Respiratory disease in poultry Flashcards
Look at poultry integrator system?
What environmental factors effect respiratory disease?
Outline some broiler site statistics?
- All in all out system
- 7 day turnaround
- ~30,000 birds per house
- 4-7 houses per site
- Whole house brooding
- >20 lux lighting (4 hours dark/day)
- Pan feeders
- Nipple drinkers
- All have to be on concrete floors for hygiene and salmonella control
- When chicks arrive they are 50g
- Shavings used as bedding
- Controlled ventilation/humidity
- Thinning at 35 days, depleted 42 days
- Stocking level = 33Kg/m² (25kg/m² for broiler breeders)
Discuss laying systems in UK?
- Enriched cages 750cm² to include 600cm² of useable area
- Barn layers should be stocked @ 9 birds/m²
- Free-range layers should have the same internal space and there should be no more than 2500 hens/ha on the range
Discuss UK turkey production?
- UK Turkey Production
- Breeders use artificial insemination due to size discrepancy between males and females
- Young turkeys are reared in brood rings
- Often stags are grown to six weeks, then moved to grow-out accommodation (brood and move can be a cause of stress)
- Hens: all in/all out single site systems
Give a lung and air sac overview?
Not surprise we see resp disease so frequently in reared poultry as they have delicate air sac structures .
Inspiration one: caudal airsac (inspired air goes there before lungs)
- On PM therefore more likely to see air sacculitis first
What are the clinical parameters?
Hen may mouth breathe initially in consult but if this does not go away as she calms then this is something to be concerned about
What are the respiratory disease clinical signs in poultry?
- Coughing (snicking)
- Sneezing
- Ruffled feathers
- Huddling
- Ocular/nasal discharges
- Discharge on wing feathers
- bletharospasm
- Conjunctivitis
- Sinusitis
- Head shaking
- Swollen heads
- Inappetent
- Abnormal water consumption
- Mortality (flipovers)
- In a shed want to see even spread of birds if they are all clumped this is indicative of disease.
What the differential diagnosis for the coughing bird in all poultry?
Avian influenza
Newcastle disease
What are the differential diagnosis for the coughing bird in hens?
Hens:
- Infectious Bronchitis (IB)(sneezing)
- Avian Rhinotracheitis (ART) (sneezing)
- Infectious Laryngotracheitis (ILT) (gasping)
- Mycoplasma gallisepticum (Mg)
- Ornithobacterium rhinotracheale (ORT)
- Pasteurella multocida
- Infectious Coryza
- E. coli
- Gapeworm (gasping)
What are the differential diagnosis for the coughing bird in turkeys?
Turkeys:
- Turkey rhinotracheitis (TRT) (sneezing)
- Pasteurella multocida
- E. coli
- Mycoplasma gallisepticum (Mg)
- Ornithobacterium rhinotracheale (ORT)
What are the differential diagnosis for the coughing bird in ducks?
Ducks:
- E. coli
- Reimerella anatipestifer (sneezing)
- Aspergillosis
Discuss avian influenza?
- Will infect, but not necessarily affect all poultry species
- Turkeys are most susceptible to mortality
- Waterfowl, esp. ducks, carry disease with no mortality and no clinical signs
Why is avian influenza notifiable?
- Massive economic loss in an uncontrolled outbreak
- Welfare issue of high mortality and morbidity
- Possible zoonotic risk (though no human cases of last year’s H5N8)
- LPAI (H5 or H7) could mutate to HPAI
What does avian influenza look like?
H and N are important because:
- H is for attachment to and release within cells, N allows the virus to leave the cell (KEYS)
- They define species specificity
- We can easily target them with vaccines
Why are we so concerned about avian influenza?
We are concerned because it can cause massive mortality in poultry also if it occurs during human flu outbreak may lead to pandemic if it mutates
Discuss highly pathogenic and low pathogenic influenza A in poultry?
Highly pathogenic
- severe disease
- high mortality up to 100%
- to date only[but not all] viruses of H5 or H7 subtype
- Swollen comb and wattles
Low pathogenic
- mild respiratory disease, depression, egg production problems
- may exacerbate other infections/conditions
What are the clinical signs of avian influenza?
High Pathogenic virus infection
- Anorexia
- Mortality –up to 100% in 36 hours
- Respiratory signs −Coughing (snicking), sneezing, ruffled feathers, swollen heads
- Nervous signs like depression
- Diarrhoea
Discuss low pathogenic avian influenza?
Low Pathogenic virus infection
- Anorexia
- Respiratory signs (like HP)
- Nervous signs
- Diarrhoea
- Egg production drop
- Blood seen at nose and cloaca
Discuss newcastle disease?
Paramyxovirus type 1
5 pathotypes:
Viscerotropic velogenic –high mortality with haemorrhages
Neurotropic velogenic –high mortality following respiratory and nervous signs
Mesogenic –low mortality following respiratory & nervous signs
Lentogenic respiratory –mild respiratory disease
Asymptomatic enteric –inapparent enteric infection
What are the clinical signs of newcastle disease?
