. Maxillary stylets (Laciniae) - paired structures which are segmented at the tip like saws. Used to puncture the host's skin 2. Labrum - epipharynx - the tip enters the capillary, allowing blood to flow up to the food canal. Blood feeding may take 2-10 minutes to complete, with females taking almost twice as much blood as male. 3. Maxillae (maxillary plates) - large pyramidal structures with a spine at the tip which used to hold the flea in position while feeding... 44 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Life cycle Adult cat fleas are possibly phototactic and negatively geotactic, which cause them to move to the top of carpets, grass or another substrate. Visual and thermal cause trigger jumping, and the presence of CO2 Increases orientation of fleas towards the host animals. After locating a host, adult female mate and feed. Newly emerge female increases in weight by 75 percent after feeding on a cat for 12 hours. Within 10 minutes of feeding, adult begin to produce feces. Feces quickly dries-up into reddish black fecal pellets known as "flea-dirt". Twenty-four to forty-eight hours of first blood meal, the females begin to oviposit. Eggs are pearly white and oval and about 0.5 mm length eggs are usually oviposit on the host but fall to the ground within a few hours. The rate of oviposition is highest at times of day when cats normally rest, early in the morning and late afternoon. 70 percent relative humidity and 35 °C, 50 percent of the eggs hatch within 1.5 days. At 70 percent relative humidity and 15 °C it takes 6 days for percent to hatch. Eggs cannot survive below 50 percent relative humidity. The larvae have limited powers of movement and crawl about their environment at random but are positively geostatic and negatively phototactic. The feces of adult flea are the major primary food source for the larvae of all 3 larval sages. At 75 percent relative humidity and 24 °C, the duration of the 3 larval stages is about 1 week. Larvae will survive at temperatures between 13 and 35 °C. When fully developed, the mature 3rd stage larva empties its gut and spins a thin, silk cocoon. Within the cocoon, the larvae pupate. At 24 °C and 78 percent relative humidity the duration of the pupal stage is about 8-9 days. If the pupal stage is disturbed the larvae will either spin another cocoon or developed into a naked pupa, showing that the cocoon is not essential for development into an adult. When fully developed, adult emerge from the pupal cuticle but may remain the cocoon. They remain for up to 140 days at 11 °C and 75 percent relative humidity. Emergence of the adult from the cocoon is triggered by stimuli such as mechanical pressure, vibrations or heat. Fully formed adults begin to feed almost as soon as they are on the host. Within 36 hours of adult emergence most females will have mated. The total development of C. f. felis may be completed in 17-22 days in females and 20-26 days in males. Under most household conditions, C.f. felis have a life cycle of 3-5 weeks, however it may be extended to as long as 190 days in adverse conditions. Clinical features each female flea can ingest as much as 13.6 µl of blood per day. severe infestation may lead to iron-deficiency anemia. Flea allergy dermatitis-most common causes of dermatological causes of dogs and cats. 2 distinct clinical manifestations: 1. Miliary dermatitis - signs include papules, crust, pruritus, excoriations, and secondary alopecia. Lesions mostly occur on the dorsum, around the tail base and neck. 2. Symmetrical alopecia - due to excessive grooming stimulated by pruritus. There are no lesions on the skin itself, but the cat has broken hairs usually on the ventrum and hind legs. Flea antigens react within canine IgG or IgE IH of Dipetalonema reconditum - a subcutaneous filaroid nematode of dogs suspected of transmitting murine typhus to human. implicates in the transmission between cats of the bacterium Bartonella henselae - responsible for cat scratch disease in human Eosinophilic granuloma complex Diagnosis Based on history, clinical signs, and identification of fleas. Intradermal skin testing using a flea extract- diagnosis of flea-bite dermatitis 45 VPARA 141 Lecture Handout_GG Calderon 2019-2020  biopsy and histopathology in case of "eosinophilic granuloma complex" Microscopic examination of the hair tips reveals fractured ends - symmetrical