Lecturer 12
Transcript of Lecturer 12
The entire carcase is condemned in one case of the following
Types of T.B.Localized T.B. with emaciation (This mean that T.B. is the direct cause
of emaciation)Generalized T.B. (T.B. is said to be generalized when
there is evidence of recent invasion of the arterial blood )
The entire carcase, organs, viscera , should be condemned
such evidences are:1-heavy miliary T.B. of both lungs:Acute military T.B. mean heavy invasion of blood stream
with tubercle bacilli occur in *Early generalization during primary infection.*Acute late generalization.In such case . miliary T.B. not only found in lungs but
also found in kidney ,spleen……etcThe affected lungs are oedematus and emphyse-
matous with infection in apical L.n. the miliary T.B .found on the surface, In lung tissues and
beneath the visceral pleura.
2-multiple and actively progressive lesions of T.B.
Lesions of T.B. should multiple and actively Progressive …..for total Condemnation……..This assumed If:
a) There is a congestion in the surrounding tissues b) The regional L.ns……. enlarged and oedematous c) An older caseous focus………… surrounded with
several small millet –sized lesions d) Breakdown lesions are dotted with small
haemorrhages with enlarged L.n w has either miliary T.B. or stellate radiation
3-wide spread infection of the carcase L. ns
For T.C. of the carcase……..lesions in carcase L.nsshould be acute infiltrative and caseous in nature this
mean that T.B. present in blood and muscles If lesions are chronic…. encapsulation and
calcification, this indicate absence of bacilli from the muscles.
For T.C. of carcase there must be a)2 or more carcase L.ns. have T.B. b) 2 or more carcase L.ns not confined to thoracic or
abdominal cavity. c) Lesions are acute.
4-diffuse acute lesions of both pleura and peritoneum ass. with an enlarged or T.B. carcase L.ns
Acute T.B. infection of pleura & peritoneum……red velvety granulation.
Although in most cases, the condition is not caused by a haemotagenous spread.
This condition become active ,if ass. with the presence of bacilli in the muscles.
Chronic lesions……..pearly from( less important) …….. muscles are free form T.B.
5-T.B lesions in the respiratory and digestive tracts
where in addition to the presence of T.B lesions in the respiratory and digestive tracts .
There are also active lesions in the substance of any twoof the following spleen, kidney, udder, uterus, ovary,testicle, brain ,spinal cord or other membranes.For T.C. of carcase T.B. should be present in bothrespiratory and digestive tracts together with acute orrecent lesions in 2of the said organs.*If the lesions are acute or recent……..condemned the
carecase.*If the lesions are chronic………..condemned the
affected organs or parts…….. pass the carcase.
6-congenital T.B
congenital T.B………… followed haematogenousspread………… Generalized nature.Congenital T.B. spread via the faetus from primary infect.
Offaetal liver by blood streamLymph nodes are enlarged +caseated with out formation ofT.B. nodules.Liver infect … peritoneum by lymmphatics on post aspectDiaphragm infect by…… the thoracic cavity give….. lesionsIn post mediastinal L.ns ,brsnchial L.ns ,lungs and rarely
pleuraThe affection to be congenital, there must be 1- lesions with out calcification in splenic substance, liver,kidney and parotid L.n.2- the age of the calf less than 14 days.
Differential diagnosis
A-Bacterial infection1-Johne’s diseaseCaused by an acid fast bacillus (Johne’s bacillus)ccc. by much thickening and corragation of theintestinal mucous membraneThe condition is locally confined to the affected intestine
and mesenteric l.ns with out purulent or caseous fociJohne’s bacillus can not inoculated into G. pig or rabbits
and vica versa in T.B
Differential diagnosis
2-actinomycosis or actinobacillosisIt is difficult to differentiate two conditions from T.B., if nolesions in tongue or maxilla.Early lesions appear as shot like ,glistening hardprojecting nodules at the prephary of the nodeL.ns are firmer…………. white fibrous C.T. Microscopic examination………. Actinobac. Ligner. ……… Actinomyces bovis.
Differential diagnosis3-bacillary necrosis of the liver ccc. by abcence of lesions from portal L.ns.4-metastatic supurative foci in the organ s due topyaemia*ccc. by absence of caseation and caseation andcalcification*absence of T.B lesion in L.n & presence of pyaemicsymptoms5-corynebacterium infection in pigs *T.B like changes in the submaxillry L.n of pig *Lesions appear as small yellow, necrotic foci surrounded by
C.T. The affection is caused by corynebacterium equi Judgment ………….remove the affected L.n. only
Differential diagnosis
6-Brucella suis infection in pigs Ccc. by originate in the inter –vertebral space as sacro-lumber regions and extend to bodies of the
vertebraeRarely occur in the carcase l.nsThere is no involvement of the visceral organs7-nodular necrosisCheesy necrotic foci in superficial muscle, specially tail it does not involve the viscera and l.nsT.B. is rarely in muscles
Differential diagnosis
B-Parasitic affection1-Degenerated cysts (Echinococci) :Ccc. by caseous or gritty centers can be easily squeezedout leaving intact cystL.ns are free from any lesions Microscopically examamination…………. hooklets
2-linguatula Larvae found in l.n with greenish degenerated mass
Anthrax
It is septicaemic disease→ affect all animals +manInfection most common among butcher →wounds orabrasion →malignant pastille red swollen finger or →byinhalation →wool sorter’s disease. Judgment:*all infected animals or suspected one →destroyed at six
feet deep →burning or burial *condemn the hides, fat, blood and internal organs *condemn the other carcases slaughtered in same hall
Actinobocillosis (wooden- tongue)
*it caused by Actinobocillus lignieresi bacteria *lesions are most common in tongue andmuscles of the jaw appear as fibrous tumorswith purulent foci.
