Topic 091.

Pneumonias of
carnivores and rabbits
Paramyxovirus pneumonia of dogs
• Pathogen: Paramyxo viridae, Morbilli virus
• Infection: per os, aerogen
• Pathogenesis:
– Proliferation in the pharyngeal lymphatic tissue
– Viraemia in macrophages
– Proliferation in other organs
• Lymphoreticular tissue of spleen, bone marrow, lymph
nodes
• In organs with ectodermal origin (skin, brain)
– Also in mucosal membrane of the airways!
Inclusion bodies in the bronchus epithel
Viral pneumonias of dogs
• Canine distemper
• Adeno viral pneumonia
• Herpes viral pneumonia
• Parainfluenza-2 (PI-2)
Paramyxovirus pneumonia of dogs
• Pathology:
– Degenerative changes in the epithel cells
• Due to virus proliferation
– Increased activity of the gobblet cells
• Serous-catarrhal bronchitis
– Interstitial pneumonia
• Due to viraemia! (usually survival)
– Secondary lobar bronchopneumonia
• Bordetella bronchiseptica, Pasteurella multocida
1

CDV
• Symptoms:
– Fever
– Nasal and ocular
discharge
– Hyperkeratosis of
footpads
– Neurological signs
Distemper: purulent
conjunctivitis
2

Distemper: interstitial and alveolar bronchopneumonia, syncytium
Cytoplasmic-inclusion bodies in the epithelium of the trachea, dog,
distemper
Distemper: diffuse interstitial
pneumonia
accompanied by
serous pneumonia
in the cranial
lobes
Distemper: hyperkeratosis on
the nose and footpads
Distemper
Bronchiole
occluded by
inflammatory cells
and cell debris
Multiple eosinophilic
intracytoplasmic viral
inclusions (arrows) in
bronchiolar
epithelium
Distemper: encephalitis
3

Adenovirus pneumonia of dogs
• Pathogen: CAdV-2
• Infection: mostly aerogen
• Age group: after 3 weeks (maternal antibodies!)
• Pathogenesis:
– Proliferation in the epithelial cells of the airways
• Rhinitis, laryngitis, tracheobronchitis, bronchiolitis
• Canine infectious laryngotracheitis
• Kennel cough
– Usually together with other pathogens
• PI-2, reo-1 and 2, Bordetella br., Pasteurella m.
• Secondary bronchoalveolar pneumonia develops
Canine herpesvirus infection
Temperature sensitive virus, may be lethal in newborn puppies,
most adult dogs are permanently but inapparently infected.
Bacterial pneumonias of dogs
• Pasteurella-pneumonia
• Bordetella bronchiseptica
• Klebsiella pneumoniae
• E. coli and Streptococcus ssp.
• Tuberculosis
• Mycoplasma
• Nocardiosis
• Actinomyces hordeovulneris
Herpesvirus pneumonia of dogs
• Pathogen: CHV-1
• Infection: transplancental, per os, aerogen
• Age group: all, with different pathogenesis:
– Fetus: viraemia (necrotic foci, serous hepatitis)
– Older than 1 months: changes only in the airways
• Proliferation in the epithelial cells of the airways
• Serous-catarrhal macro- and microbronchitis
• Secondary bronchoalveolar pneumonia develops
– Adult: no clinical changes
– Pregnant bitches: death of the embrios, abortion
• Vesicular vaginitis
Parainfluenza-2 pneumonia of dogs
• Age group:
– Independently: in young dogs only (Autumn)
– With other pathogens
• CAV-2, reo 1-2, Bordetella br., Mycoplasma sp.
• Pathogenesis:
– Proliferation in the epithelial cells of the airways
• Tracheobronchitis
– Serous-catarrhal-desquamative
• Viremia – interstitial pneumonia also develops
• Secondary bronchoalveolar pneumonia
Bacterial pneumonias
• Pasteurella, Bordetella, Klebsiella
– independently rare – with others
• In young dogs – sometimes independent
– infectious tracheobronchitis (kennel cough)
• Lesions:
– Catarrhal-purulent tracheobronchitis
– Lobar bronchoalveolar pneumonia
• Catarrhal-purulent
4

