Cecal filling and defecation of chickens infected with Eimeria tenella

Zbl. Bakt. Hyg. A 264, 337-342 (1987)

Cecal Filling and Defecation of Chickens Infected with Eimeria tenella ~. A. ARAKAWA, M. SA YAMA, E. BABA, and T. FUKAT A Department of Veterinary Medicine, College of Agriculture, University of Osaka Prefecture, Sakai, Osaka, Japan

With 3 Figures' Received March 20, 1986

Abstract White Leghorn cockerels, 11 to 22 days old, were inoculated each with a single oral dose of 4-5 x 104 sporulated oocysts of Eimeria tenella. Radiographic study of urinary backflow in infected chickens injected with sodium iothalamate subcutaneously indicated that retrograde movement of ceca was impaired particularly 7, 10, and 14 days after infection. No inflow was noted 7 days after infection when barium sulfate was inoculated into cloaca. Weight of cecal contents examined 7 days after infection was significantly smaller than uninfected control. Number of cecal feces was counted every 24 h beginning 4 through 14 days after infection. The counts in infected birds were significantly fewer than uninfected control 8, 9, and 10 days after infection. Outflow of cecal contents was studied in chickens surgically injected with barium sulfate into cecum 7 days after infection. Radiographic study indicated that most of uninfected control ceca excreted or evacuated the medium between 10 and 24 h after injection, while a few infected birds cleared ceca during the same period. Introduction When chickens are infected with sporulated oocysts of Eimeria tene/la, a cecal coccidium, and necropsied 6 to 8 days later, contracted ceca with thickened wall often contain a small volume of exudate or large caseous cores consisting of clotted blood, mucosal debris, and oocysts (4, 6). The cores generally pass out of ceca by 8 to 9 days after infection, but may remain for a longer period (4, 6). It is obvious that motility of infected ceca is impaired during the acute stages of the infection and even during the recovery phases. A limited number of papers reported the influence of E. tene/la infection on cecal motility. Ceca showed depressed (5) or increased (8) response to acetylcholine application in vitro. In vitro activity of cecal pouches ceased at the end of the fourth day following infection and did not return to normal function for three weeks (7). Hemorof Presented at the 5th German-Japanese Cooperative Symposium on Protozoan Diseases, Tokyo, Japan, Sept. 25-28,1985.

338

A. Arakawa, M. Sayama, E. Baba, and T. Fukata

rhagic cecal feces were excreted by infected chicks regardless of illumination of the room, while cecal feces were seen only during the light illumination period in uninfected birds (3). The purpose of the present study was to examine the effect of E. tene/la infection on cecal filling and defecation during the critial stage of coccidiosis.

Materials and Methods

Birds and diets. White Leghorn, Hy-Line®, cockerels were purchased from a local commercial hatchery when less than one day old. They were caged in battery brooders in an air conditioned room with continuous artificial illumination until use. They were kept in wiredfloor cages under 24 h illumination during the study. Basal feed (1) and water were available

ad libitum. E. tene/la. The strain used was originally supplied from the National Institute of Animal

Health, Japan. Oocyst culture was prepared routinely from donor chickens 7 to 8 days after oocyst inoculation. A dose of 4-5 x 10 4 sporulated oocysts suspended in 1 ml of tap water was inoculated to each chicken. Urinary backflow from cloaca into ceca. This experiment consisted of three identical trials. In each trial, 60, II-day-old birds were divided into two groups, uninfected control and infected with E. tenella, of 30 birds each. One part of sodium iothalamate, 80% w/v, was diluted with 5 parts of sterilized saline solution and injected subcutaneously to chicken at the rate of 3 ml per 100 gm of body weight 1, 3, 5, 7, 10, and 14 days after E. tene/fa infection. Chickens in uninfected control group were similarly injected. Chickens were killed two hours later. Ceca were isolated and examined for the presence of contrast medium. Radiograph was taken by Hitachi ZU-D3G model with Kodak X Omat K, 2H-II film at 1.0 mAs and 42 Kv at 1 m focus-film-distance. Inflow from cloaca into ceca. Thirty 12-day-old chickens were divided into two groups, uninfected control and infected. Each bird received an inoculation of 0.5 ml of 50% barium sulfate emulsion into cloaca 7 days after E. tene/La infection. Uninfected controls were also inoculated. Immediately afterward, birds were examined radiographically for the presence of contrast medium in the ceca. Weight of cecal contents. Sixty 11 days old chickens were allotted to two groups, uninfected control and infected, of 30 each. Seven days after E. tene/la infection, all birds were killed and one cecal pouch, either left or right randomly selected, was removed at the ileoceca-colic junction. Entire weight of the cecum was recorded. Cecal pouch was incised, washed thoroughly with saline, and blotted. The pouch was weighed again, and the difference in weight, gm, was expressed as the weight of the contents. Weight of control cecum was similarly measured. Number of cecal feces. A total of 60 22-day-old chickens were divided into two groups of 30 each. The groups were uninfected control and infected. Five birds were placed in one cage and 6 cages were assigned to one group. Number of cecal feces was counted every 24 h beginning 4 through 14 days after infection. Uninfected controls were similarly examined. Outflow of cecal contents. Thirty 11 days old chickens were assigned into two groups of 15 each. In each of three replications, 5 birds in uninfected control and 5 in infected groups were anesthetized with ketamine HCI injected intramuscularly at 35 mg per kg of body weight 7 days after E. tene/la infection. Cecum, either left or right, was exposed through the right abdominal incision and 0.3 ml of 50% barium sulfate emulsion was injected with 26gauge needle through blind end. Incision was closed and 2, 6, 8, 10, and 24 h later, birds were examined radiographically for the presence of the medium in cecum. On the basis of silhouette observed 2 h after injection of the medium, degree of silhouette seen later hours in each bird was graded as the same, decreased, or no silhouette (Fig. 1).

