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A 7-month old intact female Husky was presented with 2 -month hematuria and intermittent vomiting. The patient had lived most of her life in Northern Canada and very recently was moved to the Vancouver area. The diet was occasionally contained raw freshwater fish.


Sagittal ultrasound video clip of the right kidney

Transverse ultrasound video clip of the right kidney

Sagittal ultrasound video clip of the left kidney

  • The right kidney was enlarged when compared to the left one.
  • The right kidney is diffusely heterogeneous with minimal detectable normal renal architecture.
  • Multiple tubular structures containing echogenic foci are seen within the right kidney.
  • There is mild abdominal effusion.
  • In the caudal abdomen, there are multiple tubular structures containing echogenic foci.
  • The left kidney is normal in size, echotexture, and contour.

Multiple tubular structures with echogenic foci within the right kidney are consistent with a parasitic infestation. The tubular structure outside of the kidney may be additional parasites ventral or around the right kidney.

The hematology showed a mild normocytic, normochromic anemia with Hct of 32%(normal range is 38-57). Mild eosinophilia and reactive thrombocytosis were noted. The blood chemistry panel showed a mild increase in SDMA and urea(BUN), phosphorus, calcium, and potassium. Na: K ratio was 26(normal is 28-37). Urinalysis showed a USG of 1.049 with a high number of WBC and RBC/HPF. The urine sediment microscopic exam showed the ova of Dioctophyma renale.

Treatment: The surgical exploration of the abdomen was performed. Three worms were found in the retroperitoneal area around the right kidney. The right kidney and its ureter were removed. A worm was also found within the right kidney. A parasitology laboratory confirmed the definitive diagnosis of Dioctophyma renale.

Discussions: Giant kidney worms (Dioctophyma renale) have been reported most often in dogs but occasionally in cats. These parasitic roundworms have a predilection for the right kidney in dogs but have been found in other sites (e.g., abdominal cavity, and less commonly bladder, uterus, mammary gland). The gradual destruction of renal parenchyma by the parasites may cause no overt clinical signs or may result in hematuria, polydipsia, polyuria, pollakiuria, anemia, urinary tract infection, weight loss, peritonitis, and anorexia.

Diagnosis of renal involvement is by ultrasound or CT, in which ring-like or tubular structures are seen within the kidney. Ova can also be detected in the urine if female parasites are present. The current treatment is ureteronephrectomy; at this time there appear to be no drugs effective against these worms.


Editors Note: Notice how both cases of the month had worms in the RIGHT kidney, and spared the left kidney.  Cool!




D. renale inside right kidney after nephrectomy

Relative length of worm found in right kidney

Retroperitoneal worms