Introductory Lecture on veterinary informaticsFull description
jjk
torts
Full description
Descripción completa
Full description
envi
Descrição completa
Description of various important parasites of animals
Full description
environmental case digest
Free of charge. For last resort.
Lecture Notes about veterinary histologyFull description
radiologyFull description
legal opinion
VETERINARY HELMINTHOLOGY TAPEWORM/ CESTODES General Characteristics: Characteristics: 1. ribbon-like and dorsoventrally flattened 2. most most of the the show show indi indire rect ct type typess of life life cycl cycle. e. The The exceptional type of life cycle is found in Hymenolepis spp where direct and indirect types are found. 3. they are hermaphrodite 4. cysts or bladderworms are intermediate or larval stage of the parasite 5. the final host gets infection by ingestion of intermediate host host or flesh flesh of inter intermed mediat iatee host host contai containin ning g the the bladde bladder r worms 6. the body can be divided into three broad parts Head/ Scolex -very minute as compared to other parts -shape varies which may be roughly triangular,ball shaped or round -there is presence of sucker (armed or unarmed ) which is not used for taking food but used as apertures for attachment -anteriorly there is structure called rostellum Neck -immediately -immediately behind the head and without any segment -segmentation starts here Body -area is completely segmented
Three types of segments are present: IMMATURE- the reproductive system and eggs are absent MATURE- completely developed reproductive system GRAVID- reproductive system is replaced by the eggs -either detached from the parasite or its disintegrated and the eggs are expelled out Eggs: -have basic structure structure comprising comprising oncosphere oncosphere or hexacanth hexacanth embry embryo, o, a striat striated ed shell shell or embry embryoph ophore ore and a delica delicate te membrane -the following are the events which occur during biological development: a. Eggs are expelled expelled out from the gravid segment b. the eggs are ingested by the intermediate hosts and hatchi hatching ng occurs occurs in the intermed intermediat iatee host host or hatch hatch in the environment ( Cotyloda) -metacestodes / bladderworms / cyst / larval stages are formed in the intermediate host -final host gets the infection by ingestion of the intermediate host host or the the musc muscle less and and fles flesh h cont contai aini ning ng the the cyst cystss or bladderworms
Poultry Tapeworm Genus Raillietina -small -small to medium medium-si -size zed d tapew tapeworm orm that that inhabi inhabitt the small small intestine -cosmopolitan in distribution
Species: R. cesticillus R. echidnobothrida R. tetragona R. asiatica R. celebensis R. demerariensis R. cesticillus Morphology: 1. smaller (4-15 cm) than R. tetragona, R. echidnobothrida 2. broad rostellum which is armed with 400500 hooks 3. circular sucker is unarmed 4. egg capsule contains single egg R. echidnobothrida Morphology 1. size is 8.5-22 cm 2. suckers are circular and surrounded by several rows of hooks 3. rostellum is very small 4. egg capsule contains multiple eggs R. tetragona 1. 25 cm long and largest tapeworm in poultry 2. rostellum is small and possesses one or two rows of hooks 3. egg capsule contains multiple eggs 4. sucker is oval and surrounded by several rows of hooks
Ants and Musca domestica acts as IH of R. tetragona and R. echidnobothrida. The beetle acts as IH for R. cesticillus Pathogenesis: 1. nodule formation in the intestine by R. echidnobothrida 2. enteritis by R. tetragona and R. cesticillus Genus Davainea D. proglottina D. meleagridis
2. constant irritation of the anal sac resulting to anal pruritus 3. intoxication due to absorption of the metabolites released by the parasites which affects the nervous system Diagnosis: 1. examination of fecal sample 2. dragging anus over the ground or any hard objects Family Anoplocephalidae: common cestodes cestodes of equine
Morphology 1. very small only several mm that’s why it is advised to take mucosal scraping for its detection 2. has prominent rostellum armed with hammershaped hooks 3. presence of single set of reproductive organ which alternates regularly 4. has 4-9 segments 5. egg capsule contains single egg Life cycle: Egg Oncosphere Cysticercoid Cysticercoid in IH (infective stage on ants or slugs) Adult
Morphology: 1. rostellum and hooks are present 2. segments are noticeably broad\ 3. presence of egg capsule or paruterine organ 4. eggs have 3 coverings; the outermost formed by the vitelline gland, middle albuminous and inner chitinous 5. eggs of many members bear a pear shaped structure called pyriform apparatus Genera: Anoplocephala Paranocephala Pseudanocephala
Moniezia Cittotaenia
Other Species The gravid gravid segmen segments ts crawl crawl out of the host. The gravid gravid segments are actively motile and crawl onto the grass blade due to its phototactic nature. The eggs are released during the act of crawling. The eggs hatch after ingested by IH and cysticercoid is formed within a month. The final host gets the infection when the infected snails are ingested by the birds. Family Dipyliidae: Dipylidium caninum- double pored tapeworm of dogs
Morphology: 1. head or scolex is pyriform in shaped having hooks characteristically rose-thorn shaped 2. presence of two sets of reproductive system like Moniezia spp 3. mature segments are cucumber seed shape LIFE CYCLE: egg onchosphere cystercercoid cystercercoid in IH (flea C. canis, C. felis, T. canis, Pulex sp ) adult Gravid segments get detached from the adult tapeworm and crawl. During crawling the eggs are released from the gravid segment. The IH ingest the eggs and hatched in the gut and oncospheres are released and these migrate in the body cavity. A cysti cysticer cercoi coid d with with tail tail append appendage age is formed formed withi within n few few weeks weeks.. Final Final host host gets gets the infect infection ion by inges ingestio tion n of the infected IH. Pathogenesis: 1. sloughing, denudation of mucosa