Chickens Infected with Eimeria tenella

339

b

a

Fig. 1. Radiograph of cecum taken two h after surgical injection of barium sulfate. a: A chicken in uninfected control group. b: A chicken in infected group 7 days after E. tene/fa infection. Bar: 10 mm.

Results and Discussion Results of backflow of contrast medium from cloaca into ceca are summarized in Tables 1 and 2. Sodium iothalamate was inoculated subcutaneously, absorbed, and excreted through kidneys to cloaca. Although presence of the medium in ceca was the outcome of urinary backflow by retrograde movement, it was best suited for the present purpose. Trace of contrast media via oral route tested in preliminary studies certainly reflected to the movement of intestinal contents, but the remains of the media in the upper intestine hampered radiographic reading of cecal silhouette.

Table 1. Presence of sodium iothalamate in the ceca of chickens infected with E. tene/fa Days after E. tene/fa infection Groups

1

3

5

7

10

14

13/15

13/15

12/15

13/15

-

a

Uninfected control

12115" 12/15

Infected with E. tene/fa

13/15

9/15

5/15

0/15*

1/15*

5/15"

Number of birds positive for contrast medium / Number of birds examined.

* Significantly different (P < 0.05) from uninfected control (Student's t test).

340

A. Arakawa, M. Sayama, E. Baba, and T. Fukata

Table 2. Retention of barium sulfate in the ceca of chickens inoculated with the medium into cloaca 7 days after E. tenelfa infection Groups

Number of chickens positive for barium sulfate / Number of birds examined

Uninfected control

12/15

Infected with E. tenelfa

0/14*

* One bird died of cecal coccidiosis. Number of chickens positive for sodium iothalamate in the ceca of E. ten ella infected chickens was fewer than that of uninfected control three days after infection and thereafter. Difference was particularly significant 7, 10, and 14 days after infection (P < 0.05). These findings indicate that retrograde movement of ceca was impaired by developing coccidia, and no movement was suggested 7 days after infection. The lack of inflow movement was confirmed by another trial where barium sulfate was inoculated into cloaca 7 days after infection (Tables 1 and 2). Weight of cecal contents examined 7 days after E. ten ella infection was significantly smaller than that of uninfected control (Fig. 2). Uninfected cecum contained as much as 1.5 gm of the contents, while infected ceca had less than 0.6 gm. It seems likely that the contents, if any, found in infected ceca 7 days after infection were the remainings of the contents entered the ceca beforehand and the very limited volume of contents was allowed to remain in narrowed cecal space caused by thickened wall of contracted ceca.

I

21

T

10 ~

~

:0

....0 ~

'" "

~

5

o

0

0.3 0.6 0.9 1.2 1.5 0

0.3 0.6

Weight of cecal contents (gml

o : Uninfected control ~

: Infected with

~.

tenella

Fig. 2. Weight of cecal contents of chickens 7 days after E. tenelfa infection. Values of E. tenelfa infected group are significantly (P < 0.05) smaller than uninfected control (Wilcoxon's non-parametric U-test).