alopecia Subspecies a) Ctenocephalides felis felis - worldwide b) Ctenocephalides felis strongylus - Africa c) Ctenocephalides felis damarensis - Africa d) Ctenocephalides fells orientis - India and Australia Ctenocephalides canis dog flea, affects dogs and related species 7-8 genal spines and 16 pronotal spines 1st genal teeth is shorter than the 2nd genal teeth On the dorsal border of the hind tibia (metathoracic) in both sexes, there are eight notches bearing stout setae. Echidnophaga gallinacea "tropical hen flea or stick tight flea" No genal or pronotal combs. Burrowing flea Spilopsyllus cuniculi "rabbit flea" that occurs in the ears. Rabbits and hares Vector of myxomatoxis and may transmit a nonpathogenic protozoan, Trypanosoma nabiasi Life cycle Reproductive is under the control of the hormones in the blood of the mammalian host. The presence of progesterone inhibits or delays flea maturation. Following mating, the adult female rabbit ovulates and about 10 days before parturition, the levels of estrogens and corticosteroids in the blood increases. These hormones cause the fleas to attach tightly to their host and stimulate development of the eggs of the female flea. When the young rabbits are born, the fleas move down the face where 80% are likely to be transferred to the young rabbits on which they feed, mate and lay their eggs. Copulation of S. cuniculi only takes place ill the presence of young rabbits (1 to 10 days Old). An airborne kairomone emanating from the newborn rabbits and their urine boost copulation and reproduction. The hormones of the hosts also cause adult fleas to increase the rate feeding and defecation by about 5 times. This provides an abundance of food in the burrow for the newly hatched larvae. Population of S. cuniculi may increase dramatically during the rabbit breeding season. Adult female fleas on bucks and non-pregnant does are more mobile and will move to pregnant does if able. The rise in Bar temperature during rabbit mating will also stimulate movement of fleas from one rabbit to another. Pulex irritans "human flea" Absent genal and pronotal ctenidia May occur in pig, badger, dog, cat and rats Can transmit Dipylidium caninum Xynopsylla cheopis "Oriental rat flea", “Black rat flea” Genal and pronotal ctenidia absent Associated with the transmission of typhus and bubonic plague (Pasteurella pestis) (+) in rodents in ports, mice IH of Hymenolepis nana and H. diminuta Ceratophyllus niger "the western chicken flea" Genal ctenidium absent; pronotal- more than 24 spines Ceratophyllus gallinae "European chicken flea" Similar to C. niger Ceratophyllus columbae Common in pigeons Ceratophyllus (Nosopsyllus) fasciatus "Northern rat flea" Genal ctenidium absent; 18-20 pronotal spines. Transmit Hymenolopis diminuta 46 VPARA 141 Lecture Handout_GG Calderon 2019-2020 Leptopsylla segnis European mouse flea Tunga penetrans sand flea; jigger; or chigoe They exhibit neosomy - the ability to produce new cuticle without moulting. Maybe present in pig, baboon It burrows into the tissues of humans and some domestic animals that may lead to tetanus and gangrene from secondary bacterial infection PRONO MESO GENAL Flea Species HOST COMB TAL EYES HEAD PLEURAL NOTES COMB ROD Female: head twice as long as Ctenocphalides felis felis height; pointed anteriorly Sloping elongated Dog 7–8 16 Present Present front of head Male: head is long as wide; slightly elongated anteriorly More rounded on Cannot interbred with C. felis et felis Ctenocephalides canis 7–8 its upper and Cat (same 16 Present Present anterior surface Male & Female: first genal spine is size) than that of cat flea shorter than the rest Rounded head; Spilopsyllus sp. Rabbit 4–6 16 Present Frontal tubercle With two stout spines beneath the eye conspicuous Domestic Sharply angled at Echidnophaga sp. Poultry 0 0 Present frons Absent With two setae behind the antenna Distinguished with Xenopsylla Pulex sp. Humans & presence of a single ocular bristle Smoothly rounded other 0 0 Present Absent below the eye and absence of a row anteriorly mammals of bristle along the near margin of the head With conspicuous row of bristles Xenopsylla sp. Rats 0 0 Present Smoothly rounded Present along tile near margin of the head & anteriorly stout ocular bristle in front of eye More Head bears a row of strong setae Ceratophyllus sp. Birds 0 than 24 Present Normal Present below the