Investigations of the Pathology a n d C h e m o t h e r a p y of Infectious Enterohepatitis ( B l a c k h e a d ) in T u r k e y s
Dr. László
PELLÉRDY
Veterinary Research Institute of the Hungarian Academy of Sciences,
Budapest
I n 1967 c o n s i d e r a b l e economic l o s s e s , o f t h e o r d e r o f s e v e r a l m i l l i o n F o r i n t s were caused by i n f e c t i o u s e n t e r o h e p a t i t i s i n t u r key f l o c k s . T h i s was p a r t l y due t o inadequate knowledge o f e f f e c t i v e c o n t r o l measures, b u t above a l l t o l a c k o f an a f f i c i e n t s p e c i f i c drug such as has been w i d e l y a p p l i e d I n o t h e r c o u n t r i e s where t u r k e y s a r e b r e d on a l a r g e s c a l e . D u r i n g t h e f i r s t h a l f o f 1967 t h e s o l e a v a i l a b l e c h e m o t h e r a p e u t i c i n t h i s c o u n t r y was f u razolidone ( T i k o f u r a n ) w h i c h has been found i n our c o u n t r y t o have o n l y weak a n t i b l a c k h e a d a c t i o n . D u r i n g t h e second h a l f o f t h e y e a r a l a r g e amount o f 2-amino-5n i t r o t h i a z o l e , w i d e l y used a g a i n s t b l a c k h e a d , was i m p o r t e d . A f i e l d t r i a l of t h i s drug i n t h e form o f the premix H e p a m i x * w h i c h c o n t a i n s i t a t a c o n c e n t r a t i o n o f 10 was c a r r i e d o u t i n n e a r l y 300.000 t u r k e y s and p r o v i d e d abundant m a t e r i a l f o r i n v e s t i g a t i o n . T h i s communication comprises a r e v i e w o f r e l e v a n t o b s e r v a t i o n s w h i c h b o t h c o n f i r m and ''complement t h e known f a c t s about b l a c k h e a d . 1. ) G r o s s l e s i o n s i n t h e l i v e r . I n most t e x t b o o k s t h e s i t e s o f g r o s s l e s i o n s o f b l a c k h e a d a r e g i v e n as t h e caeca, c a e c a l w a l l s , p e r i t o n e u m a d j o i n i n g t h e caeca, and l i v er. I n p r a c t i c e , however, e x c l u s i v e l y c a e c a l l e s i o n s have o f t e n
* „Phylaxia" S t a t e Serum I n s t i t u t e , Budapest
been found on post-mortem examination, l i v e r l e s i o n s being e i t h e r absent or recognized o n l y w i t h d i f f i c u l t y . I t i s , t h e r e f o r e , n o t p a r t i c u l a r l y s u r p r i s i n g t h a t because o f t h e i r s i m i l a r i t y t o caecal c o c c i d i o s i s o f c h i c k e n s , t h e caecal l e s i o n s have f r e q u e n t l y been confused w i t h c o c c i d i o s i s .
F i g . 1 . Turkey l i v e r w i t h l e s i o n s c h a r a c t e r i s t i c o f blackhead from the m a t e r i a l designated „Tiszaroff". This l i v e r i s about 1/3 o r i g i n a l s i z e . J e l l e g z e t e s blackheades elváltozásokat feltüntető p u l y k a máj a „Tiszaroff" elnevezésű anyagból. Az e r e d e t i nagy ságnak k b . az egyharamda.
