Infectious diseases

1
Infectious diseases

• Arnaud Van Wettere DVM
• The Raptor Center

2
Principal Viral Agents

• Herpes Viruses
• Adenoviruses
• Orthomyxoviruses
• Paramyxoviruses
• Poxviruses
• Circoviruses
• Polyomaviruses

3
Herpes Virus

• Pachecos disease
• Psittacid HV-1,2,3
• South American Origin (New World Birds) - Legacy
  of Importation prior to 1991.
• Old World Birds die acutely (budgies, cockatoos,
  Eclectus, Greys)
• Conures (Nanday and Patagonian) incriminated as
  carriers, but

4
Herpes Virus

• Clinical signs
• Acute death
• lethargy, inappetency, yellow urates
• may be source of liver disease in old birds
  (biliary hyperplasia, papillomas)
• Transmission
• Shed in respiratory, ocular secretions and feces
• aerosol and fecal-oral contamination

5
Herpes Virus

• Diagnostic
• necropsy
• hepato-spleno-megaly, epicardial hemorrhage
• viral inclusion bodies liver, kidney, spleen
• Treatment
• Acyclovir will reduce death rate in an aviary
• Supportive care

6
Herpes Virus

• Prevention
• Vaccine
• side effect reported death -gt granuloma
• several viral strain possible
• used to protect susceptible birds in proximity to
  sick birds or detected carriers
• PCR test available to detect carriers
• Fragile virus -- susceptible to disinfectants,
  UV, drying
• Quarantine

7
Herpes Virus

• Other herpes virus
• Falcon hepatosplenitis,
• Duck viral enteritis, duck plague
• Pigeon herpes virus
• Finch herpes virus (Cytomealovirus)
• Mareks disease
• ILT - chickens

8
Polyomavirus

• Budgerigar fledging disease (BFD), French molt
• Clinical signs
• Acute death,
• high mortality in juvenile psittacine (near 100
  mortality in birds lt 15d)
• Feather dystrophy
• Subcutaneous hemorrhage
• Digestive, respiratory, neurological symptoms

9
Polyomavirus

• Transmission
• vertical and horizontal transmission
• Adult birds can be carrier
• Diagnostic
• Feather lesions indistinguishable from PBFD
• Antemortem
• AB titer, Cloacal swab/fecal -gt PCR

10
Polyomavirus

• Necropsy
• large intranuclear inclusion bodies liver,
  spleen, feather follicles..
• PCR, IF, EM...
• Control
• Vaccine
• Isolation of shedders away from neonates
• Control feather dust and other hygiene
• Quarantine

11
Circovirus

• Beak and feather disease
• Endemic in wild cockatoos (Australia)
• New World Parrots are hard to infect
• Clinical signs
• Septicemia and peracute death in nestlings
• progressive atrophy and necrosis of the feathers
  follicles, worsening with each successive molt

12
Circovirus

• Abnormal growth of the beak and nails with
  necrosis
• Most birds die within 6 months to 1 year
• Bird die of secondary infections
• HIV of psittacines -gt immunosuppression in
  recovered birds

13
Circovirus

• Transmission
• horizontal
• high number of viral particles in feather dust
• Diagnostics
• PCR (blood)
• histopathology
• intranuclear and intracytoplasmic inclusions

14
Circovirus

• Control
• No treatment, no vaccination
• PCR
• Reservoir of infection is agapornis (lovebirds)
  -- keep them away from other birds.
• quarantine

15
Unknown etiology

• Proventricular dilatation disease (PDD, PDS,
  Macaw Wasting Disease, MWD)
• virus suspected
• Neurotropic
• lymphoplasmacytic ganglioneuritis
• Myenteric plexus of mid g.i. tract, crop
• Other neural tissue -gt ataxia
• Higher incidence in macaw

16
PDD

• Clinical signs
• regurgitation
• weight loss
• undigested seed in droppings
• ataxia, paresis in some birds
• Diagnostic
• radiograph
• delay GI transit time
• crop biopsy

17
PDD

• Transmission
• Fecal - oral ?
• Treatment
• supportive care
• treat secondary infections
• Celebrex 10 mg/kg

