Bird 9 Flashcards
avian chlamydiosis
- agent, type
- agent developmental forms
- transmission
- what birds are susceptible
Chlamydia psittaci
o Small obligate intracellular bacteria
o Biphasic development (elementary and reticulate bodies)
o Transmission: fecal-oral, aerosol, secretions
o All birds are susceptible
- In pet birds, cockatiels and budgerigars are the most commonly infected
<><><>
- reticulate bodies replicate in cells
- elementary bodies infect new cells
avian chlamydiosis clinical signs
o Multisystemic with a tropism for respiratory system and liver
o Rhinitis, conjunctivitis in mild cases (pigeons, cockatiels)
avian chlamysiosis zoonotic risk
- where do most human infections come from?
- signs in humans?
- should we tell someone?
Zoonosis (only important one)
o Most human cases come from exposures to urban pigeons
and other carriers
o Parrots can definitely transmit disease to humans o Atypical pneumonia in humans
o NOTIFIABLE
avian chlamydiosis Dx
o PCR on oro-choanal-cloacal swab
o Serology: EBA (elementary body agglutination), ELISA
o Culture
o Cytology and histopathology
- Inclusions on HE
- Special stains: Gimenez or Macchiavello
o Blood work: non specific but important
- Marked inflammatory leucogram (heterophilic and/or
monocytic leucocytosis)
- May see liver involvement (elevation in liver enzymes and bile acids)
avian chlamydiosis Tx
o Antibiotic with intracellular distribution
- Older tetracyclines
- Doxycycline (drug of choice)
- Azithromycin
o Recommended length of treatment (20 to 45 days)
o For flocks of budgerigars
- Incorporate drug into food (medicated feed)
o For flocks of cockatiels
- Incorporate drug into water (doxycycline)
what agents can cause avian mycobacteriosis?
which are most common in pet birds?
zoonotic potential?
o M. avian-intracellulare complex
- M. avium avium
- Low zoonotic potential
<><>
o M. genavense
- Low zoonotic potential
- Most common in pet birds
<><>
o M. tuberculosis and M. bovis
- Typically reverse zoonosis
mycobacteria characteristics
- what type of organisms?
- who do they cause problems in
- species affected
- stain?
- Saprophytic organisms
- Immunocompromised individuals - All species are susceptible
- all are acid fast organisms
avian mycobaacteriosis clinical signs
o Chronic weight loss, emaciation
o Gastrointestinal/liver
o Less commonly respiratory signs
avian mycobacteriosis diagnosis
o PCR on biopsied tissues
o Histopathology
- Acid-fast stain
o Cytology
- “Ghost” organisms (does not pick up stain)
o Culture
- Very slow growing (M. genavense may take 6 months!!)
avian mycobacteriosis treatment
o Euthanasia when too advanced
o Lots of people recommend euthanasia because of zoonotic risk, but never been documented
- Very low probability
- Still a risk in immunocompromised people
o Anti-mycobacterial antibiotics
- Triple or quadruple therapy
- Isoniazid, clarithromycin, ethambutol, rifampin
- Tends to come back several years later
mycoplasmosis mainly an issue in what birds? what does it cause? mainly what agent?
what other birds is it found in?
Mainly an issue in backyard chickens and passerines
o Current epizootie in house finches and gold finches
o Sinusitis
o Mycoplasma gallisepticum
<><>
* Commensal organism in most other species, in particular raptors
mycoplasmosis Dx
o PCR on lesions, sinus flush
o Culture but slow growing
clostridiosis in raptors
- symptoms
- causes
- Dx
- Tx
- Issue in raptors
o Sudden death, necrotic enteritis
o Associated with food, thawing process
o Toxin-producing organisms - Clostridium perfringens
o Fecal cytology → safety pin appearance
o Treatment: hypovolemic shock, fluids,
metronidazole
<><><> - Also big issue in chickens (C. perfringens) and quails (C. colinum)
clostridiosis - botulism
- mechanism of action, outcomes
- who is affected?
- environmental associations
o Toxin produced by C.
botulinum
- Prevents acetylcholine release at neuromuscular junction
- Ascending flaccid paralysis
o Wild water birds, mainly anseriformes
o Associated with changes in water temperature
o Self-amplifying cycle with maggots
salmonellosis is mainly an issue in what birds? outcomes? Dx?
- Mainly in passerines (especially at bird feeders)
o Septicemia
o Clean feeder and stop feeding
the birds for a while
<><> - Also in raptors fed birds and rodents
o Enteritis
<><> - And also in pigeons
o Salmonella copenhagen
o Causes arthritis
<><> - Culture needs enrichment,
must specifically look for it - Zoonosis
avian cholera
- agent
- aquatic birds signs
- chickens signs
Pasteurella multocida
o In aquatic birds: die-off
o In chickens (Fowl cholera): from chronic (swollen wattles, decreased egg production) to acute (sudden death)
o Systemic disease
systemic/ internal infections in birds are often caused by what bacteria?