eye Frontal tubercle Head carries a row of 3 setae below Nosopsyllus sp. Rats 0 18 – 20 Present conspicuous Present the eye Humans & Tunga penetrans domestic 0 0 Present Angular with acute Absent Capable of neosomy (produce new frontal angle cuticle without moulting) mammals C I A Ctenocephalides felis felis E Oropsylla montana I Myodopsylla insignis B C. canis F Xenopsylla cheopis J Cediopsylla simplex C Pulex irritans G Hoplopsyllus anomalus D Nosopsyllus fasciatus H Leptopsylla segnis Pathogenesis Direct effect – restless, lose condition, spoils their coats by biting and scratching Flea bite dermatitis – caused by the hapten in the saliva of flea that becomes immunogenic by fixation to host’s skin collagen Clinical signs vary mild pruritus often unnoticed moderate to severe pruritic reactions -lumbar, sacral, abdomen, inside hindlegs and neck moist dermatitis (wet eczema) - secondary bacterial infection, consists of discrete papules with scaling acanthosis, hyperpigmentation and hyperkeratinization are features of long-standing cases diffuse alopecia may result from excessive grooming/scratching Echidnophaga gallinacea - females attach to wattles, comb, around the eyes of birds. Young birds are killed, adults may succumb to heavy infection. Female burrows into skin → swelling → may ulcerate 47 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Pathogen / Parasite (Disease) Flea Vector Yersinia pestis (Bubonic plague) Xynopsylla cheopis, Pulex irritans, Ceratophyllus fasciatus Ricketsia typhi (Endemic typhus) X. cheopis Fibromavirus (Rabbit myxomatosis) Spilopsyllus cuniculi Trypanosoma lewisi C. fasciatus Acanthocheilonema (= Dipetalonema reconditum) Ctenocephalides spp. Dipylidium caninum (Dipylidiosis) Ctenocephalides spp., P. irritans Treatment dichlorvos, Coumaphos, Ronnel, hexachlorocvclohexsne, carbaryl (Sevin), and steroids to reduce pruritus Control treat animals to kill fleas eliminate developmental stages in host's environment prevent re-infestation of environment biological control: ants, histerids (clown beetle), staphylinids (rove beetles and tenebrionid (darkening beetle), parasitic nematode Steinerma carpocapsae wingless, usually 2-4 mm long ectoparasites of birds and mammals dorsoventrally flattened bodies photosensitive spots powerful claws adapted for clinging to hair feathers legs short but stout and each terminates in claws, the lice of mammals having one claw on each leg, whereas those birds have two abdomen has 5-8 distinct segments metamorphosis is gradual / incomplete (egg, nymph, adult) Habits o Slow moving but with powerful legs o Attach their eggs in hairs and clothing’s fibers o 3 nymphal stages – live and feed like the adult o Thigmotactic – move less in rough surface o Negatively phototactic – move toward dark objects o highly host specific o permanent parasites, most unable to survive away from the host for more than a day or two lice found on atypical host are termed stragglers Old classification: ORDER PHTHIRAPTERA o 2 SUBORDERS Mallophaga (biting lice) – elevated to Order Anoplura (sucking lice) – now Order Siphunculata Difference between Biting and Sucking Louse ORDER MALLOPHAGA ORDER SIPHUNCULATA (formerly Suborder) (formerly Suborder Anoplura) Biting Lice – feed on scales, secretions, skin detritus Sucking lice – feed on blood Well-developed mandibles Protrusible proboscis – 3 piercing stylets (dorsal, medial, ventral, without mandibles Affects mammals and birds Affects mammals Head rounded anteriorly Head pointed anteriorly Antennae not so visible Visible on side of the head Characteristically the head is small in relation to the body size, but narrow and elongated. Antennae have 5 segments Eyes are reduced or absent Mouth parts are adapted for piercing the skin and for sucking the blood and tissue fluids of the host or which these lice feed (solenophagy) Vessel feeders or solenophages that imbibe blood through hollow dorsal stylet derived from hypopharynx They are composed of 3 stylets in a ventral pouch which form a set of cutting structures. The true mouth, the prestomum is usually lined with fine teeth and opens at the anterior extremity of the ventral pouch. During feeding, the prestomum is inverted and the teeth help to secure the louse to the host's skin. 48 VPARA 141 Lecture Handout_GG Calderon 2019-2020  The stylets are then used to puncture the skin and blood is sucked into