Tonkinese screening splits into 1 finding you check once at the kitten exam and 3 that need a calendar: a heart echo from 12 months, a dilated eye exam every 12 months, and a urine protein to creatinine ratio (UPC) from age 2. The inward turn of the eyes that the breed is known for is usually cosmetic and needs no treatment, but it must be told apart from a sudden squint, which is not. Budget 350 to 550 dollars in year 1 and 250 to 400 dollars a year after that.
The kitten exam: eyes, not just weight
At 8 to 12 weeks, 3 checks take 5 minutes. First, the eyes should turn inward, not outward: a kitten whose eyes drift outward needs a vision check, because divergent eyes are more often a sign of poor sight than of breed type. Second, the menace response, a hand moving toward the eye, should be present by 10 to 12 weeks. Third, a pupillary light reflex should be brisk in both eyes. Convergent strabismus present since 6 to 8 weeks, equal on both sides and not worsening is a note, not a diagnosis; surgery on the medial rectus after 6 months changes appearance, not vision. A squint that appears in an adult cat over 24 to 48 hours is a different problem and belongs in the hours table below.
HCM: the echo that sets the schedule
Hypertrophic cardiomyopathy (HCM) is the reason the calendar exists, and the numbers are the same ones used for other breeds with a heavy HCM history, set out in the Maine Coon heart screen: wall thickness under 5.0 mm is normal, 5.0 to 5.9 mm earns a recheck in 6 months, and 6.0 mm or more meets the usual definition. The left atrium to aorta ratio (LA/Ao) above 1.5 is the second flag, and above 1.7 the plan changes within the week. Echo at 12 months, then every 12 months through age 6, is what most cardiologists use for a breed without a validated DNA test; after 6 clean scans the interval can go to 24 months. The echo costs 220 to 450 dollars and takes 20 to 30 minutes. Ask for wall thickness, LA/Ao and the presence or absence of systolic anterior motion (SAM) on paper, and keep every report in 1 folder so the trend is readable.
The calendar by age
| Age | Echo | Eye exam | UPC | Interval (months) | Cost USD |
|---|---|---|---|---|---|
| 10 weeks | 0 | 1, kitten check | 0 | 6 | 90 |
| 12 months | 1 | 1 | 0 | 12 | 420 |
| 24 months | 1 | 1 | 1 | 12 | 420 |
| 3 to 6 years | 1 per year | 1 per year | 2 per year | 12 | 390 |
| 7 years and up | 1 per year | 1 per year | 2 per year, plus blood pressure | 12 | 460 |
The table assumes normal values at every step. Any abnormal number moves the next visit to 6 months, and a UPC above 0.4 moves it to 4 weeks, because 1 raised value after a car trip and 2 raised values 4 weeks apart are different findings.
PRA: the exam, and the 30 second dusk test
Progressive retinal atrophy (PRA) in this breed is a slow degeneration of the photoreceptors, and the useful screening tool is a dilated fundus exam, 2 to 5 minutes, 90 to 180 dollars. Ask for the tapetal reflex and retinal vessel calibre in writing, so next year's note is comparable. If the exam is equivocal, an electroretinogram (ERG) under sedation gives a functional answer in about 30 minutes for 250 to 450 dollars. Ask whether a DNA test is validated for this breed before paying: a test validated elsewhere answers a different question. Between visits, run the cotton ball test at dusk: drop it from 30 cm in a dim hallway and see whether the cat follows the fall. Repeat the eye exam every 12 months, and every 6 months once any change is recorded.
Amyloidosis: 2 urine tests and 1 blood pressure
Familial amyloidosis in this line deposits protein in the kidney and sometimes the liver, and the first measurable sign is protein in the urine. The UPC is the test: under 0.2 is normal, 0.2 to 0.4 is a grey zone rechecked after 4 weeks, and anything above 0.4 counts as proteinuria and needs a plan. Collect at home with non-absorbent beads, in a clean box, and deliver within 2 hours or refrigerate. Add SDMA, a chemistry panel and a systolic blood pressure, where 160 mmHg is the usual ceiling, at the same visit from age 2. An ultrasound showing small, irregular kidneys with a bright cortex supports the picture but does not diagnose alone, which is why numbers get repeated rather than guessed.
