Fecal ova & parasites
Stool ·Also called: O&P, ova and parasites, fecal float, flotation, worm egg count
What it is
Most intestinal parasites shed eggs into the stool. Mixing a sample with a heavy solution floats those eggs to the top, where they can be collected on a coverslip and identified by shape and size under the microscope.
Why your vet measures it
Several of the parasites this test finds are transmissible to people, particularly children — roundworm and hookworm among them. It also explains diarrhoea, weight loss and poor coat condition in young animals, and it guides which wormer to use rather than treating blindly.
What a positive result can mean
- Roundworms, extremely common in puppies and kittens and passed from the mother
- Hookworms, which can cause anaemia in young animals
- Whipworms in dogs, a cause of long-standing large-bowel diarrhoea
- Coccidia, especially in young or recently rehomed animals
- Tapeworm segments, though these are more often seen by the owner than found on a float
What a negative result means
- A negative result does not rule parasites out. Eggs are shed intermittently, some parasites are not yet laying, and Giardia and lungworm are poorly detected on a standard float — which is why three samples over several days are often requested
Dogs and cats differ
Puppies and kittens are commonly born with or quickly acquire roundworms from the mother, so routine worming schedules for the young do not wait for a positive test. In adult cats that hunt, tapeworm from rodents and roundworm reinfection are the usual finds.
Questions worth asking your vet
- Should we submit samples from three different days rather than one?
- Does this parasite pose any risk to the people in the household?
- Which wormer treats what was found, and when should we recheck?
Related terms
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