Five tests decide whether a pairing should happen at all, and together cost less than one emergency cesarean. For a Persian-line queen and a Maine Coon stud the list is PKD1, HCM, SMA, PKDef and blood type; a full panel plus 1 cardiac ultrasound runs 400 to 900 USD per pair. Order them before the mating date is fixed, because 3 of the 5 change the pairing rather than the kitten.
The 5 tests and what each one decides
Each test removes a different risk, and none substitutes for another. A swab answers yes or no about one gene; an ultrasound answers a question about the heart today. That is why HCM needs both.
| Test | What it reads | Breeds to test | Inheritance or timing | Typical cost |
|---|---|---|---|---|
| PKD1 | Single gene, cysts in kidney tissue | Persian, Exotic, British lines | Dominant: 1 copy is enough | 40–75 USD |
| HCM DNA | Known MyBPC3 variants only | Maine Coon, Ragdoll | Complex: 2+ variants known | 60–140 USD |
| Cardiac echo | Wall thickness and function | Maine Coon, Ragdoll, Sphynx, Bengal | Phenotype: test at 12 months | 200–450 USD |
| SMA | Spinal muscular atrophy allele | Maine Coon and crosses | Recessive: 2 copies needed | 40–70 USD |
| PKDef | Pyruvate kinase deficiency | Abyssinian, Somali, Bengal | Recessive: 2 copies needed | 40–70 USD |
| Blood type | A, B or AB | Every breeding cat | Typing: 10 minute card | 25–60 USD |
Send the swab to a university genetics lab or a large panel lab; both publish prices, and results take 5 to 15 business days. The echo needs a cardiologist and a 30 to 45 minute slot.
PKD1: 1 copy is enough to disqualify
Polycystic kidney disease in Persian lines is autosomal dominant: a cat with 1 copy passes it to roughly half its kittens, a cat with 2 copies to all of them. Cysts are usually visible on ultrasound only from 10 months to 3 years, so a clear scan at 8 months proves very little. The DNA test is the clean answer — swab, 40 to 75 USD, a result that does not change with age.
Never pair 2 positives, and do not breed a positive cat at all unless the line is being worked down deliberately and every positive kitten leaves on a desexing contract. Clear to clear ends the question in 1 generation.
HCM: the DNA test is not screening
Hypertrophic cardiomyopathy is the most common heart disease in cats and the one that ends the most breeding programmes. In Maine Coons and Ragdolls a few MyBPC3 variants are testable, but they explain only part of the risk: many affected cats carry no known variant, and many carriers reach 10 years without disease.
Screening is echocardiography, read by someone who measures the wall properly: baseline at 12 months, repeat at 24 months, then every 12 to 24 months until 8 years. A murmur is absent in a meaningful share of affected cats, so auscultation at a show is not screening. Cats at or above the breed cut-off leave the programme, and the cut-off is the cardiologist's call.
SMA: the test that saves a whole litter
Spinal muscular atrophy in Maine Coons is recessive: 2 carrier parents produce 25% affected kittens, 50% carriers and 25% clear, on average per kitten. Affected kittens look normal for 3 to 4 weeks, then develop a swaying gait, a low head carriage and hind-limb weakness; most are euthanised before 6 months.
Carriers are healthy, so a pedigree can hide the allele for generations. A 40 to 70 USD swab turns a guess into a fact. Carrier to clear is acceptable — no affected kittens, and the clear offspring stay in the programme. Carrier to carrier is not.
PKDef: the one Abyssinian breeders skip
Pyruvate kinase deficiency is recessive and shows up as episodic hemolytic anemia: pale gums, weakness, jaundice, a cat that is fine on Monday and flat by Friday. Onset runs from 6 months to several years, so a healthy 3-year-old is not evidence. The allele is best documented in Abyssinians and Somalis, and appears in some Bengal lines.
Two carriers give the same 25% affected ratio as SMA. Test both sides before the first mating; clear to carrier is safe for the kittens and keeps the line open.
Blood type: the test with a 24 to 72 hour clock
Type B queens carry naturally occurring anti-A antibodies. A type A kitten that drinks type B colostrum absorbs them through the gut in its first 16 to 24 hours, and neonatal isoerythrolysis follows within 24 to 72 hours: kittens fade, pass dark red urine, and develop tail-tip necrosis. It moves fast and is preventable.
Type B sits under 5% in domestic shorthairs, but it is common enough in British Shorthairs, Devon Rex, Cornish Rex and some Persian lines to make testing mandatory. A card test costs 10 to 25 USD and answers in 10 minutes; a lab tube test at 25 to 60 USD confirms it. If the queen is B and the tom A, either change the tom or separate the kittens for 24 to 48 hours and feed a colostrum substitute, under veterinary direction.
Reading results without over-reading them
Three outcomes are possible per test, and only 1 is a stop sign: positive to anything changes the pairing, and with a dominant condition such as PKD1 the cat should not be bred at all.
Record the lab, the accession number, the test date and the result beside the mating date and the weight curve, because a buyer asking at 14 months wants a document, not a memory (what a breeding record has to hold). Labs archive for 2 to 5 years; keep your own copy longer.
What the whole screen costs
For a Maine Coon pairing: PKD1 at 40 to 75, HCM DNA at 60 to 140, SMA at 40 to 70, blood type at 25 to 60 per cat, plus 1 echo at 200 to 450 per adult. That is 420 to 900 USD once, then 200 to 450 every 12 to 24 months. Across a litter of 4 to 6 kittens it is 70 to 150 USD per kitten, less than the first vaccine series.
If the budget is tight, the order is blood type first, then PKD1 or SMA by breed, then echo. Skipping the echo is the one shortcut that can produce a heartbroken buyer at 3 years (what laboratory work actually costs).
Before the first mating: 4 steps
- Week −6: swab both cats for the breed-relevant panel; do not book the stud before results land.
- Week −4: blood type both cats, and if the queen is B, change the plan rather than the kittens.
- Week −3: echocardiogram on both adults if either breed is on the HCM list; file the measurement, not the word normal.
- Week −1: results, dates and lab names into the breeding file, and a copy of the 2 relevant tests to the buyer.
The last check is the kitten: track the first 8 weeks on a percentile curve (kitten weight percentile tool), and a kitten 2 weeks behind its littermates is a reason to reread the mother's record.
Frequently asked
Can I breed a carrier if I only sell pets?
For the recessive tests, SMA and PKDef, yes: a carrier paired with a clear cat produces no affected kittens, so each kitten can go to a pet home or be kept. For a dominant condition such as PKD1, no, because 1 copy is enough to produce cysts and roughly half the litter inherits it. The rule that holds across all 5: never pair 2 carriers, and never pair 2 positives of anything.
Does a clear HCM DNA test mean the cat will not develop heart disease?
No. The testable MyBPC3 variants in Maine Coons and Ragdolls explain only part of the risk, and a meaningful share of affected cats carry no known variant. That is why cardiologists screen with echocardiography: a baseline at 12 months, a repeat at 24 months, then every 12 to 24 months until 8 years, with the wall measurement written into the record instead of a one-word verdict.
Why does blood typing matter if I am not transfusing anything?
Because of colostrum, not transfusion. A type B queen has naturally occurring anti-A antibodies, and a type A kitten that nurses in its first 16 to 24 hours absorbs them through the gut. Neonatal isoerythrolysis follows within 24 to 72 hours: fading, dark urine, tail-tip necrosis, often death. A 10 to 25 USD card test on both cats removes the risk — change the tom, or separate the kittens for 24 to 48 hours under veterinary direction.