Respiratory Labs Flashcards
History: Tissue from a 5 week old Charolais calf that presented for a 3 day history of respiratory distress. She had a respiratory rate around 100 bpm, her neck was extended, had white foam coming from her mouth. Describe the lesion.
Lung: The cranioventral aspects of approximately 80-85% of the left lung are very firm (consolidated), extensively red to tan in color (hyperemia) and have multifocal regions that are black in color (hemorrhage). The interlobular septa are mild to moderately expanded by a cloudy, cream to tan colored material (exudate).
History: Tissue from a 5 week old Charolais calf that presented for a 3 day history of respiratory distress. She had a respiratory rate around 100 bpm, her neck was extended, had white foam coming from her mouth. Provide an appropriate morphologic diagnosis.
Lung: Acute, locally extensive, anteroventral hemorrhagic bronchopneumonia
History: Tissue from a 5 week old Charolais calf that presented for a 3 day history of respiratory distress. She had a respiratory rate around 100 bpm, her neck was extended, had white foam coming from her mouth. Outline the classic gross features of this type of pneumonia.
Texture - very firm
Location - anteroventral distribution
Other features: lung may sink in formalin, express an exudate from airways when sectioning a portion of consolidated lung, may observe a free, coughed-up exudate in trachea
History: Tissue from a 5 week old Charolais calf that presented for a 3 day history of respiratory distress. She had a respiratory rate around 100 bpm, her neck was extended, had white foam coming from her mouth. Describe risk factors that have the potential to contribute to the development of this type of pneumonia in a feedlot bovine.
Stress (weaning, shipping, feed change, castration)
Dust / ammonia (decreases mucociliary clearance)
Exposure to new pathogens (mixing)
Viral infection (following exposure to new pathogens)
History: This is tissue from a steer with dyspnea and a “red nose” Describe this lesion.
Diffuse to multifocally, there is a layer of tan friable material (fibrin) adherent to the mucosal surface of the trachea. When this material is removed, the underlying submucosa is dark grey-black in color (which would be bright red in a recently dead, non-fixed specimen). These changes also involve the larynx.
History: This is tissue from a steer with dyspnea and a “red nose”
Give a morphologic diagnosis.
Trachea and larynx: Acute, diffuse, fibrinous (or fibrinonecrotic) laryngotracheitis
History: This is tissue from a steer with dyspnea and a “red nose”
What is the most likely causative agent?
The most likely agent is IBR (infectious bovine rhinotracheitis) which is also known as bovine herpesvirus 1 (BHV-1).
History: This is tissue from a steer with dyspnea and a “red nose” During the necropsy you also identify a bronchopneumonia.
How might the observed lesions have predisposed the animal to develop a bronchopneumonia?
Pneumonia is either caused by direct aspiration of the exudates from the trachea or as a result of impairment of the pulmonary defense mechanisms
History: Tissue from a 14 year old female spayed domestic long hair cat with a 2-3 week history of nasal discharge and an apparent upper respiratory infection that developed a seizure last evening
Describe the lesion.
Nearly the entire nasal cavity is extensively effaced and replaced by a tan, firm, relatively homogeneous, cream-colored mass, approximately 5x7 cm that tapers rostrally. The mass appears to have infiltrated through the cribiforme plate, which is cram-colored a softer than the adjacent bone of the cranial vault.
History: Tissue from a 14 year old female spayed domestic long hair cat with a 2-3 week history of nasal discharge and an apparent upper respiratory infection that developed a seizure last evening
Provide an appropriate morphologic diagnosis.
Nasal cavity: Chronic, locally invasive nasal mass
History: Tissue from a 14 year old female spayed domestic long hair cat with a 2-3 week history of nasal discharge and an apparent upper respiratory infection that developed a seizure last evening
What is your most likely diagnosis and how might you confirm this in practice in your clinic?
Mass is solid and homogeneous, so likely a neoplasm, most likely a nasal lymphoma, which is the most common nasal tumor in cats.