4 signals you can check at home
Sleeping respiratory rate: count chest movements for 30 seconds in deep sleep, twice a week, with 30 breaths per minute as the ceiling. Water: above 45 ml per kg per day, more than 225 ml for a 5 kg cat. Weight: log it monthly in a weight trend chart, since a 5 percent drop in 8 weeks is easy to miss on a fluffy cat. Eyes: photograph the face monthly in the same light, so a change in eye angle is a comparison, not a memory.
Call within these hours
| What you see | Call within | Why the clock matters |
|---|---|---|
| Open-mouth breathing at rest | 0 to 1 hour | fluid in the lungs or a failing heart |
| Back legs dragging, cold paw pads | 0 hours, emergency | a clot in the aorta |
| Sudden squint with head tilt or circling | 6 to 12 hours | vestibular or neurologic, not breed type |
| Straining in the box with no urine | 4 to 6 hours | blockage can kill within 24 to 48 hours |
| No food for 24 hours plus hiding | 24 hours | fatty liver risk after 48 to 72 hours |
What it costs, and what to skip
Year 1 runs 350 to 550 dollars: echo 220 to 450, eye exam 90 to 180, kitten visit 60 to 120. After that, 250 to 400 dollars a year, with the UPC at 35 to 70 dollars twice a year and blood pressure at 25 to 50. Skip 3 things: annual X-rays with no lameness, a DNA test validated only in another breed, and supplements sold for heart disease without an echo to measure against. Prescription heart drugs such as beta blockers, calcium channel blockers and diuretics are veterinarian decisions, by prescription only, and human medicines are a hazard, as the toxicity checker explains.
5 steps for this month
- Photograph the face straight on, then book the 12 month echo and eye exam in 1 visit.
- Start the sleep breathing log: 30 seconds, twice a week, ceiling 30.
- Weigh monthly and write it down, so a 5 percent drop has a reference.
- Ask for wall thickness, LA/Ao and the vessel description in writing.
- Switch 1 litter box to beads for a day, so the first UPC sample is easy.
None of this diagnoses anything. HCM needs an echo read by a vet, PRA needs a retinal exam, and amyloidosis needs repeated urine protein values. What the calendar delivers is a 12 month baseline while the cat still looks perfect, the only time a baseline is cheap.
Terms mentioned in this article
Frequently asked
Is the cross-eyed look in a Tonkinese a health problem?
Usually not. Convergent strabismus that is present by 6 to 8 weeks, equal on both sides and stable is a cosmetic trait that needs no treatment, and surgery on the medial rectus after 6 months changes appearance only. What does need attention is a squint that appears in an adult over 24 to 48 hours, especially with a head tilt, since that points at a vestibular or neurologic cause.
How often does the heart need scanning?
Once at 12 months, then every 12 months through age 6, then every 24 months if all 6 scans were clean. Each echo reports wall thickness, where 6.0 mm or more meets the usual definition of HCM, and the left atrium to aorta ratio, where 1.5 is normal and 1.7 means the plan changes that week. Add a sleeping respiratory rate log at home, with 30 breaths per minute as the ceiling.
What does the first year of screening cost?
About 350 to 550 dollars: an echo at 220 to 450 dollars, a dilated eye exam at 90 to 180 dollars, and a kitten visit at 60 to 120 dollars. From year 2 the yearly cycle runs 250 to 400 dollars, with the UPC at 35 to 70 dollars twice a year and blood pressure at 25 to 50 dollars. X-rays without lameness and supplements without an echo to compare are the 2 items to skip.