The m a t e r i a l designated „ T i s z a r o f f " provides a good example o f t h e i n e x p l i c a b l e a l t e r n a t i n g i n c i d e n c e o f l e s i o n s I n v o l v i n g e i t h e r t h e caeca alone or b o t h caeca and l i v e r . T h e t u r k e y f l o c k o f a c o l l e c t i v e farm, t o t a l l i n g a p p r o x i m a t e l y 15,000 b i r d s , was housed i n two premises s e v e r a l k i l o m e t r e s a p a r t . C o n d i t i o n s o f management amd f e e d i n g were s i m i l a r i n t h e two places and me dication with T i k o f u r a n a g a i n s t blackhead was c a r r i e d out t o an i d e n t i c a l schedule.The outbreak o f t h e disease occurred s i m u l t a n e o u s l y i n b o t h premises w i t h comparable m o r b i d i t y . Yet
necropsy m a t e r i a l f r o m one p l a c e showed,in every c a s e , d i s t i n c t i v e l e s i o n s o f b o t h caeca and l i v e r , w i t h t y p i c a l c o n c e n t r i c h e p a t i c f o c i , whereas i n m a t e r i a l f r o m t h e o t h e r f a r m characteristic c a e c a l l e s i o n s , enlargement o f t h e l i v e r w i t h i n d i s t i n c t d i s c o l o r a t i o n s , b u t no f o c a l l e s i o n s were f o u n d . S e v e r a l t r a n s i t i o n a l f o r m s were found t o e x i s t between h e p a t i c changes t h a t m a c r o s c o p i c a l l y were s c a r c e l y d i s c e r n i b l e and the f o c a l l e s i o n s c o n s i d e r e d pathognomic o f b l a c k h e a d . Enlargement o f t h e l i v e r was a t y p i c a l f i n d i n g i n t u r k e y s t h a t d i e d o r were k i l l e d a t the height of i n f e c t i o n . I n s u r v i v o r s regression of the liver t o n o r m a l s i z e t o o k p l a c e o v e r s e v e r a l weeks. On t h e e n l a r g e d l i v e r t h e l e a s t conspicuous l e s i o n s were p o o r l y de marcated d i s c o l o r a t i o n s o f v a r y i n g s i z e , p a l e r i n c o l o u r t h a n normal l i v e r t i s s u e , and seen o n l y a t h i g h i l l u m i n a t i o n ( i n sun s h i n e ) a f t e r t h e l i v e r s u r f a c e had been smoothed. I n o t h e r - supposedly more c h r o n i c - cases t h e c o n s i d e r a b l y en l a r g e d l i v e r showed r o u n d f o c i o f c o i n s i z e s l i g h t l y depressed beneath t h e s u r f a c e o f t h e organ, y e l l o w i s h o r g r e e n i s h i n c o l o u r and o f c o n c e n t r i c p a t t e r n ( E i g . l ) . I n some cases these f o c i pe n e t r a t e d deeply i n t o t h e parenchyma. Such l e s i o n s a r e n o t r e a d i l y confused w i t h those due t o o t h e r d i s e a s e s . The t h i r d t y p e o f l e s i o n was e n c o u n t e r e d i n t h e l i v e r s of t u r k e y s t h a t had r e c o v e r e d f r o m b l a c k h e a d , t h e c o n c e n t r i c f o c i d e s c r i b e d above h a v i n g been r e p l a c e d by c i c a t r i c i a l t i s s u e . R e g e n e r a t i o n o f t h e n e c r o t i c areas by c i c a t r i z a t i o n produced s h a r p l y c o n t o i i r e d d i s c o l o u r e d spots on t h e s u r f a c e o f t h e l i v e r . The c i c a t r i c i a l t i s s u e was p a l e r t h a n the s u r r o u n d i n g h e p a t i c t i s s u e , y e t t h e more advanced t h e p r o c e s s o f r e g e n e r a t i o n t h e l e s s marked was t h e d i f f e r e n c e . Since, however, r e g e n e r a t i o n o f l i v e r c e l l s was i n c o m p l e t e , .the l a r g e r a r e a s o f scar t i s s u e i m p a r t e d a s p o t t e d appearance t o t h e l i v e r t h r o u g h o u t t h e l i f e t i m e o f t h e bird, 2.) M i c r o s c o p i c t i o n s were p e r f o r m e d on