18
Pox virus

• Avipoxvirus
• many strain
• High degree of host specificity
• Clinical signs
• dry form
• papules, crust on unfeathered area (eyelids,
  feet)

19
Pox virus

• Wet form, diphtheritic
• fibrinous exudate on oral mucosa
• dysphagia, dyspnea
• Septicemic form -- Canary Pox
• Transmission
• biting insects - virus can live in salivary gland
  for several weeks
• direct and indirect contact

20
Pox virus

• Treatment
• Early lesions debride or cauterize
• Control secondary bacterial infections
• Diagnostic
• clinical signs
• biopsy, viral culture
• Control
• vaccine
• species specific canary pox
• Quarantine

21
Paramyxovirus

• Newcastle disease
• PMV-1
• Strain varies in pathogenicity
• lentogenic mild or inapparent infection
• Mesogenic mild to severe diseases
• Velogenic severe to lethal
• Viscerotropic, pneumotropic, neurotropic

22
Paramyxovirus

• Transmission
• fecal-oral
• direct and indirect contact
• asymptomatic carrier up to 1 years after recovery
• Clinical signs
• acute death
• respiratory or digestive symptoms
• neurologic signs

23
Paramyxovirus

• Diagnostic
• clinical sign
• serology
• virus isolation
• Control
• vaccine
• Quarantine
• Also...PMV 1 to 9

24
Orthomyxovirus

• Avian influenza
• Most species are susceptible
• Clinical signs
• digestive, respiratory, neurological, death
• Diagnostic
• Cloacal swab PCR
• virus isolation
• Treatment ?

25
Adenovirus

• Aviadenovirus
• group I quail bronchitis, inclusion body
  hepatitis of chicken, pigeon, budgerigard, duck,
  geese.
• group II hemorrhagic enteritis virus of turkey,
  marble spleen disease of pheasant
• group III egg drop syndrome of chickens
• Unclassified falcon adenovirus

26
Adenovirus

• Clinical signs
• Psittacines
• depression, anorexia, enteritis
• pancreatitis, hepatitis, encephalitis
• death
• Transmission
• vertical and horizontal (strain variability)

27
Adenovirus

• Diagnostic
• AB (HI, ELISA, VN)
• Virus isolation
• intranuclear inclusion body are routinely seen on
  histopathology and are not diagnostic
• Control
• very resistant virus
• hygiene

28
West Nile Virus

• Flavivirus
• Over 140 avian species affected
• Clinical signs
• neurological ataxia, head tremors, star gazing,
  blindness, wing drop

29
West Nile Virus

• Transmission
• biting insects
• fecal-oral
• Diagnosis
• blood, cloacal swab (PCR, ELISA)
• post-mortem immunohistochemistry, PCR

30
West Nile Virus

• Treatment
• supportive care
• Prevention
• mosquito control
• vaccination

31
Principal Bacterial Agents

• Chlamydiophila psittaci
• Mycobacterium avium
• E. coli
• Pasteurella
• Salmonella

32
Chlamydiophila

• Agent Chlamydiophila psittaci
• Other C. trachomatis, C. pneumoniae
• Character Intracellular parasite
• Infective form Elementary Body (EB)
• Reproductive Reticulate Body (RB)
• Infection Aerosol, water, direct contact
• Incubation Days to years
• Zoonotic

33
Avian Species Most Affected

• Budgerigars
• Cockatiels
• Amazons
• Macaws (most severely affected)
• Love birds (endemic)
• Pigeons
• Not Cockatoos

34
Clinical Appearance Classical Psittacosis

• Respiratory symptoms
• Leukocytosis, heterophilia, monocytosis
• Anemia
• AST elevation, TP, bile acids
• Radiographic signs
• Fibrinopericardititis

35
Treatment

• Chlortetracycline Impregnated Pellets -- 45 day
  treatment required
• Oral Doxycycline
• Injectable Doxycycline (1/w)
• Fluoroquinolones

36
Diagnostic Dilemmas

• Life Cycle of organism
• Stage of disease when sample is taken -- largely
  unknown
• Latency -- may last for years -- no footprints
• Variability in virulence
• Sensitivity and specificity of available tests