• Pathogen
Tuberculosis in dogs
– Mycobacterium bovis, M. tuberculosis
• Infection: per os, aerogen
• Age group: young age (puppies)
• Pathogenesis:
– Primary complex
• In the lungs or in the GI tract
– Early generalization
• predominantly proliferative tuberculosis
Mycoplasma pneumonia
• Pathogen: Mycoplasma canis
– Extracellular, degeneration of the cilia
• Infection: transplacental, aerogenous
• Pathogenesis:
– Proliferation in the epithelial cells
• Macro- and microbronchitis
• Viremia (mycoplasmaemia)
– interstitial pneumonia also develops
• Secondary bronchoalveolar pneumonia
Diffuse interstitial pneumonia
accompanied by purulent
pneumonia in the
cranial lobes
Lung tuberculosis
• Aerogenous infection:
– Primary process – subpleural
• Thorasic cavity – exudative pleuritis
• Bronchi – bronchitis, bronchiectasis
– Endobronchial spreading
• Per os infection:
– Lesions during the early generalization
– Disseminated miliary proliferative
tubercles
Nocardia pneumonia
• Pathogen: Nocardia asteroides
• Infection: through skin lesions
• Pathogenesis:
– Abscess formation in the subcutis
– Purulent pericarditis and pleuritis
• With pyogranulome formation
• Subacute-chronic
– Purulent bronchoalveolar pneumonia
5

Lesions caused
by Actinomyces hordeovulneris
• Pathogen:
– Gram positive, Ziehl-Neelsen negative
• Infection:
– Aerogenous or through skin lesions
• Pathogenesis:
– Purulent pericarditis and pleuritis
• Subacute-chronic with pyogranulome
formation
– Purulent bronchoalveolar pneumonia
6

• caused by fungi
Other pneumonias
– Aspergillosis
– Blastomycosis
– Coccidioidomycosis
– Histoplasmosis
– Cryptococcosis
• caused by other special stimuli
– Toxic pneumonia
– Pneumonia due to uremia - pneumopathy
7

Parasitic pneumonias of dogs
• Toxoplasmosis
• Pneumocystis carini
• Filaroides hirthi
• Crenosoma vulpis
• Aerostrongylus vasorum
• Dirofilaria immitis
• Paragonimus kellicotti
• P. westermani
Toxoplasma pneumonia
• Changes in the lung:
– tachyzoites proliferate
• in the alveolar macrophages
– Exudative inflammation, later necrosis
• Appearance:
– Soliter or multiplex small nodules
• Converge (slur)
• In larger number on the area of the lobar
bronchopneumonia
Toxoplasma pneumonia
• Pathogen: T. gondii
• Infection: per os
– Raw meat
– Cysts containing bradyzoites, tachyzoites
• Pathogenesis:
– Immunesuppression is needed
• General or local
• Distemper infection
– Generalized toxoplasmosis
8

Infectious rhinotracheitis
• Pathogen: FeHV-1, alpha-herpes virinae
• Infection: direct contact, aerogenous
• Age group: all
• Pathogenesis:
– Proliferation in the epithelial cells, than viraemia
• Conjunctivitis (keratitis), rhinitis, tracheitis
– Serous-purulent, fibrinous (pseudomembrane formation)
• Secondary bronchoalveolar pneumonia
– Pregnant animals transplacental spreading
• death of the embrios, abortion
Pneumonias of cats
• Viral
– Infectious rhinotracheitis
– Adeno viral pneumonia
– Feline tracheobronchitis
• Bacterial
– Feline pneumonitis - Chlamydophila
– Pasteurella, tuberculosis
• Fungal
• Parasitic
• Other
Conjunctivitis
9

