When to Spay or Neuter Your Lagotto

This essay exists because the science has moved — decisively, in a direction that matters for every Lagotto owner — and most veterinary practices have not yet caught up. In 2024 and 2025, three major publications from the world's leading veterinary institutions have reshaped how this question is approached. We believe our families deserve to make this decision with the best available evidence, not the guidelines written for shelter populations in 1990.

Here is what we know.

Why Timing Matters More Than Most Breeders Admit

The recommendation to neuter at six months was not based on a study of what is best for individual dogs. It was based on what was operationally manageable for population control — a way to ensure that dogs adopted from shelters would not produce more dogs. The recommendation migrated from shelter medicine into general practice and sat there, largely unchallenged, for three decades.

The biology tells a different story.

Testosterone and oestrogen are not merely reproductive hormones. They are architectural hormones — they govern the timing of growth plate closure in the long bones, regulate immune surveillance against certain cancer pathways, influence cognitive ageing, and shape the musculoskeletal proportions of the developing dog. When you remove the gonads before the body has finished using them, you do not simply switch off reproduction. You remove the biological signal that tells the skeleton when to stop growing.

There is also a second mechanism now under active investigation. After gonadectomy, luteinising hormone (LH) levels rise persistently to supra-physiological levels — often for the life of the animal. The WSAVA's landmark 2024 guidelines explicitly cite chronic LH elevation as a likely contributor to the increased cancer rates observed in neutered dogs, independent of the loss of sex hormones themselves. This mechanism was not well understood even five years ago.

The result of premature growth plate closure disruption is a dog whose bones have grown slightly too long relative to the joints they serve. The hip sockets, the elbow joints, the stifles — all calibrated by evolution for a particular bone length. A dog altered before that calibration is complete will carry those joints through a lifetime of activity that the joints were not built for.

The Evidence: What the Latest Studies Actually Show

Orthopaedic Health

The first major signal came in 2013. Drs. Benjamin and Lynette Hart at UC Davis published a study in PLOS ONE examining Golden Retrievers and found that dogs neutered before 12 months showed significantly elevated rates of hip dysplasia, elbow dysplasia, and cranial cruciate ligament (CCL) rupture — in some categories more than double the rate of intact animals.

That study was criticised for being breed-specific. Hart et al. spent the following decade answering it. In 2024, a comprehensive study covering 41 distinct breeds was published in Frontiers in Veterinary Science (DOI: 10.3389/fvets.2024.1322276). The findings were unambiguous:

The mechanism is well understood: sex hormones close the growth plates. When hormones are removed early, the long bones grow slightly beyond their calibrated length. The resulting geometry — longer femur and tibia relative to the hip socket and stifle joint — creates abnormal mechanical loading that, sustained over years of normal activity, produces the joint damage that shows up in X-rays at age four or five.

Cancer

A study of over 40,000 dogs (PLOS ONE, Hoffman et al. 2013) found that neutered males and females were significantly more likely to die of cancer than intact dogs. The relationship is not universal — some cancers are reduced by early sterilisation — but the cancers increased by early sterilisation are often the aggressive, late-presenting ones:

The Rottweiler data from Purdue University's Gerald R. Murray Cancer Center makes this vivid: female Rottweilers who retained their ovaries beyond six years of age were four times more likely to reach exceptional longevity (13+ years) compared to those spayed earlier. The longer the hormone exposure, the longer the life.

Urogenital Health — Where the Honest Tradeoffs Live

Pyometra is the legitimate counterargument to delayed spay in females. It is a life-threatening condition, it occurs in intact females, and it requires emergency surgery. The risk is real. It is also manageable: pyometra does not develop invisibly. The symptoms — excessive drinking, lethargy, vaginal discharge — are recognisable, and an engaged owner can act quickly. This risk must be weighed honestly against the irreversible orthopaedic damage of early spay — not dismissed, and not dramatised.