Respiratory signs -Coughing, sneezing, ruffled feathers, swollen heads
Nervous signs -Depression -Ataxia -Prostration
Opisthotonus
Mortality –similar to AI
Egg drop -Soft shelled eggs -Concentric rings on shell
What species are affected by Newcastle disease?
- Will infect, but not necessarily affect all breeds of avian (over 250 species found to be carriers)
- Racing Pigeons were the cause of the January 2018 outbreak in French Poultry
- Any migrating bird poses a potential risk
Discuss vaccination for newcastle disease and AI?
Newcastle Disease
- All commercial layers are vaccinated (2 x live & 2 inactivated in rear)
- All broiler breeders are vaccinated
- Hitchner B1(MSD), NDW (Zoetis), Avinew (Boehringer-Ingelheim)
AI
- No vaccination allowed under control programme
Discuss infectious bronchitis?
- Corona virus
- Disease first recognised in USA in 1931 (Massachusetts Strain)
- Worldwide problem in chickens
- Now variant viruses common -793B, D274, 1466 & Italian O2, QX
- Waves of viruses affect different countries
- Coronaviruses found in intestines of gamebirds and turkeys
What are the clinical signs of infectious bronchitis?
- Respiratory signs include sneezing, nasal discharge, lacrimation
- Poor performance –weights in pullets
- Egg drop in layers (up to 25%) as it does replicate in the repro tract
- Blind layer syndrome (hydrosalpingitis)
- Poor egg shell quality (can last 4-6 weeks) – pale shells or thin shells
- Kidney effects (nephritis) –excess drinking / wet litter
Brown hens produce brown eggs unless they have infectious bronchitis they will get paler and paler
How is infectious bronchitis controlled?
Control by vaccination
- Farm –Mix of vaccines
- 2 doses –2 weeks apart
- Older birds at 10 –12 week intervals
- Vaccines: (1000 dose vials minimum)
So if you have backyard rescue hens they most likely will have had these vaccines
Discuss Avian Rhinotracheitis(ART)/ Turkey Rhinotracheitis(TRT)/ Swollen Head Syndrome?
- Avian meta-pneumovirus
- A & B strains seen in UK
- C strain in USA
- Started in turkeys in 1978
- Now seen in chickens
What are the clinical signs of Avian Rhinotracheitis?
- Decreased appetite
- Poor growth in young birds
- Egg production drops in hens
- facial & head swelling
- ocular & nasal discharge
- conjunctivitis, snick, dyspnoea, sinusitis
- Post-mortem lesions:-serous rhinitis and tracheitis, pus in the bronchi
- Live vaccines used extensively in the turkey industry
Discuss infectious laryngotracheitis (ILT)?
Herpes virus
- Only affects chickens (occasionally pheasants) –commonest in young birds
- Respiratory route
- Virus can survive for several weeks on ground –when cold even longer
- Peracute form –sudden death
- Haemorrhagic tracheitis / laryngitis
- Vaccination by eye drop with live vaccines
- Vector vaccines can be used in the hatchery
- Broiler chickens don’t live long enough to get this
- A nasty pharyngitis is seen on PM
Discuss mycoplasma infections?
A big one for backyard poultry
Vet school has had it a few times
This is a disease of wild birds wild pheasants and partridges and this is how it gets in.
Has a long incubation period. Nasty conjunctivitis and infraorbital sinusitis.
Many free range poultry are vaccinated against it
Discuss Mycoplasma gallisepticum?
- Epithelium of the conjunctiva, nasal passages, sinuses, and trachea are most susceptible to initial colonization and infection; however, in severe, acute disease, infection may also involve the bronchi, air sacs, and occasionally lungs.
- Once infected, birds may remain carriers for life. There is a marked interaction (polymicrobial disease) between respiratory viruses, Escherichia coli , and M gallisepticum in the pathogenesis and severity of chronic respiratory disease.
- Commonly seen in gamebirds, free range layers and seasonal turkeys. Very rare in breeder birds due to control measures. Live attenuated vaccines available
Discuss Ornithobacterium rhinotracheale?
- A pasteurella-like bacterium
- Unrelated to ART / TRT
- Causes respiratory disease in young turkeys and chickens, and locomotor disease in older turkeys and chickens
- A very common reason for poultry airsacculitis condemnation in processing plants; other lesions include bronchopneumonia, tracheitis and Achilles tendon abcessation
- Spreads vertically and horizontally
- Culture difficult / ELISA serology
- Inactivated vaccine available for breeders
Discuss Primary pathogenic E. coli?
Environmental organism
Can be typed to determine pathogenicity
Usually secondary to other conditions e.g. IB/Mg
Serositis distribution
- Pericarditis
- Peritonitis
- Perihepatitis
Treatment based on Culture & Sensitivity
- Wide range of antibiotics can be successful
- Live vaccine available E. coli
Discuss pasteurellosis?
