JPC SYSTEMIC PATHOLOGY
URINARY SYSTEM
January 2018
U-M19

Signalment (JPC Accession #1802815):  18-month-old female German shepherd Dog

HISTORY:  This dog was bitten on the nose by a Mojave Desert rattlesnake.  After 4 days of treatment, the dog became anorexic and began vomiting.  Treatment was discontinued and the dog was euthanized.

HISTOPATHOLOGIC DESCRIPTION:  Kidney:  Diffusely within glomerular tufts capillaries are variably dilated and often displace and replace the remaining glomerular tuft and efface glomerular architecture (capillary ballooning).  Within these capillaries, there are aggregates of abundant brightly eosinophilic fibrillary, beaded,hyalinized and polymerized fibrin admixed with neutrophils and erythrocytes (organizing fibrin thrombi).  Multifocally there is loss of mesangium (mesangiolysis) with replacement by a scant to small amount of cellular and nuclear debris (necrosis) and hemorrhage.  Multifocally there is hemorrhage within Bowman’s space admixed with fibrin, neutrophils, lymphocytes, plasma cells, and macrophages.  Multifocally, tubules are either ectatic and lined by attenuated epithelium or lined by degenerate epithelium with pale, swollen and vacuolated cytoplasm (tubular degeneration).  Occasionally within the tubular epithelium, there are individual cells that are shrunken and hypereosinophilic with a pyknotic nucleus (tubular necrosis).  Multifocally there are tubule epithelial cells that have more basophilic cytoplasm, are mildly piled up with disorganized architecture and the presence of mitotic figures (regeneration). Multifocally, tubules are ectatic and/or contain abundant eosinophilic homogenous proteinaceous material (tubular proteinosis) admixed with moderate amounts of hemorrhage and fibrin, occasional sloughed epithelial cells, cellular debris, few foamy macrophages that often contain phagocytized erythrocytes, and neutrophils (cellular casts).

MORPHOLOGIC DIAGNOSIS:  Kidney, glomeruli:  Mesangiolysis, diffuse, severe, with fibrin thrombi, hemorrhage and tubular degeneration, necrosis, and proteinosis, German shepherd dog, canine. 

ETIOLOGIC DIAGNOSIS:  Toxic glomerular vasculopathy

ETIOLOGY:  Snake (pit viper) venom

GENERAL DISCUSSION: 

PATHOGENESIS: 

Venom Constituents Snake Type Major Mechanism of action

Cholinesterase

Most dangerous species (particularly elapidae)

Blocks neuromuscular transmission by splitting acetylcholine to choline and acetic acid

Phospolipases (PLA2)

Virtually all venomous snakes, esp. elapids

PLA2 cleave platelet membrane AA forming thromboxane A2; induce platelet aggregation

L-Amino acid oxidase (LAAO)

Vipers

Digests tissues

Hyaluronidase

All venomous snakes

Dissolves intercellular matrix

Proteinase

Vipers

Accelerates protein breakdown in prey

Adenosine triphosphatase

Most snakes, esp. vipers

Lowers blood pressure through enzyme catabolism of ATP into toxic substances

Phosphodiesterase

Virtually all venomous snakes

Induces negative cardiovascular effects

Metalloproteinases

Vipers (high quantities)

Degrade extracellular matrix, esp. type IV collagen; induce vascular endothelial lesions

 

TYPICAL CLINICAL FINDINGS:

Clinical Pathology:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS:

 DIFFERENTIAL DIAGNOSIS:

 References:

  1.  Boudreaux MK, Spangler EA, Welles EG. Hemostasis. In: Latimer KS, ed. Duncan and Prasse’s Veterinary Laboratory Medicine:Clinical Pathology. 5th ed. Ames, IA: Wiley-Blackwell; 2011:107-144.
  2. Cianciolo RE, Mohr FC. Urinary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. St. Louis, MO: Elsevier; 2016:418.
  3. Goddard A, Schoeman JP, Leisewitz AL, Nagel SS, Aroch I. Clinical abnormalities associated with snake envenomation in domestic animals. Vet Clin Pathol. 2011;40(3):282-292.
  4. Mauldin EA, Peters-Kennedy J. Integumentary system. In: Maxie MG, ed. Jubb, Kennedy and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:568.
  5. Mosier DA. Vascular disorders and thrombosis. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. Saint Louis, MO: Elsevier; 2017:60-72.

 

 


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