JPC SYSTEMIC PATHOLOGY
URINARY SYSTEM
January 2018
U-T09 (NP)

Signalment (AFIP # 1947461):  A neutered male Morgan horse

HISTORY:  Tissue from a Morgan horse that was castrated.  Hemorrhage from the surgical site was excessive, so the animal was treated with a single dose of vitamin K3.

HISTOPATHOLOGIC DESCRIPTION:  Kidney:  Multifocally 70% of the renal tubules within the cortex and medulla are mildly ectatic and lined by either attenuated, degenerate (hypertrophied with vacuolated cytoplasm), or necrotic (hypereosinophilic angular cytoplasm with pyknotic nuclei) epithelial cells.  There is rare tubular epithelial regeneration characterized by tubules which are lined by hypertrophied epithelial cells which pile up, have more basophilic cytoplasm, vesiculate nuclei, prominent nucleoli, and rare mitotic figures.   Multifocally, tubules contain one or more of the following: red blood cells, fibrin, sloughed epithelial cells, granular eosinophilic material and rare oxalate-like crystals (birefringent, 40-70 um). Focal glomerular changes include: mild dilatation of the uriniferous spaces, small amounts of granular to smooth eosinophilic material within uriniferous spaces, and hypertrophied parietal epithelial cells.  There is mild, multifocal interstitial infiltration/expansion by congested vessels, small amounts of edema, and scattered small aggregates of lymphocytes, plasma cells, macrophages and rare neutrophils.

MORPHOLOGIC DIAGNOSIS:  Kidney, tubules:  Degeneration and necrosis, multifocal, moderate, with mild lymphoplasmacytic interstitial nephritis, rare tubular regeneration, and congestion, Morgan, equine.

ETIOLOGIC DIAGNOSIS:  Renal menadione (Vit K3) toxicosis

GENERAL DISCUSSION:

PATHOGENESIS:

The mechanism for renal toxicity of vitamin K3 may relate to oxidative damage

TYPICAL CLINICAL FINDINGS:

TYPICAL GROSS FINDINGS: 

TYPICAL LIGHT MICROSCOPIC FINDINGS: 

 DIFFERENTIAL DIAGNOSIS:

Toxin-induced acute renal failure in horses:

REFERENCES:

  1. Boudreaux MK, Spangler EA, Welles EG. Hemostasis. In: Latimer KS, ed. Duncan & Prasse’s Veterinary Laboratory Medicine Clinical Pathology. 5th ed. Ames, IA: John Wiley & Sons, Inc; 2011:124-125
  2. Cianciolo RE, Mohr CF. Urinary System. In:  Maxie MG, ed.  Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals, Volume 2. 6th ed.  St. Louis, MO:  Elsevier; 2016:  424.
  3. Haschek WM, Rousseaux CG, Wallig MA. Fundamentals of Toxicologic Pathology. 2nd ed. San Diego, CA: Elsevier; 2010: 294
  4. Talcott P. Toxicologic problems. In: Reed SM, Bayly WM, Sellon DC, eds.  Equine Internal Medicine. 4th ed. St Louis, MO: Elsevier; 2018: 1507.

 

 

 


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