Judgment:*the man →cannot infected via meat.*condemn the effected organs → head ,stomach or liver.
Actionmycosis (lumpy Jaw)
*Caused by Ray fungus (Actinomycis bovis) →incattle →Lumpy Jaw In pigs →chronic mastitis insaws
*The man can acquired infection from same sources innature that animals acquire it →not from meat ,accidental, inoculation or animals Judgment In cattle→ condemn the affected organs In saws → condemn the affected portion of mammarygland
Caseous lymphedenitis
Chronic disease of sheep →caused by corynebactrium-pseudo tuberculosis .*Ccc. by Caseous purulent foci →in organs & L.nsJudgment :*condemn the affected parts *Condemn whole carcass if generalized or associatedwith emaciation
Contagions bovine pleuro-pneumonia
*It is a contagious disease the of cattle →Sudanesebreeds *Ccc .by chronic inflammation of the lungs and pleura .The lung undergo necrosis and encapsulation but withoutgangrene Judgment*condemn the affected lung.*Total condemnation of the carcase → if associated with fever
Foot and mouth disease (aphthus fever)
It is in acute and highly contagious disease of clovenanimals Disease →trans .to man through consumption of milkand milk product but not through consumption of meat Due to a powerful destroying effect of lactic acid on the virus The disease →common among butcher through woundsor abrasions of their hands → during slaughter orskinning
Foot and mouth disease (aphthus fever)
Judgment :*if there is no fever→ condemn the head, stomach,intestines, lungs, udder and feets. *The carcase should be passed after 24hrs. *Peracute cases → may be passed for food if well bled In spreading the disease by but danger bone marrow orother infected tissues. Can persist in bone marrow for months
Rinder pest
Cattle plague is an acute febrile infectious dis.→ cattle and may be buffaloes ,sheep and goats.
The virus found in blood ,muscles and organs during the course of the disease.
Judgment The flesh of infected cattle is harm less to man after 6
days while in bone marrow after 1month. The affected carcase should be condemn due to fever
,emaciation, spread the disease among other animals
Rabies
It is a dis. of dogs can infect other animals via bitingJudgment Rabies not transmission to man through consumption
of meat. The transmission to man occur by inoculation during handling of meat.
Animal without symptoms.→ harmless → pass for consumption and condemn nerves connected with udder, pancreas, C.N.S., salivary gland bite.
Animal with symptoms. → condemn the whole carcase
Haemorrhagic septicaemia
It is an infectious and very fatal disease of cattle and buffalo and may be Pigs and sheep
Judgment The disease not transmitted → to man But animal infected with disease should be
condemned.
Brucellosis
It is cause contagious abortion → in cattleInfectious abortion → in goat and sawBrucella suis Organism in swine give rise to lesions in vertebra and
joints and bursae like T.B.In spleen form chronic nodular formation up to1/6 inch
in size have yellowish white contents may be tinged with light green
Brucellosis
Br. abortus (undulant fever)→ brucellosis in man Ccc. by fever with recurrent irregular temperatureinfection → occur by drinking milk or inoculation via
handing of infected meat or animals Does not occur through → consumption the meat of
infected animals
Brucellosis
Br. meletensisHighly infective to man via consumption of goat milk or
productsAir –borne infection from faeces, dust Via contact with infected flocks Br. meletensis and Br. Suis are more pathogenic for man
than Br. Abortus
Brucellosis
Judgment Brucella→ easily destroyed by lactic acid still viable for
a short time in the muscles Brucella can resist the refrigeration for excess one
month Can resist the pickling and inadequate soukingCarcase affected with brucella pass for consumption
after condemnation of lungs ,liver, spleen, kidney, intestine, udder, blood and carcase L.ns
Carcase affected with localized lesions of brucellosisPassed after remove and condemn the affected parts
Pox (variola)
*the term variola applied to a class of contagious diseases.
It is ccc. by fever and vesico-pustular lesionsThe blood and lymph are not virulent unless they are
taken from lesions.By direct inoculation to man → vaccine
Judgment If carcase slaughtered during develop of pox condemnIf temperature of animal returned to normal+ pox are
healed carcase may pass for food
Tetanus (lock jaw)
*It is an acute dis. caused by clostridium tetani (anaerobic spore forming bacillus)
Judgment Affected carcase cond. although there are no danger in
cating or handling of infected meat but carcase are badly bled setting rapidly putrefied.
*Swine diseasesSwine erysipelas + swine fever*Calf diseasesCalf paratyphoidCalf dysenteryCalf Diphtheria
Rift vally fever (RVF)
RVF or enzootic hepatitis is an acute arthropod born viral disease that affect several species of animals mainly sheep, cattle and goats
The disease is caused by an arbo virus of the phlebotomus fever group
The disease was investigated among sheep of the rift vally of Kenya.
the virus produces 70-100%mortaqlity in calves and lambs of less than 7 days of old age but only 10-20% in adult animals
Rift vally fever (RVF)The most consistent clinical sing in adult animals isabortion.In Egypt causing extensive morbidity and mortality inhumans and domestic animals. Humans become infected especially by contact withinfected animals and carcases.In some severely affected areas about70% of the humanpopulation wear infected with signs of encephalitis,blindness and hemorrhagic fever at leastabout 200.000clinical cases showed the symptomsamongst them 600 deaths occurred.
Rift vally fever (RVF)
*In natural infection, the blood as well as the liver andspleen contained the virus at the time of fever or death *Also the only sign of the disease in many ewes isabortion*The primary lesion in RVF is focal hepatic necrosis
Judgment Total condemnation of RVF carcase.