Pathology of the Respiratory System 4: Pneumonia

Shannon Martinson, March 2016 http://people.upei.ca/smartinson/ VPM 222 Systemic Pathology

Review –Classification of Pneumonia

LUNG – PNEUMONIA

Diffuse

Examples of Diseases that Cause Bronchopneumonia in Domestic Animals

Suppurative Bronchopneumonia Fibrinous Bronchopneumonia

LUNG – BRONCHOPNEUMONIA

LUNG – BRONCHOPNEUMONIA - CATTLE

Multifactorial Etiology:

• Environmental factors*

• Crowding, humidity, temperature, air quality, stress

• Viral infection*:

• BRSV

• BPIV-3

• BoHV-1 (IBR)

• Bacterial infection

• Pasteurella multocida*

• Histophilus somni*

• Mycoplasma bovis

• Trueperella pyogenes

• Mannheimia hemolytica

Enzootic Pneumonia of Calves

High morbidity / Low mortality

LUNG – BRONCHOPNEUMONIA - CATTLE

Enzootic Pneumonia of Calves

• Suppurative bronchopneumonia • Should do bacteriologic culture

and virologic testing!

LUNG – BRONCHOPNEUMONIA - CATTLE

Shipping Fever (Pneumonic Mannheimiosis)

Etiology:

• Mannheimia hemolytica (biotype A)

• Part of the normal URT flora

• Impairment of pulmonary defence mechanisms:

• Environmental factors / stress

• Transit, crowding

• Viral infections

Low morbidity / High mortality

LUNG – BRONCHOPNEUMONIA - CATTLE

Fibrinous bronchopneumonia → Sepsis and leukotoxins

Shipping Fever (Pneumonic Mannheimiosis)

LUNG – BRONCHOPNEUMONIA - CATTLE

Shipping Fever (Pneumonic Mannheimiosis)

Coagulative necrosis

LUNG – BRONCHOPNEUMONIA - CATTLE

Other bacteria causing similar lesions:

• Histophilus somni*

• Mycoplasma mycoides ssp. mycoides small colony type

• Contagious bovine pleuropneumonia – exotic / reportable disease

• Often affects the caudal lobes and sequestra are common

Shipping Fever (Pneumonic Mannheimiosis)

LUNG – BRONCHOPNEUMONIA - CATTLE

Mycoplasma bovis

• Necrotizing / Necrosuppurative bronchopneumonia and bronchiectasis

• Dilation and destruction of bronchioles

• Difficult to differentiate grossly from abscesses

Gross images: Dr E Aburto

Lung abscesses

LUNG – BRONCHOPNEUMONIA - CATTLE

Mycoplasma bovis

• Necrotizing / Necrosuppurative bronchopneumonia and bronchiectasis

• Dilation and destruction of bronchioles

• Difficult to differentiate grossly from abscesses

Doesn’t grow on routine culture: Mycoplasma culture or Histology and PCR or IHC

Gross images: Dr E Aburto

LUNG – BRONCHOPNEUMONIA – SHEEP

Ovine Enzootic Pneumonia

Multifactorial Etiology:

• Environmental factors

• Crowding, humidity, temperature, air quality, stress

• Viral infection:

• RSV

• BPIV-3

• Adenovirus

• Bacterial infection

• Mannheimia hemolytica

• Pasteurella multocida

• Mycoplasma ovipneumonia

• Histophilus somni

High morbidity / Low mortality

• Suppurative bronchopneumonia • Should do bacteriologic culture and

virologic testing!

LUNG – BRONCHOPNEUMONIA – SHEEP

Pneumonic Mannheimiosis

• Etiology:

• Mannheimia hemolytica

• Predisposing factors

• Viral infection, Stress

Septicemic Pasteurellosis (previously Mannheimiosis)

Etiology:

• Bibersteinia trehalosi

• Sepsis +/- ulcerative lesions in the esophagus/oral cavity

LUNG – BRONCHOPNEUMONIA - PIGS

Porcine Enzootic Pneumonia

Etiology:

• Mycoplasma hyopneumonia

• Impairment of pulmonary defence mechanisms:

• Environmental factors

• Crowding ammonia, temperature, stress

High morbidity / Low mortality

Mycoplasma hyopneumonia

Suppurative bronchopneumonia

Porcine Enzootic Pneumonia Histology, IHC and PCR for diagnosis

P. multocida is often isolated in suppurative bronchopneumonia of pigs

LUNG – BRONCHOPNEUMONIA - PIGS

Porcine Pleuropneumonia Etiology:

• Actinobacillus pleuropneumonia (APP)

