Three diagnoses set the calendar for an American Bobtail: polycystic kidney disease, hypertrophic cardiomyopathy, and hip dysplasia. Book them in this order: kidney ultrasound at 10 months, echocardiogram at 12 months, hip radiograph at 24 months, then repeat at 12, 12, and 24 month intervals. Published breed-specific figures are limited here, so the evidence base is thin: every number below is a protocol number borrowed from Persian-lineage and general feline medicine, not this breed's prevalence.
Kidney first, because 10 months is the earliest useful date
Polycystic kidney disease is autosomal dominant: a cat with 1 copy passes it to roughly 50 percent of kittens. Cysts read on ultrasound as round dark structures in the cortex from about 10 months, and a clean scan at 7 months proves almost nothing. Add a DNA swab for the PKD1 variant, valid at any age including 8 weeks. A positive swab with clean imaging at 12 months means recheck at 18 months, not a diagnosis at 10. A negative swab in a cat with known parents closes the question and saves 4 to 6 scans over a lifetime. Baseline labs from age 3: creatinine 1.6 to 2.5 mg/dL, SDMA above 14 µg/dL, urine specific gravity below 1.035 in a cat with free water, urine protein to creatinine ratio above 0.4. Two of those 4 drifting in one year moves the recheck from 12 months to 6.
The screening calendar, item by item
| Test | First at | Repeat every | Detects | Stop if |
|---|---|---|---|---|
| PKD1 DNA swab | 8 weeks | 1 time | inherited cyst gene | negative, parents known |
| Abdominal ultrasound | 10 months | 12 months to age 3 | cysts from 2 mm | 2 clean scans plus negative swab |
| Echocardiogram | 12 months | 12 months | wall 6.0 mm, LA/Ao 1.5 | never, continue past age 8 |
| Hip radiograph | 24 months | 24 months | laxity, DJD, remodeling | 2 normal films at 24 and 48 |
| Urine and blood pressure | 12 months | 12 months | USG, UPC, systolic 160 | never |
Heart: 12 months, then yearly, no skipping
Hypertrophic cardiomyopathy is the most common feline heart disease, and this breed appears on the list of breeds where it is reported, but no trustworthy breed-wide rate exists. Treat the echo as routine rather than optional. A cardiologist, or a GP with Doppler, measures left ventricular wall thickness at end-diastole in the free wall and septum: 6.0 mm is the usual cut-off, 5.5 to 5.9 mm is equivocal and earns a 6 month recheck, and a left atrium to aorta ratio above 1.5 shifts the plan to a 6 month interval plus a conversation about clopidogrel, a platelet inhibitor available only by veterinary prescription. Ask for the millimetres in writing, because a report saying mild thickening without numbers cannot be compared next year. At home, count sleeping breaths for 30 seconds and double it: 30 per minute or less is the target, and 3 readings above 30 in one week moves the echo forward, not back.
Hips: one film at 24 months answers most of it
Feline hip dysplasia is under-diagnosed because a cat in pain stops jumping instead of limping. Radiograph at 24 months, once growth plates have closed, in 2 views: ventrodorsal extended and lateral, with light sedation so the pelvis sits straight. The report should grade laxity and name degenerative change: femoral head remodeling, shallow acetabulum, subluxation. Some clinics offer a PennHIP-style distraction index, where above 0.5 indicates laxity. Surgery, if it comes to that, is a femoral head excision at 1,200 to 3,000 dollars per side. Weight is the variable an owner actually controls: each 500 g added to a 4.5 kg cat puts about 11 percent more load through each hind limb at every landing.
Four signals you can read at home
- Litter clumps. More than 3 a day, clumps bigger than a golf ball, or a cat drinking over 60 ml per kg per day, which is 270 ml for a 4.5 kg cat, points at the kidney before bloodwork does.
- Sleeping respiratory rate. Count 30 seconds while the cat is asleep, double it, write it down. Three days in a row above 30 per minute buys an echo within 72 hours.