l e s i o n s . H i s t o l o g i c a l examina a t o t a l o f 50 t u r k e y l i v e r s , p a r t l y t o
i d e n t i f y by m o r p h o l o g i c a l and s t a i n i n g p r o p e r t i e s t h e a n i m a l , (Histomonas) o r p l a n t ( C a n d i d a ) , o r i g i n o f t h e e t i o l o g i c a l a g e n t , and p a r t l y t o examine t h e h i s t o p a t h o l o g y o f l i v e r s w i t h v a r i o u s l e s i o n s . F o r t h i s p u r p o s e , p a r a f f i n embedded s e c t i o n s were s t a i n e d w i t h h e m a t o x y l i n and e o s i n , M a l l o r y ' s s t a i n and p e r i o d i c a c i d S c h i f f (PAS). The initial h y p o t h e s i s assumed t h a t t h e two m o r p h o l o g i c a l l y d i s t i n c t l e s i o n s were due t o two d i f f e r e n t e t i o l o g i c a l a g e n t s o f b l a c k h e a d . T h i s a s s u m p t i o n was s u p p o r t e d by f i n d i n g s i n t h e l i v e r ( d e s i g n a t i o n „Boldogasszonyfa") o f a t u r k e y w h i c h on postmortem e x a m i n a t i o n showed t y p i c a l c a e c a l l e s i o n s , b u t o n l y enlargement and d i f f u s e d i s c o l o r a t i o n o f t h e l i v e r . M i c r o s c o p i c e x a m i n a t i o n o f t h i s l i v e r r e v e a l e d l a r g e numbers o f conspicuous r o u n d homo genous b o d i e s ( P i g s . 2a, 2 b ) , 7-lO^tc i n d i a m e t e r , staining pale p i n k w i t h e o s i n , v i v i d r e d w i t h M a l l o r y ' s s t a i n and deep l i l a c w i t h PAS. The p a r a s i t e s , c l u s t e r e d d e n s e l y t o g e t h e r , o c c u p i e d t h e spaces between t h e rows o f l i v e r c e l l s , sometimes g i v i n g t h e i m pression of being i n t r a c e l l u l a r i n l o c a t i o n . A s i m i l a r i n t r a c e l l u l a r p o s i t i o n was p r e v i o u s l y d e s c r i b e d by CHESTER and ROBIN (1900) a l t h o u g h l a t e r TYZZER (1920) advocated t h e i n t e r c e l l u l a r l o c a t i o n o f t h e p a r a s i t e s . I n t h e p a r t i c u l a r case b e i n g d e s c r i b e d o n l y a few p a r a s i t e s o t h e r t h a n t h o s e mentioned above were f o u n d ; t h e y a l s o s t a i n e d p a l e p i n k b u t showed an i n t e r n a l s t r u c t u r e .
P i g . 2a. Causative agents o f blackhead i n a s e c t i o n from t u r k e y l i v e r , a: The round s t r u c t u r e l e s s b o d i e s resemble f u n g i . H e m a t o x y l i n and e o s i n . X 300 Blackhead-kóroközók p u l y k a májában, a: A kerek,struktúra nélküli képletek gombára emlékeztetnek. Hem-eozin 300 X P i g . 2b. M a g n i f i e d p a r t o f F i g . 2. PAS. X 1000 Uaz, m i n t 2a. PAS. 1000 X F i g . 3a. C a u s a t i v e a g e n t s o f b l a c k h e a d i n t u r k e y l i v e r , a: Bodies r e s e m b l i n g t o Histomonas. H e m a t o x y l i n and e o s i n . X 300 Blackhead-kóroközók p u l y k a májában, a: histomonasnak meg felelő képletek. Hem-eozin. 3OO X P i g . 3b. M a g n i f i e d p a r t o f F i g . 3a. H e m a t o x y l i n and e o s i n . x 800 7az, m i n t 3a. Hem-eozin. 800 X
