By the time a puppy is eight weeks old you have had more chances to notice something wrong with it than anyone will have for the rest of its life — which makes the question not whether a defect exists, but whether you looked for it, had it confirmed, and wrote down what was found.
The most important first
- Your daily observation and the veterinary examination do different jobs: you supply the history and the trend, the vet supplies the findings that need a stethoscope, a scope and trained hands.
- Some breed screening is genuinely possible now. Hearing can be tested by brainstem auditory evoked response from 35 days of age, and a puppy can already be affected by patellar luxation by eight weeks.
- Other screening is not. Official hip, elbow and patella evaluations require an older dog, and many inherited conditions declare themselves months or years later.
- At eight weeks the strongest health evidence you hold is not about the puppy at all: it is the parents’ screening results and what is known about the lines behind them.
- Disclosure is where breeders fail most often. Among 60 owners of puppies later diagnosed with congenital heart disease, only about one in five had been told about a murmur by the breeder before they bought the puppy.
What you can assess yourself
The health picture you build is cumulative, and nobody else has access to it. Weight gained every day or every other day, plotted rather than remembered, is the single most useful record you hold — the method is in weighing and tracking growth and the interpretation in growth and body condition in puppies. Alongside it sit the daily checks in daily care and hygiene routines: appetite, fecal consistency, eyes and nose, skin and coat, gait on a non-slip surface, whether a puppy tires before its littermates, and whether it responds to a sound made behind it while asleep.
You can also notice things most vets will never see: the puppy that always sits down after a short play session, the one that coughs only after drinking, the one that has never barked. Write them down as they happen, with dates: a finding with a history — “noticed at five weeks, unchanged at eight” — is far more useful to your vet than one first raised in the consulting room.
What you cannot do is diagnose, and the temptation to interpret is the trap. A soft swelling at the navel, an asymmetric bite, a testicle you cannot find, a puppy that lags behind: each belongs on a list for the vet, not in a conclusion of your own.
Signs that cannot wait for the eight-week check
Some findings belong with the vet now, not on a list. Call your veterinarian promptly if a puppy breathes fast or with effort at rest, coughs, faints or tires far sooner than its littermates; if milk comes out of its nose when it feeds; if a navel or groin swelling becomes firm, painful or cannot be pushed back, especially with vomiting; or if it stops gaining weight or loses weight on your chart.
What needs the vet, and what eight weeks is too early for
The examination, the microchip and the registration paperwork are covered in vet checks, microchipping and registration, and the paperwork that travels with the puppy in pre-sale health checklist. What this article adds is the boundary between screening that is age-appropriate at eight weeks and screening that is not.
Testing that can be done now includes cardiac auscultation by an experienced examiner, an ophthalmic examination for congenital abnormalities where a litter screen is customary in the breed, palpation of the abdominal wall and inguinal rings, an oral examination for cleft defects and bite, palpation for descended testicles in male puppies, and hearing testing: the Orthopedic Foundation for Animals specifies that brainstem auditory evoked response testing is done on dogs at least 35 days old, comfortably within the period a litter is still with you. That matters in the roughly 80 breeds in which congenital deafness has been reported — in Dalmatians, around 8% are bilaterally and 22% unilaterally deaf — and it matters for breeding as well as placement, since a unilaterally deaf dog carries the same genetic risk as a bilaterally deaf one.
Many puppies have a soft murmur that is innocent. These often first appear at six to eight weeks, are usually quiet, and normally fade by about four to six months. A loud murmur, a murmur heard between beats (diastolic), or any murmur with symptoms points to heart disease. When it is unclear, your veterinarian may suggest an echocardiogram or referral to a cardiologist — and the buyer should know the recheck date.
In males, both testicles are normally in the scrotum by six to eight weeks. If one is not, write it down and tell the buyer: the diagnosis is usually confirmed at about six months, the condition is heritable, and retained testicles carry a higher risk of cancer and of painful twisting, so veterinarians generally advise neutering.
Patellae are a more nuanced case. The OFA notes that animals can be affected by the time they are eight weeks of age, and that the examination is done on a conscious dog rather than under sedation, so palpation now is meaningful. Its database numbers, however, are issued only from 12 months of age, and hips and elbows are further off still, with final evaluation at 24 months. Anything described as a “clear” hip or elbow at eight weeks is a category error, and so is presenting a normal puppy examination as a clean bill of health for life — the Merck Veterinary Manual is explicit that congenital defects are those present or apparent at birth, while other developmental defects may not become apparent until later.
The parents’ results are the real evidence at this age
Because so little can be tested in the puppy, the health argument you make at eight weeks rests almost entirely on the generation above. That is not a weakness in the argument; it is where the information genuinely is. Hand over the sire’s and dam’s screening results in full — scheme, date, result and identification number, not “both parents fully health tested” — with the reasoning for the combination. The background is in health screening and health schemes and genetics and inherited health, and helping a buyer read a carrier result rather than panic at it is in modes of inheritance. Be equally clear about what those results do not cover: conditions with no scheme in your breed, polygenic conditions, and the ordinary possibility that a screened pairing produces an affected puppy anyway.