• Primary pathogen

• Highly contagious

• 2-5 month old pigs

• Sudden death with blood tinged froth from the nares

• Dyspnea and coughing

High mortality in naïve herds

LUNG – BRONCHOPNEUMONIA - PIGS

• Coagulative necrosis

• Sepsis / Shock

• Sequestrum

Porcine Pleuropneumonia

Images: Cornell Veterinary Medicine

Fibrinous bronchopneumonia • Often dorsocaudal in distribution

LUNG – BRONCHOPNEUMONIA - PIGS

LUNG – BRONCHOPNEUMONIA – DOGS AND CATS

• Most often secondary

• Common bacterial isolates:

• Pasteurella multocida

• Streptococcus spp

• Escherichia coli

• Klebsiella pneumoniae

• Bordetella bronchiseptica

• Streptococcus equi zooepidemicus

• Fatal hemorrhagic pneumonia in dogs

Aspiration Pneumonia

LUNG – BRONCHOPNEUMONIA – ALL SPECIES

Dog Aspiration Pneumonia

LUNG – BRONCHOPNEUMONIA – ALL SPECIES

LUNG – BRONCHOPNEUMONIA – ALL SPECIES

Aspiration Pneumonia

Examples of Diseases that Cause Interstitial Pneumonia in Domestic Animals

LUNG – INTERSTITIAL PNEUMONIA

Rib Imprints and Elastic Texture

LUNG – INTERSTITIAL PNEUMONIA

• BPIV-3

• BRSV

• BoHV-1

• Infectious Bovine Rhinotracheitis

• Virologic testing: PCR, FAT, IHC

LUNG – INTERSTITIAL PNEUMONIA - CATTLE

Viral Pneumonia

• Extrinsic Allergic Alveolitis

• Bovine Pulmonary Edema and Emphysema

• Reinfection Syndrome

• BRSV

• Dictyocaulus viviparous

• Inhalation of gases (H2S or NO2)

LUNG – INTERSTITIAL PNEUMONIA - CATTLE

Atypical Interstitial Pneumonia

Tryptophan

Tryptophan 3-methyl indole (3-MI) in rumen

3-methyl indole (3-MI) in blood to Club cells

LUNG – INTERSTITIAL PNEUMONIA - CATTLE

Bovine Pulmonary Edema and Emphysema (BPEE) Pathogenesis

LUNG – INTERSTITIAL PNEUMONIA - CATTLE

Bovine Pulmonary Edema and Emphysema (BPEE)

Edema and Emphysema

Etiology:

• Inhalation of bacterial spores from moldy hay:

• Saccharopolyspora rectivirgula

Pathogenesis:

• Antibody response circulating antibodies Formation and deposition Ag- Ab complexes in air-blood barrier Activation of Complement (C’)

Extrinsic Allergic Alveolitis

LUNG – INTERSTITIAL PNEUMONIA – CATTLE AND HORSES

Etiology:

• Inhalation of bacterial spores from moldy hay:

• Saccharopolyspora rectivirgula

Pathogenesis:

• Antibody response circulating antibodies Formation and deposition Ag- Ab complexes in air-blood barrier Activation of Complement (C’)

Extrinsic Allergic Alveolitis

LUNG – INTERSTITIAL PNEUMONIA – CATTLE AND HORSES

• Equine Influenza*:

• Transient with high morbidity

and low mortality.

• Equine Viral Rhinopneumonitis*

• Equine Herpesvirus 1 and 4

• Also neurologic disease and

abortion

• Virologic testing: PCR, FAT, IHC

LUNG – INTERSTITIAL PNEUMONIA –HORSES

Viral Pneumonia

Others viruses affecting the lung

• Equine Viral Arteritis (Arterivirus)

• Mainly hemorrhage and edema

• African Horse Sickness (Orbivirus)

• Massive pulmonary edema

• Hendra Virus (Henipavirus)

• Edema, vasculitis, thrombosis

• Zoonotic

LUNG – INTERSTITIAL PNEUMONIA –HORSES

Viral Pneumonia

• Swine Influenza:

• Transient with high morbidity

and low mortality.

• Porcine Reproductive and

Respiratory Syndrome (PRRS)

• PRRS virus (Arterivirus)

• PCV-2 Associated Respiratory

Disease

• Porcine Circovirus type-2

Viral Pneumonia

LUNG – INTERSTITIAL PNEUMONIA – PIGS

Viral Pneumonia

LUNG – INTERSTITIAL PNEUMONIA – PIGS

Virologic testing: PCR, FAT, IHC

Other causes of interstitial pneumonia in pigs: • Nipah virus • Sepsis

• Salmonella spp. • Ascaris suum migration

• (Hypersensitivity)

Other

LUNG – INTERSTITIAL PNEUMONIA – PIGS

DOGS • Canine Distemper (Morbillivirus)

• Lesions are more significant in brain

• Canine Parainfluenza

• Canine Adenovirus

• Canine Influenza

Viral Pneumonia

LUNG – INTERSTITIAL PNEUMONIA – DOGS AND CATS

CATS • Feline rhinotracheitis (FeHV-1)

• Feline Calicivirus

Questions?