T h e i r shape was g e n e r a l l y r o u n d , h u t o f t e n o v o i d o r ameboid. I n l a t e r s t u d i e s on b o t h t y p e s o f l i v e r l e s i o n one o r o t h e r pa r a s i t e was n o t e d w i t h o u t apparent r e l a t i o n s h i p t o t h e t y p e o f lesion. The m a c r o s c o p i c a l l y d i s t i n g u i s h a b l e l i v e r l e s i o n s showed no c o r responding v a r i a t i o n o f microscopic s t r u c t u r e . I n t h e l i v e r pa renchyma n e c r o t i c f o c i w i t h k a r y o l y s i s and subacute i n f l a m m a t i o n o f t h e a d j o i n i n g t i s s u e were f o u n d . The f o c i d i d not become e n c a p s u l a t e d by f i b r o u s t i s s u e ; o n l y a s l i g h t i n c r e a s e o f c o n n e c t i v e t i s s u e b e i n g n o t e d i n i n f l a m m a t o r y a r e a s around t h e b l o o d v e s s e l s and b i l i a r y d u c t s . Besides i n f i l t r a t i n g lymphocytes and mono n u c l e a r c e l l s these i n f l a m e d areas c o n t a i n e d many e o s i n o p h i l i c and pseudoeosinophilic c e l l s . G r a n u l o c y t e s and numerous g i a n t c e l l s were a l s o f o u n d . I n t h e a f f e c t e d areas t h e l u m i n a o f b l o o d v e s s e l s and s i n u s o i d s were d i s t e n d e d w i t h r e d b l o o d cells (Fig. 5 ) . I n t h e p r e s e n t e x a m i n a t i o n s t h e p a r a s i t e s c o n s i d e r e d t o be t h e etiological agent o f b l a c k h e a d were o f two morphologically d i s t i n c t t y p e s . They o c c u r r e d e i t h e r s i n g l y or i n groups ( n e s t s ) , most o f them, i n t ere v - l l u l a r l y . One t y p e , a round s t r u c t u r e l e s s body o f 7-11 s* d i a m e t e r , stained v i v i d red with Mallory's stain. S t a i n i n g p o s i t i v e l y w i t h PAS, i t was v e r y l i k e l y a f u n g u s . The o t h e r t y p e , s t a i n i n g p a l e p i n k w i t h e o s i n e , appeared as s i n g l e o r m u l t i p e r o u n d i s h bodies surrounded by a c l e a r r i n g (Pigs.3a,3b, 4). M a l l o r y ' s s t a i n i m p a r t e d t o them an u n c e r t a i n g r e y i s h hue. They were l a r g e r t h a n t h e f u n g u s - l i k e organisms,-of s l i g h t l y o v o i d shape and some had d i a m e t e r s above 40 Occasionally they were seen i n an a p p a r e n t l y i n t r a c e l l u l a r p o s i t i o n , a d j a c e n t t o t h e e n l a r g e d and f l a t t e n e d n u c l e u s o f t h e h o s t c e l l . Some o f t h e pa r a s i t e s showed one o r more t i n y b r i g h t r u b y - r e d g r a n u l e s , sur rounded by a c l e a r halo-, s i t u a t e d c l o s e t o t h e n u c l e u s . The occurrence o f such g r a n u l e s seemed t o be a s s o c i a t e d w i t h division o f t h e p a r a s i t e . S i n g l e g r a n u l e s were u s u a l l y seen c l o s e t o t h e nucleus, whereas when s e v e r a l g r a n u l e s were p r e s e n t t h e y were d i s t r i b u t e d i n t h e cytoplasm,sometines w i t h obvious s i g n s o f c e l l d i v i s i o n a r o u n d them. I n l a r g e r p a r a s i t e s t h e c l e a r h a l o was mere
