Fig.1-6.
(1) Multifocal to coalescing, subacute exudative and hyperkeratotic dermatitis; haired skin; bovine. Disease: dermatophilosis. Shape analogy: Paintbrush. Multifocal to coalescing, firm, 0.2-2.5cm thick, brown to gray crusts with entrapped hair. Inset: when the firm to hard spikes are pulled off, they resemble the bristles of an artist’s brush. (2) Locally extensive, subacute, necrotizing and serocellular dermatitis; muzzle; bovine. Etiology: hepatogenous (type III) photosensitization due to Senecio sp. Shape analogy: Tree bark. Necrosis of the skin of the muzzle sloughs off as the dried barks of a tree. (3) Multifocal to coalescing, acute vasculitis with rhomboid infarcts; haired skin; swine. Shape analogy and name of the disease: Diamond skin disease. The red square areas resemble diamonds and are highly suggestive of acute infection of Erysipelothrix rhusiopathiae. Photo courtesy: Dr. Joaquim Segales, Universitat Autonoma de Barcelona. (4) Locally extensive, chronic, proliferative, fibrogranulomatous panniculitis; prescapular region; bovine. Etiology: Mannheimia granulomatis. Shape analogy and name of the condition: Lechiguana. Inset: wasp nest mimicking the shape of the subcutaneous lesion of lechiguana. Photo courtesy: Dr. Franklin Riet-Correa, Universidade Federal da Bahia. (5) Alopecia; tip of the tail; bovine. Etiology: ingestion of the mushroom Ramaria flavo-brunnescens. Shape analogy: Rat tail. (6) Locally extensive subcutaneous edema; submandibular region; bovine. Etiology: hypoproteinemia due to endoparasitism. Shape analogy: Bottle jaw.
Fig.7-8.
(7) Multifocal to coalescing, chronic, granulomatous and eosinophilic cellulitis; equine. Etiology: Pythium insidiosum. Shape analogy: Kunkers. Photo courtesy: Dr. Roger Kelly, University of Queensland, Australia. (8) Multifocal to coalescing, chronic, pyogranulomatous omentitis; omentum; canine. Etiology: Nocardia sp. Shape analogy: Sulfur granules. Histologically, the pale tan to yellow, granules seen on the surface of the red and thick omentum contain colonies of branching filamentous bacteria surrounded by Splendore-Hoeppli deposits and inflammatory cells.
Fig.9-14.
(9) Uneven growth and wear; molar and premolar teeth; equine. Shape analogy: Wave mouth. The undulating appearance of the occlusive surfaces of the cheek teeth leads to poor mastication and impaction of the large colon. (10) Esophageal gongylonemiasis; bovine. Etiology: Gongylonema pulchrum. Shape analogy: Serpiginous tracks. (11) Abomasal haemonchosis; caprine. Etiology: Haemonchus contortus. Shape analogy: Barber’s pole. The red and white stripe corresponds to the egg-filled uterus that is wrapped around the intestine containing blood. (12) Plicated small intestine; feline. Shape analogy: Accordion-folded intestine. The plicated intestine indicates an intraluminal linear foreign body. Inset: linear mucosal ulceration along the mesenteric border due to linear foreign body in a dog. (13) Colonic adenocarcinoma; canine. Shape analogy: Napkin-ring stricture has resulted in partial obstruction of the intestinal lumen. (14) Pyogranulomatous colitis; large colon; equine. Etiology: Rhodococcus equi. Shape analogy: Crateriform. The mucosa is randomly elevated by contains semi-confluent nodules with a craterous ulcerated center. Photo courtesy: Dr. Roger Kelly, University of Queensland, Australia.
Fig.15-16.
(15) Multifocal, ulcerative typhlitis; cecum; swine. Disease: classical swine fever. Shape analogy: Button ulcers are a characteristic macroscopic finding for chronic classical swine fever and enteric salmonellosis. Photo courtesy: Dr. Murilo Nogueira dos Santos. (16) Multifocal to coalescing, chronic, granulomatous pleuritis; pleura; bovine. Disease: tuberculosis. Shape analogy: Tuberculous pearls. Serosal generalization of tuberculous granulomas may resemble pearls. Photo courtesy: Dr. Ingrid Saccol Wiethan.