In practice
At the eight-week check the vet hears a soft murmur in one puppy and cannot say whether it is innocent. The breeder’s instinct is to wait, because puppy murmurs often fade. Instead the buyer is told the same day, in writing, before any balance is paid, and given the choice to withdraw; a recheck is booked and referral for imaging discussed. The murmur turns out to be innocent — such murmurs usually disappear by about four to six months, which is why the recheck date matters — and the puppy goes to the same home — but the family decided knowing, and they tell the next people who ask about the breeder.
(Illustrative, composite scenario.)
Putting findings in writing without hiding or inflating them
The murmur study describes exactly the failure mode to avoid. Of 60 owners whose puppies were later confirmed to have congenital heart disease, 77% did not know a murmur existed when they bought the dog, and 72% said they would not have gone ahead had they known. The referring vets’ own readings varied widely — 15% considered the murmur certainly serious, 73% potentially serious and 12% probably innocent — which shows how much room there is for a finding to soften as it passes down the chain.
Write findings the way a clinician would: what was found, by whom, on what date, what it might mean, what is planned. “Soft left-sided murmur noted by our veterinary surgeon on 12 September; recheck booked 3 October; may be innocent, may not” is disclosure. “Vet says nothing to worry about” is not, even when it turns out to be true. Overstating is its own failure: calling an umbilical hernia a heart problem, or a temporary limp dysplasia, misleads a buyer just as effectively and usually costs the puppy a good home. A finding that changes what the puppy will need for life also changes the placement — see placing puppies with special needs.
What travels with the puppy
Send the health information in a form the new owner can still use six months later: the vet’s written findings, the vaccination and worming record, the growth chart, the parents’ screening documents, and your dated notes on anything still under review. Then ask the buyer to report back, because collecting health and longevity data over years is the only way you learn whether your screening decisions were sound.
Make the vaccination and worming record usable: product, date and who gave it, plus what is still due. Under the WSAVA guidelines the core puppy vaccinations continue every three to four weeks until at least 16 weeks of age, so every eight-week puppy leaves with its course unfinished. CAPC recommends deworming puppies from two weeks of age at two-week intervals and several fecal checks in the first year. Tell the buyer to book their own veterinarian within the first week to continue the plan.
When to call your vet
- A puppy that breathes fast or with effort at rest, coughs, faints, or tires much sooner than its littermates.
- Milk from the nose during feeding, repeated choking, or a puppy that is not keeping up with its littermates’ weight gain.
- A navel or groin swelling that becomes firm, painful or cannot be pushed back, especially with vomiting.
- A murmur noted at any check — book the recheck before the puppy leaves and tell the buyer the date.
- A male with a testicle not in the scrotum at the eight-week check; same day if there is sudden pain or swelling.
- No startle to sound, or hearing that seems one-sided — ask about BAER testing (from 35 days).
- If in doubt, call — your vet would rather hear from you early.
Work on it
A few minutes here will teach you more than re-reading the article.
Ask yourself
- If a buyer asked tomorrow what health checks this puppy has actually had, could I answer with dates and findings rather than reassurances?
- Have I ever softened a veterinary finding when passing it on, in either direction?
- Do my buyers receive the parents’ screening results as documents, or as a claim in a conversation?
Find out & check
- Ask your veterinary practice which screening in your breed is age-appropriate at eight weeks and which is not, and whether litter hearing or eye screening is available locally and at what age.
Do one thing
- Draft the written health summary for one puppy in your current or next litter, with every finding dated and every pending recheck named.
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Sources & further reading
- Orthopedic Foundation for Animals — Congenital Deafness. ofa.org
- Orthopedic Foundation for Animals — Patellar Luxation. ofa.org
- Vos VR, Szatmári V (2022), Veterinary Sciences — Information Provided by Breeders and Referring Veterinarians about the Presence and Meaning of a Murmur to Owners of Newly Purchased Puppies with a Later Confirmed Congenital Heart Disease. pmc.ncbi.nlm.nih.gov
- Merck Veterinary Manual — Overview of Congenital and Inherited Anomalies in Animals. merckvetmanual.com
- VCA Animal Hospitals — Heart Murmurs in Dogs. vcahospitals.com
- Merck Veterinary Manual — Congenital and Inherited Disorders of the Cardiovascular System in Dogs. merckvetmanual.com
- WSAVA — Dog vaccination table (2025). wsava.org
- Companion Animal Parasite Council — General Guidelines. capcvet.org
Where evidence is limited, recommendations rest on established practice and expert judgment, and may be updated as knowledge develops. Nothing here is veterinary advice: every finding described belongs to your veterinary surgeon to examine, interpret and record. What a seller must disclose, and in what form, differs between countries — that question belongs with your own professional adviser.
Next steps
- Read next: Choosing a future breeding prospect.
- Related: Pre-sale health checklist.
- Return to the area hub: Understanding and placing each puppy.