How the Miwuki Report on Pet Adoption in Spain is produced

The report describes the adoption activity recorded on Miwuki in Spain: the animals listed, the interest they receive, and the adoptions and returns that are recorded.

It is not a statistic of every animal abandoned or adopted in Spain. It does not include organisations or families that do not use Miwuki. Nor can it be used to calculate national shares or to rank provinces or organisations as “better” or “worse”.

From the Miwuki platform database, extracted on 22 October 2026 (cut-off date). Contact details and credentials are removed before the analysis. Only aggregated results are published, never individual records.

• Case listed: the profile of an animal listed for adoption, with country Spain. It may be listed by a shelter or another organisation (association, rescuer, feral cat colony, public administration) or by a private individual.
• Recorded adoption: the adoption recorded by the publisher, with its adoption date. A case may have more than one if the animal is adopted more than once. If the same adoption is recorded several times on the same day, it counts once (unless different adopters are recorded).
• Adoption request: a person's request to adopt a specific animal. Several messages from the same person about the same animal on the same day count as one request; one person may ask for several animals.
• Person sending requests: each distinct person who sends at least one request in the period. These cannot be added up across periods.
• Recorded return: the record that an adopted animal has gone back to whoever listed it, with its date. Repeats on the same day count once.

The full definitions of each indicator (formula, unit, period and limitations) are in the indicator dictionary at the end of this page.

• Reasons given by private individuals. When listing, the private individual chooses a reason from a list (since December 2018) and, since June 2023, explains it in their own words. Texts are classified into topics with a word dictionary, on our own systems; one reason may cover several topics. To check it, we reviewed several hundred randomly chosen reasons one by one and blind, with names and contact details hidden. In the last control sample, which was not used to tune the dictionary, more than nine in ten detected topics were correct and about four in five of the topics present were detected; some, such as lack of space or litters, are detected less well. Texts are never published.
• Age in years. Calculated from the date of birth in the profile, which is often estimated.
• Breed and PPP dogs. Breed has been mandatory since June 2023. We group breeds into mixed breeds, PPP breeds, hunting breeds (greyhounds, podencos, scent hounds and pointing dogs) and others. The potentially dangerous dog flag is set by the publisher.
• Health, temperament and identification. The profile records flags such as microchip, sterilisation, vaccination, deworming, leishmaniasis, feline immunodeficiency or leukaemia, medical treatment, shyness or independence, and whether the animal gets on with children or cats. Miwuki has confirmed the meaning of each flag, which we also checked against the animal's description. We only use flags with a clear relationship.
• Who sends requests. Age and province from the profile of the people who send requests. It does not describe adopters.
• “Perfect pet”. A voluntary form, available since June 2019, in which people who want to adopt describe what they are looking for. Only those who fill it in answer. We publish its questions with fixed options: home, hours the animal would be alone, budget, children and other animals at home, moving house, work, lifestyle, walks, first dog or cat and preferred size.
• Days to adoption. Median days between listing and the first recorded adoption, among shelter cases adopted within 180 days.
• Cases without requests. Cases that received no request through Miwuki in their first 90 days. Organisations also receive interest through other channels.
• Calendar. Summer means July and August, and Christmas the period from 15 December to 6 January, which we compare with the three weeks before and after. We always compare daily averages.

• Cases are counted by the date they were created on the platform; adoptions by their adoption date; requests by the date they were sent; returns by their return date.
• Period: case series start on 12 February 2017, the day Miwuki officially opened to the public. Cases listed earlier, during the test phase that began in November 2016, are not included. Adoptions are counted by their date, and all of them come after the launch. The last year ends on the cut-off date and is not compared with complete years; neither is 2017, which starts in February.
• Status at the cut-off date: when we say a case “appears as adopted”, we mean its status on the cut-off date. More recent cases have had less time and are not compared with older ones.
• Requests: dated data are only available from 14 June 2023.
• One report per year. In addition to the 2025 edition, there is a report for every year since 2017, produced in 2026 with the same data cut-off. Each one only includes the data that the platform recorded that year and explains what changed.

The platform has changed over the years, and some changes affect the figures. In December 2018 private individuals arrived and the profile was extended with temperament, compatibility, vaccination and deworming; in June 2023, the new platform added the reason written by private individuals, mandatory breed, the health record book and dated requests. We list them on the timeline and mark them on the charts. For example, since June 2023 the size of dogs has been derived from their breed or from the mixed-breed category by weight. That is why we do not compare size before and after that date, and we do not analyse it for cats.

Before each version we check, table by table and month by month, that records have a valid date before the cut-off, that there are no duplicates, that codes (species, age, province, status) are in their catalogues, that each adoption, return or request belongs to an existing case, that the publisher of each case can be identified and that there are no days with abnormal data loads. This review is internal and is not published record by record.

What we have found and how we handle it:

• Records repeated on the same day. Sometimes the same adoption or the same request is recorded several times within a few seconds, because the form was submitted more than once. They count once.
• Data that used to be recorded poorly. Returns have been recorded regularly since June 2023, and requests have reliable dates from 14 June 2023. Each series starts when its data are reliable.
• Fields that depend on the publisher. Age is a stated estimate and is sometimes unknown; the hard-to-place flag is voluntary; private individuals record few adoptions, so time to adoption is measured only for shelters.
• Fields under review. Origin is filled in for every case and may be a default value: we will not publish it until this has been checked.

If a review finds an error that affects figures already published, it is corrected in a new version with its note.

• We do not publish names, contact details, addresses, identity documents, dates of birth, microchips or any identifier of people, animals or organisations.
• We publish all aggregated figures, including those for small groups. They are counts of cases or people, with no data that could identify anyone.
• Percentages and medians based on fewer than thirty cases carry a “small base” warning: they are unreliable and we do not use them in findings or comparisons.

• Whether an adoption took place through Miwuki or outside the platform: the study does not make that distinction.
• The origin of shelter animals before 2019: almost all cases have the same one, so the series starts that year.
• Adoption of the animals listed by private owners: most of them do not record it on Miwuki, so adoption rates and days to adoption are only given for shelters.
• Illnesses of a cat already living with the person who wants to adopt (“Perfect pet” form): the question has no fixed options.
• How long an animal spends at the shelter before being listed: there is no reliable intake date.

Every release carries a data version. Annual editions are frozen: if something needs correcting, we publish a new version, explain what changes and keep the previous one so that citations remain verifiable.

Always state the period, the metric, the version and the cut-off date; the format is given in each edition's summary. The published figures, reports and infographics are licensed under CC BY 4.0 (Creative Commons Attribution): you may reuse them for any purpose, including commercial use, crediting the source, the data version and the cut-off date. The Miwuki logo and the illustrations are not covered by the licence.