Could do an impression smear to differentiate lymphoma from carcinoma from sarcoma from inflammation
History: Tissue from a 14 year old female spayed domestic long hair cat with a 2-3 week history of nasal discharge and an apparent upper respiratory infection that developed a seizure last evening
What is the expected biologic behavior for your most likely diagnosis?
Slow growing, locally invasive, but limited metastatic potential. About 20% of cats with nasal lymphoma have or develop lymphoma elsewhere in the body.
History: Tissue from a 14 year old female spayed domestic long hair cat with a 2-3 week history of nasal discharge and an apparent upper respiratory infection that developed a seizure last evening This animal was reported to have had a seizure.
Describe two ways in which this lesion could potentially cause seizures.
Possible mechanisms that would produce neurologic signs include: 1) neoplastic infiltration into brain, or 2) bacterial meningitis (disruption of cribiforme plate by tumor leading to bacteria from non-sterile nasal cavity enter cranial vault leading to meningitis). In this case, option 2 was more likely.
History: Tissue from a 10 week old pigs with respiratory distress. Describe this lesion.
Tan colored anteroventral consolidation involving approximately 40% of the right lung. There are moderate numbers of multifocal random firm white nodules varying in size from 2-6 mm in diameter scattered throughout all lung lobes. Nodules have a cream-color friable center surrounded by a firm, white (fibrous) capsule. Multifocally, patchy areas of the pleural surface are thickened by opaque, white material that cannot be readily removed by manual manipulation (pleural fibrosis). The caudal aspect of the right middle lung lobe is firmly adhered to the cranial aspect of the right caudal lung lobe by firm adhesions that cannot be readily separated (fibrous pleural adhesions).
History: Tissue from a 10 week old pigs with respiratory distress.
Provide an appropriate morphologic diagnosis.
Lung: Chronic, locally extensive, anteroventral bronchopneumonia with multifocal abscesses, pleural fibrosis and fibrous pleural adhesions.
History: Tissue from a 10 week old pigs with respiratory distress. These animals have a bronchopneumonia.
What other type of pneumonia is present and what type of pre-existing condition(s) may have contributed to the development of this type of pneumonia?
These pigs also have an embolic pneumonia. Embolic pneumonia is preceded by bacterial infection and suppuration at another location. Common sources:
- liver abscesses,
- navel infection,
- contaminated catheters
- vegetative valvular endocarditis
History: Tissue from a 10 week old pigs with respiratory distress.
Are these pneumonias acute or chronic and why?
The bronchopneumonia is chronic: tan instead of red (hyperemia). Abscesses have a fibrous capsule and are chronic. There is pleural fibrosis and fibrous pleural adhesions = chronic
History: Tissues from a 5 day old Boer goat kid named Liza which had failed to gain weight and then developed respiratory distress.
Describe the lesions.
There is a diffuse longitudinal cleft in the palate approximately 2cm in width allowing communication between the oral and nasal cavities. Approximately 40% of the left anteroventral lung is very firm and there is a band of redness (hyperemia) between normal and consolidated lung.
History: Tissues from a 5 day old Boer goat kid named Liza which had failed to gain weight and then developed respiratory distress.
Provide appropriate morphologic diagnoses.
Head: Diffuse, chronic palatoschisis (cleft palate)
Lung: Acute locally extensive anteroventral bronchopneumonia (aspiration pneumonia)
History: Tissues from a 5 day old Boer goat kid named Liza which had failed to gain weight and then developed respiratory distress. In this case, the lesion involving the palate was helpful in determining the likely type of pneumonia.
In general, what additional gross changes might we see to help confirm this type of pneumonia?
Might observe milk in the trachea or large airways. In an older animals you might observed plant material / rumen contents in airways.
History: Tissues from a 5 day old Boer goat kid named Liza which had failed to gain weight and then developed respiratory distress.
What histologic changes might help to confirm this type of pneumonia?
Foreign material in lung (airways):
Examples: plant material, cooked meat protein, milk
± Necrotizing bronchiolitis: aspirated material may be caustic (gastric acid)
History: Tissue from a 14 week old pig with a history of chronic cough and thumping
Describe the lesions.