d i s t i n c t and a t h i n , f i l a m e n t was seen t o connect i t s b o r d e r w i t h the body o f t h e p a r a s i t e . The m o r p h o l o g i c a l appearance and p a r t i c u l a r l y t h e f i l a m e n t suggested t h e p a r a s i t e t o be a Histomonas meleagridis I n h e a l e d l e s i o n s t h e l i v e r c e l l s were a r r a n g e d more d e n s e l y and t h e i r n u c l e i stained darker w i t h hematoxylin than d i d healthy l i v e r t i s s u e ( P i g . 6 ) . I n a d d i t i o n , a few r e s i d u a l g r a n u l o c y t e s and s t r u c t u r e s r e s e m b l i n g t h e p a r a s i t e s were encountered i n p a l e r a r e a s where t h e l i v e r t r a b e c u l a e had been r e p l a c e d by d i s o r d e r l y aggregates o f l i v e r c e l l s . Thus h i s t o l o g i c a l e x a m i n a t i o n f a i l e d t o p r o v i d e evidence as t o the p r e c i s e n a t u r e o f t h e e t i o l o g i c a l agent o f b l a c k h e a d . The P A S - p o s i t i v e s t r u c t u r e l e s s organisms were p r o b a b l y f u n g i , whereas the p a l e p i n k s t r u c t u r e d organisms c l o s e l y resembled H. m e l e a g r i dls. I t seems f e a s i b l e , t h e r e f o r e , t h a t b o t h organisms a n d , a c c o r d i n g t o more r e c e n t f i n d i n g s , even c e r t a i n b a c t e r i a , p l a y a r o l e i n t h e c a u s a t i o n o f b l a c k h e a d ( T A I L and PRAKKER, 1 9 6 3 ) . 3 - ) A c t i o n o f H e p a m i x . Mixed i n t h e d i e t o f t u r k e y f l o c k s s e v e r e l y a f f e c t e d w i t h blackhead (10-20 $> l o s s e s ) , 1 $> H e p a m i x f e e d a d d i t i v e stopped t h e o u t b r e a k i n 5 days. l a t e r deaths were m o s t l y due t o i n t e r c u r r e n t d i s e a s e s . Given i n t h e i n i t i a l s t a g e o f t h e o u t b r e a k , t r e a t m e n t w i t h H ep a m I X minimized losses. N a t u r a l l y , e a r l y medication r e q u i r e s e a r l y c o r r e c t d i a g n o s i s . The e x p e r i e n c e d v e t e r i n a r i a n , and even t e c h n i c a l a s s i s t a n t s can r e c o g n i z e b l a c k h e a d by t h e c l i n i c a l symtomps p r i o r t o o c c u r r e n c e o f l o s s e s . Diseased birds lose
Pig.
4. H i s t o m o n a s - l i k e p a r a s i t e s - i n t h e l i v e r o f a t u r k e y a f f e c t e d w i t h blackhead. Adjacent t o t h e nucleus r u b i n g r a n u l e s a r e a p p a r e n t . O i l i m m e r s i o n . X 1500 Histomonas-szerü élősködők blackheades p u l y k a májában. A mag m e l l e t t a rubinszemcsék i s feltűnnek. Immerziós f e l vétel. 1500 X
a p p e t i t e , a r e s l e e p y , l a g b e h i n d t h e r e s t and have d i a r r h o e a , t h e y e l l o w i s h pasty droppings of s i c k turkeys beiny immediately n o t i c e d . I n such c i r c u m s t a n c e s b l a c k h e a d i s e a s i l y diagnosed by postmortem e x a m i n a t i o n o f t h e most a i l i n g b i r d s Delayed t r e a t m e n t f o r b l a c k h e a d I s o f t e n due t o erroneous d i a g n o sis. C o n s i d e r a b l e d i s t e n t i o n o f t h e ceaca o f a f f e c t e d b i r d s and c a s e o u s - f i b r i n o u s plugs i n the caecal lumina s u p e r f i c i a l l y r e semble l e s i o n s encountered i n t h e c a e c a l c o c c i d i o s i s o f c h i c k e n s . I n f a c t , l i k e most d o m e s t i c a t e d a n i m a l s , t h e t u r k e y has s e v e r a l c o c c i d i a n p a r a s i t e s . Yet o o c y s t s a r e a l w a y s demonstrable i n t h e droppings, o f t e n even i n t h e p a s t y s t o o l seen d u r i n g t h e e a r l y phase o f b l a c k h e a d . Although the presence of oocysts a p p a r e n t l y s u p p o r t