Dachshund spinal health (IVDD) by coat and size type

A 2026 paper in the Journal of Veterinary Internal Medicine looked at 4,295 Dachshunds from the UK, Norway, and Denmark to ask a practical question many breeders and owners care about:

Does spinal health risk differ by coat type (smooth/long/wire) and by size (standard vs small)?

The headline finding: smooth coats had worse spinal health metrics

Across all three countries, smooth-coated Dachshunds were consistently associated with worse spinal health metrics compared with long- and wire-coated dogs.

The authors used different measures depending on the country:

• UK: owner-reported signs of disc disease in dogs ≥10 years old. (source: DachsLife 2021 survey)

• Norway & Denmark: radiographic disc calcification number (KN) recorded at ages 2–4 (higher KN groups correlate with higher IVDD risk).

Even with those different measures, the overall pattern was the same: smooth > long/wire for risk.

Small (miniature) smooth Dachshunds stood out as the highest-risk variety

When the researchers compared coat-and-size combinations (long/small, long/standard, wire/small, wire/standard, smooth/small, smooth/standard), one group repeatedly came out worst:

small smooth Dachshunds.

In 12 of 15 comparisons, small (miniature) smooth dogs had worse spinal health metrics than the other size–coat combinations. In some comparisons, the difference was several-fold.

Size mattered… but not reliably

If you’ve heard “miniatures are always worse,” this study suggests it’s more complicated.

Within a given coat type, small size was only inconsistently associated with worse spinal health. In some coat types and countries it showed up; in others it did not—suggesting that “small” is genetically complex and may be produced by different gene combinations that don’t all carry the same disc risk.

Why might coat type matter? The study’s genetic hypothesis (in plain English)

The paper discusses plausible biological mechanisms:

• Dachshund coat type is largely driven by two genes: FGF5 (hair length) and RSPO2 (wire “furnishings”).

• RSPO2 is linked to WNT/β-catenin signaling, a pathway involved in intervertebral disc development and health.

The authors propose a model (simplified):

• Smooth (functional FGF5, no RSPO2): potentially detrimental

• Long (no functional FGF5): potentially protective

• Wire (RSPO2 present; also functional FGF5): RSPO2 may be very protective and could offset risk

They also discuss FGF4L2 (CDDY), a known genetic risk factor for disc disease, but note that current public database summaries don’t clearly support coat-type differences in FGF4L2 frequency as the full explanation.

Practical advice for breeders (risk reduction without over-simplifying)

This paper reinforces an important point: IVDD risk appears to be polygenic (many genes + combinations), so “one test” or “one rule” is unlikely to solve it.

Here are actionable takeaways that fit the evidence:

1. Treat smooth coat, especially small smooth, as a higher-risk grouping. This doesn’t mean “don’t breed or buy smooths,” but it does mean risk management should be more deliberate.

2. Use objective spinal health screening where available. The study highlights KN scoring (radiographs at 2–4 years) as a meaningful metric tied to IVDD risk and, where possible, incorporate it into breeding decisions.

3. Avoid overly narrow selection based on a single gene. The authors caution that excluding dogs solely based on one genetic factor (such as CDDY) could reduce valuable diversity and potentially cause more harm than good.

4. Track outcomes by variety in your own breeding programme. Because countries differ and breeding restrictions differ, local populations may not match the exact odds ratios reported in this study. Keep records of:

   • coat/size

   • KN results (if available)

   • clinical IVDD events and ages

   • lines with repeated early cases

5. Talk to your breed club about research-aligned next steps. The authors recommend future work that could directly help breeders, including:

   • CDDY (FGF4L2) allele frequency by coat/size

   • which small-size gene combinations are most common in Dachshunds

   • mechanisms by which RSPO2 and FGF5 influence disc health

Practical advice for owners (what you can do day-to-day)

Coat type doesn’t doom a dog, but it can help you calibrate prevention.

• Assume IVDD risk is real in all Dachshunds, and be extra proactive with smooth coats, especially miniature smooths.

• Keep your Dachshund lean. Excess weight increases load on the spine.

• Limit high-impact jumping and repetitive stairs. Use ramps/steps and train consistent use.

• Build safe muscle. Regular, controlled exercise (walking, appropriate conditioning) supports overall function.

• Know early warning signs (pain, reluctance to move, hunched posture, weakness, wobbliness) and seek veterinary care quickly, early intervention matters.

Conclusions

This study adds strong, multi-country support for a pattern many have suspected: coat type, especially smooth, tracks with spinal health risk in Dachshunds, and the miniature smooth variety appears at the highest risk.

For breeders, the best response is not panic or blanket exclusion, it’s measured, data-driven risk reduction using available screening tools, careful record-keeping, and selection that respects both health and genetic diversity.

Source: Hopper M, Liu C-C, Embersics C, Otamendi A, Sullivan S. “Dachshund spinal health by coat and size type.” Journal of Veterinary Internal Medicine (2026).