The Longevity Question

Population-level statistics show neutered dogs tend to live longer than intact dogs. This is true but deeply confounded. Intact males roam, get hit by cars, and engage in fights. Intact females develop pyometra. In managed, responsible households, those variables are controlled. The relevant question is: for a dog in a responsible home, does the timing of sterilisation affect lifespan? The Rottweiler data — and the 2024–2025 WSAVA guidelines — say yes, and strongly in favour of later sterilisation.

Breed-Specific Insights for the Lagotto Romagnolo

The Lagotto Romagnolo weighs 24–35 lbs at maturity. An important nuance worth stating honestly: some evidence suggests that dogs under 20 kg may not show the same elevated orthopaedic risk from early neutering as larger breeds. Female Lagottos — typically 24–28 lbs — fall at or near this threshold.

We acknowledge this because credibility matters. However, three factors lead us to maintain our 18–24 month recommendation regardless:

1. The orthopaedic data for sub-20 kg dogs is less studied, not absent. Absence of evidence is not evidence of safety — particularly for a working breed with active joint demands.
2. The cancer and immune function data is not weight-stratified in the same way. Hormone-related cancer risk does not follow the same size threshold as orthopaedic risk.
3. We err on the side of full skeletal maturity. Waiting costs nothing. Proceeding early, if it causes harm, is irreversible.

Hip dysplasia is a documented concern for this breed. It is one of the primary reasons breed clubs mandate OFA certification before breeding. We certify every dog in our programme. Anything that elevates hip dysplasia risk — including early sterilisation — is an active concern, not an abstract one.

The Lagotto is a working sporting dog. These dogs should be able to work, hike, and move freely well into middle age. Joint integrity is not a cosmetic consideration for the breed — it is functional.

The Lagotto is a breed with known neurological sensitivity. While this is primarily related to a specific genetic condition (benign familial juvenile epilepsy, discussed in our genetics essay), it underscores the importance of cautious, evidence-based health management across all dimensions, including hormonal development.

Our position: treat the Lagotto as you would a comparable working medium breed. Apply the Hart et al. medium-breed guidelines and the 2024–2025 WSAVA guidance. Wait.

Male vs Female: A Side-by-Side Timing Comparison

Practical Recommendations for Responsible Owners

1. Wait until 18 months at minimum. This is our contract requirement and our recommendation. Eighteen months is when growth plates are reliably closed in medium-breed dogs. Before this point, the orthopaedic risk of sterilisation is not theoretical — it is documented in the data.
2. Aim for 24 months if circumstances allow. The additional six months allows fuller hormonal development, better muscle mass development, and the opportunity to complete OFA certifications concurrently with the sterilisation procedure.
3. Combine OFA radiographs with the neuter or spay. Your dog requires general anaesthesia for both. The OFA X-rays add minimal time and cost to an existing procedure. This is the single most efficient health decision you can make as a Lagotto owner.
4. Learn to manage intact dogs. This is straightforward with basic knowledge. For females in heat: secure fencing, no off-leash time in areas with intact males. For intact males: recall training, consistent leash management. We are happy to walk any of our families through this.
5. Discuss the research with your vet. You are not asking your vet to accept your word. You are presenting published, peer-reviewed research from UC Davis and guidelines from the WSAVA and AAHA — the two largest veterinary professional bodies in the world. A vet who dismisses this evidence without engaging with it is telling you something important.
6. Monitor your intact female carefully. Pyometra is the legitimate risk of extended intact status. Know the signs: excessive drinking and urination, lethargy, abdominal distension, vaginal discharge. Any of these warrant same-day veterinary contact. Caught early, pyometra is treatable. The risk is real; the management is not complicated.

Alternatives to Traditional Spay and Neuter

The binary of "early spay/neuter" versus "leave intact forever" is a false one. The 2024 WSAVA guidelines explicitly discuss these alternatives and recommend they be considered on a case-by-case basis.

Our families most commonly proceed with delayed traditional spay/neuter at 18–24 months. A small number have opted for vasectomy or OSS. We support any of these approaches and are happy to discuss what fits your household.