Fig.1.
(A) Chylothorax, thorax, cat. Food analogy: milky fluid. Approximately 80mL of white, opaque fluid fills the thoracic cavity. The pressure of the accumulated fluid resulted in pulmonary atelectasis. (B) Marked, diffuse, chronic, pyogranulomatous pleuritis with secondary pulmonary atelectasis, thoracic cavity, dog. Food analogy: tomato soup. A thick red exudate partially fills the thoracic cavity. Note the atelectasis of the lungs. Mesothelial hyperplasia and hypertrophy is on the caudoventral area of the thoracic cavity, which it is typical in chronic inflammation of serosal surfaces. (C) Marked, diffuse, urate deposits; coelomic cavity; parrot; visceral gout. Food analogy: frosting or sugar icing. The heart and liver are diffusely covered by a thin layer of white, opaque, gritty material (urates). (D) Mild to moderate, multifocal to coalescing, chronic, fibrinous and granulomatous splenic and hepatic capsulitis, cat; feline infectious peritonitis. Food analogy: frosting or sugar icing. The splenic and hepatic capsular surfaces are multifocally covered by fibrin. (E) Fibrinous pleuritis, thoracic cavity, horse. Food analogy: scrambled eggs. Large accumulations of yellow, friable exudate (fibrin) loosely adhered to the parietal and visceral pleurae. (F) Moderate, multifocal to coalescing, acute, fibrinous peritonitis; peritoneum; pig; Glasser’s disease. Food analogy: scrambled eggs. Multifocal strands of fibrin are on the surface of the liver and spiral colon.
Fig.2.
(A) Focal, chronic, hepatic abscess; liver; horse. Food analogy for the abscess content: sweetened condensed milk. On cut section, the contents are slightly yellow and liquefied (pus) surrounded by a thick fibrous capsule. (B) Multifocal, subcutaneous, chronic abscesses; haired skin; goat; caseous lymphadenitis. Food analogy for the abscess content: cream cheese. The contents of these abscesses are slightly yellow and creamy (pus) and are surrounded by a thin fibrous capsule. (C) Marked, diffuse, chronic, pyogranulomatous lymphadenitis; mesenteric lymph node; foal; Rhodococcus equi infection. Food analogy for the content: caseous. The mesenteric lymph node is markedly enlarged and replaced by abundant caseous material. (D) Moderate, multifocal, acute, suppurative embolic nephritis or glomerulitis; kidney; foal; septicemic actinobacillosis. Food analogy for the distribution of the lesions: miliary. Miliary, 0.1-0.3cm in diameter, pale tan foci are randomly distributed through the renal cortex.
Fig.3.
(A) Esophageal sarcocystosis; esophagus; sheep. Food analogy: rice grains. Scattered throughout the muscular layer of the esophagus are many 3-7mm long, white macrocysts of Sarcocystis gigantea. (B) Intestinal dipylidiasis; small intestine; dog. Food analogy: rice grains or cucumber seeds. The lumen of the small intestine contains numerous gravid segments of Dipylidium caninum. (C) Moderate, multifocal to coalescing, subacute, gastric ulcers; stomach, dog. Food analogy of the stomach contents: coffee ground. Multiple, linear ulcers are in the mucosa and cover by brown to black fluid (digested blood). (D) Marked, multifocal, chronic, granulomatous and eosinophilic colitis with mucosal and submucosal edema and cyathostomin larvae; colon, horse. Food analogy: salt and pepper colon. The colon contains numerous, 1- 5 mm long, red, coiled nematode larvae encysted in the mucosa and submucosa.
Fig.4.