s t h e d i a g n o s i s o f c a e c a l c o c c i d i o s i s no t u r k e y c o c c i d i u m i s known t o cause such e x t e n s i v e c a e c a l l e s i o n s . Good d u r a b l e t h e r a p e u t i c r e s u l t s can be o b t a i n e d i f 1 $> H e p a m i x i s g i v e n i n t h e d i e t f o r 7-10 days. S u b s e q u e n t l y t r e a t m e n t must n o t be s t o p p e d b u t c o n t i n u e d a t h a l f t h e dose r a t e f o r a t l e a s t as l o n g a t i m e . As i n d i c a t e d i n t h e l i t e r a t u r e , t h e d i s e a s e i s l i a b l e t o r e c u r even t h e n , i n d i c a t i n g t h a t t h e immune response t o b l a c k h e a d i s v e r y low ( f o r r e f . s e e BIESTER and SCHWARTE,1965). 4.) P r o p h y l a x i s o f b l a c k h e a d . I n t h e spread o f b l a c k h e a d t h e most i m p o r t a n t r o l e has been a t t r i b u t e d t o t h e eggs o f H e t e r a k i s g a l l i n a r u m . The e t i o l o g i c a l a g e n t s o f blackhead a r e c a r r i e d e i t h e r by these eggs, o r by t h e l a r v a e hatched f r o m them, t h r o u g h t h e w a l l o f t h e caecum and invade t h e h o s t . There f o r e , t u r k e y s s h o u l d be housed and managed so t h a t t h e y r e m a i n f r e e o f i n f e c t i o n w i t h H e t e r a k i s eggs. I n t h i s r e s p e c t , H e t e r a k i s eggs shed w i t h c h i c k e n d r o p p i n g s seem t o be even more dangerous t h a n t h o s e e x c r e t e d by t h e t u r k e y s t h e m s e l v e s . I t i s known t h a t b l a c k h e a d a l s o occurs i n g a l l i n a c e o u s b i r d s , b u t a f f e c t s them o n l y s l i g h t l y or n e t a t all» N e v e r t h e l e s s , t h e H e t e r a k i s eggs shed w i t h t h e d r o p p i n g s o f g a l l i n a c e o u s b i r d s may i n f e c t r e l a t i v e l y l a r g e areas f o r l o n g periods of time. The
f i r s t and most i m p o r t a n t r u l e o f b l a c k h e a d
prophylaxis i s
p r e v e n t a l l c o n t a c t o f t h e t u r k e y s w i t h H e t e r a k i s ova.
These
to pa-
r a s i t e egga may r e m a i n v i a b l e i n t h e s o i l f o r aa l o n g as 2 y e a r s although t h e o v u m - t r a n s m i t t e d agent o f b l a c k h e a d d e t e r i o r a t e s i n a f e w months. T h e r e f o r e , c a r e s h o u l d be t a k e n t o p l a c e t h e t u r k e y f l o c k i n „virgin" p r e m i s e s , where n e i t h e r t u r k e y s n o r c h i c k e n a have been k e p t f o r t h e p r e c e d i n g two y e a r s , o r a t l e a s t one. Ex p e r i e n c e w i t h m a t e r i a l d e s i g n a t e d „Orosháza" emphasise t h e i m p o r tance o f t h i s p a r t i c u l a r requirement. W i t h i n a g i v e n area, con t a i n i n g f a r m s n o t f a r d i s t a n t f r o m each o t h e r , b l a c k h e a d o c c u r r e d o n l y where c h i c k e n s and t u r k e y s had been k e p t d u r i n g t h e p r e c e d i n g y e a r . Farms where t h i s was n o t t h e case remained f r e e o f blackhead. A n o t h e r method o f p r e v e n t i n g b l a c k h e a d i s t o r e a r t u r k e y p o u l t s up t o 3-4 weeks' age i n i s o l a t i o n on a deep l i t t e r n o t i n f e c t e d w i t h H e t e r a k i s egga. I f subsequent exposure i s i n e v i t a b l e , l o s s e s can be m i n i m i z e d by s t a r t i n g p r e v e n t i v e medication a t t h e proper t i m e .
