Last updated: 28 September 2026
Before a litter goes to new homes, the most important screening is parvo and Giardia for dogs, and panleukopenia, Giardia and the parents' FIV/FeLV status for cats. Tests are best done before vaccination or well apart from it, because a live vaccine can cause a false positive result. Hand the documented results over to the buyer.
Screening is not an extra but part of responsible breeding: it protects the puppies and kittens, the buyer's other animals and the reputation of your kennel or cattery.
What should you screen for in a litter of puppies?
In a litter of puppies, parvo and Giardia are the two most important pathogens; depending on symptoms, canine coronavirus and distemper too.
| Pathogen | Who and when? | Test | What to watch out for? |
|---|---|---|---|
| Parvovirus (CPV) | A puppy with diarrhoea or vomiting immediately; a symptom-free litter before rehoming | CPV Ag or 3-in-1 | Can be falsely positive for 4–10 days after a live parvo vaccine (Merck). |
| Giardia | With recurring, mucousy diarrhoea, and as screening before rehoming | Giardia Ag or 3-in-1 | According to CAPC, the antigen can remain positive for a while even after successful treatment. |
| Canine coronavirus (CCV) | Puppies with diarrhoea | 3-in-1 | Usually mild on its own, more severe together with parvo. |
| Distemper (CDV) | Puppies with eye and nasal discharge, coughing or fever | CPV/CDV or 4-in-1 | The sample must be taken from eye, nasal or oral discharge. |
What should you screen for in a litter of kittens?
In a cattery, the parents' FIV/FeLV status is the foundation, and for kittens, panleukopenia and Giardia are the most important.
| Pathogen | Who and when? | Test | What to watch out for? |
|---|---|---|---|
| FIV/FeLV | The parents before breeding, and every new breeding cat when introduced | FIV/FeLV combined | According to ABCD, FeLV also spreads from mother to kittens. In kittens up to 6 months, maternal antibodies can cause a false positive FIV result (AAFP). |
| Panleukopenia (FPV) | A kitten that is vomiting, has diarrhoea or is lethargic, immediately | FPV Ag | Can be positive for at least 4 weeks after a live vaccine (ABCD). |
| Giardia | With recurring diarrhoea, and as screening before rehoming | Giardia Ag | According to ABCD, as many as 30–40% of cats in catteries may be infected. |
| Coronavirus shedding | Breeding cats, if you want to reduce the risk of FIP | FIPV Ag | Shows which cats are shedding the virus, not FIP. |
More about FIP and coronavirus shedding: FIP is no longer a death sentence.
When should you do the tests before rehoming?
Screening of a symptom-free litter is best done before vaccination or well apart from it, but a puppy or kitten with symptoms must always be tested immediately.
- After vaccination: a stool test can be falsely positive for 4–10 days after a live parvo vaccine (Merck) and for at least 4 weeks after a panleukopenia vaccine (ABCD). If you test during this period, have your vet interpret the result.
- Litters of puppies: legal requirements vary by country; in Hungary, for example, Government Decree 41/2010 requires puppies to stay with their mother until 8 weeks of age, and dogs may only be handed over if microchipped.
- Intermittent shedding: virus and cyst shedding is not continuous, so one negative sample is no guarantee. Repeat the test if symptoms appear.
- If positive: see a vet, isolate the animal, test its littermates, disinfect, and postpone rehoming until your vet decides otherwise.
What should the buyer receive?
The buyer should receive a written summary of the puppy's or kitten's health background, with the dates and results of the tests:
- which test was done on which animal, when, and what the result was (with a dated photo of the cassette),
- vaccination record, deworming dates and, for dogs, the microchip number,
- for cats, the parents' FIV/FeLV results,
- a recommendation to take the animal to a vet in the first week.
Useful summaries for buyers: Bringing home a puppy: checklist and Adopting a cat: screening tests.
How do you build screening into your breeding routine?
- Fixed protocol: write down what you test, when and on whom (breeding animals, litters, new animals).
- New animals: isolate and test before they join the breeding group; for cats, an FIV/FeLV test repeated after 60 days (AAFP).
- Hygiene: against parvo, diluted household bleach (1:30) or a peroxygen-based product (Merck); against Giardia, according to ABCD, quaternary ammonium compounds, followed by thorough drying.
- Documentation: keep the results for each individual animal.
- Honest communication: a negative test applies to the moment it was done, not a lifelong guarantee. Only state in your advert what you actually do.
How much does screening cost for breeders?
MancsLab tests are also available in 5-packs at 10% off the single-test price, which makes a difference when screening a whole litter – see the product pages for current prices. We have collected tests for breeders here: rapid tests for breeders. For larger quantities and partnerships: for partners.
Frequently asked questions about screening by breeders
What does the law require when a puppy is handed over?
This depends on the country. In Hungary, for example, Government Decree 41/2010 requires puppies to stay with their mother until 8 weeks of age, and a dog may only be sold or given away if microchipped, regardless of age. Screening for infectious diseases goes beyond this and is part of responsible breeding practice.
Is it enough to test a few puppies from the litter?
Always test animals with symptoms individually. In a symptom-free litter, testing a few puppies or kittens is informative but not a guarantee for the whole litter, because shedding of pathogens can be intermittent.
One puppy tested positive. What should I do?
Take it to the vet, isolate it, test its littermates, disinfect, and postpone rehoming until your vet decides otherwise. Inform the buyer honestly.
Can I test after vaccination?
Yes, but interpret the result with caution: a stool test can be falsely positive for 4–10 days after a live parvo vaccine and for at least 4 weeks after a panleukopenia vaccine. For a symptom-free litter it is therefore better to test before vaccination.
How do I prove the result to the buyer?
Take a dated photo of the read cassette with the animal's identification, and give a written summary of tests, vaccinations and dewormings. If the buyer asks, a veterinary examination can also confirm the result.
Summary
Before rehoming a litter, a responsible breeder screens puppies for parvo and Giardia and kittens for panleukopenia, Giardia and the parents' FIV/FeLV status, pays attention to vaccination timing and hands over documented results. This protects the young animals, the buyer's pets and the reputation of the kennel or cattery.
Sources
- Hungarian Government Decree 41/2010 (II. 26.) on the keeping and trade of pet animals. Nemzeti Jogszabálytár
- Merck Veterinary Manual: Canine Parvovirus Infection. merckvetmanual.com
- ABCD – European Advisory Board on Cat Diseases: Guideline for Feline Panleukopenia. abcdcatsvets.org
- ABCD – European Advisory Board on Cat Diseases: Guideline for Giardiasis. abcdcatsvets.org
- ABCD – European Advisory Board on Cat Diseases: Guideline for Feline Leukaemia Virus Infection. abcdcatsvets.org
- Little S, et al.: 2020 AAFP Feline Retrovirus Testing and Management Guidelines. Journal of Feline Medicine and Surgery, 2020. journals.sagepub.com
- Companion Animal Parasite Council (CAPC): Giardia. capcvet.org
Important: this article provides general information and does not replace veterinary advice. Always agree your kennel's or cattery's health protocol, treatment and vaccination plan with a vet. MancsLab rapid tests are intended for preliminary screening.