Adenovirus pneumonia of cats
• Pathogen: FeAdV
• Infection: mostly aerogen
• Age group: young age
• Pathogenesis:
– Proliferation in the epithelial cells of the
airways
• Rhinitis, laryngitis, tracheobronchitis,
bronchiolitis
• Feline tracheobronchitis, feline influenza
• Secondary bronchoalveolar pneumonia
Feline pneumonitis
• Pathogen: Chlamydophila psittaci
• Infection: mostly aerogen
• Incubation: 3-5 days
• Lesions:
– conjunctivitis
– Rhinitis (sneezing)
– Bronchitis (coughing)
– Bronchoalveolar pneumonia (fever)
• Secondary to rhinotracheitis or calici infection
Calici viral pneumonia
(feline tracheobronchitis)
• Lesions:
– Oral erosions
– Interstitial pneumonia
• Impression
of the
conjunctiva
Chlamydophila
10

Lung tuberculosis in cats
• Pathogen
– All types of Mycobacteria
• Infection: per os
• Pathogenesis:
– Lesions during the early generalization
– predominantly proliferative tuberculosis
Aelurostrongylus abstrusus lesions
• Most common lung worm of cats
• Life cycle:
– Eggs (1st stage larvae) taken by snails, slugs
• First intermediate host – two moulting
– Larvae – encysted
• Transport hosts eaten by the cats
• frogs, lizards, rodents, birds
– Larvae migrate
• from the stomach to the lung
Pasteurella pneumonia in cats
• Pathogen: Pasteurella multocida type-A
– Part of the normal flora
– Secondary to viral pneumonias
• Lesions:
– Bronchoalveolar pneumonia
• Purulent
– Tonsillitis-myocarditis syndrome
• Other Pasteurella-like pathogens
Other pneumonia in cats
• Fungal:
– Cryptococcus pneumonia
– Pathogen: Cryptococcus neoformans
• Endogenous lipid pneumonia
• Aspiration pneumonia
• Parasitic:
– Aelurostrongylus abstrusus
– Toxoplasma gondii
– Paragonimus kellicotti
11

Amyxomatic myxomatosis
• Pathogen: Chordopox, Leporipox
– Special type of myxomatosis virus
• Lesions:
– interstitial pneumonia
• Focal or diffuse
– With early degenerative changes in the
macrophages
Bacterial pneumonias of rabbits
• pasteurella-pneumonia
• bordetella-pneumonia
• staphylococcus-pneumonia
• mycoplasma-pneumonia
• chlamydophila-pneumonia
• Yersiniosis, tularaemia, brucellosis
Pneumonias of rabbits
• Viral
– Adeno viral pneumonia
– Amyxomatic myxomatosis
• Bacterial
– Chlamydophila, Pasteurella, tuberculosis
• Fungal
• Parasitic
• Other
Pasteurella-pneumonia
• Pathogen:
– Pasteurella multocida A
– P. pneumotropica
• Lesions:
– Rhinitis (purulent)
– Tracheitis
– Otitis media
– Croupous pneumonia with large necrosis
– Serous-fibrinous pleuritis
13

Pasteurella-pneumonia
• Predisposing factors!
• Enzootic pneumonia
– red-grey foci of consolidation
– cranioventral lung lobes
– with or without hemorrhage
• Chronic pneumonia
– generalized consolidation
– encapsulated abscesses
– fibrinopurulent or mucopurulent pleuritis
– pyothorax
Torticollis
Bordetella pneumonia
Lobar bronchopenumonia
with sharp edges
14

Staphylococcus-pneumonia
• Pathogen: Staphylococcus aureus
• Lesions:
– In young rabbits
– Pneumonia with large necrosis
– In adults:
– Multiplex abscess
formation
Chlamydophila-pneumonia
• Bacterial:
Other pneumonias
– Mycoplasma
• rare
– Chlamydophila
• Chlamydophila psittaci
• Lobar bronchoalveolar pneumonia
• Fungal:
– Aspergillus fumigatus – inhalation of spores
• Parasitic:
– Toxoplasma gondii, Protostrongylus rufescens
Aspergillosis
15