S u m m a r y
A f i e l d t r i a l o f t h e f e e d a d d i t i v e H e p.a m 1 x, c o n t a i n i n g 2a m i n o - 5 - n i t r o t h i a z o l e a t a c o n c e n t r a t i o n o f 10 was c a r r i e d o u t
Eig.
Eig.
5. M i c r o s c o p i c l e s i o n s i n t h e l i v e r o f a t u r k e y a f f e c t e d w i t h blackhead. I n f l a m m a t o r y f o c i c o n t a i n i n g d e t r i t u s , granu l o c y t e s and f u n g u s - l i k e p a r a s i t e s . H e m a t o x y l i n and e o s i n . X 150 Kórszövettani elváltozások blackheades p u l y k a májában. Gyulladásos gócok a májban, törmelékkel, granulocytákkal és gombaszerü élősködőkkel. Hem-eozin. 150 X 6. M i c r o s c o p i c p i c t u r e o f l i v e r i n t h e c o n v a l e s c e n t stage a f t e r b l a c k h e a d . Note h e a l t h y l i v e r i n t h e c e n t r e . Hema t o x y l i n and e o s i n . X 150 A b l a c k h e a d gyógyuló e s e t e , a középen az érintetlen máj szövet. Hem-eozin. 150 X
on n e a r l y 300,000 t u r k e y s . D e t a i l e d e x a m i n a t i o n o f g r o s s and mic roscopic lesions o f the l i v e r indicate that i n the etiology o f b l a c k h e a d b o t h presumed c a u s a t i v e a g e n t s , v i z . Histomonas m e l e a g r i d i s and Candida a l b i c a n s , a r e i m p l i c a t e d . H e p a m i x proved t o be v e r y o f f i c i e n t a g a i n s t b l a c k h e a d ; when mixed i n t h e d i e t a t a concentration of 1 i t stopped t h e o u t b r e a k i n 3-5 days. P r a c t i c a l e x p e r i e n c e suggests t h a t p l a n n e d p r e v e n t i o n o f b l a c k head remains t o be e s t a b l i s h e d .
P E L L É R D Y , L . : Patológiás és terápiás vizsgálatok fertőző enterohepatitisben beteg (blackheades) pulykaállom ányokban
A b l a c k h e a d Magyarországon 1967-ben több millió P t kárt o k o z o t t . Ennek az v o l t az oka, hogy egyrészt nem rendelkeztünk kellő t a p a s z t a l a t t a l a betegségnek időben történő felismeréséhez, más részt p e d i g nem v o l t b i r t o k u n k b a n blackhead e l l e n b i z t o s hatású gyógyszer. Amikor 2 - a m i n o - 5 - n i t r o t h i a z o l - t nagyobb mennyiségben H e p a m i x nevű takarmányimportáltunk és a z t a P h y l a x i a gyógykeverékben elkészítette,alkalmam n y i l o t t kórbonctani és kór szövettani megfigyelések végzésére. A kórbonctani elváltozások számos esetben csak a v a k b e l e k b e n v o l t a k feltűnők, azonban a máj m i n d i g megnagyobbodott v o l t és azon erős megvilágítással (napon) a máj lesimitása után f o l t o s szinkülönbséget l e h e t e t t találni az egyes területek között. A b l a c k headre t i p i k u s májelváltozásokon ( 1 . kép) kivül a gyógyuló ese t e k b e n a májénál világosabb szinü gócos elváltozásokat találtam, amelyek mindenek s z e r i n t regenerálódó hegszcvetnek f e l e l t e k meg. Ezt. a szövettani vizsgálatok i s igazolták. Jóllehet a b l a c k h e a d két feltételezett kórokozójának,a Histomonas m e i e a g r i d i s n e k és a Candida a l b i c a n s n a k a -májból való kitenyésztése csak néhány e s e t ben sikerült, a szövettani vizsgálatok alapján a r r a az eredményre k e l l e t t j u t n o m , hogy a b l a c k h e a d előidézésében a C. a l b i c a n s n a k ( 2 a , 2b. kép) és a H. m e i e a g r i d i s n e k ( 3 a , 3b, 4.kép) egyaránt sze r e p e l e h e t . A betegség okozójának megállapítására további vizsgá l a t o k vannak f o l y a m a t b a n .