Systemic/internal infections often caused by gram- bacteria
o E. coli (especially passerines)
o Pseudomonas aeruginosa
o Klebsiella spp.
what gram + bacteria are of clinical importance in birds and why?
Gram+ of clinical importance
o Staphyloccocus aureus
- Sepsis, bumblefoot, skin infections
o Streptococcus spp.
poxvirus (wet form) affects what body system?
respiratory
pacheo’s (PHV1) affects what body system?
liver
psittacine circovirus affects what body systems?
immune, integument
poxvirus (dry form) affects what body system?
integument
polyomavirus affects what body systems?
liver, integument
avian bornavirus affects what body systems?
GI, CNA
west nile virus affects what body systems?
CNS
psittacine circovirus
- agent of what disease?
- DNA or RNA? size?
- environmental survival?
- excretion?
o Agent of Psittacine Beak and Feather Disease (PBFD)
o DNA virus
* Very small virus
* Extremely resistant in environment
* Excreted through feather dander
what animals are susceptible to psittacien circovirus?
o Mainly old world parrots (cockatoos, African species)
o Also new world species, but much more resistant
o Cockatiel tends to be resistant, so rare
o Mainly young birds < 1 year old
psittacine circovirus clinical signs
o Babies: beak dystrophy necrosis
(mainly in cockatoos)
o Feather dystrophies, loss
- African greys do not tend to lose feathers
o Immunosuppression
- Secondary infections common
▪ Aspergillosis
▪ Candidiasis
▪ Opportunistic bacterial infections
▪ Frequent co-infection with polyomavirus
what type of bird tends not to lose feathers from psittacine circovirus?
African greys
psittacine circovirus Dx, Tx
- Diagnosis
o CBC: pancytopenia, usually severe
o PCR - Blood: confirmatory, most birds are actively viremic when sick
- Feathers: chronic carrier, disease
o Histopathology: bursal atrophy, inclusions not common - No effective treatment
avian polyomavirus
- agent of what disease?
- who is susceptible?
- “Budgerigar fledgling disease”, psittacine polyomaviral disease
<><><> - Susceptible individuals
o Nestlings
o Adults are carriers
o Mainly a problem in aviculture setting
avian polyomavirus clinical signs and lesions
o Feather loss and dystrophy
o Subcutaneous hemorrhage
o Renal disease
o Hepatitis
o Systemic disease, sudden death
o Surviving nestlings may be poor doer and develop chronic ascites
Avian Polyomavirus Dx, Tx
- Diagnosis
o PCR on blood or cloacal swab
(DNA virus)
o Serology - Persistently positive
o Histopathology
<><> - No effective treatment
o A vaccine is available
- Psittacid herpesvirus 1
- what type of herpesvirus?
- causes what diseases?
o 4 genotypes, alphaherpesviruses, DNA
o Pacheco’s disease: acute liver necrosis
o Internal papillomatosis: chronic cloacal papillomas
Avian Herpesviruses
Pacheco’s disease
- mortality
- lesions
- surviors and shedding
- species affected
- carriers?
o High mortality rate
o Hepatic necrosis
o Survivors are persistently infected
- May start shedding again when stressed
o Amazon parrots are frequently affected
o Conures implicated as potential carriers
Pcheco’s disease Dx, Tx
- Diagnosis
o PCR on oral-cloacal swabs
o Histopathology (large inclusions)
<><> - Treatment
o Outbreak may be managed with acyclovir
Avian Herpesviruses
* Internal papillomatosis
- what species affected?
- lesions
- Tx
- sequelae
o Mainly Amazon parrots and
some macaws
o Lesions on latently infected
birds
o Cloacal papillomas in proctodeum
o No treatment except surgical excision of papillomas
o Birds may develop bile duct and pancreatic duct carcinomas later on
Internal papillomatosis Dx
o Histopathology
o PCR on tissues
o Cloacoscopy
avipoxvirus
- size, genome
- caldes
- species specificity?
- immunity?
- environmental survival
- transmission
- cells affected
- Large DNA viruses
o Two main clades:
✓ Fowlpox
✓ Canarypox
o Mild species specificity
o Cross-immunity
o Very resistant in environment
o Transmitted by arthropods or fomites
o Affects epithelium
avipoxvirus forms
- who do they affect?
- lesions? outcomes?
- Cutaneous “dry” form
o Most birds - Mainly seen in chicken and raptors
o Lesions on unfeathered areas - Face and feet
- Frequent concurrent bacterial contamination
<><><>
- Diphteric “wet” form
o Mucous membranes - Trachea
- Conjunctiva and eyelids
<><><>
- Systemic form
o Acute death, high mortality
o Mainly seen in canaries
avipoxvirus Dx
o Biopsy of lesions (ICIB =
Bollinger bodies)
o PCR of lesions
Avipoxvirus Tx
o Cutaneous form is self-
limiting
o Treat secondary infections
- Antibiotics, foot baths
o Vaccines
