Ratites

1. Ratites Dr./ Wafaa Abd El-ghany Assistant Professor of poultry dis., Fac. Vet. Med., Cairo Univ.

3. Ratites are classified into Ostriches, Rhea and Emus. • Ostriches is the only birds that has 2 toes. • It has no crop. • It has a diaphragm and prominent sex organs in males. • It related to birds as it has wings, feathers and muscular stomach. • The diseases diagnosis in ostriches could be assessed through X rays, endoscopy, Blood parameters (PCV, HB, etc..) and Blood chemistry (liver and kidney function). • Ostriches begins in laying at 2 years old. • The incubation time to hatch is 39-44 days.

4. Diseases of respiratory system • Mycoplasmosis. • Coryza. • Aspergillosis. • Respiratory helminthes.

5. Diseases of gastro-intestinal tract • Salmonellosis. • Campylobacteriosis. • Clostridial enteritis. • Viral entertidis. • Necrotizing typhlocolitis of Rheas. • Zygomycosis. • Candidiasis. • Endoparasites.

6. Diseases of integument (skin) • Ostrich pox. • Dermatomycosis. • Conjunctivitis. • Ectoparasites.

7. Diseases of central nervous system • Western equine encephalitis. • Newcastle disease. • Borna disease. • Baylisascaris encephalitis. • Chandlerella encephalitis.

8. Systemic disease • Anthrax. • Erysipelas. • Tuberculosis. • Pasteurellosis. • Chlamydiosis. • Colibacillosis. • Avian influenza. • Adenovirus infection. • Infectious bursal disease. • Viscerotropic eastern equine encephalitis. • Crimean-congo haemorrhagic fever. • Protozoal diseases infection.

9. Bacterial diseases

10. Campylobacteriosis • It is a bacterial disease causing high mortality and morbidity in young ostriches (2-16 weeks of age). • The causative agent is Campylobacter (C) C. jejuni and C. coli. • The disease is associated with enteritis and hepatitis in ostriches and rheas. • This disease is of public health importance (zoonotic) (occupational disease) as it could be infect humans through consumption of ostriches meat which are serve as a vehicle for food borne infection, or through handling of infected carcasses in the processing plants.

11. Infection and transmission • Feeding of the birds on lucerne pasture irrigated with water from sewage treatment plants, or ingestion of contaminated fed and water by the droppings of chronic carriers. • Free living birds (sparrows), rodents, insects, mammals, pets, cattle and pigs are reservoirs of infection. • Mechanical transmission through foot wears contain faeces. • Infection may pass through he embryos by unhygienic handling of eggs (faecal surface contamination). • C.jejuni is sensitive to desiccation and it survives in a dry environment for longer than a few hours. The organism can persist in moist biological material for up to 5 days and for longer periods in water and biological films lining piping and tanks.

12. Signs • Sudden death without obvious signs. • Some birds showed depression, anorexia, lethargy, poor growth rate, weakness and ataxia before death. • Sick birds showed watery lime-green urinary fraction of the faeces, these green ureats often stained and matted the feathers around the vent and were seen spotting the floor of pens (due to liver damage). • Slight icterus. • Mortality rate ranged from 20-100%, mortalities are less for older ostriches.

13. Lesions • Enlarged liver with multiple pale white to yellow, irregular and variable sized foci on the surface and through out the parenchyma. Many foci were confluent and some were tinged green. • Catarrhal or mucoid enteritis. • Ascitis. • Hydropericardium. • Anaemic carcass. • Pale coloured kidneys and spleen. • Sporadic stomach ulcers.

14. Diagnosis • The sample could be taken from the intestinal contents, liver, bile, heart and ascetic fluids. • Samples could be taken from living birds either from cloacal or faecal swabs or from heart blood. • Due to severe sensitivity of the organism to desiccation so it requires special precautions during sample transportation 9transport in ice box or in the following transportation media).

15. Diagnosis • Swabs should be put in transported media (Cay-Blair, Butzler’s, Campy-BAP, Blaser’s and Skirrow’s, Blaster’s BU40, Stuart’s, Preston and selective media contains brucella agar, blood agar base, ovine, bovine or equine blood), the media should be contain antibiotics (bacitracine, novobiocine, polymixine B, trimethoprim, colistine and cephalothin) as inhibitors to any bacterial contaminants. • A blood free selective media contain charcoal, campychoc agar and a charcoal and blood free media could be used.

16. Diagnosis • The organism is thermophilic requires 37°C-42°C to grow under microaerophilic conditions (10% Co2, 5% oxygen and 85% nitrogen) in commercial gas panks, torbal or candle jar or in CO2 incubator for 2-3 days. • Primary isolation revealed flat, translucent, gray colonies have a tendency to coalease. Sometimes, raised, opaque, brown gray colonies with discrete margin. Swarming colonies attributed to high moisture. • Colonies are non-haemolytic on blood agar.