- Jump refusal. Skipping the 60 cm counter, landing short, sitting to eat, or a bunny-hop gait on stairs is a hip signal, not laziness.
- Weight trend. Weigh monthly on a baby scale. A 5 percent loss in 8 weeks, or 10 percent in 6 months, means labs within 14 days.
Emergency thresholds in hours, not days
| Sign | Threshold | Vet within | Concern |
|---|---|---|---|
| Open-mouth breathing at rest | 0 to 1 min | 0 hours, now | heart failure, effusion |
| Respiratory rate asleep | over 40 per minute | 1 hour | pulmonary edema |
| Hind limbs dragging | under 5 min | 2 hours | saddle thrombus, spinal lesion |
| No urine, straining, crying | 12 hours | 3 hours | urethral obstruction |
| Not eating, vomiting | 24 hours | 12 hours | kidney, pancreatitis |
| Weight loss of 10 percent | over 6 months | 72 hours | progressive CKD |
What the first 3 years cost
| Item | USD | CNY | Frequency |
|---|---|---|---|
| PKD1 DNA swab | 60 to 120 | 430 to 870 | once |
| Abdominal ultrasound | 120 to 250 | 500 to 1,100 | 12 months |
| Echocardiogram | 250 to 500 | 1,200 to 2,600 | 12 months |
| Hip radiograph, 2 views | 150 to 300 | 700 to 1,600 | 24 months |
| Urine, UPC, blood pressure | 80 to 180 | 350 to 800 | 12 months |
| Cardiology consult | 150 to 250 | 600 to 1,200 | as needed |
CNY figures are typical mainland clinic prices, not a conversion at 7.2 to the dollar: imaging is cheaper there and imported cardiac consults cost more, so the totals land close to the dollar column. A 3 year total of 1,700 to 3,400 dollars is realistic and is roughly the cost of 1 emergency night for a blocked bladder, which is the argument for the calendar rather than against it.
Five things to put in the calendar this month
- Book the 10 month ultrasound now; a 2 week wait is normal for a cardiologist, longer for a radiologist.
- Order the PKD1 swab if the cat is under 12 months and the parents are unknown.
- Start a 30 second sleeping breath log tonight; 3 rows of numbers beat a memory of the cat being a bit breathy.
- Buy a baby scale, 2 kg capacity, 5 g resolution, and weigh on the same day each month.
- Photograph the gait on stairs at 24 months, so a change at 30 months is a comparison rather than an opinion.
If the budget only stretches to 2 tests, take the echo and the urine panel: both are 12 month items from age 1, and both catch the 2 diseases here that shorten life rather than the one that mostly affects comfort. A cat with a clean heart and clean urine at 3 years is not a cat you can stop screening, because hypertrophic cardiomyopathy in this breed often appears between 4 and 7 years, and the kidney stays quiet until roughly 70 percent of function is gone. To see how the schedule shifts for related tail shapes and common breeds, compare the Japanese Bobtail screen and the American Shorthair screen, or run the breed quiz first if the cat's ancestry is a guess.
Terms mentioned in this article
Frequently asked
Can I skip the hip radiograph if the cat never limps?
No, and limping is the wrong trigger. Cats with hip dysplasia usually stop jumping onto high surfaces months before any visible lameness, and the 24 month film is the only way to see laxity while weight control can still change the outcome. Skip it and the first sign you notice is often a cat that cannot climb stairs at 6 or 7 years, when the options are narrower.
Does a negative PKD1 DNA test mean the kidneys are safe?
It rules out the inherited cyst gene behind most polycystic kidney disease, which is the main reason to run the test. It does not protect against chronic kidney disease from other causes, so the annual urine, specific gravity, SDMA and blood pressure checks from age 3 still matter. Keep the swab report with the medical record.
How often should an older bobtail see a vet?
From age 8, move to a 6 month visit rather than 12, with blood pressure, urine protein to creatinine ratio and a heart scan at each one. Cats hide both kidney and heart disease well, and a 6 month interval catches a trend while there is still something to slow down.