Hereditary screening for a breeding cat is 3 tests on 2 clocks and 1 folder: a kidney ultrasound from 10 months, an echo for HCM every 12 months, and 3 DNA tests run once and never repeated. Clearing all of it for a pair costs USD 400-900, takes 6-14 days of lab turnaround and needs appointments booked 3-4 weeks out. The money does not buy a guarantee. It buys 3 documents that a buyer, a vet or a future co-owner can read. Which of these tests run once and which expire is the subject of pre-breeding tests.
What a test proves, and what it does not
A DNA test reads 1 or 2 copies of a named mutation and never changes in that cat's life: clear, carrier or affected. An ultrasound reads 1 organ on 1 day, in 1 clinic, and can be normal in a cat that develops disease at 4. That is why the record matters as much as the result. A certificate with no lab name, no accession number, no microchip and no date is paper, not a screening result; ask for the lab report and keep the PDF for life.
PKD: DNA once, ultrasound from 10 months
PKD is autosomal dominant, which makes it the simplest item here: 1 copy of the PKD1 variant means affected, and 2 affected parents pass it to roughly 3 in 4 kittens. The DNA test runs once, at any age, on a cheek swab or 0.5 mL of blood. The ultrasound does a different job, looking for cysts in the renal cortex, and most programs start at 10 months because cysts under 2 mm are easy to miss earlier. A clean scan is a good result, not a lifetime proof, so many programs repeat it at 24 months. Budget USD 60-150 for the scan, and expect a swab result in 7-14 days; a cat tested at 6 months never needs the DNA test again, only the scans.
HCM: 1 echo, every 12 months, for life
HCM is the item that never finishes. The measurable number is left ventricular wall thickness in diastole: under 5 mm reads as normal in most breeds, 5.0-5.9 mm as equivocal, 6.0 mm or more as consistent with HCM, with breed cut-offs a cardiologist applies. The disease can show at 2 years or at 8, so the schedule is a first echo at 12 months and a repeat every 12 months, not 1 scan before a first litter. Maine Coon, Ragdoll, Sphynx, British Shorthair, Persian and Bengal carry the strongest case for it. A cardiologist echo runs USD 150-350; a general scan is cheaper and answers less. A 5.5 mm reading is a recheck in 6 months, not a verdict. If the 12-month echo is normal, the 24-month one is what catches early disease; breeding at 3 years on the strength of 1 scan at 1 year is the most common hole in a record.
The 3 DNA tests worth running once
Three single-gene tests settle most of what a swab can: PKD1, SMA for spinal muscular atrophy in the Maine Coon, and PKDef for pyruvate kinase deficiency in Bengal, Abyssinian and Somali lines. Each runs once at USD 40-80; 3 on 1 swab usually totals USD 100-200, and the 5-test guide to what each one decides is in genetic testing before breeding. A carrier is not a sick cat, it is a cat to pair with a clear partner. The 2 HCM variants, A31P in the Maine Coon and R820W in the Ragdoll, do not clear the heart, because most feline HCM is not explained by them.
The screening schedule on 1 page
| Test | First age | Repeat | What a result changes | Typical cost (USD) |
|---|---|---|---|---|
| PKD1 DNA | 4 weeks or later | 1 time only | 1 copy means do not breed | 40-80 |
| PKD ultrasound | 10 months | 24 months | Cysts from 2 mm change the plan | 60-150 |
| HCM echo | 12 months | Every 12 months | 6.0 mm or more ends the plan | 150-350 |
| SMA DNA (Maine Coon) | 4 weeks or later | 1 time only | Carrier pairs with clear only | 40-80 |
| PKDef DNA (Bengal, Abyssinian) | 4 weeks or later | 1 time only | Carrier pairs with clear only | 40-80 |
| FeLV and FIV | 12 months | Every 12 months | A positive changes everything | 30-60 |
Two clocks show in that table: DNA is answered once, imaging is answered again every year. Treat the yearly echo as a running cost, put its date beside the vaccine booster so it does not slide to 14 months, and price the programme against the annual cost of a cat.
Reading a result the way a vet does
Clear means 0 copies of the variant tested, carrier 1 copy, affected 2 copies in a recessive disease or 1 in a dominant one. For imaging the 3 useful words are normal, equivocal and abnormal, and an equivocal result needs a recheck date rather than a yes or no. None of it is a diagnosis, and none of it should drive a pairing decision without a vet holding the report. Words like suggestive or cannot exclude are instructions to recheck in 3-6 months, not a clearance.
Why the record is part of the test
Keep 5 fields per test: cat ID (15-digit microchip or tattoo), test name, lab and accession number, date, result. Store the PDF and photograph both sides of the paper certificate, because thermal printers fade in 2-3 years and the back usually carries the lab's signature and date. Keep results for 10-15 years. When a kitten leaves, hand over the parents' reports, not the sentence that the parents were tested.
What clearance does not buy you
Three DNA tests and an echo cover PKD, SMA, PKDef and common HCM. They do not cover blood type, FeLV and FIV, calicivirus or mycoplasma carriage, patella scoring, or the many mutations with no test. Clear parents can still produce a cleft palate or a murmur at 8 weeks. Screening lowers the odds on 4 named risks; a vet still decides whether a particular pairing is reasonable.
Do this before the next litter
- Book the echo at 12 months and diarise the next one 12 months out; a 14-month gap is a missed year.
- Order PKD1, SMA and PKDef as 1 panel on 1 swab, and file the raw lab report.
- Scan the kidneys at 10 months and again at 24 months if the first was clean.
- Record 5 fields per test and keep them for 10-15 years, including for each kitten's owner.
- Take any abnormal or equivocal result to a vet before deciding, and date the decision.
Terms mentioned in this article
Frequently asked
If both parents test clear, is the kitten guaranteed healthy?
No. Clear results cover the specific mutations tested, which on a standard panel means PKD1, SMA and PKDef, plus whatever the parents' echoes showed on the day they were scanned. HCM can appear later, blood type incompatibility is a separate risk, and structural problems like cleft palate have no DNA test at all.
Why scan for PKD at 10 months instead of at 6 months?
Cysts smaller than about 2 mm are hard to see before the kidney has grown, so most programs wait until 10 months, when the renal cortex is thick enough to image reliably. A clean scan then is a good result but not a lifetime pass, which is why many programs repeat it at 24 months.
Do the HCM DNA tests replace the yearly echo?
No. The A31P variant in the Maine Coon and R820W in the Ragdoll explain only a small share of feline HCM, so a negative DNA result leaves most of the risk unmeasured. The echo measures wall thickness directly, which is why it stays on a 12-month schedule even when every DNA test is clear.