Lecture 27. Respiratory Infections 3

Agents of Canine Infectious Tracheobronchitis (Kennel Cough)

1. Bordetella bronchiseptica

2. Canine Adenovirus 2 (CAV-2)

3. Canine Parainfluenza 2 (PI-2)

Bordetella bronchiseptica etiology

1. Gram-negative obligate anaerobic rod

2. Catalase, oxidase, urease positive

3. Virulent strains hemagglutinate mammalian RBCs

4. Slight hemolysis on sheep agar

Bordetella spp.

this bacteria is associated with varying strains and types of diseases in different species but can primarily lead to respiratory infections in dogs, pigs, and turkeys

Virulence factors of B. bronchiseptica

1. General: fimbriae, LPS, dermonecrotoxic toxin

2. Specific: filamentous hemagglutination, type III secretion, adenylate cyclase hemolysin

Transmission of Kennel Cough

1. Direct contact or aerosolized respiratory secretions

2. Fomites

Pathogenesis of Kennel Cough

1. Most prevalent canine respiratory complex

2. Low mortality, generally self-limiting

3. Risk of bronchopneumonia

Clinical signs of Kennel Cough

Coughing, gagging, oculonasal discharge but otherwise BAR and non-febrile for about 14 days

Diagnosis of Kennel Cough

MacConkey culture or PCR of tracheal fluid showing organism

Treatment for Kennel Cough

1. Mild cases may not need treatment

2. Antibiotics (Amoxicillin, Tetracycline, Fluoroquinolones) if persists >2 weeks

Control of Kennel Cough

Isolate infected dogs and give intranasal vaccines for B. bronchiseptica and PI-2

Cause of Atrophic Rhinitis in pigs

Bordetella bronchiseptica

what addition infection can occur in pigs experiencing Atrophic Rhinitis

Pasteurella multocida type D infection

Pathogenesis of Atrophic Rhinitis

Piglets <4 weeks show turbinate hypoplasia without snout distortion

Clinical signs of Atrophic Rhinitis

Atrophic rhinitis and Lacrimation, with Shortened, wrinkled snout

Diagnosis of Atrophic Rhinitis

Nasal/tracheal samples, MacConkey culture, PCR

Treatment for Atrophic Rhinitis

Tetracyclines and Enrofloxacin (Does not clear bacteria)

Control of Atrophic Rhinitis

Vaccination with whole cell bacterins and P. multocida or MLV

B. brochiseptica

Based on C/s of lacrimation and a small and wrinkled snout, this pig was likely infected with....

Cause of Turkey Coryza

Bordetella avium

Etiology of Bordetella avium

1. gram negative obligate anaerobic rod

2. catalase and oxidase postive only

3. virulent strain hemagglutinate guinea pig RBCs

4. no hemolysis on sheep agar

Transmission of Turkey Coryza

Direct contact, aerosol, environmental contamination

Pathogenesis of Turkey Coryza

Highly contagious respiratory disease in poults leading to High morbidity, low mortality disease

B. avium

the pathology of this turkey trachea combined w/ additional beak breathing likely indicates what pathogen

What bacteria are turkeys infected with B. avium predisposed to

E. coli

Clinical signs of Turkey Coryza

Mucus in nares, Beak breathing, Lacrimation, Sneezing

Diagnosis of Turkey Coryza

Nasal/tracheal samples, MacConkey culture, PCR, Clinical signs and pathology

Treatment and Control of Turkey Coryza

Early antibiotics, Bacterin and MLV vaccines, Disinfection

Cause of Infectious Coryza in chickens

Avibacterium paragallinarum

Characteristics of A. paragallinarum

1. Motile gram-negative facultative anaerobic rod

2. Requires factor V (NAD), 5-10% CO₂, Grows on chocolate agar with "dew drop" colonies

Infectious Coryza of Chickens

this pathogen causes what disease that leads to loss of condition and facial swelling

Transmission of Infectious Coryza of Chickens

Direct contact, aerosol, contaminated drinking water,

what acts as reservoirs for Infectious Coryza of Chickens

Chronically ill and asymptomatic birds

Pathogenesis of Infectious Coryza of chickens

Infection of respiratory tract → loss of condition and reduced egg production

Clinical signs of Infectious Coryza of chickens

1. Mild: depression, serous nasal discharge, facial swelling

2. Severe: major infraorbital sinus swelling

3. general Tracheitis, bronchitis, airsacculitis

Avibacterium paragallinarum

what bacteria is likely associated with the pathology shown in this image

Diagnosis of Infectious Coryza of chickens

1. Necropsy: exudate in sinuses, 2. Facial swelling + bacterial isolation

3. PCR or immunoperoxidase staining

Treatment and Control of Infectious Coryza of chickens

Sulfonamides or Oxytetracycline in water, Bacterin vaccine

Cause of of Avian Chlamydiosis

Chlamydophila psittaci

what are the main species affected by avian chlamydiosis

psittacines and pigeons

Transmission of Avian Chlamydiosis

Ingestion or inhalation of infected respiratory secretions or feces, Triggered by stress

Clinical signs of Avian Chlamydiosis

1. Respiratory and digestive tract infection

2. Loss of condition

3. Nasal/ocular discharge

4. Diarrhea

5. Respiratory distress

Diagnosis of Avian Chlamydiosis

1. Necropsy: hepatosplenomegaly, airsacculitis, peritonitis

2. Tissue smear staining

3. ELISA, PCR, egg isolation, CFT

Avian Chlamydiosis

the pathology present in this chicken shows that it likely suffered from what condition

Treatment and Control of Avian Chlamydiosis

Tetracycline, No vaccine, Quarantine new birds, good husbandry

Zoonotic potential of Avian Chlamydiosis

Zoonotic: can cause pulmonary issues, meningitis, meningoencephalitis

what is true of Psittacosis in the US

notifiable disease!!