Anoplocephala magna
Anoplocephala perfoliata
Pseudoanoplocephala mamillana
1. Largest cestode found in the horse found in SI and stomach 2. 80 cm long
Small Small intes intesti tine ne
Si and and stom stomac ach h
1-8 cm
0.6.6- 5 cm
3. Testes are arranged in rows. The number of testes are 400500 4. Pyriform apparatus is not strong and large Lappets are absent
250
100
Large and strong
Large and srong
present
absent
LIFE CYCLE: Egg Onchosphere Cysticercoid in IH ( mite) Adult Pathogenesis: A. perfoliata particularly affects the ileocecal orifices and they produce depressed ulcers which is dasrk in color and may cause perforation of SI A. magna causes hemorrhagic enteritis obstruction of the intestinal lumen P. mamillana less significant
Taenia pisiformis
Cysticercus pisiformis
rabbits
Taenia taeniaformis
Cysticercus fasciolaris
rodents
Taenia multiceps
Coenurus cerebralis
Sheep And goat
Taenia saginata
Taenia solium
Host is man
man
Rostellum is absent
Present armed with hooks
1000-2000 segments
800- 1000 segments
Family Hymenolepididae H. carioca
H. diminuta
1. 3-8 cm
2-6 cm
H. nana dwarf tapeworm 7-80 cm
2. 500 segments
500 500 segm segmeents nts
Few segm segmen ents ts
Ovary is bilobed
trilobed
3. testes lie across the segment
Testes are ovoid
Testes lie in line and separated by the ovary
Oval egg
Spherical
Uterus has 14-32 branches
16 branches
LIFE CYCLE: egg onchosphere cysticercoid in IH adult
Taenia solium
Family Taeniidae Morphology 1. large tapeworm 2. proglottids are rectangular 3. rostellum may or may not be present 4. segments are longer and broader 5. uterus has median stem and lateral branches 6. egg capsule is easily lost and the embryo pore is striated in appearnace
Intermediate Stage
Intermediate host
Cysticercus cellulosae
pig
Taenia saginata
Cysticercus bovis
cattle
Taenia hydatigena
Cysticercus tenuicollis
Sheep, ruminants
Taenia solium
Life cycle: egg ( hatch after being ingested) Onchosphere ( migrates in different organs and tissues) Cysticercus Cysticercus ( infective stage in the pork ) Adult ( ingestion of infected ham and pork ) Man gets infection by the ff: ways 1. ingestion of pork containing cysticercus 2. ingestion of eggs through the food and cysticercus develops in man 3. by autoinfection due to retrosperistaltic movement. The eggs return to the stomach and hatch Predisposing factors: 1. eating habits of people 2. large scale implementation implementation of insewcticide Pathogenesis: Man 1. utilize the nutrition of the host 2. causes enteritis 3. neurocysticercosis neurocysticercosis Pig 1. measly pork- presence of cysticerci in different organs or tissue
Neurocysticercosis 1. encephalitis and meningitis 2. epileptic fit and excitement
Taenia multiceps
Life cycle: egg Onchosphere Coenurus ( infective stage in the brain of sheep and goat ) Adult Pathogenesis: Migrator Migratory y onchospher onchospheres es care dangerous dangerous in the sheep. sheep. This causes meningitis and encephalitis Gradually the cyst creates pressure in the brain as per the advanceme advancement nt of developmen developmentt of cyst. cyst. The brain muscles muscles get atrophied The skull gets atrophied and ultimately maybe soft and easily felt when touching Aside from brain several nerves are also affected ( ocular, auditory ) Clinical signs: 1. the animal looses the condition and fails to respond to the environment 2. circling movement ( gid ) is an important sign 3. sometimes the animals move in straight and keep its head on the hard surface Genus Echinicoccus E. granulosus E. vogeli E. multilocularis multilocularis E. oligarthus
Morphology: 1. very small only few segments are present 2. terminal segment is the gravid segment 3. scolex has the rostellum which is armed with hooks 4. ovary is kidney shaped Life cycle: egg onchosphere hydatid cyst in IH adult
individual and there would be hypersensitive reaction within 15 mins or less in positive cases Family Mesocestoididae: Genus Mesocestoides M. lineatus M. jonesi M. variabilis M. tenuis
Morphology: 1. head or scolex is devoid of rostellum and hooks 2. presence of single set of reproductive system 3. genital pore is dorsally situated 4. bilobed ovary and vitelline glands 5. testes are situated on either side of the excretory canal DH- dog, fox, cat IH- 1st – mites 2nd - birds Developmental stages: egg onchosphere cysticercoid cysticercoid in IH tetrathyridium tetrathyridium in birds, lizards, snakes adult *M. corti can asexually multiply in the IH and DH
Pathogenesis: 1. enteritis 2. nervous disorder 3. anal priritus Genus Diphyllobothrium Species: D. latum D. mansonoides
Morphology: 1. long and maybe reaching up to several meters 2. thousands of segments are presents 3. head is spatula shaped with a deep groove in the middle called bothria 4. no rostellum 5. genital organs are situated mid-ventrally 6. eggs are oval and operculated and have fair resemblance to trematodes 7. ovary is bilobed and uterus is rosette-shaped
Pathogenesis: 1. enteritis 2. pressure atrophy in the vital organs due to pressure of large- sized cyst 3. functional disturbance
Diagnosis: 1. examination of feces 2. detection of cysticercus in the tongue and other palpable areas 3. Casonis Test- hydatid fluid is inoculated in the suspected
Pathogenesis 1. enteritis 2. anemia ( B12 def. or Pernicious anemia ) 3. anal pruritus 4. epileptic fit
