Botulism In broilers

1. Vet. Mohammed Abdel Fattah Tel.+46 0709245692 E-mail: Bmoaf@slv.se Botulism In broilers

2. Botulism in Broilers • Botulism is an intoxication which can affect man and animals, including rodents and a variety of avian species.

3. Etiology • Clostridium Botulinumis a straight rod, gram positive anaerobic bacterium which at a pH near or above neutrality produces oval, subterminal spores. • The spores are very resistant but are killed at 1210C for about 15 minutes. • The optimum pH for clostridium Botulinum is neutral to slightly alkaline (7.0-7.6) and the optimal temperature is between 30- 370C.

4. Natural habitat • The endospores are widely, but unevenly distributed in soils and aquatic environments. • Germination of the endospores, with growth of vegetative cells and production of toxin, occurs in anaerobic situations such as carcasses of vertebrate and invertebrate animals, rottingvegetation and baled silage.

5. Botulism Toxins • Botulinum toxins are high-molecular thermolabile proteins. They are neurotoxins whichacting by blocking the cholinergic synapse of the nervous system. • The toxin is very potent1mg of the neurotoxin contains more than 120 million mouse lethal doses. • There are seven types of Clostridium Botulinum A, B, C, D, E, F and G. • The toxins are identical in actions but differ in potency, distribution and antigenicity.

6. Botulism Toxins • Type C toxins (Alfa & Beta) are more readily absorbed through the intestinal wall of chickens and pheasants. • Almost all outbreaks in poultry and game birds are caused by type C, D. The oral toxicity of type D toxin is high for cattle (feeding poultry litter containing botulinum toxins). • There are no recorded cases of type C causing disease in avian and subsequently giving rise to disease in humans who usually succumb to types A, B, E and F.

7. Spread and influencing factors • The concentration of these organisms in the environment and their opportunity to producetoxins can be influenced by many factors: • The standard of management. • Regular removing of carcasses at the broilers house. • The type of the feeding system out-inside the broilers house (food chain). • The type of the drinking water system out-inside the broilers house. • The litter (type, quality and thickness)

8. Spread and influencing factors • High temperature, ventilation, humidity and anaerobic conditions. • The litter beetles (Alphtobiusdiaperinus), flies and maggots. • Wasted feed-stuff on the litter – carcasses at the same area. • Iron level in the drinking water and/or in the foodstuff. • Improper using of Iron rich product (stalosan F) which contains 41,6% FeSO4. • Low phosphorus, protein and carbohydrates and salt in feed-stuff (Eating carcasses)

9. Spread and influencing factors • Excessive light, extremely bright light or excessively long periods of light willcause the birds to become hostile. • Improper ventilation, heat stress may increase corticosterone levels. • Increase cortisol levels and necrotic intestinal lesions are believed to be involved in the pathogenesis of toxico-infection botulism. • Heat stress may decrease food consumption and increase water consumption which may contains high level of iron.

11. Pathogenesis • Botulism is usually caused by ingestion of preformed toxin in feed-stuff. • The toxin is absorbed from the intestinal tract and is transported via the bloodstream to peripheral nerve cells where it binds to susceptible cells and suppresses the release of acetylcholine at the myoneural junctions. This results in flaccid paralysis, death being caused by circulatory failure and respiratory paralysis.

13. Pathogenesis • Less common method of acquisition of toxin are wound botulism (shaker foal syndrome), and infant botulism where spores germinate in the intestine when the normal flora has not yet been fully established (floppy baby, syndrome). • Intraintestinaltoxico-infection form of botulism in broiler where • C. Botulinum may grow in and produce the toxins in the cecum. • High iron level in the drinking water and/or in the feed can enhance the proliferation and toxigenesis of many pathogenic enteric bacteria including C.botulinum.

14. Signs • Incubation time varies from 1-2 days and it may take 5 days from the beginning of signs until death occurs. • Morbidity and mortality are related to the dose of the toxin and environmental conditions. • Mortality can reach up to 50%. Signs usually start at one area in the broilers house and then spread in the rest of the house (like throwing a stone in the water).

15. Signs • The signs include weakness with in- coordination first of legs, the wings and eventually the neck (Limberneck) eyelids, followed by flaccid paralysis. • The feathers of the neck and the back are loose and easily shed. • The skin is hyperemic. • White-green diarrhea with excess urates is seen especially in case of the intraintestinaltoxico-infection form of botulism.