the prestomum by a muscular cibarial pump. The mouth parts are usually retracted into the head when not in use. No palps. Haustellum or mouth cone - pouch within the head through a small tube-like where the dorsal, median and ventral stylets protrude. Dorsal and ventral stylets are fork at their proximal ends in the stylets sac which the ventral is believed to represent the fused maxillae. When not used the 3 stylets are retracted into a blind sac lying under the pharynx. Thoracic segments are usually fused together and are difficult to distinguish. One pair of spiracles on the mesothorax and six pairs on segments 3-8 of the abdomen. The abdomen may have sclerotized paratergal plates along the sides. paratergal plates - dark brown or black areas of thickened chitin found at the lateral sides of the abdomen. Pair of legs are generally smaller with weaker claws "crab-like claw" on each leg. These are single claw projecting from the tarsus. Projection from the last tibia called tibial spur - enables lice to cling to hairs. Tibial pad - padlike structure between the claw and tibial spur which is being thrust up to prevent the louse's hold on the hair from slipping down. The female has two pairs of lateral gonopods giving the abdomen a blunt- ended shape, whereas the sclerotizes genitalia of the male give a more pointed posterior tip. FAMILIES Paratergal Temporal Row of hairs on Family Eyes Leg Pairs Size plates Angles abdominal segment Hematopinidae; - + (marked) Similar sizes + 1 Large Genus Hematopinus Linognathidae;Genera: - 1stpair is - - many Small Linognathus, Solenopotes smallest Pediculidae; Genera: + + Similar sizes - Medium Pediculus, Phtirus The large sucking lice of mammals about 4-5 mm in length Eyes absent Possess prominent angular processes known as ocular points or temporal angles behind the antennae. Broad thorax Thoracic sternal plate is dark and well developed Sclerotized paratergal plates present 1 row of spines on each abdominal segment Legs equal in length. The legs are of similar sizes which opposes the tibial spur Species Hematopinus asini – equine, horse sucking louse. 3 - 3.5 long with yellow-brown and has a longer, more robust head than H. suis. H. suis – swine, the pig louse. Largest blood - sucking louse found in domestic animals characterized by a long, narrow head and long mouthparts. It is 4-6 mm long. H. eurysternus – short-nosed cattle louse, average 2.5 mm in length with a short-pointed head and broad body. Head and thorax are yellow-brown, and the abdomen is blue gray. H. tuberculatus – carabaos, buffalo louse H. quadripertusus – cattle tail louse Life cycle one to six eggs per day which are glued to the hairs and hatch in 1-2 weeks. Nymphs mature to adult in 12 days Within 4 days after feeding and mating, the female lice may begin to lay eggs 24 eggs laid per female. Dies after 10 - 15 days of oviposition Haematopinus suis - female lays 3-6 eggs per day, producing up to 90 eggs over 25-3 days Pathology Haematopinus suis - occurs in the folds of the neck and jowl, around the ears, flanks and back. May survive for up to 3 days off its host. Transfer can occur when animals are put into recently vacated dirty accommodation. Haematopinus asini - found on the head, neck back and inner surface of the upper legs. Symptoms include dandruff and greasy skin and eventually bald spots with raw red centers. Haematopinus eurysternus - primary around the horns and top of neck, ears, tails of mature animals in tropical and subtropical region. 49 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Haematopinus quadripertusus - found largely in long hair around the tail. The normal host is a Zebu cattle - Bos indicus. No eyes or ocular points smallest sucking louse of mammals 2nd and 3rd pairs of legs are larger than the 1st pair. Abdomen has numerous hairs, 1st pair of legs smallest thoracic sternal plates are absent and no paratergal plates Species Linognathus vituli – long-nosed cattle louse L. africanus – blue louse of sheep in Africa L. pedalis – foot louse of sheep L. ovillus – face louse of sheep L. stenopsis – goats L. setosus – dogs and foxes Life cycle lay single egg per day eggs hatch in 10-15 days 3 nymphal stages requires 2 weeks 20-40-eggs to adult Pathology Linognathus ovillus - ears and face of sheep Linognathus pedalis - occurs in aggregation on the lower and less wooly parts of the feet, legs