ESTADOS BIDIMENSIONALES

INTRODUCT I ON

The ante and mortem inspection o f s tock and c arcas s e s carr i ed out a t the meat works are t h e mos t important aspects o f me at hygi ene . T h e purposes of pos t mortem i nspect i on are : f i rs t , to s egregate and/ or iden t i fy d i s e ased or defec t i ve anima l s ; second , to prevent cruel ty to the animals and f in a l l y , t o di agnose exo t i c or i n fe c t ious d i s e a ses dangerous f o r the anima l population o f t h e country .

The pos t -mortem i nspect ion o f meat i s carr i ed out a f ter dre s s i ng is c ompleted . Wholesomene s s and s afety o f the meat are the ma i n a i ms o f the procedure . Thi s means that any produc t con t a i n i ng endogenous or exogenous infec t i ous agen t s , or other defects render i ng the product unwholesome , mus t not reach the market ( Pe t er s e n 1 9 7 9 ) .

The mortem i n spect ion procedures vary from country t o country but are generally based on the princ i p l e s that the presence of d i sease i n carcass e s can be s een and palpated and that l ymphnod e s re f l e c t the heal th status o f the anima l s . Wh i l e inspect i on procedures based on these pr inciples w i l l i d en t i fy many d i s e a s e s and de f e c t s , s ome o f the mos t serious c ond i t i on s of con s i derable publ i c health s igni f ic ance ( ye r s i n i os i s , campyl obact e r i o s i s ) go undetected through the inspe c t i o n s y s tem .

was car r i ed out b y " The i nspector" o f " Doe bank " , b y c areful vi sual examina t i on and palpat ion of the l iver , fol lowed b y v i sual examinat i on of the carcas s . The ' i nspector ' pa id s pec i al atten t i on to the presence o f abnormal colour and les i on s on the carcas s , carcass c onformation , as we l l as the presence of any l i ver l e s ions .

Common D iseases o f Rabb i t s Detected a t Post Morten

( a ) Hepatic cocc idios i s : this d i sease w i l l be d e s c r ibed in d e t a i l i n Chapters E i ght and N i ne .

( b ) Contagious catarrh ( snuf f l e s ) : Con t agious c a tarrh or snuffles , i s very common i n rabb i ts . I t i s genera l l y caused b y Pas teurel la but o ther bacteria i n c lud ing

spp . , Bordetella and

spp . may also be i nvolved . Pneumoni a is the c ommon feature o f the di sease with the anteri or l obes of the lungs mos t ly af fected . Pleur i sy , pericard i t i s and acute t rache i t i s may also be present ( Wi l son , 1 9 8 5 ) .

A large s c a l e mi crobi olog i cal i nves t i gat ion of almo s t four thous and lungs , f rom. 8 - 1 0 week old rabbi t s s l aughtered a t s everal aba t t oirs in the U . S . A . , revealed a 2 0 % prevalence of P a s teurel l a mul toc ida i n f e c t i on . Some of the l ungs presented a t e l e c tas i s , conso l i dation or abscesses ( Flatt and Dungworth , 1 9 7 1 ) .

( c ) C y s t i cerco s i s : Cys t i cerco s i s i n

rabb i t s i s mani fes ted b y sma l l c y s t s approx . 5 - 1 O mm i n

c y s t s repres ent the interme d i a t e s tage o f the tapeworm Taen i a The f i nal hos t i s the dog in wh i c h the 2 mm long tapeworm i nhabits the sma l l intest ine . At pos t mor t em inspe c t ion , depending on the number as we l l a s the s i z e of the l e s ions , the who l e c arca s s , or the a f fe c t ed organ s onl y , are re j e cted ( Wi l son , 1 9 8 5 ) . Cys t i cercos i s a l s o occurs i n the musculature o f c a t t l e sheep

ovis ) and pigs ( C . cellulosae ) .

( d ) Coenurias i s i s a paras i t i c d i se a s e o f the rabbi t , man i fes ted by the pres ence of c y s t s up to 5 cm in diameter i n the intermuscular and subcutaneous t i s sue o f the j aw . The c y s t s , c a l l ed Coenurus are the interme d i a t e s tage of t h e t apeworm i nhab i t ing i n t h e s m a l l inte s t ine of t h e dog . At pos t mortem inspec t i on , the a f fec ted part may be removed and the rema i nder pas s e d for food if onl y a few c y s t s are pres ent , but i f the c y s t s are numerous , the carcas s s hould be condemned ( Grac e y , 1 9 8 6 ) . ( e ) S t aphylococco s i s : Staphylococcal d i s ea s e in rabb i t s i s

man i f e s ted a s pneumon i a , sept i c aemia , os teomyel i t i s , pododerm i t i s , subcutaneous absces s e s , exudat ive dermat i t i s , purulent rh i n i t i s and con j unc t i v i t i s in the newborn and abs c e s s e s of the mammary gland . The bacte r i a may however , be present i n the flora of the upper respi ratory trac t , and the skin w i thout caus ing diseas e ; ( Okerman et 1 9 8 4 ) . S t aphylococ c a l absces s e s and skin l e s i ons are common in mos t animal s , includ i ng lambs ( Fuente and Suares , 1 9 8 5 ) , p i g s ( Shaz ados , 1 9 8 5 ) , goats and cattle ( Menes e t al 1 9 8 4 ) . In Spa i n , Menes e t ( 1 9 8 4 ) , i solated a total of 7 1 s trains o f Gram pos i t iv e , catala s e pos i tive cocci from 1 1 2 absces s e s found duri ng pos t mortem inspection of s l aughtered animals ( sheep , c a t tl e , pigs and goat s ) , and in a large survey , Snyder e t ( 1 9 7 6 ) , found that dur i ng a three year period o f i nve s t i gat i on , 7 . 6 % o f the necrops i ed rabb i t s had absces s e s c aused b y S taphylococ c i .

rabb i t s .

