Respiratory Pathology up to Sp Pneumonias (AH) Flashcards
What makes up the Conductive respiratory system?
nostrils, pharynx, larynx, trachea, and bronchi
What makes up the Transitional respiratory system?
bronchioles
What makes up the gas exchange system?
Pneumocytes in alveoli
What are the two types of pneumocytes and which one can regenerate?
Type I-membranous (BM)- no regeneration –> fluid into alveoli from blood vessel. Type II- granular. Type II regenerates.
What makes up the detox system?
Goblet cells in the bronchioles are replaced by clara cells (detox similar to hepatocytes)
***What are the main routes of entry of etiological agents?
Aerogenous (infectious/non-infectious). Hematogenous (infectious/toxins). Direct extension (infections through trauma)
What are the main defense mech against aerogenous entry?
- Sneeze, cough, reflex bronchoconstriction. 2. Mucocilliary effect: mycociliary clearance, antibodies, lysosomes, mucus. 3. BALT: bronchiole associated lymphatic tissue (immunologic). 4. Alveolar macrophages
What does mucocilliary defend against?
***Particles >10um, about 5% of particles 1-2um in Bronchi
**Which bacteria are resistance to alveolar macrophages?
Mycobacterium, Rhodococcus, Lysteria spp.
**Which spp. defend against blood borne agents with pulmonary intravascular macrophages?
Ruminants, pigs, cats and horses
**In what spp. are hepatic and splenic macrophages key in fighting blood borne agents?
Dog, rodent, human
How do viruses impair pulmonary defense mechanisms?
Destruction of mucocilliary blanket and Impaired alveolar macrophage function
How do bacteria impair pulmonary defense mech?
Some live and replicate within macrophages. Produce toxins –> direct destruction of cells
Rhinitis
Inflammation of the nasal cavity
Main causes of rhinitis?
virus, bact, fungi, chemicals and allergens, parasitic.
How is rhinitis characterized?
by the nature of the exudate which varies by causative agent
What are the types of exudate associated with Rhinitis?
Serous - serum. Catarrhal - Mucous membranes. Purulent - pus. Hemorrhagic - blood. Granulomatous - granulation/ ulcers
What is the only dz of the nasal cavity and sinuses is found in bovine?
Infectious bovine rhinotracheitis (red nose)
What is the etiology of IBR?
Bovine herpes virus
What type of discharge is associated with IBR?
Serous to mucopurulent
When is IBR fatal?
2* M. hemolytica infection –> pneumonia
What are the CS of IBR? (5)
Pyrexia, anorexia, coughing. Serous to mucopurulent nasal discharge. Lacrimation and corneal opacity. Inflammed nares (red nose). Dyspnea of laryngitis develops.
What is a micro lesion of IBR?
INIC bodies
In addition to nasal infections what else can IBR cause?
Genital infections in breeding cattle
Nasal Granulomas are found in which animals?
almost all animals
Etiology of nasal granulomas?
*Mycotic is the main cause: R. seeberi in cattle, dog horse, cat. C. neoformans in cat. Aspergillus and penicillium in dogs. Blood fluke - Schistosoma nasalis in cattle. Allergic - all spp.
Gross lesions of nasal granulomas?
granuloma is seen as polypoid nodules Cauliflower like). Soft, pink and bleed easily. Large growths may obstruct the nasal passage –> resp. distress.
What are diseases of the nasal cavity in sheep and goats? (3)
Non-specific Dz. Nasal granuloma, Myasis (O. ovis larvae), Endemic Ethemoidal Carcinoma
What diseases of the nasal cavity do horses get? (6)
Eq. viral Rhino, Eq. Influenxa, Eq. Viral Arteritis, Strangles**, (Glanders, Meliodiosis)
Etiology of equine viral rhinopheumonitis (EVR)?
Herpes 4 (occasionally Herpes 1)
Type of exudate associated with EVR?
