Dogs and people share homes, yards, parks, and sometimes parasites. Understanding parasites dogs can pass to humans starts with knowing what testing can find—and what a test result cannot tell us.
A recent Phys.org report describes work on diagnosing parasites that can create health concerns for both dogs and people. The report highlights an important public-health issue, but diagnosis matters because parasites differ widely: some live in the intestine and may be found in stool, while others require different kinds of tests.
What the news story means for dog households
A dog can carry an intestinal parasite without an owner seeing anything unusual in the stool. That is one reason veterinarians may use fecal, or stool, testing as part of routine preventive care or when a dog has digestive signs.
For US households, the practical point is not that every dog is a danger to its family. It is that prompt cleanup of dog feces, good handwashing after handling waste or soil, and veterinary-guided parasite prevention can reduce opportunities for exposure. This is especially relevant in homes with young children, who may have more contact with soil and may be less consistent about handwashing.
Animal shelters also deserve particular attention. Dogs entering shelters may have unknown health histories, and close quarters can make monitoring, sanitation, and appropriate testing important for animal welfare and for people who work with or adopt animals.
What fecal testing can detect
A fecal parasite examination, also called a coprological examination, looks for parasite material in a stool sample. In a 2024 study of 382 owned dogs in Serbia, researchers used qualitative fecal examination with a concentration method. Concentration means processing the sample to make parasite eggs, larvae, or similar material easier to find under examination.
The study detected several intestinal parasites, including Giardia intestinalis, Toxocara canis, hookworms in the Ancylostomatidae family, Alaria alata, and taeniids (a group of tapeworms). Several of these organisms have zoonotic potential, meaning they can be relevant to human health under some circumstances.
This is direct support for the narrow claim that routine fecal parasite testing can identify intestinal parasites in dogs that may matter to public health. The study’s authors concluded that routine parasitological testing and regular deworming strategies are important components of care.
Importantly, finding a parasite in a dog does not demonstrate that the dog infected a person. It shows that the dog may be shedding, or carrying, a parasite that warrants veterinary interpretation and appropriate prevention steps.
Why parasite identification can be complicated
Not every positive-looking finding provides a species-level answer. A 2018 study of stray dogs in an Italian shelter found taeniid eggs in fecal samples, but the eggs could not distinguish Echinococcus granulosus from other taeniids. In other words, microscope-based stool testing can sometimes identify a parasite group without resolving the exact parasite species.
More specialized methods may help answer follow-up questions. A 2023 survey of shelter dogs and cats in Austria combined fecal flotation and larval migration testing with molecular genotyping for Giardia. Genetic testing identified potentially zoonotic Giardia genotypes, illustrating why a basic positive result and an assessment of human-health relevance are not always the same thing.
Some parasites are not primarily diagnosed through a routine fecal examination. The available evidence includes studies using serological tests, which measure certain immune responses, and molecular tests such as PCR, which look for genetic material. For example, a 2024 shelter study in northeastern Italy used serological, molecular, and microbiological diagnostics to investigate a broad set of zoonotic agents in dogs and cats, including gastrointestinal parasites. However, its abstract does not provide enough parasite-specific detail to establish which test is best for a particular canine parasite.
What the evidence does not establish
The Serbia study was conducted in Serbia, not the United States. Its 62.6% overall parasite detection rate describes the sampled dogs, their environment, and the methods used there; it should not be treated as a prevalence estimate for US dogs.
It also was a prevalence and risk-factor study, not a head-to-head test of diagnostic accuracy. It does not tell us the sensitivity or specificity of its fecal method, whether one sample is sufficient in every circumstance, or how it compares with antigen tests, PCR, imaging, or blood-based testing.
The supplied research therefore supports fecal testing as a practical way to find several intestinal parasites, not as a complete screening tool for every parasite associated with dogs and people. The news report’s broader focus on diagnosis is reasonable, but the available studies do not validate one universal diagnostic approach.
What You Can Take Away from This Reading
- Fecal parasite testing can detect several intestinal parasites in dogs that have zoonotic potential. - A positive fecal result does not prove a dog transmitted an infection to a person, and some findings cannot identify the exact parasite species. - Different parasites may require different diagnostic tools, including stool examinations, molecular testing, or blood-based tests. - Results from studies in Serbia, Austria, and Italy provide useful evidence about testing methods, but they do not measure parasite rates in US dogs. - Discussing routine fecal testing and parasite prevention with a veterinarian is a practical part of protecting a dog’s health and reducing household exposure opportunities.
Sources
PubMed PMID 38791680. “Gastrointestinal Parasites in Owned Dogs in Serbia: Prevalence and Risk Factors.” Animals, 2024. Jovanovic NM, Bisenic O, Nenadovic K, Bogunovic D, Rajkovic M, Maletic M, Mirilovic M, Ilic T. DOI: 10.3390/ani14101463. https://pubmed.ncbi.nlm.nih.gov/38791680/
PubMed PMID 37741041. “Parasites and zoonotic bacteria in the feces of cats and dogs from animal shelters in Carinthia, Austria.” Research in Veterinary Science, 2023. Joachim A, Auersperg V, Drüe J, Wiedermann S, Hinney B, Spergser J. DOI: 10.1016/j.rvsc.2023.105022. https://pubmed.ncbi.nlm.nih.gov/37741041/
PubMed PMID 39664895. “Zoonoses in dog and cat shelters in North-East Italy: update on emerging, neglected and known zoonotic agents.” Frontiers in Veterinary Science, 2024. Mazzotta E, Lucchese L, Corrò M, Ceglie L, Danesi P, Capello K, Natale A. DOI: 10.3389/fvets.2024.1490649. https://pubmed.ncbi.nlm.nih.gov/39664895/
PubMed PMID 29351076. “Parasites in stray dogs from Italy: prevalence, risk factors and management concerns.” Acta Parasitologica, 2018. Liberato C, Berrilli F, Odorizi L, Scarcella R, Barni M, Amoruso C, Scarito A, Filippo MMD, Carvelli A, Iacoponi F, Scaramozzino P. DOI: 10.1515/ap-2018-0003. https://pubmed.ncbi.nlm.nih.gov/29351076/