Fig.17-20.
(17) Multifocal, subacute, necrotizing hepatitis; liver; turkey. Disease: histomoniasis. Shape analogy: Target. In turkeys and chickens, these lesions are characteristic of Histomonas meleagridis infection. Photo courtesy: Department of Primary Industries, Victoria, Australia. (18) Cholangiocarcinoma; liver; canine. Shape analogy: Umbilicated. The necrotic center of the tumor makes a central depression resembling an umbilicus. Photo courtesy: Dr. Brian Porter, Texas A&M University. (19) Chronic hepatic fascioliasis; bovine. Shape analogy: Pipe stem. Enlarged bile ducts are prominent on the visceral surface of the liver. (20) Chronic hepatic fascioliasis; bovine. Shape analogy: Pipe stem. Opened bile ducts with thickened, white, and firm wall containing leaf-shaped flukes and dark brown debris (fluke exhaust).
Fig.21-24.
(21)Marked, acute, fibrinosuppurative, vegetative endocarditis; mitral valve; swine. Shape analogy: Cauliflower. Large, pale, vegetative growths on the mitral valve secondary to bacterial infection resemble a cauliflower. (22) Locally extensive, acute, aorto-iliac thrombosis secondary to hypertrophic cardiomyopathy; feline. Shape analogy: Saddle thrombus. The lumen of the aortoiliac junction is occluded by a Y-shaped thrombus. (23) Horseshoe kidney; equine. Shape analogy: Horseshoe. The caudal poles of the kidneys are fused by an isthmus. (24) Focally extensive renal infarct; canine. Shape analogy: Wedge-shaped. Affecting both the renal cortex and medulla is a focally extensive, wedge-shaped, red area of ischemic necrosis surrounded by a pale rim halo.
Fig.25-26.
(25) Marked, locally extensive, pyogranulomatous osteomyelitis; bovine. Etiology: Actinomyces bovis. Shape analogy: Lumpy jaw. A large, ulcerated hard mass expands the left mandible. (26) Marked, locally extensive, pyogranulomatous osteomyelitis; mandible, bovine. Shape analogy: Lumpy jaw. The affected bone was macerated, and the honeycomb aspect can be appreciated. The “holes” were once filled by pyogranulomatous inflammation that protruded over the borders of the holes, giving the jaw a lumpy look.
Fig.27-30.
(27) Chronic, pyogranulomatous dermatitis with club-shaped Splendore-Hoeppli material, muzzle; bovine. Shape analogy: Club-shaped. HE, obj.20x. (28) Chronic, eosinophilic and granulomatous dermatitis; haired skin; equine. Disease: habronemiasis. Shape analogy: Flame figure. A focal aggregate of brightly eosinophilic collagen fibers is covered and surrounded by eosinophils. HE, obj.20x. (29) Follicular dysplasia; haired skin; canine. Disease: cyclical flank alopecia. Shape analogy: Witches feet. Atrophy of the hair follicles along with marked infundibular hyperkeratosis and the extension of keratin into the opening of secondary follicles resemble a broad, malformed foot with irregular toes and sharp nails. HE, obj.4x. Photo courtesy: Dr. Dominique J. Wiener, Texas A&M University. (30) Marked, diffuse parakeratotic and neutrophilic dermatitis with abundant filamentous bacteria; haired skin; bovine. Disease: dermatophilosis. Shape analogy: Railroad track. Cocci of Dermatophilus congolensis are arranged forming parallel branching filaments. HE, obj.40x
Fig.31-34.
(31) Anaplastic pulmonary carcinoma; lung; canine. Shape analogy: Owl’s eye nuclei. The neoplastic cells often have large, atypical nuclei bearing a prominent nucleolus and some perinucleolar clearing. The atypical nuclei resemble an owl’s eye with the nucleolus representing the pupil. HE, obj.40x. (32) Squamous cell carcinoma; haired skin; equine. Shape analogy: Keratin pearl. Central laminated masses of keratin are surrounded by concentric layers of neoplastic squamous epithelial cells. HE, obj.20x. (33) Trichoblastoma, ribbon type; haired skin; canine. Shape analogy: Ribbons. The cords of cells resemble bundles of ribbons or streamers. HE, obj.10x. (34) Trichoblastoma; medusoid type; haired skin; canine. Shape analogy: Medusa head. The ribbons of cells radiating out from a central point resemble the head of the well-known monster of Greek mythology. HE, obj.4x.