and scrotum. Linognathus vituli - dewlap; side of the neck, shoulders and rump. Linognathus setosus - long ears of breeds of dogs particularly spaniel, basset and Afghan hounds. Genus Solenopotes/ Solenoptes Solenoptes capillatus -little blue cattle louse. Smallest of the Anopluran lice found on cattle Eyes and ocular points are absent. Prominent abdominal tubercles bearing the spiracles project from the sides of each abdominal segments No paratergal plates pigmented eyes present paratergal plates present legs equal in size Species Pediculus humanus capitis – human head louse P. h. corporis – body louse of man Phtirus pubis – crab louse, pubic louse of man LIFE CYCLE Incomplete / Direct: eggs are laid attached to hairs “nits” → become nymphs in 13-15 days and molts 3 times → adult. Mode of transmission: contact with infected animals / persons, spread by farm equipment / personnel Treatment DDT, BHC, toxophene, dieldrin, Ops (Neguvon®, Malathion®, Asuntol®), Carbamates (Sevin®), repeat after 2 weeks 50 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Biting louse Mammals = 1 claw, Birds = 2 claws 2 suborders Basis of comparison Suborder Amblycera Suborder Ischnocera Antenna Lies in grooves; not readily seen; 4 3-5 segments visible segments, 3rd stalked – egg shaped Maxillary palpi Present, 4 segments and 3rd not stalked Absent Mandibles Bite horizontally Bite vertically First two segments of the thorax are visible. Single pair of thoracic spiracles are on the ventral side of the mesothorax. Typically, there are six pairs of abdominal spiracles. Three pairs of legs are week and slender and end in their one or two claws depending on the species. 51 VPARA 141 Lecture Handout_GG Calderon 2019-2020  The mandibulate mouth parts which are typical of chewing insects, composed of a labrum, a pair of mandibles and pair of maxillae attached laterally to the labium which is reduced to a simple broad plate. In the Amblycera, the mandible lies parallel to the ventral surface of the head and cut in a horizontal plane. A pair of maxillary palps which are 2-4 segmented. In the Ischnocera, the mandibles lie at the right angles to the head and cut vertically. No maxillary palps. Life Cycle Eggs are operculated cemented to hairs on feathers → nymph, molts 3 times → adult. Lifespan depends on species of biting lice and environmental conditions. Whole life cycle is spent on the host. Large, rounded heads which the eyes are reduced or absent. Chewing lice with mouthparts consisting of distinct mandibles on the ventral surface of the head and a pair of 2-4 segmented maxillary palps. 4-segmented antennae are protected in antennal grooves, so that only the last segment is visible. Species affecting mammals Heterodoxus spiniger – dogs o Large yellowish louse about 5 mm in length o Dense covering of thick, medium and long setae H. longitarsus and H. macroplus – kangaroos / wallabies Species affecting birds Menopon gallinae (M. pallidum) – shaft louse of domestic chicken (poultry), o pale yellow in color o female- tapered posteriorly; male- rounded o Sparse covering of small to medium-length setae on its dorsal surface. o Highly mobile and move rapidly o Life cycle Eggs clusters at the base of the feathers. 3 nympal stages o Pathology does not usually infest young bids until they are feathered thigh and breast M. phaestomum – peacocks Menacanthus stramineus – yellow body louse, chicken body louse, breast, thighs, around anus o Adults 3.5 mm in lengh o Head almost triangular in shape and the ventral portion of the front of the head is armed with a pair of spine-like process. o Palps and segmented antennae are distinct o Antennae are club-shaped and mostly concealed beneath the head. o Flattened abdomen is elongated and broadly rounded posteriorly with two rows of setae on each abdominal segment. o Life Cycle Eggs laid 2-3 days after lice mature which are glued to the base of the feather in dense clusters. particularity around the vent. Hatch after 4-7 days to nymph which passed through 3 nymphal stages with 3 days each stage. Adult females deposit 1-4 eggs per day over their lifetime of 12-14 days. Each female lay about 20 eggs. 2-3 weeks to complete life cycle. o Pathology Lice eat the barbs and barbules of the feathers. Common on breast; thighs and around the vent. In heavy infestations, lice maybe found under the wings and on other parts of the