(A) Moderate, multifocal to coalescing, chronic, capsular fibrosis; liver, pig. Food analogy: milk spots. Scattered throughout the Glisson’s capsule and adjacent hepatic parenchyma are multifocal to coalescing white firm areas of fibrosis. (B) Multinodular hepatocellular regeneration and fibrosis; liver, dog. Food analogy: chocolate with crisped rice. Nodules of attempts of hepatocellular regeneration are imprisoned (and therefore not fully functional) by bands of fibrous tissue. This lesion is also called end-stage liver or nodular hepatic cirrhosis. (C) Chronic congestive heart failure; liver, calf. Food analogy: nutmeg liver. Alternate areas of congestion and fibrosis in the liver imparts an aspect of nutmeg liver to the hepatic cut surface. This lesion is caused by right heart failure. (D) Chronic congestive heart failure; liver, calf. Food analogy: nutmeg liver. For comparison, a round fragment of the fixed liver from a dog with chronic congestive heart failure (left) is placed side by side with a piece of nutmeg of similar shape and size. (E) Mucocele; gallbladder; dog. Food analogy: kiwi gallbladder. On cross section, the mucosa of the gallbladder is hyperplastic and the center is filled with inspissated bile and mucus. (F) Multiple renal cysts; kidney, cat; polycystic kidney disease. Food analogy: swiss cheese kidney. The renal cortex and medulla are distorted by variably-sized cysts.
Fig.5.
(
A) Fibrinous pericarditis, pericardial sac, ox; hardware disease. Food analogy: bread and butter pericarditis. The surface of the epicardium is rough, granular and diffusely covered by fibrin. (
B) Multifocal, marked, barbiturate salt crystals deposition; endocardium, right ventricle, dog; Food analogy: salt precipitates. The endocardium has incrusted barbiturate salt crystals that appear as opaque white plaques. (
C) Postmortem clots, heart, dog. The right ventricle contains a pale yellow clot (Food analogy: chicken fat) and dark red clots (Food analogy: currant jelly). (
D) Diffuse, marked, acute, necrohemorrhagic and emphysematous myositis; skeletal muscle (hindquarter); heifer. Food analogy: aerated chocolate. The skeletal muscle contains multifocal to coalescing areas of hemorrhage and necrosis admixed with many air bubbles cavities (emphysema). Reproduced with permission from
Abreu et al. 2017.
Fig.6.
(A) Hemoglobinuria; urinary bladder, sheep; copper toxicosis. Food analogy: cola colored urine. The urinary bladder contains dark red urine. The adipose tissue is moderately yellow (icterus). Inset: hemoglobinuric nephrosis; kidney, sheep. The renal cortex and medulla are diffusely dark red due to acute tubular necrosis with intratubular hemoglobinuric casts. (B) Marked, multifocal, lymphoid follicular hyperplasia, spleen, dog. Food analogy: sago spleen. Traditionally sago spleen is the term for splenic follicular amyloidosis. However, some pathologists by analogy refer to marked lymphoid hyperplasia as sago spleen. Image courtesy of Dr. Laura Bryan.
Fig.7.
(A) Necrosuppurative bronchopneumonia, lung, pig; pulmonary actinobacillosis. Food analogy: oat cells. The alveolar lumina are obliterated by numerous elongated degenerated and necrotic leukocytes with nuclear streaming. HE, obj.40x. (B) Mast cell tumor, haired skin, dog. Food analogy: fried egg appearance. Well-differentiated mast cells containing abundant granular cytoplasm and round nucleus are intermixed with eosinophils. HE, obj.40x. (C) Oligodendroglioma, brain, dog. Food analogy: fried egg appearance. Neoplastic cells contain round, uniform, central nuclei surrounded by a halo of clear cytoplasm. The clear halo is an artifact of tissue fixation. HE, obj.20x. (D) Histiocytic interstitial pneumonia, lung, horse. Food analogy: honeycomb material. The alveolar spaces and septa are expanded by foamy, eosinophilic material, macrophages and numerous round, intra and extracellular, inconspicuous fungal bodies. HE, obj.60x. (E) Protozoal cyst, myocardium, dog. Food analogy: onion skin cyst. Encysted stages of Hepatozoon americanum contain a host cell (macrophage) in the center, surrounded by multilamellar, basophilic, amorphous material. HE, obj.20x. (F) Granulomatous bronchointerstitial pneumonia with lymphoid depletion and histiocytic intracytoplasmic botryoid inclusion bodies; lung; pig. Porcine circovirus-associated disease. Food analogy: botryoid inclusion bodies. HE, obj.40x.