Serous inflammation
CS of EVR?
serous inflammation of nasal mucosa, sometimes edematous swelling of pharyngeal lymph nodes, conjunctivitis, cough, , fever, coughing, congestion.
Lesions of EVR?
**Ulceration and necrosis of resp. epithelium with INIC in epithelial cells.
Ddx of EVR?
equine influenza and equine viral arteritis. (VI, serology)
Equine influenza etiology?
Type A Orthomyxovirus
Type of discharge associated with Eq. flu?
Serous discharge first, then mucopurulent later.
Lesions of Eq. flu?
*Usually not seen in the nasal passages. Mild Dz but may lead to *interstitial pneumonia and pulmonary edema.
Dx of Eq. flu?
Need lab confirmation to differentiate for other resp. viruses. VI/serology
Etiology of Eq. Viral Arteritis?
Arterivirus
Lesions of Eq. viral arteritis?
*serous (to mucopurulent) rhinitis. Conjuctivitis and plapebral edema. Fibrinoid degeneration of muscular arteries. –> hemorrhage in varius tissues
CS of Eq. Viral arteritis?
edema of the limbs and ventral abdomen. Respiratory distress, feer, diarrhea, colic, abortion in 50-80% of mares.
Etiology of Strangles?
Strep. equi equi*
CS of strangles?
bilateral mucopurulent nasal discharge. Lymphadenopathy and painful swalling of lymph glands. Fever.
Lesions of Strangles?
*suppurative rhinitis and lyphadenitis
***Sequelae of strangles?
Purpura hemorrhagica (type III hypersens.) Extension of infection to: paranasal sinuses, Guttural poush, internal organs. Facial paralysis and horners syndrome. Laryngeal hemiplagia.
Dx of strangles?
isolation of bact from surgically drained abscess of lymph gland
What is a nasal polyp?
growth on nasal or septum mucosa made of chronic inflammatory leasions. Cause is unknown. Surgery is curative.
What are the diseases of nasal cavity in dogs?
Transitory rhinitis, Nasal granuloma, Linguatula serrata, Allergic rhinitis.
What is transitory rhinitis is a generlized dz associated with?
*Generalized bacterial and viral Dz. (Bact. - B. bronchiseptica, E.coli, P. multocida. *Viral - canine distemper, canine adenovirus 1,2, reovirus, canine herpes virus, and areainfluenza virus)
Nasal granuloma is associated with what type of infection?
Fungal
What is Lingualtula serrata ? What kind of inflammation does it produce and in which type of animals?
Specialized arthropod. Produce catarrhal inflammation in carnivores.
*What are the diseases of the nasal cavity in cats?
Feline virus rhinotracheitis (FVR), Feline Calicivirus, Feline Chlamydiosis, Feline Respiratory Disease complex
Etiology of FVR?
Feline herpesvirus 1
Besides respiratory infection, what else can FVR cause?
Ulcerative keratitis, hepatic necrosis, abortion and stillbirths
Where is FVR found?
Worldwide
CS of FVR?
Suppurative rhinitis, conjunctivitis with oculonasal discharge
What other resp. disease is similar to FVR in cats?
Feline calicivirus
Which two viruses account for 80% of resp. disease in cats?
FVR and FCV
CS of FCV? What is unique?
Conjunctivitis, rhinitis. Unique: herpes virus in immunocompromised cats –> ulcers of the tongue and hard palate.
FCV Dx?
differentiate from FVR by** ulcers on tongue and hard palate. **
What is limping kitten syndrome?
An acute self limiting arthritis caused by infection of vaccination with some FCV strains.
What does Feline Chlamydiosis cause?
Conjunctivitis and serous to mucopurulent rhinitis
***Feline respiratory disease complex causative agents? (5)
FCV, FVR, Chamydia, Mycoplasma, FIP* - usually generalized Dz as well as resp. dz*
What are the diseases of the nasal cavity in pigs?
Inclusion body rhinitis and Atrophic rhinitis
Etiology of Inclusion body rhinitis?