- Bacterial respiratory disease
- Pasteurella multocida
- Pasteurella often associated with rodents (rats not mice) or sheep
- Common in layers and turkeys
- Causes severe pneumonia
- High mortality potentially
- High rejects in meat birds
- Poorly responsive to medication other than Enrofloxacin and Amoxicillin
- Inactivated commercial and autogenous vaccines used
Discuss Infectious Coryza(IC)?
- Avibacterium avium (formerly Haemophilus paragallinarum )
- Severe respiratory disease first identified in backyard flocks by APHA and now seen in commercial free range layers
- Impact on egg production
- Low to significant mortality in non-protected flocks
- Poor response to antibiotic treatment and no UK licenced vaccines
Discuss Riemerella anatipestifer?
- Probably more widespread in the UK duck industry than first thought
- Certainly common in Asia
- Poor hygiene increases the risk of infection
- Diagnosis on culture (48 hours)
- Responds well to antibiotic therapy Amoxicillin Chlortetracycline in food
- Prevention -Hygiene Autogenous vaccination Management
- Ducks usually very robust but this is one of the things that will knock them for six
Discuss aspergillosis?
- Contaminated bedding usual source: Straw-ducks
- Young chicks often affected most
- With age comes immunity
- Gasping & mouth breathing
- Sudden death
- Fungal lesions in air sacs / lungs
- Change the bedding source if it is a persistent problem
What is this?
Gape worm (syngamus trachea)
- Never see this in meat birds but common in backyard poultry.
- CS: gasping for air and gaping.
- Longer female and shorter male worm with mouth parts attached to trachea.
- Can scope to see them
- Or do a worm egg count.
Discuss syngamus trachea treatment regimes?
Licensed products
Flubendazole
Flubenvet: Feed for 7 days at 30ppm
Fenbendazole
Panacur Aquasol: In water 1mg/Kg for 5 days
Scratching area management
Range management
Remove faeces Replace scratching material Harrowing grassland Treatment Regimes
Discuss diagnosis of poultry respiratory disease?
- Clinical signs (nothing pathognomic)
- Performance data
- Post mortem examination
- Culture for bacteria
- Serology
- Tracheal swabs or FTA cards for PCR
- Virus isolation
- Histopathology
Discuss post mortem examination?
- Because of flock sizes kept, mortalities are inevitable
- Post mortem examination of fresh dead allows a unique opportunity to examine the internal organs of the birds
- It is the mainstay of our examinations, but is complemented by other testing
- Sample selection can impact on findings
- Culls vs. Dead
- Ideal batch size ~ 6 birds Post Mortem Examination
Outline blood sampling technique in poultry?
- Good restraint is very important
- Brachial vein exposed by plucking feathers
- Use 19 –23g needle or nick vein with sharp blade
- Half fill blood tube
- Bleeding will usually stop once wing is lowered
- Put cap on tube and lie on side to clot
- Send to laboratory asap (with paperwork)
- DO NOT FREEZE
Discuss assessment of antimicrobials in poultry treatment?
- Sensitivity plates are still the standard test despite limitations
- Must remember in vitro vs. in vivo differences
- Main criteria for success is a drop in mortality
- Other health & performance criteria can also be used
- Most licensed products have a 3 to 7 day treatment period
- Consider -cidal drugs for immunocompromised birds
- In vitro resistance is frequently seen; consider your approach
- Egg dipping & in ovo can impact on hatchability
- Intensive antibiotic use high up the genetic pyramid may dramatically reduce use in commercial birds
Discuss responsible use of antibiotics?
- Responsible use of antimicrobials
- Antibiotics must not be used as growth promoters
- A constraint is the cost/benefit of treatment
- Refer to RUMA http://www.ruma.org.uk/guidelines/vaccines/short/poultry%20vaccine%20s hort.pdf
- Treatment is not an alternative to good husbandry, biosecurity measures and preventative programmes
- MIC testing is used on isolates in epidemiological studies, sensitivity testing is used in diagnostic cases • Polypharmacy should be avoided
- Meat withdrawal 28 days, eggs 7 days (what are the caveats?)
- Abide by the law: http://www.legislation.gov.uk/uksi/2009/2297/pdfs/uksi_20092297_en.pdf
- & restrictions placed by assurance codes e.g. ACP, Lion Code, Freedom Foods, Soil Association
- Be sensitive to the principles of the prescribing cascade http://www.vmd.defra.gov.uk/pdf/vmgn/VMGNote13.pdf
Discuss routes of administration for poultry vaccines?
- Drinking water
- Spray: Hatchery cabinets On farm
- Intra –ocular
- In ovo ((vaccinated whilst they are still embryo in egg)
- Injection (importance of maternally derived antibodies for commercial birds)
What is this?
Avian influenza: Pancreatitis & tracheitis
Look at this newcastle disease?
What is this?
Infectious bronchitis
What is this?
Mycoplasma gallisepticum
Look at these images if infectious laryngotracheitis?
What is this?
Avian Rhinotracheitis
What is this?
E. coli septicaemia
What is this?
Fowl Cholera Pasteurella multocida
