L22-23 Flashcards
(23 cards)
Avian clostridial diseases and agents
Botulism (Cl. Botulinum) Ulcerative enteritis (Cl. Colinum) Necrotic enteritis (Cl. Perfringens) Necrotic/gangrenous dermatitis (Cl. Perfringens) Wound infections (Cl. Spp.)
Botulism aka
Limber neck
Western duck sickness
Cycle of botulism in ducks
1) decayed vegetation in shallow lakes creates anaerobic env.
2) botulinum exotoxin kills larvae, which are eaten by ducks
3) toxin kills ducks
4) biting flies feed on dead ducks, flies die
5) flies eaten by ducks, ducks die again
6) cycle starts over
*cycle similar in chickens (they eat chicken carcasses that have infected maggots in them)
Type C botulism toxin is produced where?
In live intestine
CS of botulism in poultry
- complete neck and wing paralysis
- head on ground, neck extended
- loose feathers
- signs begin 1-2 days after ingestion of toxin
- mild cases may survive (char. By progressive mild paralysis/weakness)
Dx of botulism
- CS, Hx of outbreak
- evidence of toxin via serum inoculation of mice or feeding mice crop and intestines of dead birds
- isolation of C. Botulinum or toxin in feces, wound, tissue
Tx of botulism**
- antitoxin not effective in commercial poultry
- epson salts in feed
- molasses in water
- bacitracin and selenium sometimes help
Prevention of botulism
- feed fresh ration
- remove all dead birds
- vax valuable birds with type A and C toxoid
- abx in feed?
- litter clean and dry
- acidify soil/litter with sulphur
Ulcerative enteritis cause
Clostridium colinum
Ulcerative enteritis is primarily a disease of?
Quails (young chickens too)
Mt of Ulcerative enteritis in quail
Up to 100% Mt
Lesions caused by Ulcerative enteritis
- caseous plugs in intestine
- massive necrosis in liver and spleen
- watery to bloody diarrhea
control of necrotic enteritis caused by clostridium perfringens
- sanitation/disinfection
- raise backyard birds on wire cages
- control Gumboro, chicken infectious anemia, coccidiosis
Tx of necrotic enteritis (Clostridium perfringens)
Abx: bacitracin, lincomycin, penicillin, tetracycline
Gangrenous dermatitis cause
Clostridium perfringens type A and C
Staph aureus
E. Coli
Pathophys. Of Gangrenous dermatitis
Invades traumatized skin and occurs in immunosuppressed birds
Cause of colibacillosis
E. Coli
Involved in chronic respiratory disease (CRD) complex
Usually opportunistic only
Has many serotypes with little cross-protection
Colibacillosis mainly occurs as:
- acute fatal septicemia
- sub-acute pericarditis
- airsacculitis
- cellulitis
Trans. Of Colibacillosis
- bacteria shed in feces, eggs
- transovarian infection
- egg shell penetrated in env.
- bacteria enter bloodstream from resp. Or intestinal tracts
Predisposing factors for systemic E. Coli outbreaks
- mycoplasmoses
- infectious bronchitis
- NCD
- hemorrhagic enteritis in turkeys
- bordetella in turkeys
- env. Factors: high ammonia lvls, too hot or too cold poultry env, high humidity, poor air quality, insects, etc.
Disease syndromes caused by colibacillosis
- omphalitis
- peritonitis
- resp. Dz complex
- arthritis/synovitis
- enteritis, salpingitis, metritis, cellulitis
- Coligranuloma or Hjarre’s disease (acute septicemia and sudden death)
Colibacillosis = very common cause of secondary bacterial infection**
:)
Dx of colibacillosis
Bacterial culture and typing
Strict sanitation
Control other dzs
Abx added to water