Porcine cytomegalovirus (herpes virus)
CS of Inclusion body rhinitis?
affects pigs up to 10wks of age*, high morbidity, low mortality. -sneezing, conjunctivitis, lacrimation–> mucopurulent with bacterial infection.
Lesions of Inclusion body rhinitis?
Necrotizing and non-suppurative
Dx of Inclusion body rhinitis?
INIC bodies in *nasal gland epithilium
***Main difference between Atrophic rhinitis and Iclusion body rhinitis?
INIC Rhinitis - young, no distortion of snout. Atrophic - older with distortion of snout.
Etiology of Atrophic rhinitis?
not clear. Maybe infection of B. bronchiseptica and toxigenic strain of P. multocida.
CS of Atrophic rhinitis?
Slow progressing Sneezing/nasal discharge. Slow progressing Dz over months resulting in dypsnea and death.
Lesions of Atrophic rhinitis?
retarded growth of snout, atrophy of chonchae or missing conchae
What is Bronchiectasis?
Permanent abnormal dilation of the bronchi from chronic bronchial obstruction/inflamation.
Types of Bronchiectasis?
Saccular - less common, in all animals, local obstruction by inhaled foreign body or tumor or granuloma cause saccular bronchiectasis. Cylindrical - sheep/pig/goat, usually seen in parasitic bronchitis.
In what animal is Necrotic layringitis most commonly seen?
Calves, but call also occur in sheep.
Etiology of Necrotic laryngitis?
F. necrophorum
Sequelae of necrotic laryngitis?
Toxemia / bronchoneumonia –> death
Dz. Of larnynx, trachea and bronchi of horses?
Laryngeal paralysis, Equine pharyngeal lymphoid hyperplasia, Guttural pouch mycosis, Guttural pouch tympany, Chronic obstructive pulmonary Dz
*What is Laryngeal paralysis due to? What is another name for it?
Due to paralysis of recurrent laryngeal nerve from compression or damage due to inflammation –> in atrophy of cricoarytenoid muscles. “Roaring”
*Common causes of laryngeal paralysis due to inflammation of nerve (5)
Mycosis of Guttural pouch, retropharyngeal abscess, neoplasm involving cervical lymph glands, injury and inflammatory lesions in the neck, Empyema of Guttural pouch (strangles)
What causes mycosis of the Guttural pouch?
Aspergillus spp. (A. fumigatus)
What do CS of Mycosis of Guttural pouch arise from?
Damage to cranial nerves (9-12) and arteries w/i the mucosa of Guttural pouch.
***What is the most common CS of Mycosis of Guttural pouch?
***Dysphagia with Epistaxis due to fungal erosion of internal carotid or external carotid. May proceed to fatal hemorrhage if not treated
What may develop due to nerve damage with mycosis of guttural pouch?
Dysphagia, horner’s syndrome, dorsal displacement of soft palate.
Lesion associated with Mycosis of Guttural pouch?
Mucosa of Guttural pouch is covered with fibrinonecrotic exudate, located at the caudodorsal aspect of the medial pouch.
Guttural Pouch Tympany is observed in what horses?
Horses from brith to 1yr of age
CS of Guttural pouch tympany?
Guttural pouch is distended with air –> non-painful swelling in parotid region. Stertorous in severely affected animals. Usually unilateral.
Sequela of guttural pouch tympany?
Inflammation/ defect of the eustatchean tube.
Chronic Obstructive pulmonary Dz is comparable to what in humans?
*Allergic bronchitis
What causes COPD?
fungal spores and dust.
Lesions of COPD?
Chronic Bronchitis
In severe cases of COPD what happens?
*accumulation of mucus –> incomplete obstruction of bronchioles and alveoli –> ALVEOLAR EMPHYSEMA
K9 Dz of larynx, trachea, bronchi?
K9 Infectious Tracheobronchitis and Laryngeal Paralysis
Etiology of CIT?
complex. Flu viruses, adenoviruses and bacterium have been suggested
CS of CIT?