17. Diagnosis • Campylobacter organisms could be inoculated into CAM of ECE or I/V inoculation of the embryos with the faecal material or bile or liver suspension which resulting in embryonic death 11 days post inoculation. Yolk sac inoculation revealed death of the embryo with congestion and hepatic necrosis. • Campylobacter organisms could be inoculated on tissue cultures like chinese hamaster ovary cells and Hela cells. • Campylobacter organisms could be inoculated in laboratory animals like rat, mice (I/C induces nervous signs), rabbit (I/P induces hepatic necrosis), hamster and G.pig. • The organism could be inoculated I/P or I/M in day old poults or chicks.

18. Diagnosis • Campylobacter organisms are gram-negative spiral or comma shaped curved rods, S shaped or “Seagull winged” shaped organisms. They are motile posses single polar flagellum. • It could be observed with characteristic darting motility under dark filed illumination microscope. • Campylobacter species are unable to ferment carbohydrates energy released from the degeneration of amino acids. They are positive oxidase, catalase and selenite, rapid producers to H2S and reduce nitrates but negative indole and urease.

19. Diagnosis

20. Diagnosis • Serotyping of Campylobacter species: • Panner scheme: Depends on soluble heat stable (O antigen lipopolysacharride) that identify 60 serotypes of C.jejuni. • Lior scheme: Depends on heat labile (H antigen). • Panner scheme is more specific and faster than Lior scheme. • Restriction endonucleasehydrolysis is also used for differentiation.

21. Prevention • All in –all out policy. • Restrict the movement of the persons. • Eradication of free living birds, rodents and insects. • Prevent direct contact between ratites and mammals as cattle and pigs. • Water chlorination. • Thorough cleaning and disinfection of the equipments as feeders and drinkers using QAC and phenol. • No recycling of the litter.

22. Prevention • Avoid infection of human by exposure of the carcasses in the slaughter plants to Gamma irradiation or pasteurization to reduce the number of the organism without induction of any undesirable change in the product like organoleptic or biochemical changes. • Post processing decontamination of the carcasses (lactic or acetic acids) treatment rinse effectively to limit the organism. • there is no available vaccine.

23. Control • Quarantine measures on the affected farm. • Hygienic disposal of dead birds. • Thorough cleaning and disinfection. Treatment with injectable enrofloxacin and erythromycin in water. • Furaltadone (250 mg/L Dw) in younger birds and norfloxacin injection (30 mg/kg) in older birds to reduce the mortality. • Treatment must be followed by restoration of the normal intestinal flora.

24. Necrotizing typhlocolitis • Necrotizing pseudomembranous typhlocolitis associated with a spirochete was demonstrated in rheas. • Intestinal spirochetosis are a group of spiral bacteria colonize in the large intestine of avian, mammalian and human hosts. This colonization is a part of the normal intestinal flora or associated with the cause of clinical disease. • Avian spirochaetes has been classified into; S.hyodysentriae, S.intermedius, S.pilosicoli and un-named group of chick spirochaetes.

25. Infection and transmission • Ingestion of contaminated soil or feed. • Contact with clinically or healthy carriers. • Multiage farms, high stocking density and defects in hygiene predisposing infection. • Multispecies farms.

26. Signs • Juvenile rheas aged one month and older (over 6 months) are susceptible to the infection. • Birds showed depression, anorexia, and decreased body weight. • Watery or mucoid diarrhea for a short period before death. • Some birds showed sudden death without signs. • Flock mortality rate may exceed 80% especially following introduction of older birds or mixing of flocks. • Experimental infection of day old rhea chicks reproduce P/M and histopathological lesions, but it requires synergism between various spirochaetes and non spirochaetal anaerobic caecal flora.

27. Lesions • Marked distention of the terminal colon and caeca with accumulation of intra-luminal fluid in acute cases and hypermia may be seen. • Advanced cases showed fibrino-necrotic and pseudomembranous colitis and typhlitis. • Caecal core similar to those observed in histomoniasis in turkeys are observed in chronic cases. • The liver had a focal 1 cm yellow raised nodules.

28. Histopathology • He caeca and colon showed areas of necrosis with lymphocytic infiltration into the lamina propria. • The necrosis was frequently accompanied by a variable amount of surface fibrin deposit which cause pseudomembrane formation. • The nature of inflammatory response is variable from suppurative to granulomatous. • Goblet cell hyperplasia, caecal crypts cell hyperplasia and excessive mucous secretion. • Warthin-starry staining revealed presence of numerous spirochaetes within the lamina propria and submucosa of caeca. • Acute coagulative necrosis of the liver and spleen.