Approximately 25 of the right anteroventral lung is tan colored and firm. The entirety of the remaining lung is tan-red mottled, rubbery and noncollapsing.
History: Tissue from a 14 week old pig with a history of chronic cough and thumping
Provide an appropriate morphologic diagnosis.
Lung:
- Chronic diffuse interstitial pneumonia.
- Chronic locally extensive anteroventral bronchopneumonia
History: Tissue from a 14 week old pig with a history of chronic cough and thumping This pig had two types of pneumonia. There are a number of mechanisms that can lead to the development of the diffuse lung lesion.
Propose a pathogenesis for the development of the diffuse lung lesion.
Septicemia, especially Gram negative bacteria (ex: Salmonella cholerasuis) → Diffuse injury to alveolar capillary endothelium by endotoxin → Activation of Pulmonary Intravascular MØs → Increased vascular permeability → fibrinosuppurative exudate accumulates in alveolar walls
Agent disseminated via bloodstream to the alveolar wall or alveolar macrophages (e.g. PRRSV) → Macrophages release cytokines which recruit additional inflammatory cells into the alveolar wall and adjacent interstitium
History: Tissue from a 14 week old pig with a history of chronic cough and thumping In our descriptions, we have been describing the severity of today’s pneumonias.
What is a good way to describe the overall severity of lung lesions?
Describe the percentage of each lung involved.
History: Tissue from a 14 week old pig with a history of chronic cough and thumping
Briefly outline the classic gross pattern (distribution) of bronchopneumonia, interstitial pneumonia, embolic pneumonia
Bronchopneumonia and aspiration pneumonia: anterioventral distribution.
Interstitial Pneumonia: diffuse
Embolic pneumonia: multifocal and random lesions throughout all lung lobes
History: Tissue from a 1 month old calf – acute respiratory distress Describe pertinent features.
The caudodorsal lung is uniformly light pink in color, very light weight (like a marshmallow), will retain your figure impression and is slowly collapsing outside the negative pressure of the chest.
Approximately 15% of the cranioventral lung is darker red in color and more firm.
The trachea contains a small to moderate amount of white froth in the tracheal lumen admixed with a small amount of green colored foreign material.
History: Tissue from a 1 month old calf – acute respiratory distress Provide a morphological diagnosis.
Antoventral lung – acute cranioventral aspiration pneumonia (cranioventral consolidation with foreign material in the trachea)
History: Tissue from a grow/finish pig from a production facility undergoing an outbreak of respiratory disease with approximately 12-15% of pigs effected.
Describe the lesion.
The lung is multifocally very firm (consolidated) and dark red to black (hemorrhage) in color. Approximately 30% of the total lung volume affected, including the dorsal portion of the caudal lung lobe in the region of the hilus. The capsular and cut surfaces were mottled dark red-to-black and tan and the interlobular septa were expanded. Diffusely on the visceral pleural surface, there were tags of tan, loosely adherent, friable (fibrinous) material. In cross section, there are irregular pale friable regions (necrosis) varying in size from 3-10mm.
History: Tissue from a grow/finish pig from a production facility undergoing an outbreak of respiratory disease with approximately 12-15% of pigs effected.
Give a morphologic diagnosis.
Acute multifocal fibrinous and necrohemorrhagic pleuropneumonia or severe acute multifocal necrohemorrhagic bronchopneumonia and acute fibrinous pleuritis
History: Tissue from a grow/finish pig from a production facility undergoing an outbreak of respiratory disease with approximately 12-15% of pigs effected.
What is the most likely cause of disease in this population of pigs and what is your next most likely differential?
Actinobacillus pleuropneumonia (APP) or Actinobacillus suis
History: Tissue from a grow/finish pig from a production facility undergoing an outbreak of respiratory disease with approximately 12-15% of pigs effected.
What would be a classic description of the pre-necropsy gross appearance of this pig?