Highly contagious. Coughing rhinitis, conjunctivitis and pharyngitis. Between bouts of coughing animals tend to appear normal.
Lesions of CIT?
Necrosis and suppuration in trachiobronchi
Laryngeal paralysis is most common in what dogs?
Older, large breed, male
CS of Laryngeal paralysis?
abnormal barking, exercise intolerance. May predispose to aspiration pneumonia
What Dz of larynx, trachea, and bronchi does type I hypersensitivity cause in cats?
Feline Asthma (feline allergic bronchitis)
How would you treat Feline Asthma?
Responds well to steroids
Lesions of Feline Asthma?
chronic bronchitis and in severe cases obstruction of small bronchioles
List pathologies of the lung?
Atelectosis, Emphysema, ARDS, Pulmonary hypertension, Inflammation of the lungs (bronchopneumonia, interstitial pneumonia, embolic pneumonia, granulomatous pneumonia)
**What is the main difference between Atelectosis and Emphysema?
Atelectosis = no air in alveoli. Emphysema = air
**What are the two types of Atelectosis?
Congenital or Aquired
Congential Atelectasis can be caused by what?
Obstructions: muconeum, aspriate, amniotic fuild. Hyaline membrane disease (piglets/ foals)
Aquired Atelectasis can be caused by what?
Compressive - pneumothorax, hydrothorax, bloat, neoplasm. Obstructive - exudate, parasites, neoplasms, foreign material.
Describe the lung tissue associated with atelectasis?
dark red, flabby and depressed below the surface of surrounding lung. Micro: alveolar walls are gongested and in close opposition.
Two types of Emphysema?
Alveolar and Interstitial
What causes alveolar emphysema?
- Pressure of inhaled air 2. Incompletely closed bronchioles,
Lesions of alveolar emphysema?
excessive air in the alveoli –> abnormal, permanent enlargement of albeoli with destruction of alveolar walls. Emphysematous areas are raised, pale or whilte, dry, and can be easily compressed. Usually alternates with areas of atelectasis.
What causes interstitial emphysema?
Forced respiratory efforts. 1. when death is followed by violent efforts in anoxia. 2. during quick loss of blood in trauma, slaughter or fully conscious animal. 3. death after protracted illness.
Where is air found with interstitial emphysema?
Air collects in connective tissue of lungs (interalveolar septa, interlobular septa, below pleura, around bronchi and blood vessels.)
In what animal is Interstitial emphysema mostly commonly found? Why?
In cattle. Developed interlobular septa and lack of collateral ventilation in adjacent lobules –> thick, shiny septa filled with bubbles.
what is the most commonly encountered pulmonary abnormality?
Plumonary edema= very important**
Two categories of causes for pulmonary edema?
Non-Inflammatory = increase in capillary hydrostatic pressure. Inflammatory = increasing permeability of the air-blood barrier
Examples of non-inflammatory causes of pulmonary edema? (3)
- increased left atrial pressure in left sided or bilateral CF (cardiogenic edema). 2. Excessvie fluid transfusion. 3. Pulmonary venous occlusion.
Examples of inflammatory causes of pulmonary edema? (4)
- inhalation of corosive gases (SO2, Cyanides, Smoke). 2. Infectious agents (mycoplasma, viruses) 3. Systemic toxins. 4. Anaphylaxis in certain spp. (horse and cow)
Pulmonary edema is almost always?
Fatal
What causes Acute respiratory distress syndrome (ARDS)?
Diffuse alveolar damage due to… 1. systemic diseases 2. direct injury to lungs. 3. leasions in other organ systems.
Pathogenesis of ARDS?
Triggering of macrophages to release large amounts of cytokines –>s prime neutrophils in lung and capillairies –> release enzymes and free radicals –> diffuse endothelial/epithelial changes –> permeability edema –> accumulation of inflammatory cells,
Lesions of ARDS?
Diffuse damage to alveolar wall epi and or endothelium –> Congestion and edema. Hyaline membrane formation. Alveeolar epithelial hyperplasia (pneumocyte II). Interstitial emphysema.
