Giant Kidney Worm
(Dioctophyme renale)
The giant kidney worm is a parasitic nematode that locates in the right kidney, which may result in destruction of the functional tissue or within the peritoneal cavity.
| Parasite: Dioctophyme renale |
| Common name: Giant kidney worm |
| Host: Dogs, mustelids, cats, humans |
| Pre-patent period: 2 to 6 months |
| Location of adults: Right kidney, peritoneal cavity |
| Distribution: Worldwide |
| Transmission route: Oral [ingestion of intermediate (oligochaete annelid; “aquatic worms”) or paratenic hosts (fish or frogs)] |
| Zoonotic: Yes |
Distribution
Dioctophyme renale is found worldwide, except in Africa and Oceania.
Clinical signs
Many dogs are asymptomatic due to compensatory hypertrophy of the unaffected kidney. Clinical signs may include haematuria, right kidney pain, right limb claudication, lumbar and abdominal pain and potentially paresis of the hind quarters. If the left kidney is also compromised, the dog will develop clinical signs of renal failure such as polydipsia and polyuria. Worms migrating within in the peritoneal cavity may produce abdominal pain.
Diagnosis
Eggs are passed via the ureteral lumen into the urine if there is at least one female worm present in the kidney. Brownish, thick-shelled eggs with bipolar pigs (68 x 45 μm) containing a single cell, can be detected by the examination of urine sediment under light microscopy. If the slide is covered with red cells they should be removed by means of acetic acid to enable visualisation of the eggs. Ultrasound can be used to visualise the worms within the kidney or peritoneum. Dioctophyme worms are red, the female can reach 1 m in length and 1 cm in diameter.
Treatment
Surgical removal of the worm is the only current treatment option.
Control
Do not allow dogs to drink from fresh-water bodies or ingest aquatic worms or frogs. Dogs should not be fed raw fish.
Public health considerations
Humans get infected in the same way as dogs, most commonly by ingesting undercooked fish and frog.