Fuen t e and Suarez ( 1 9 8 5 ) , found i n l ambs up t o four months of age an " abscess d i seas e " wi th a mortal i ty rat e of 6 5 . 7 % due

to whereas absces ses i n p i g s , accord i ng

to Shazados ( 1 9 8 5 ) , are mos t l y as soc iated wi th

and beta haemo l y t i c Streptococc i rather than w i th Staphylococ c i .

Other cond i t i ons , l ike gas troenter i t i s , yers i n i os i s , myxomatos i s , nephr i t i s , rabb i t syph i l i s , and tuberculos i s are rare f i ndings at pos t mortem i nspect ion ( Wi l s on , 1 9 8 5 ) .

The i ntent ion o f thi s s tudy was to i nve s t ig a t e any l e s i ons found a t post mortem inspec t i on of rabb i t s at the Masterton aba t to i r .

MATERIALS AND METHODS

The material for t h i s i nve s t i g a t i on was c o l l ected from approx . 2 5 0 rabb i t s k i lled dur i ng four v i s i ts to the aba t t o i r i n Mas terton . After c arcass e s and o f fal had been i nspected by the " i nspector " , they were re- exam i ned v i sually and by palpa t i on by the author . Les ion s were transported to the laboratory in pla s t i c bags and kept in a refrigerator overni ght unt i l further i nve s t i g a t i on the following day .

I n add i t i on , a femal e Angora doe w i th a swel l i ng on the r i ght j aw was s ubm i t ted to the author by a breeder . After the animal had been k i l l ed , the l ower j aw w i th the a t tached l e s ion

was cut into 3 - 4mm thick sec t i on s w i th an e l ectric s aw . The s e s ec t i ons , were decal c i f i e d i n R . D . O . sol u t i on ( Du Page Kine t i c Laboratory ) , for three t o four days and subsequent l y wax embedded s e c t i ons were cut and s t a i ned by hematoxyl i n and eos i n ( H+E ) for micro s copi ca l examinat i on .

Smears of the contents from all les ions were s ta i ned by the Gram me thod and cul tures were also carri ed out aerob i c a l l y at 3 7°C for 24 hrs , on blood and McConkey agar . Further inve s t igat i ons were carr i ed out , u s i ng cat a l a s e tes t ( Cru i ckshank et 1 9 7 5 ) as wel l a s s l i de coagul a s e and DNA- ase te s t s ( Devr i e se and H a j ek 1 9 8 0 ) .

The l iver les ions col lected from the abat toir were f ixed i n 1 0 % forma l i n for a t leas t three days and s ta ined by H + E and exami ned m i croscopical l y , as explained in greater de t a i l i n Chapter E i ght .

RESULTS

Of approx . 2 5 0 rabb i ts examined at the abattoi r , onl y two carcasses , each with one absce s s , and 5 7 l ivers w i th les i on s r e s embl ing those of hepa t i c cocc idios i s , were found .

One o f the absces s e s was located on t h e ventral aspect o f the front l eg , wh i l e t h e other was i n t h e lumbar area . Both l e s i ons were ovoid in shape , approx . 2 x 3 cm , were soft i n cons i s tency and the content was thick and whi t i sh i n colou r . Exam i nation of Gram s t ained smears , revealed Gram pos i t ive cocc i . Bacteriolog i cal inve s t igation o f cultures f rom both abs ces s e s , revealed that the organi sms i solated were c a t alas e , coagulase and DNA-ase pos i t ive ind i c a t i ng that the organi sms were s tra i n s o f

not i c ed that t h i s abs c e s s was d i v i ded i nto i rregular chambers by

t r abeculae o f bone . The methods used for bact e r i ol og ic a l

i n ve s t igat ion o f t h e content of t h i s abs c e s s were t h e s ame as for the o ther two abs c e s s e s and the resu l t s were iden t i cal . The h i s tological examina t i on of the s e c t ions taken from thi s absce s s , s howed areas of necro s i s and f i bros i s , as wel l as a mas s ive i n f i l trat i on of i n f l ammatory c e l l s w i th a predomi nance o f neutroph i l s and macrophages . Th i s l e s ion was d i agnos ed as a chron i c s t aphy lococcal o s teomye l i t i s .

M

7 . 1 -Ab s c e s s the mandible o f an rabbit­

S ide numbers indicate centimeters

A l l the l e s ions found in 57 l i vers ( se e t able 8 . 2 , page 1 3 3 )

f rom commer c i al rabb i t s at the abat to i r , were c l as s i f i ed as chron i c l e s ions of hepa t i c coc c i d i os i s . ( Se e Chapter E ight ) .

None of the laboratory rabb i t s exami ned showed any macroscopi c l e s i on s .