Pulmonary Hypertension is caused by what?
Increase in pulmonary vascular resistance. 1. vasoconstriction 2. vascular obstruction. 3. vascular volume overload.
***What is pulmonary hypertension secondary to?
***Almost always secondary. 1. Cardiac Dz. (septal defects, left to rt shunts.) 2. Lung Dz. ( interstitial pneumonia with fibrosis, occlusion of pulmonary vessels.
What does sustained pulmonary hypertension result in?
Increased pressure load to rt ventricle with compensatory rt ventricular hypertrophy –> rt hear failure.
What is inflammation of the lungs called?
Pneumonia, Pnemonitis
What are the classification of inflammation of the lungs based on site and pattern of spread? Aka: list types of pneumonia…
Bronchopneumonia, interstitial pneumonia, embolic pneumonia, granulomatous pneumonia.
Which classification of pneumonia is most common in domestic animals?
Bronchopneumonia, of major ecomonic improtance.
When does Bronchopneumonia occur?
when risk factors tip the balance. STRESS. Exposure, crowding, dehydration other infections and chronci Dz.
What causes bronchopneumonia?
Bacteria, mycoplasma, apriration of feed/gastric content
Why are bronchopneumonia lesions only found in the cranio-ventral part of the lung?
- Shortness and abrupt branching of broncus. 2. Gravitational sedimentation of exudate. 3. Deposition of infectious agent in the 1st broncus. 4. Regional differences in ventilation
Exceptions to cranio-ventral restriction of bronchopneumonia lesions?
- Actinobacillus pleuropneumonia and Actinobacillus suis –> middle and caudal lobes. 2. dogs/cats also have a patchy distribution throughout the lung. 3. bovine respiratory syncytial virus can also look like bronchopneumonia as it is cranio-ventrally
Two subtypes of bronchopneumonia?
Suppurative and Fibrinous
Leasions of Suppurative Bronchopeumonia?
* Supporutive, cranioventral lobular pattern= bronchopnuemonia* Always cranio-ventral. Mosaic apperance (red/gray).
Sequelae of Suppurative Brochopneumonia?
Usually resolves within a few weeks. Complications:
- Death by toxemia and hypoxia.
- May cause metastatic abscesses in other organs.
- May become chronic.
- Plugging of bronchi and resultant atelectasis.
Lesions of Fibrinous bronchopneumonia?
Starts lobular –> involves part or complete lobe. Fibrinous rather than neutrophilic exudate found on pleural surfaces, septa, alveoli and thoracic cavity. Marbled pattern.
***Etiology of fibrinous bronchopneumonia by spp.?
Strong pathogens are involved. Cattle: M. hemolytica, Mycoplasma mycoides, Hemophilus somnus. Swine: P. multocida, Actinobacillus pleuropneumonia. Sheep/Goats: M. hemolytica, mycoplasma mycoides (mainly in goats)
Complications of Fibrinous Pneumonia?
Inflmmatory responses are more severe than suppurative pneumonia –> rarely resolves. 1. Death is more frequesnt due to pleuritis and pericarditis. 2. Necrosis with formation of pulmonary sequestra (Foci of coagulative necrosis encapsulated by connecti
Predisposing causes of Aspriation Pneumonia?
Any cause of dysphagia or regurgitation. Pharyngeal paralysis and megaesophagus.
Lesions of aspiration pneumonia?
Liquid gruel or inhaled milk - widespread distribution. Plant material, dry dusty particulate food - localized lesions = descrete foreign body granulomas, lobar pneumonia or gangrene. Aspriration of vomitus –> edema development. Long standing cases –
Interstitial Pneumonia is what?