29. Diagnosis • Samples from fresh faecal (caecal) droppings or caecal mucosa. • It is anaerobic organism needs enriched media like trypticase soya agar with 5-10% sheep blood, antibiotics as spectinamycin, spiramycin, vancomycin and or colistin are essential to inhibit the growth of non spirochetes enteric anaerobs. • Incubate at 37-42C for minimum 10 days, growth usually occur in 2-5 days. • Because of vigorous motility of the organism, it spread rapidly over agar plates (don’t for discrete colonies) and some isolates cause haemolysis of the blood while others are non or B haemolytic. • Bacterial growth determined by characteristic motility on wet mounts using dark field microscope.

30. Diagnosis • Avian intestinal spirocheatas are Gram negative helix shape bacteria stained with Silver impregnation (brown) and with wrights Giemsa (blue), it could be seen under dark field microscope. • The organism contains envelop and periplasmic flagellae. • Highly motile organism permit it to transverse highly viscous liquids as mucous. • The organism could be demonstrated in Ultra-thin section of caecal mucosa or in negative stained preparation of faeces.

31. Diagnosis • Biochemical identification revealed that the organism is positive alkaline and acid phosphatase, estrase and estrase lipase and B-galactosidase. • The bacterial antigen could be demonstrated by FAT and immunohistochemistry, while antibodies could be detected using AGP, ELISA and agglutination test.

32. Virulence factors • The haemolysin group of proteins are the major virulence factor involved in the pathogenicity of the organism as haemolysin induces epithelial cell degeneration and necrosis. • Other toxins as lipopolysaccharides, an uncharacterized inhibitor of Na, Cl2 transport across enterocyte cell membrane and trypsin like protease. • The vigorous motility of the organism in the mucous gel of large bowl gives the advantages of survival and proliferation. • Proliferative organism secretes waste products that inhibit the growth of some and enhance the growth of other flora resulting in alteration of fluid absorption by changing the contents of organic ions excreted and or absorbed.

33. Prevention • Separation of different ages groups. • Rheas should be raised on a single species farm with separation of neonates, juvenile and adult rheas. • A complete and appropriate hygiene and disinfection of clothing, shoes, equipments and brooding pens should be carried out before restocking with a group of younger birds. • All introduction of new rhea stock should be quarantine and take place after 2-3 negative caecal culture. • Discourage visiting of other rhea housing. • Avoid contact with swine either direct or indirect to avoid mixing between species. • It may be necessary to use concrete flooring in brooding pens to facilitate inter-cycle decontamination to decrease the contact with faeces.

34. Control • Quarantine measures on the affected farm. • Hygienic disposal of dead birds. • Thorough cleaning and disinfection. • Treatment of the affected birds using oral metrendazole (25-30mg/kg bwt) once or twice daily with lincomycin (25mg/kg) twice daily to reduce mortalities in the affected flock. • Using erythromycin (15-25mg/kg) once daily for 5-7 days. • Increase the daily fibers, reduce losses through stimulation of peristalsis or alteration of caecal pH. • Probiotics to relapse the lost normal enteric flora.

35. Salmonellosis • Salmonellosis is now the predominant and the most important bacterial infection in ratites especially in relation to consumer food safety. • The disease in ostriches, emus and rheas is caused by different Salmonella typhoid and paratyphoid species (21 serotypes) isolated from chicks and adults from the yolk sac, liver, respiratory and intestinal tract and ovary. • The disease causes losses during incubation (high embryonic losses), brooding and rearing.

36. Susceptibility • All ages of ratites are susceptible as the organism was isolated primarily from the lesions of necrotizing enteritis. • S.typhimurium is common in multispecies collections and cause mortalities in ostrich chicks younger than 3 months, rarely found in birds older than 6 months or slaughtered birds at 12- 14 months. • S.typhimurium and S.enteritidis are associated with clinical conditions in young, stressed and immuno-compromised ostriches with high mortalities. • Intensively reared ostrich chicks that have failed to establish a normal intestinal flora are susceptible to Salmonella infection. • Older birds are relatively resistant to Salmonella infection, but can occur under stressors.

37. Infection and transmission • Because of salmonella species are ubiquitous and persist for a long time in soil or faeces, infection on a specific farm may resulted in losses during incubation, brooding and rearing and the birds can remain clinically normal carriers infecting the environment. • Horizontal infection through ingestion or inhalation of the droppings of clinically normal or asymptomatic infected carriers or indirectly through contaminated clothes, houses and equipments.

38. Infection and transmission • Vertical (congenital) (Non transovarian) transmission through faecally contaminated eggs due to improper hygienic procedures relating to eggs collection and incubation. • Mechanical transmission through rodents, mammals, free living birdsand insects. • Introduction of newly acquired birds directly into the flocks. • Trading and auction barns helped in distribution of infection. • Picking nature of ratites and husbandry practice.