Good pig. Found Dead. Blood coming from nose
History: Tissue from a grow/finish pig from a production facility undergoing an outbreak of respiratory disease with approximately 12-15% of pigs effected. Pigs can carry this organism in there tonsils without developing disease.
What sort of processes could cause a carrier pig to develop disease?
Think Impair or Overwhelm Impair respiratory defenses – ex: damage to mucociliary apparatus by SIV, M. hyo.
Overwhelm: Outbreak of disease with aerosolation of massive numbers of organisms by neighboring infected pigs facilitated by overcrowding, poor ventilation, and failure to isolate the sick.
History: Lung from a 16 week old pig with a chronic cough and decreased growth rate
Describe the tissue.
Approximately 30% of the anteroventral lung is very firm (consolidated), tan in color and slightly depressed compared to the adjacent lung.
History: Lung from a 16 week old pig with a chronic cough and decreased growth rate
Give a morphologic diagnosis.
Lung: Chronic locally extensive anteroventral bronchopneumonia.
History: Lung from a 16 week old pig with a chronic cough and decreased growth rate
List important differentials for this lesion.
M. hyo + secondary bacteria (P. mult, Strep suis, H. parasuis)
History: Lung from a 16 week old pig with a chronic cough and decreased growth rate
What is the common name for this condition?
Enzootic pneumonia
History: tissue from a 12 year old female mixed breed canine with enlarged lymph nodes, a draining skin lesion and respiratory distress. Describe the tissue.
The lung is diffusely firm, rubbery and non-collapsing with numerous 1-2 mm in diameter white, coalescing nodules scattered randomly throughout the parenchyma. Tracheobronchial lymph nodes are markedly enlarged measuring 2 x 4 x 2cm. The tracheal ring are moderately flattened with widening of the dorsal tracheal membrane. The tracheal width to height ratio is 3.2:1.4cm.
History: tissue from a 12 year old female mixed breed canine with enlarged lymph nodes, a draining skin lesion and respiratory distress. Give a morphologic diagnoses.
Lung: Chronic diffuse interstitial pneumonia with multifocal pulmonary nodules, lymphadenomegally and mild to moderate chronic collapsing trachea
History: tissue from a 12 year old female mixed breed canine with enlarged lymph nodes, a draining skin lesion and respiratory distress. Name the most likely etiology.
The etiologic agent is Blastomyces dermatitidis
History: tissue from a 12 year old female mixed breed canine with enlarged lymph nodes, a draining skin lesion and respiratory distress. Briefly outline the pathogenesis of the lung lesions based on your most likely etiology.
Fungus grows in soil → conidia inhaled → fungus becomes a yeast at elevated temperature of host (37°C) → hematogenous & lymphatic dissemination (lung, bone, skin, brain, eyes) → systemic blastomycosis → in lung, the fungus stimulates macrophages to release cytokines recruiting additional inflammatory cells into the interstitium → interstitial pneumonia
History: Tissue from a nursery pig
Describe the tissue.
Multifocally, there are lobar regions where the lung is slightly depressed, slightly more firm and darker red in color.
History: Tissue from a nursery pig
Give a morphologic diagnosis.
Acute, multifocal lobar consolidation/atelectasis
History: Tissue from a nursery pig This lesion is very characteristic of one particular disease in swine.
Name that disease
swine influenza
Based on the lesion and top differential, what clinical signs might we have expected in this herd.
- acute onset
- fever, lethargy, anorexia.
- rapidly spreading with high morbidity (nearly all pigs affected)
- barking cough
- difficulty breathing
- sneezing & nasal discharge.
History: Tissue from an adult horse with labored breathing and high fever.
Describe the tissue.
The parietal pleura of the ribs is multifocally covered by an abundance of tan friable material that can be easily removed by manual manipulation.
History: Tissue from an adult horse with labored breathing and high fever.
Give a morphologic diagnosis.
Severe, acute, focally extensive fibrinous pleuritis
History: Tissue from an adult horse with labored breathing and high fever.
Based on the gross lesions, what might the chest cavity and lungs have looked like when first opened?