An inflammator condition confined to the alveolar walls and alveolar intersitium
Interstitial pneumonia etiology? (2)
- Aerogenous injury –> alveolar epithelium 2. Hematogenous Injury –> Alveolar capillaries
What can cause hematogenous injury to the alveolar capillaries resulting in intersitial pneumonia? (5)
- intermitent bacteriemia (E.coli, lepto, salmonela, lung worms, toxoplasma and migrating parasites). 2. DIC. 3. Ingested toxins like moldy sweet potatoes. 4. Allergic condition type III. 5. endotoxins (paraquate).
What are the 4 phases of Intersitial pneumonia?
- Acute - injury to type I pneumocytes. 2. Exudative phase - inflammatory edema accumulates in the alveolar interstitium –> thickening of alveolar walls. 3. Proliferative phase: often follows acute. Hyperplasia of type II pneumocytes. 4. Chronic: ac
Where are lesions of intersititial pneumonia founds?
throughout the whole lung. May be more pronounced in dorso-caudal region.
**Important features of Interstitial Pneumonia (5)
Due to proliverative phase, alveolar walls thicken –> 1. Lung does not collapse on opening thoracic cavity. 2. Rib impressions on lungs. 3. Lack of visible exudate in lungs and meaty appearance. 4. Heavy, elastic, rubbery lungs. 5. Red to pale grey c
Sequelae of interstitial pneumonia?
-Complete resolution (recovery). -10% death due to pulmonary edema (cattle) -Healing by fibrosis and epithelization of alveoli –> glandular appearance.
Halmarks of Chronic intersitial pneumoina?
- Accumulation of mononuclear inflammatory cells in intersitium and alvioli and bronchi. 2. persistence of hyperplasitic type II pneumocytes. 3. Alveolar fibrosis 4.Formation of microscopic granulomas. 5. Hyperplasia of sm. Mm in airways or pulmonary
What are two causes of Embolic pneumonia and the resulting lesions?
- Bronchopneumonia -> large abscesses, isolated, confined to anterioventral part of lung. Are seen extending from bronchial tree. 2. Metatstatic from septic emboli arrested in pumonary vessel. –> small abscesses, multiple and widely distributed in wh
Etiology of infectious/ non-infectious granulomatous pneumonia?
infectious - bact, fungi, parasites, type III sensativity, FIP. Non-infectious - Inhaled forgein intert material
Lesions of granulomatous pneumonia?
Soft yellow to gray caseous. Encapsulated = hard gritty and white-gray
Pneumonia of Cattle
Enzootic Pneumonia of Calves, Shipping Fever, Bovine Pasteurellosis Hemorragic Septicemia, Respiratory hemophilosis, Contagious Bovine Pleuropneumonia, Tuberculosis, Acute Bovine Pulmonary Edema “Fog Fever”, Acute Bovien Pulmonary Edema and emphysema, Hyp
Pneumonia of Pigs
Porcine Enzootic Pneumoina, Porcine Pasteurellosis, Porcine Pleuropneumoniae**, Hemophilus Pneumonia, Strep pneumonia, Tuberculosisi, Swine Influenza, Porcine Repro&Resp Syndrome (PRRS), Post weaning Multi-systemic wasting syndrom, Parasitic Pneumonia.
Pneumonia of Sheep and Goats?
Pasteurellosis (Ovine Pneumonic Pasteurellosis, Chronic Enzootic pneumonia and Septicemic Pasteurellosis), Contagious Caprine Pleuropneumonia, Maedi Visna Ovine Progressive Pneumonia, Lymphoid Interstitial pneumonia, Caprine arthritis encephalitis, parasi
Horse Pneumonias?
Rodococcosis, Eq. Viral Rhinopneumonitis, Equine flu, Chamydial infection, Tuberculosis, Diffuse proliferative intersititial pneumonia, Parasitic
Dog Pneumonia?
Canine Distemper, Canine adenovirus Type 2 Infection, Cainine Herpesvirus 1 “fading puppy syndrome”, Canine flu, bact. Pneumonias, tuberculosis, mycotic, Toxic (paraquat and uremic) , Parasitic
Cat Pneumonias?
Bact., tuberculosis, mycotic, lipid pneumoina, parasitic,