39. Signs • Elevated embryonic or post hatching mortalities. • Hatched chicks showed: • per-acute mortalities (sudden death without premonitory signs). • Acute (non specific) signs of depression, anorexia, weakness and some birds showed diarrhea. • Chronic signs of growth retardation, emaciation and sporadic episodes of diarrhea.

40. Signs • The most severe clinical signs and the highest mortalities were noted in birds less than 60 days old. • Adult breeder hens showed non shelled infertile eggs and early embryonic deaths of fertile eggs. • Respiratory distress. • Clinically affected chicks showed un-absorbed persistent yolk sac which could be palpated or visualized as pea-sized abscess at the navel encapsulated on the wall of the peritonium. Death started within a few days after hatching and continue for 2 weeks. The yolk sac should be absorbed within 14 days of age in ratites, older than 18 days considered abnormal.

41. Lesions • Un-absorbed yolk sac (omphalitis) of the neonates. The yolk sac is too large for the age of the chicks with signs of inflammation. it’s content may be inspissated or putrescent with dull or dirty green discolouration of the yolk contents. • Flabbiness and greenish discolouration of the chick belly. • In per acute and acute stage: A) Echymotic to suffusive haemorrhages in the serosa of GIT with marked engorgement of the mesenteric blood vessels.

42. Lesions B) Congestion of the caudal small intestinal mucosa with patchy areas of necrosis and ulceration covered with a layer of adherent fibrinous exudate or a thick fibrinous cast. C) Generalized vascular congestion. D) Fibrino-necrotic cecitis. E) Fibrinous peritonitis with excess peritoneal fluid. F) Enlargement and congestion of spleen.

43. Lesions G) Congestion of the liver with white multifocal hepatic granulomas. H) Pneumonia with lung nodules. • Impaction of the proventriculus. • Multifocal whitish firm nodules on the kidneys. • In chronic stages there were emaciation and fluidly small intestinal contents.

44. Diagnosis • History, clinical signs, hatchery parameters, mortality in newly hatched chicks, positive serological tests are suggestive. • The sample must be taken from ailing birds (showing signs) or from freshly dead birds (not after 2-4 hrs after death). • Samples should be taken under complete aseptic conditions using sterile instruments, during transportation, and preserve the samples in sterile swabs immersed in transportation media.

45. Diagnosis • The best sites for isolation of Salmonella species are the gall bladder and the liver. In systemic infection, samples could be taken from heart blood. • If the death happen from more than 4 hrs, the best site for isolation is the bone marrow. • Faecal swabs could be taken from the ailing birds also intestinal swabs, oviduct swabs and yolk sac swabs could be used.

46. Diagnosis • Samples from the pericardial sac, spleen, and kidneys are important. • Egg shells or eggs contents (yolk) are important sites for Salmonella isolation. • Samples should be macerated in test tubes containing selenite F broth or tetra thionate broth with brilliant green as enriched media that increase the number of Salmonella species and inhibit the growth of other enterbacteriacae like E. coli. Incubate under aerobic conditions at 37-43C for not more than 12-16 hours. Positive reaction appears as broth turbidity.

47. Diagnosis • Don’t incubate more than 16 hrs to avoid the growth of lactose fermenting organisms like E. coli which shift the media to the acidic side and kill Salmonella. • It should be sub-culture from enrichment media, incubate under aerobic conditions at 37-42C for 24-48 hours on one of the following media: • MacConkey lactose bile salt neutral red media: it used for inhibition of the growth of non- intestinal bacteria, also used for differentiation between lactose fermenting organisms (E. coli) which give pink colonies and non lactose fermenting one (Salmonella) which give colourless (white), large and thick colonies.

48. Diagnosis • Brilliant green MacConkey agar media: it suppresses the growth of enteric organisms other than Salmonella which appear as translucent and pale green colonies. Subgenous III of salmonella (S.arizona) produces purple colonies due to it is lactose fermenter. • DCA (Deoxycholate citrate agar) media: it inhibits he growth of both coliform bacteria and Gram positive ones. Salmonella gives smooth, translucent and colourless with black center colonies.

49. Diagnosis • XLD (Xylose lysine deoxycholate) media: it restrains the growth of E. coli and prevent the spreading of proteus. Salmonella species give red colonies with black center. • Nutrient agar and blood agar: most strains produce large, circular, gray white and moist colonies with smooth surface and entire edges. By sub-culturing, rough (R) variant strains produce opaque granular colonies with irregular surface and intended edges. Some strains showed mucoid colonies.

50. Diagnosis • Nutrient broth and peptone water: Salmonella species produce abundant growth with uniform turbidity and thin pellicle. R strains give granular deposit and thick pellicles. • Gram staining of suspected colonies revealed Gram negative bacilli, non spore former, non acid fast, non capsulated rods and non motile organism. • S. gallinarum pullorum from type 2 fimbriae (non-haemagglutinating) or from no fimbriae.