Chickens Infected with Eimeria tenella

341

Number of cecal feces is presented in Fig. 3. The counts in infected chickens were fewer than those of uninfected controls 5 through 11 days after infection. They were significantly fewer 8, 9, and 10 days after infection (P < 0.05). The findings may indicate that outflow movements of infected ceca was close to that of uninfected control upto 7 days after infection. However, counting of cecal feces does not necessarily reflect to cecal evacuation. It seems evident that hemorrhagic cecal feces are discharged 5 to 6 days, sometimes 7 days, after infection as long as bleeding in ceca continues. Fecal discharge from infected birds is reported to be unresponsive to illumination (3). Fewer cecal feces observed 8 through 11 days after infection suggest that the ceca remained considerably contracted (6) and less cecal contents retained. Although infected ceca appeared as if they returned to normal function in cecal evacuation 12 days after infection, in vitro study reported that infected cecal pouches did not return to normal function for a period of three weeks (7).

.

>,

.....

."

1':

J:> .....

~

u

2

..... '"

.. u

'" ..... u

1

o

'-

'E"

J:>

"

z

8

Days after

.s.

9

10

11

12

13

14

tene11a infection

0: Uninfected control, . : Infected with

I.

tene11a

Fig. 3. Number of cecal feces of chickens infected with E. tenella. *, Significantly different (P < 0.05) from unifected control (Student's t test).

The results of the number of cecal feces suggested slowed movement of cecal evacuation, but evacuating function remained unclear due to less volume of cecal contents. To study this, barium sulfate was surgically injected into a cecum of anesthetized chickens 7 days after infection. Though all chickens came out of anesthesia within 2 h extent of its adverse effect is unknown; if any, it is presumably limited. All uninfected control chickens retained the contrast medium in ceca until 2 h after injection, while only 11 out of 14 infected birds held the medium at varying degree. In three birds, the medium passed out of cecum while being injected. This was undoubtedly due to contracted ceca and lack of distending flexibility. Results showed that most of uninfected control ceca excreted or evacuated the contrast medium between 10 and 24 h after injection. This is contrasted by the observations in infected ceca where only two birds cleared ceca during the same period (Table 3). E. tene/la infection resulted in prolongation of passage time of a marker through the digestive tract (2). This strongly suggests adverse effect of the infection on the movement of the entire intestines. The present study was aimed only at cecal filling and

342

A. Arakawa, M. Sayama, E. Baba, and T. Fukata

Table 3. Retention of barium sulfate surgically injected into a cecum of chickens 7 days after E. tene/la infection Hours after injection of barium sulfate No. of birds

S*

D

N

S

D

N

S

D

N

Uninfected control

15

15

0

0

11

2

2

10

3

2

Infected with E. tene/la

14**

11

3

0

10

4

0

10

4

0

Groups

2-6

2-8

2-10

2-24 S

D

N

1

6

8

10

2

2

S: Same silhouette, D: Decreased silhouette, N: No silhouette.

',>, One bird died of cecal coccidiosis.

defecation, however possible effect on ceca of other parts of intestine may have to be investigated. Furthermore, biological function of infected ceca by other appropriate methods for longer period of time has to be studied.

References

1. Arakawa, A. and O. Ohe: Reduction of Clostridium perfringens by feed additive antibiotics in the ceca of chickens infected with Eimeria tene/la. Poult. Sci. 54 (1975) 1000-1007 2. Aylott, M. V., O. H. Vestal, J. F. Stephens, and D. E. Turk: Effect of coccidial infection upon passage rates of digestive tract contents of chicks. Poult. Sci. 47 (1968) 900-904

3. Clarke, P. L.: Coccidial infection with Eimeria tene/la and caecal defaecation in chicks. Brit. Poult. Sci. 20 (1979) 317-322

4. Johnson, J. and W. M. Reid: Anticoccidial drugs: Lesion scoring techniques in battery and floor-pen experiments with chickens. Exp. Parasit. 28 (1970) 30-36

5. Oikawa, H. and H. Kawaguchi: Effect of coccidial infection on acetylcholine-induced contraction of the digestive tract in chickens. I. Eimeria tene/la and E. acervulina infection. Jap. ]. Vet. Sci. 36 (1974) 433-440

6. Reid, W. M., P. 1. Long, and 1. R. McDougald: Coccidiosis. In: M. S. Hofstad et al. (ed.), Diseases of Poultry, 8th ed., pp. 692-717. Iowa State University Press, Ames Iowa (1984) 7. Schildt, C. S. and C. A. Herrick: The effect of cecal coccidiosis on the motility of the digestive tract of the domestic fowl.]. Parasit. 41 (Supp!.) (1955) 18-19 8. Witlock, D. R. and R. H. Fetterer: Eimeria tene/la: Cecal contraction in infected chickens. Exp. Parasit. 56 (1983) 186-189 Prof. Dr. A. Arakawa, Department of Veterinary Medicine, College of Agriculture, University of Osaka Prefecture, Sakai, Osaka, Japan 591