Fig. 35-36
(35) Ameloblastoma; tooth; canine. Shape analogy: Ink drop structures are characteristic of odontogenic epithelium origin. HE, obj.4x. (36) Urothelial carcinoma; urinary bladder; canine. Shape analogy: Signet ring cells. These cells are a feature of urothelial carcinomas. HE, obj.40x.
Fig.37-40.
(
37) Multifocal, random, subacute, necrosuppurative hepatitis with hepatocellular bacilli; liver; equine. Disease: Tyzzer’s disease. Shape analogy: Pick-up sticks. HE, obj.40x. (
38) Multifocal, random, subacute, necrosuppurative hepatitis with hepatocellular bacilli; liver; equine; Cause:
Clostridium piliforme. Shape analogy: Pick-up sticks. Bacilli lay in a criss-crossed arrangement within the cytoplasm of hepatocytes, better visualized with a silver stain. Steiner stain, obj.20x. (
39) Protoporphyrin accumulation; liver; chicken. Shape analogy: Maltese cross. Rounded, dark brown bodies within hepatocytes and bile ducts. HE, obj.20x. Photo courtesy: Dr. Monique França, The University of Georgia. (
40) Protoporphyrin accumulation; liver; chicken. Shape analogy: Maltese cross. Under polarization, the pigmented round structures in
Figure 39 display a characteristic bright-orange aspect with a centrally-located Maltese cross. HE, obj.20x. Photo courtesy: Dr. Monique França, The University of Georgia.
Fig.41-44.
(41) Moderate, multifocal, acute tubular degeneration and necrosis with intratubular crystals; kidney; canine. Cause: ethylene glycol toxicosis. Shape analogy: Sheaves of wheat. The renal tubules contain refractile oxalate crystals similar to sheaves of wheat. HE, obj.20x. (42) Oxalate crystals; kidney; canine. Cause: ethylene glycol toxicosis. Shape analogy: Prisms (in Portuguese: prismas). Under polarized light, the crystals are similar to prisms. (43) Marked, multifocal tubular degeneration and attenuation with intratubular crystals; kidney; canine. Cause: melamine and cyanuric acid toxicosis. Shape analogy: Pinwheel crystals. The distal tubules contain green-brown, circular crystals with radiating spokes, cellular debris and neutrophils. HE, obj.40x. (44) Acidophilic, rectangular, intranuclear inclusions; kidney; canine. Shape analogy: Brick inclusions. These are a common incidental finding in the proximal renal tubules and hepatocytes of old dogs. HE, obj.40x.
Fig.45-48.
(45) Cholesterol granuloma; choroid plexus of the lateral ventricle; brain; equine. Shape analogy: Acicular clefts. The parallel needle-shaped clefts are characteristic of cholesterol clefts. HE, obj.20x. (46) Astrocytoma, high grade; brain; canine. Shape analogy: serpiginous tracks. Area of necrosis in a serpiginous pattern with pseudo-palisading neoplastic cells are characteristic of high-grade gliomas. HE, obj.10x. (47) Astrocytoma, high grade; brain; canine. Shape analogy: Glomeruloid vessels. These are microvascular proliferations along the periphery of the tumor that resemble renal glomeruli. HE, obj.20x. (48) Medulloepithelioma; eye; equine. Shape analogy: Rosettes. Neoplastic cells are arranged in a halo of neuroblastic cells around a nearly empty central lumen containing fine cytoplasmic extensions (Flexner-Wintersteiner rosettes). HE, obj.20x.
Fig.49.
Cataract eye; canine. Shape analogy: Bladder cells. Lens fibers are swollen with abundant eosinophilic cytoplasm and retained nuclei. HE, obj.40x. Photo courtesy: Dr. Laura Bryan, Texas A&M University.
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