body including the head. Populations may reach as many as 35,000 lice per bird. Trinoton anserinum – feathers near the skin of ducks and swan Holomenopon leucoxanthum – on ducks 52 VPARA 141 Lecture Handout_GG Calderon 2019-2020  Antennae are usually filiform and are visible Species affecting mammals Damalinia (Bovicola) bovis – cattle o 1.5-1.75 mm length and 0.35-0.55 width o adults have large broad head which is red in color o reddish- brown body with dark transverse bands on the abdomen. o Legs are slender D. ovis, D. caprae, D. panei / limbata – goat, "sheep body louse" o one of the smallest mammalian lice o adult with pale-colored with several dark lateral bands across its abdomen D. equi o 1-2 mm long o head is broad and flat (head is rounded with 3- segmented antennae o pale brown body is dorsoventrally flattened. Life cycle o 3-4 weeks-egg to adult o D. bovis - maybe facultatively parthenogenetic allowing to build populations very rapidly. sex ratios of 1 :20 females but maybe higher. Lay approximately 1 egg every 35 hours each glued singly onto a hair shaft. o D. ovis - lay 2 or 3 every 5 days. o Estimated to take about 20 weeks for a population of bovis on a sheep to increase from 5000 to half a million under favorable condition. Pathology o heavy infestations may result in intense irritation. Pruritus, excoriation and alopecia o D. bovis - top of the head, neck, shoulders. Back and rump in both dairy and beef. Commonest cattle parasites in Europe and the only chewing louse found on cattle in USA. o D. ovis - areas close to the skin especially on the shoulder, neck and back area. o D. equi - most common external parasites of horses especially in temperate climates. Prevalent on the head, mane, base of tail and shoulder. Felicola substrata – domestic cat o beige or yellow in color o shape of head - triangular and pointed anteriorly o ventrally - median longitudinal groove on the head which fits around the individual hairs of the host. o 3 segments antennae and fully exposed o Abdomen - 3 spiracles and few smooth setae Life cycle o requires about 30-40 days to complete its life cycle. Eggs hatch in 10-20 days and adult stage reach in about 2-3 weeks. Pathology o problematic in long haired cats Trichodectes canis – dog o yellow louse with dark markings o head broader than long, 3-segmented antennae, short and exposed. o Legs are stout o Abdomen has 6 pairs of spiracles on segments 2-6 Life cycle o Several eggs per day for approximately 3 days. o Hatch in 1-2 weeks with 3 nymphal stages and matures in 2 weeks. 30-40 days to reach adult. Species affecting birds Cuclotogaster heterographus – head louse of poultry and feathers of head and neck o rounded body with a large. slender head, which is rounded at the front. o adult about 2.5 mm length o Three long bristles project from each side of the dorsal surface of the head o Five dorsal segmented antennae are fully exposed. o each leg has two tarsal claws. o Female - abdomen barrel-shaped o Male- abdomen more elongated o Abdomen- bears of row of dorsal hairs of each segment 53 VPARA 141 Lecture Handout_GG Calderon 2019-2020  o Life cycle Pearly white eggs are attached singly to the downy feathers close to the skin and hatch within 5-7 days into a minute, pale, translucent nymph which resemble the adults in shape. Nymphs - 3 nymphal stages. o Pathology occurs mainly on the skin and feathers of the head, although it occurs occasionally on the neck and elsewhere. Important in young birds. When birds become fairly-well feathered, head lice infestation decreases. Lipeurus caponis – slender wing louse on fowls and pheasants o elongated narrow species about 2.2 mm length. o head long and rounded at the front o antennae are 5-segmented and fully exposed o legs narrow and bears 2 tarsal claws o hind legs are about twice as long as he first two pairs o small angular projections on the head in front of the antennae o relatively few dorsal hairs on the abdomen o Life cycle eggs- hatch in 4-7 days nymph- 3 nymphal stages in 20 -40 days adults- may live up to 35 days o Pathology occurs on the underside of the wing and tail feathers. Goniodes gigas – large louse on body / feathers of chicken o broad head is concave posteriorly., producing marked angular corners at the posterior margins. o head carries 2 large bristles projecting from each side of its dorsal surface. o antennae have 5 segments and are fully exposed o 2 tarsal claws o Life cycle eggs- hatch 7 days nymph - 3 nymphal stages male - live for 20 days Female- 25 days. lays about 15 eggs in their lifetime. 