A H e p a m i x kitűnő hatásn gyógykeverék. Közel 3 0 0 , 0 0 0 p u l y kára kiterjedő megfigyelésem megerősítette,hogy a H e p a m i x nak 1 ^-ban több n a p i g történő etetése után a b l a c k h e a d 3 - 5 napon belül megszűnik. A b i z t o s s i k e r a l a p j a a gyógyszer alkalmazásánál a mielőbbi és h e l y e s diagnózis. Pulykában a vakbél-elváltozások nem téveszthetők össze a csirkék vakbélcoccidiosisa során észlel hető elváltozásokkal, de egyébként s i n c s a pulykának o l y a n c o c c i diuma, amely az E i m e r i a t e n e l l a - h o z hasonló patogén hatású volna. A b l a c k h e a d e l l e n i védekezés és a gyógyszer s i k e r e s alkalmazásá nak előfeltétele a z , hogy kellő időben a v a t k o z z u n k be és hogy a tervszerű megelőzésre nagy súlyt helyezzünk. Közismert tény, hogy a b l a c k h e a d e t a vakbélférgek ( H e t e r a k i s g a l l i n a r u m ) terjesztik o l y módon, hogy petéiket a pulykák f e l s z e d i k . A H e t e r a k i s - o k f e r főzött pulykából származhatnak, de a tyúkban élő H e t e r a k i s - o k i s a b l a c k h e a d közvetitŐi l e h e t n e k . Fontos tehát, hogy az állatokat b i z t o s a n Heterakis-tól mentes környezetben neveljük.
R e f e r e n c e s
CHESTER,P.D. - ROBIKBA.: E n t e r o - h e p a t i t i s o r b l a c k h e a d o f f o w l s . Rep.Delaware A g r i c . Exp. S t a . 6 6 - 7 0 . 1 9 0 0 . BIESTER, H.E. - SCHWARTE, H.L.: Diseases o f p o u l t r y . 5 t h ed» l o v a State Univ. Press. 1965. ( p . 1105-1107) TAIL, J.P. - FRANKER, C.K.: E x p e r i m e n t a l H i s t o m o n i a s i s i n g n o t o b i o t i c t u r k e y s . I . I n f e c t i o n and h i s t o p a t h o l o g y o f t h e b a c t e r i a - f r e e host. J . Parasit. 49. 411-414. 1963. TYZZER,E.E.: The f l a g e l l a t e c h a r a c t e r and r e c l a s s i f i c a t i o n o f t h e p a r a s i t e p r o d u c i n g „blackhead" i n t u r k e y s - H i s t o m o n a s (gen.noy.) m e l e a g r i d i s ( S m i t h ) . J , P a r a s i t . 6. 124-131. 1 9 2 0 . Received:
23.5.196-8.
Dr. L. PEL1ÉRDY V e t e r i n a r y Research I n s t i t u t e o f the
Hungo
Acad, o f S e i .
Budapest XIV. Hungária k r t . 2 1 .