37
Diagnostic Tests 2 types

• Antigen Capture
• Antibody Detection
• PCR
• Cell culture from tissue or feces
• gold standard
• not practical for routine screening

38
Control in Breeding OperationsE.G. Commercial
Cockatiels

• Testing - PCR or culture ( 10 - 20 pairs at end
  of breeding cycle or birds showing clinical
  signs)
• Frequency Year 1- every 3 months
  Year 2 - every 6
  months Annually thereafter unless
  positive result Commence with year 1 after
  positive result
• Positive case - quarantine, treat, retest 4
  weeks post treatment
• Test and quarantine any incoming birds

39
Avian Tuberculosis

• Agents M. avium, M. genavense
• Gram , acid-fast rod
• World-wide distribution
• Chronic ganulomatous disease
• Amazon and Brotogeris sp. seems more susceptible
• Potential zoonotic disease in immunosuppresed,
  very young or old adult

40
Clinical Signs

• Chronic wasting
• Subcutaneous granulomas
• Diarrhea intestinal lesions
• Dyspnea pulmonary consolidation (rare)
• Paralysis osseous tubercles

41
Avian Tuberculosis

• Transmission
• fecal - oral
• can survives 1 to 2 years
• Diagnosis
• extreme leukocytosis
• hepatomegaly, splenomegaly
• Fecal acid-fast stain
• cytology
• liver biopsy

42
TB Appearance
43
Treatment and Control

• Quarantine
• Isolation
• Depopulation
• Treatment not recommended
• Antibiotics
• Isoniazid
• Ethambutol
• Clarithromycin

44
Pasteurella multocida

• Cat bites
• Avian cholera
• wild waterfowl, chicken, turkey, raptors
• septicemia
• Transmission
• fecal - oral
• contaminated water and food
• scavenging

45
Pasteurella multocida

• Acute infection
• enlarged liver with white foci of necrosis,
  pericarditis, airsacculitis, petechia,
  neurological symptoms, mucoid enteritis
  (waterfowl)...
• Chronic
• sinusitis, esophageal abscess, synovitis...

46
Pasteurella multocida

• Diagnostic and treatment
• culture and sensitivity
• Control
• vaccine
• good husbandry (water)

47
Salmonella

• 2000 serotypes
• Few infect birds
• S. typhimurium, S. enteritidis, S. dublin, S.
  infantis.
• Pigeon S typhimurium var. Copenhagen
• Potential zoonotic disease in immunosuppresed or
  very young or old

48
Salmonella

• Transmission
• fecal - oral
• carrier state
• Clinical signs
• enteritis
• septicemia
• arthritis
• elbow in pigeon

49
Salmonella

• Diagnosis
• bacterial isolation (fecal, necropsy)
• serology
• Treatment
• good husbandry
• antibiotic
• vaccine (pigeon)

50
E. Coli

• Colibacillosis
• Economic importance in poultry
• colisepticemia
• chronic respiratory disease
• enteritis
• sinusitis
• peritonitis, salpingitis
• coligranulomatosis
• osteomyelitis

51
E. Coli

• Diagnosis and treatment
• culture and sensitivity
• Control
• good husbandry practice
• vaccine for some strain in poultry

52
Yersinia pseudotuberculosis

• Turacos and rhamphastidae ( toucans, aracaris)
  are extremely susceptible
• Clinical signs
• lethargy, diarrhea, dyspnea, wasting
• flaccid paresis or paralysis

53
Yersinia pseudotuberculosis

• Acute form
• hemoraghic to fibrinous pneumonia
• hepatomegaly, splenomegaly
• Chronic form (finch, psittacine, doves)
• miliary grayish foci in liver, spleen and ceca
• Diagnosis
• isolation of the organism

54
Yersinia pseudotuberculosis

• Treatment
• good husbandry
• antibiotics

55
Miscellaneous bacteria

• Staph, strep in wound
• Clostridium
• Pseudomonas
• Mixed bacterial infection
• ...

56
Questions ?