1 month- entire life cycle G. dissimilis – brown louse of chickens Goniocotes galinae (hologaster) – fluff louse, base of feathers of fowls, pheasants and pigeons o one of the smallest lice found in poultry. o pale yellow almost circular body o head is rounded and carries two large bristles projecting from each side of its dorsal surface. o antennae 5 segmented and fully exposed o few hairs on the dorsal abdomen Chelopistes meleagridis – common louse of turkey, large turkey louse Columbicula columbae – pigeons Companulotes bidentatus – pigeons Colpocephalum turbinatum – pigeons Anaticola crassicornis and A. anseris – ducks Oxylipeurus polytrapezius – slender turkey louse O. dentatus – chicken neck louse] Trinoton anseris – ducks, geese Pathogenic Effect Irritation, scratching, loss of feathers, hairs, wools, restlessness, decrease egg and milk production Wounds / bruises due to scratching, hairballs, matted hairs / feathers Dipetalonema reconditum, typhus fever, French fever Control Co-Ral®, Malthion®, Sevin® Effects and control of louse infestations (pediculosis) Mammals Rule of thumb: Chewing or biting lice are more pathogenic than sucking lice 54 VPARA 141 Lecture Handout_GG Calderon 2019-2020 In cattle Moderate infestation – chronic dermatitis o Large numbers of biting lice – intense irritation o Sucking lice – H. eurysternus can cause serious anemia and weight loss o Treatment: Thresholds (3 lice per sq. in. → treat; more than 10 lice/ sq. in. → severe infestation) o Organophosphates as pour-ons or dusting powders (may be combined with gamma HCH); cypermethrin pour-on; Parenteral ivermectin) In sheep Sucking louse can cause anemia Biting lice can cause great irritation leading to interrupted grazing, weight loss, self-inflicted injuries, damage to fleece, loss of wool; myiasis Treatment: spraying or dipping in organochlorines or organophosphates; pour-on cypermethrin; spot-on deltamethrin In pigs Heavy infestation – restlessness and other consequences H. suis is bloodsucking – anemia is rarely observed Treatment: gamma HCH, diazinon and malathion as powder or wash; parenteral ivermectin; phosmet pour-on In equines Biting lice – cause intense irritation Sucking lice – cause anemia Treatment: Apply by sponge gamma HCH, bromociclen, ronnel, regu;ar and thorough grooming; scald grooming equipment, wash rugs thoroughly and clean saddle to eliminate attached lice and nits. In dogs and cats Associated with neglected and underfed dogs In dogs, Trichodectes canis – more harmful → intense pruritus with serious consequences; sucking lice – cause anemia In long-haired cats, pathogenic populations of Felicola may develop under matted fur Treatment: application of insecticide in the form of powder, wash or shampoo In man Anemia and irritation Vagabonds’ or vagrants’ disease / parasitic melanoderma Vector of pathogens – Ricketsia organisms Treatment: application of insecticides in the form of powder, wash or shampoo. In birds Rule of thumb: those that are found close to the skin are more pathogenic (e.g. Lipeurus spp., Menacanthus stramineus) M. stramineus – punctures small feathers and feeds on blood that oozes out → anemia; severe irritation. Most pathogenic species in adult birds Holomenopon leucoxanthum favors the preen gland and inhibits oil secretion leading to ‘wet feather’ Young birds suffer more severely; the main loss in adults is depression of egg production Treatment: insecticide dust (malathion, carbaryl, pyrethrins / pyrethroids, herbal); insecticide – impregnated leg bands or strips Summary of Comparison Between Sucking and Biting Lice 55 VPARA 141 Lecture Handout_GG Calderon 2019-2020  The classes include scorpions, spiders, ticks and mites. They differ fundamentally in structure and function from the insect because of the absence of antennae, wings and compound eyes and the division of the body into head, thorax and abdomen. The mouth of the arachnids is small, and they feed chiefly on the tissue fluids of other animals which they suck up by means of a sucking pharynx. Many of them possess poison glands and poison claws which they paralyze their prey before they suck the juices out of them. 56 VPARA 141 Lecture Handout_GG Calderon 2019-2020