This animal would have likely had a thoracic exudate (pyothorax)
The lungs would likely have had some degree of atelectasis
History: Tissue from an adult horse with labored breathing and high fever. This lesion is most commonly caused by a bacterial infection.
List several mechanisms whereby bacteria can reach this location.
- Hematogenous (ex: Haemophilus parasuis in pigs)
- Puncture wound/migrating foreign body (Nocardia sp., Actinomyces sp)
- Extension from lung infection (ex: rupture pulmonary abscess)
- Extension from thoracic lymphadenitis (Ex: Strep equi)
- Migration down fascial planes of the neck
- Intra-thoracic esophageal perforation
History: Tissue from a pig that had been sneezing, coughing and had a nasal discharge
Describe this lesion.
The snout, as a whole, is deviated laterally to the left. There is slight to moderate lateral deviation of the median septum to the right. The left nasal turbinates are very small and misshapen resulting in increased airspace within the nasal cavity.
History: Tissue from a pig that had been sneezing, coughing and had a nasal discharge
Provide an appropriate morphological diagnosis.
Nasal cavity: chronic nasal conchae atrophy (or atrophic rhinitis) with septal deviation
History: Tissue from a pig that had been sneezing, coughing and had a nasal discharge
What is the pathogenesis that led to the development of this lesion?
These lesions are the result of a combined infection by specific strains of Bordetella bronchiseptica and toxigenic strains of Pasteurella multocida.
Bordetella bronchiseptica colonizes nasal epithelium → rhinitis → toxigenic Pasteurella multocida (usually type D) colonizes damaged nasal mucosa → elaboration of cytotoxins which disrupt osteogenesis of the turbinate bone (inhibit osteoblastic differentiation; stimulating bone resorption by osteoclasts) → turbinate atrophy (atrophic rhinitis)
History: Tissue from a feedlot bovine
Describe the lesion.
There is a clear line of demarcation between normal pink lung and darker red, more firm (consolidated) lung. When sectioned a thick, cream-colored exudate can be expressed from the airways of the consolidated lung. A small section of consolidated lung immediately sank when placed in a liquid.
History: Tissue from a feedlot bovine
Provide a morphologic diagnosis.
Acute locally extensive bronchopneumonia.
History: Tissue from a 3.5 year old female cat with a history of respiratory distress.
Describe the lesion(s).
The right cranial lung lobe is twisted approximately 180 degrees around its base. The entire lobe is markedly enlarged (swollen) and dark red to black in color. Remaining lung lobes are moderately collapsed/shrunken and focally have a wrinkled surface.
History: Tissue from a 3.5 year old female cat with a history of respiratory distress.
Give an appropriate morphologic diagnosis
Right cranial lung lobe – acute lung lobe torsion with venous infarction Lungs: moderate diffuse atelectasis
History: Tissue from a 3.5 year old female cat with a history of respiratory distress.
What might the chest cavity have looked like when the chest was opened?
There was likely abundant serosanguinous fluid in the chest cavity – which led to the respiratory distress
History: Tissue from a 3.5 year old female cat with a history of respiratory distress.
Briefly outline the pathogenesis of this condition.
Lung lobe torsion → muscular artery continues to pump blood into the lobe but vein collapses → venous congestion → infarction → serosanguinous fluid leaks from necrotic lung → serosanguinous thoracic effusion → atelectasis → respiratory distress
History: Tissue from a 400 lb bovine with a history of chronic weight loss and cough.
Describe the Lesions.
The cranioventral aspect of the right lung was extremely firm (consolidated), tan in color and has an irregular (cobblestone) appearance to the surface. This involved approximately 65% of the right anteroventral lung. When affected lung was sectioned, there were numerous small (1-2mm in diameter) cavities filled with yellow-tan friable material. The interlobular septa are mildly expanded by firm dense white tissue (fibrosis). The pleural surface was focally covered by firm white tissue, approximately 2 x 3 cm in size, which could not be easily removed by manual manipulation (pleural fibrosis). An adjacent tracheobronchial lymph node was markedly enlarged (3x1x1 cm). The right middle and right caudal lung lobes were firmly adhered to each other by thick bands of dense tissue that could not be manually separated (fibrous adhesions).
