Differential Diagnosis of Respiratory Disease in Broilers

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Aileen Wheeler
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1 UD Poultry Health System(Lasher and Allen Labs) Department of Animal & Food Sciences College of Agriculture and Natural Resources University of Delaware Newark, DE USA Differential Diagnosis of Respiratory Disease in Broilers Daniel Bautista, Jack Gelb Jr. and Jose Miguel Ruano

2 Tools Available To Establish A Diagnosis History Physical Examination Posmortem Examination Laboratory tests Treatment Response

3 History Geographic Area Past and present disease outbreaks (disease prevalence) Climate, season Individual Company Disease History, Vaccination, Biosecurity Program Individual Farm Age of Buildings, Recent ranking, Disease history, Recent vaccination, Breed and Type Individual Outbreak- Age, morbidity, mortality, clinical signs, male/female?

4 Physical Exam check FLAWSS Feed, Light, Air, Water, Sanitation, Stress Inspect normal, sick birds and dead birds Dead- may show clear and advanced lesions Sick- support dead bird lesions and for obtaining fresh lab samples Normal-for field normal reference

5 Respiratory Complex Many respiratory diseases may show very similar clinical signs and lesions. They may be concurrent infections ND/IB + CRD(MG) + E. coli IB + ORT + E. coli Recognize exacerbating factors Use a reliable diagnostic lab to support disease control and health management decisions

6 Diagnostic Tools ELISA- cheap surveillance tool AI, NDV, IBV, MG, MS, ORT, TRT, etc. NDV and IBV= GMT- presumptive field challenge PCR- AI, NDV, IBV,MG, MS, Haemophillus/Avibacterium, Pasteurella Virus Isolation and identification- important for making sound vaccination programs. Bacteriology and antibiotic sensitivity

of field samples for respiratory PCR panel (U of Georgia-PDRC) Important: Make arrangements

7 Samples into the USA for PCR/ Phenol-inactivated virus after VI in host country Genotyping Whatman Filter paper For IBV genotyping (Univ of Delaware) Tracheal impression/swab smears of field samples for respiratory PCR panel (U of Georgia-PDRC) Important: Make arrangements first w/ the laboratory and obtain necessary USDA documents from the US lab to accompany shipment

8 Infectious Respiratory diseases Viral Avian influenza-rare Newcastle disease-moderate to common Infectious bronchitis-common Infectious laryngotracheitis- sporadic, now common in some regions of the US (vaccinal LT) Turkey rhinotracheitis, Swollen Head Syndrome in broilers late 90 s in the Midwest, decreased incidence Wet pox rare, seasonal

9 Infectious Respiratory diseases Bacterial Colibacillosis-common, usually secondary pathogen Fowl Cholera- sporadic, mostly breeders Infectious Coryza- Under-reported? May be common in backyard flocks Ornithobacterium rhinotracheale (ORT) Under-reported?, not a primary pathogen in broilers in my opinion

10 Mycoplasma/CRD- common in backyard flocks, sporadic in breeders and broilers M. gallisepticum, M. synoviae, Mycotic Aspergillus fumigatus- Common in 1 week old broiler chicks Dactylaria sp.-rare

11 Predisposition to Respiratory Disease Immune suppression Infectious infectious bursal disease, chicken anemia virus, Marek s, REV, ALV, HEV Stress air quality, temperature, litter, water, lights, Pathogen load stocking density, down time between flocks, built-up litter, multi-age facilities. Prevalence of disease agents in the area Biosecurity ( or lack thereof)

12 Important Stressors Poor ventilation- high ammonia levels Daily temperature extremes cold, damp nights & early mornings, hot and dry midday and afternoon) Seasonal changes(e.g., Fall-Winter, Dry-Wet) Wet litter, overcrowding, drafty housing Split NDV,IBV live vaccination - risk for rolling vaccine reaction Uneven NDV/IBV vaccination, LT CEO vaccination - risk for rolling reaction

13 Delmarva Respiratory Cases( ) % TotalRespComplex TotalLTVaxRxn TotalLTsuspect /1/2006 1/1/2007 1/1/2008 1/1/2009

14 Non-ILT Virus Isolations from Respiratory Complex cases 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% IBV NDV

15 Differential Diagnosis of Common Respiratory Diseases in Chickens mndv IB ILT MG/CRD Coryza Spread Rapid Rapid Medium Slow Rapid Duration 2wk 2wk 2-4wk wk to mo wk to mo Egg prod. slump Mortality in chicks <3wk Mortality in adults Egg transmit Nearly stop Up to 50% 1-20% 1-20% 1-20% 25-90% 5-60% none 5-40% (rare) rare 0-5% Usually 0 Up to 50% Low, many culls No No No Yes No Low, many culls Cause virus virus virus Mycoplasma bacteria Vaccine Yes Yes Yes Yes Yes

16 LT Signs and Lesions Watery, foamy ocular exudates, almond-shaped eyes, swollen eyelids

17 Wing-wiping

18 LT Signs and Lesions -labored breathing -crowing motion -gasping, gurgling breathing sounds -head shaking -0.1% to 2.5 mortality -low morbidity Dramatic drop in water consumption 24h prior to onset of clinical signs is a common finding

19 Bloody expectoration

20 Severe ILT Doubling Mortality up to 50

21 VLT lesions Mild Severe

22 High Mortality In Broilers Non-infectious-check for FLAWSS Feed, Light, Air, Water, Sanitation, Stress Heat Stress, Water Deprivation Ventilation Failure Feed Toxicity Infectious High Path Avian Influenza Virulent Newcastle Disease Fowl Cholera

23 VVNDV or HPAI Photo: Ilaria Capua

24 Virulent Newcastle Disease Diptheritic laryngotracheitis Diptheritic oropharyngitis and esophagitis

25 Newcastle Disease (VVNDV)

26 Fowl Cholera

27 Fowl Cholera

28 ILT Mild Severe Early ILT very similar to IBV, NDV lesions

29 ILT or IBV?

30 ILT or IBV?

31 ILT or Fowl Pox?

32 Deformed Eggs- ND/IBV

33 Which Respiratory Disease? Respiratory Disease RT-PCR Screening Panel can sort it out in 3hrs. ( AI, NDV, IBV, LT, MG, MS Real Time PCR) Haemophillus PCR available in other labs

34 Chronic respiratory Disease (MG) RT-PCR: Positive for MG and MS Negative for AI, NDV, IBV ILT

35 Infectious Coryza

36 Bacteriology

37 What s your guess?

38 What s your guess? RT-PCR: Positive for IB. Negative for ILT, AI, NDV, MG, MS

39 RT-PCR: Positive for IB. Negative for ILT, AI, NDV, MG, MS

40 Respiratory Complex Respiratory Disease Air sac condemnations

41 Submandibular edema RT-PCR: Positive for IB. Negative for ILT, AI, NDV, MG, MS

42 Signs and Lesions Low Pathogenic AI: Mild respiratory signs Minimal mortality Highly Pathogenic AI Severe clinical signs High mortality

43 Exarcerbating Factors to Respiratory Disease Interval Between Flocks Vaccination Program Breed Bird Density Ventilation/A mmonia Severity Bacterial Infections Immunosupression

44 Thank You for your attention!

Infectious Laryngotracheitis Disease Prevalence Patterns

Infectious Laryngotracheitis Disease Prevalence Patterns 2012 Delmarva Poultry Conference Ocean City, MD Daniel A. Bautista, DVM, MS University of Delaware-Lasher Laboratory Elbert N. and Ann V. Carvel