17. Gross Lesions • There are usually no gross lesions and the intestine may be empty with sometimes evidence of diarrhea and staining of the tail and vent feathers. • Haemorrhagic lesions maybe seen in the gizzard, intestinal tract (small intestine, cecaltonsils).

18. Diagnosis • Case history, clinical signs, absence or the presence of the above mentioned gross lesions, and observations of decaying material, animal and a verywet-thick litter with or without wasted feed-stuff. • The quality of the drinking water and foodstuff. • The main question here is: is this botulism? • Is this intoxication due to ingestionof already produced toxins in the environment or it is due to intraintestinaltoxicinfection?

19. Diagnosis • Samples • Blood (serum) from sick living birds or fresh carcasses. Crop or intestinal contents also can be collected for Mouse inoculation test. • Feed samples for toxins, microbiological, and chemical analysis especially the iron level. The level to be toxic to immature chickens is 4500 ppm. Narasin level. • Drinking water samples for chemical analysis of the iron level which should not be exceed 0.5mg/l. • Litter samples for microbiological analysis.

20. Diagnosis • Laboratory Diagnosis for detection of botulinum toxins • Toxin demonstration by Mouse inoculation test. If toxin is present the characteristic(wasp waist) appearance in the mice will be seen in a few hours or up to 5 days. • TheAppearance is due to abdominal breathing because of paralysis of the respiratory muscles. • Toxin identification using mouse neutralization tests (antitoxins).

23. Differential diagnosis • AI, ND (epizootic diseases) if the mortality rate has been 3% or more per week. Led Poisoning, Marek,s disease.

24. Treatment • The major treatment in case of toxico-infection botulism is antibiotic Paracillin vet (Amoxicillin) which has effect on C.botulinum. The other alt. is tylosin. • Selenium, Vitamin E, A and D3. • Guanidine Hydrochloride, which reverse the neuromuscular blockade and enhances the release of acetylcholine from nerve terminals. Acidification of the drinking water. Citric acid.

25. ControlReducing the number& making the environment less suitable for C.botulinum. • Botulism can cause a nightmare for the poultry producer. Prevention is best obtained by minimizing contact between the host and toxins and this is dependent on hygiene in management, particularly the removal of sick birds and removal of carcasses before decay and the prevention of contact with decaying materials. Flies, rodents and litter insects’ control. Proper house cleaning and disinfection as following:

26. Remove litter/manure immediately after birds are removed from the house • Remove all equipment you can from the house. • Wash down the house thoroughly from top to bottom. • Clean out and disinfect the watering system and the entire feeding system fromthe bin to the pans. Use water filter to decrease the level of iron in drinking water.Discover and cover all the places in the feeding system in which the birds can be trapped.

27. Fumigate/ spray the house with a compound approved for poultry house disinfection. • Use a flame thrower on the floor. • Allow the house and equipment to dry completely and then return equipment to the house. Clean up the immediate area around the outside of the house. Keep vegetation surrounding the poultry house mowed short. Disinfect 10 feet around the outside of the house. Clean and disinfect entrances to the house and make these areas as free of litter/manure and feathers as possible.

28. Allow at least 12-14 days down time before birds are placed back in the house. Bringing birds back into the house prematurely encourages the cycling of diseases fromflock to flock. • The most effective way to get rid of the problem, once bacterium is established in the house, is to change the acidity /pH of the litter by using Sodium bisulphate (NAHSO4), (1kg/200m2). This creates an environment that is les favorable for bacterium, use then a double layer of shavings. Lactobacillus as feed additives affect the free iron concentrations through competitive exclusion by binding iron.

29. Public Health Implication • There seems to be very little evidence for poultry as a source of botulism for humans and this may partly due to type C, D toxins being mainly associated with poultry while humans seem to be susceptible to mainly Types A, B, E and F. • The identification of the toxins must already be known before slaughtering otherwise the healthy birds will be slaughtered and then frozen until the identification of the toxins. Only healthy birds will be picked out for slaughter.

31. New faktor • Narasin level – Coccidiosis – Botulism.

34. Inclusions Body hepatitis(IBH)- Botulism.