History: Tissue from a 400 lb bovine with a history of chronic weight loss and cough.
Give a morphologic diagnosis.
Chronic, anteroventral abscessing or caseonecrotic pneumonia (abscessing bronchopneumonia) with pleural and interlobular fibrosis. Tracheobronchial lymph node: marked lymphadenomegally
History: Tissue from a 400 lb bovine with a history of chronic weight loss and cough.
Is this problem acute or chronic (provide your rationale)
This lung had several distinct features of chronicity:
- Tan color (no hyperemia of acute inflammation)
- Irregular nodular surface.
- Pleural fibrosis
- Interlobular septal fibrosis
- Abscesses (microabscesses)
History: Tissue from a 400 lb bovine with a history of chronic weight loss and cough.
Based on the gross lesions, what agents may have contributed to the development of the pneumonia and which is your top differential?
Mycoplasma bovis – top differential Trueperella pyogenes Mycobacterium bovis.
History: Tissue from a 17 year old, female house cat that presented for humane euthanasia due to radiographic evidence of a lung mass and severe ataxia in the hind limbs with associated muscle atrophy.
Describe the lesion.
Lung: A firm, tan-colored, homogeneous mass measuring 5 x 3 x 3 cm occupied the caudodorsal aspect of the right caudal lung lobe. When sectioned, the mass was riddled with small cavities containing a mucoid material.
History: Tissue from a 17 year old, female house cat that presented for humane euthanasia due to radiographic evidence of a lung mass and severe ataxia in the hind limbs with associated muscle atrophy.
Give a morphologic diagnosis
Lungs - Right caudal lung lobe: Chronic focal cavitated pulmonary mass
History: Tissue from a 17 year old, female house cat that presented for humane euthanasia due to radiographic evidence of a lung mass and severe ataxia in the hind limbs with associated muscle atrophy.
Radiographically, you were sure that the lung mass was a lung tumor. However, this cat had an elevated white blood count, elevated neutrophil count, and now it appears that there are cavities in the mass, so you believe the lung changes might represent confluent abscesses. An impression smear of the mass reveals atypical epithelial cells, suggestive of an epithelial tumor, and moderate numbers of neutrophils. Speculate on a mechanism whereby a lung tumor could lead to pulmonary inflammation.
The tumor, as a space occupying mass, inhibits normal clearance via the mucocilliary apparatus and it is fairly common to see significant inflammation (due to infection) surrounding larger lung tumors, due to disruption of normal pulmonary clearance. The small cavities containing a mucoid material are because this tumor originated from the bronchiolar epithelium.
History: Tissue from a 17 year old, female house cat that presented for humane euthanasia due to radiographic evidence of a lung mass and severe ataxia in the hind limbs with associated muscle atrophy.
This animal did not have any respiratory signs despite a relatively large lung mass. How can this be and what is a potential consequence?
The lungs have significant reserve capacity and old house cats, like many of our pets, are rarely aerobically stressed, so lung disease can be well advanced before it is detected. The greater the period of time until the tumor is discovered, the more opportunity to develop subpopulations of cells with metastatic potential. In this case, at necropsy there were metastases to the kidney and spinal canal, hence the hind limb signs.
History: Tissue from a 13 Y MC Cairn Terrier presenting in acute respiratory distress
Describe the lesion(s).
Lungs: Randomly scattered throughout all lung lobes are multiple, firm, variably-sized, homogeneous, dark red to black, nodules ranging in size from 1 mm to 1cm in diameter. They were homogenous on cut surface and extended into the tissue.
Heart: There was a focal large 6x4x2 cm dark red to black mass located on the right auricle. It was solid and mottled tan-red on cut surface. There were small dark red nodules ranging in size from 1 to 5 mm extending down from the mass to the apex of the right ventricle. The pericardium was adhered to the heart over the mass.
History: Tissue from a 13 Y MC Cairn Terrier presenting in acute respiratory distress
Give an appropriate morphologic diagnosis
Lung: Chronic, multifocal pulmonary masses
Heart, right auricle and atrium: Focal hemorrhagic mass
History: Tissue from a 13 Y MC Cairn Terrier presenting in acute respiratory distress You believe the lung lesions constitute metastatic disease.
List your reasons (other than the heart mass) why you believe these are pulmonary metastases.
Pattern: The multifocal, random variably-sized masses are highly suggestive metastatic disease and secondary tumors (metastases) are much more common than primary lung tumors.
History: Tissue from a 13 Y MC Cairn Terrier presenting in acute respiratory distress Because the masses are black in color, differentials for the primary tumor would be malignant melanoma and hemangiosarcoma.
List the locations we need to look at to try and find the site of the primary tumor.
Melanoma Locations:
- nail bed
- oral cavity
Hemangiosarc Locations
- right auricle
- liver
- spleen
History: Tissue from a 3 month old female Holstein calf that presented for chronic respiratory illness of approximately 2 months duration. She has been treated multiple times with antibiotics with no response.
Describe this lesion.
Approximately 25% of both right and left anteroventral lungs were dark red-purple in color and appeared visibly collapsed compared to the adjacent normal pink lung. On palpation, these regions are moderately soft and spongy. In affected anteriventral portions of the lung, the interlobular septa were moderately expanded by clear, glistening fluid.
History: Tissue from a 3 month old female Holstein calf that presented for chronic respiratory illness of approximately 2 months duration. She has been treated multiple times with antibiotics with no response.
What are your top two differentials for this lesion?
Bronchopneumonia
Atelectasis
History: Tissue from a 3 month old female Holstein calf that presented for chronic respiratory illness of approximately 2 months duration. She has been treated multiple times with antibiotics with no response.
You believe the lesions are largely the result of atelectasis. How might a chronic pneumonia lead to atelectasis?
Bonchiolitis obliterans from the prior pneumonia obstructing airflow to portions of the lung.
History: Tissue from a 5 month old male feline presented to an animal shelter and soon developed respiratory distress.
Describe this lesion.
The lungs appeared diffusely collapsed and have a markedly wrinkled surface. The pleural surface, especially the left anterior lung, was extensively covered be opaque white material that could not be readily removed (pleural fibrosis). The lungs were dark red in color and contained multi-focal to coalescing cavitating lesions on the surface of all lung lobes. These lesions were 0.5 – 1 cm in diameter, with a white perimeter and a darker center. The lesions were round to amorphous in shape and were soft to the touch. Multifocally, these cavitary lesions appeared to have ruptured. The pericardial sac is moderately thickened and opaque.
History: Tissue from a 5 month old male feline presented to an animal shelter and soon developed respiratory distress.
Provide an appropriate morphologic diagnosis.
Severe chronic fibrosing pleuritis (pleural fibrosis) and fibrosing pericarditis
Severe, multifocal chronic pulmonary abscesses Diffuse atelectasis
History: Tissue from a 5 month old male feline presented to an animal shelter and soon developed respiratory distress. The three lung lesions are likely related.
Briefly outline how one lesion may have caused the other two?
Ruptured pulmonary abscess → chronic pleuritis/pyothorax → fluid in confined thoracic cavity → atelectasis
History: Tissue from a grow/finish pig
Describe this lesion.
Lungs are diffusely red-tan mottle, heavy, rubbery and non-collapsing. There are multifocal petechial hemorrhages scattered throughout the lung. There are small l (1 cm in diameter) multifocal, pale depressions on the capsular surface of the liver.
History: Tissue from a grow/finish pig
Provide a morphologic diagnosis.
Diffuse interstitial pneumonia with multifocal petechial hemorrhages
Chronic, multifocal, hepatic fibrosis (Milk spot liver)
History: Tissue from a grow/finish pig
List appropriate differentials for these lesions.
Ascarid Larval migration (#1 differential based on the liver lesions PRRS, PCV2, Salm choleraesuis septicemia.
