PawExact

Evidence maintenance guide

How cat litter formula changes affect compatibility evidence

A renamed bag, weight variant, grain size, or ingredient change can break the link between an older report and the product on sale now.

Decision rail

Four checks, in order

Passing one check does not override a failure or unknown in the next. This is a compatibility decision, not a popularity ranking.

  1. 01Name

    Capture the complete package

    Brand and family are insufficient; preserve formula, scent, weight, grain, and package version.

  2. 02Source

    Recheck current specifications

    Compare present official material and behavior fields with the dated record.

  3. 03Transfer

    Stop at any unresolved mismatch

    An older report cannot cross an unverified formula, grain, or weight change.

  4. 04History

    Keep older evidence visible but dated

    Historical records can explain a change without being presented as current-formula proof.

Evidence transfer ledger

How far this evidence can travel

A report stays attached to the identity and conditions it actually names. Each unresolved mismatch stops transfer; similarity alone does not fill the missing field.

Commercial name

Capture brand, family, and full formula

Can support
A match to the named evidence entity when all identifying words agree.
Stop transfer when
Only the brand or a shortened family name can be confirmed.
Variant attributes

Preserve scent, weight, grain, and package size cues

Can support
Transfer between packages only when the attributes that distinguish catalog SKUs still match.
Stop transfer when
Standard and lightweight, ordinary and large grain, or differently scented variants are conflated.
Material and behavior

Recheck material, clumping, and particle form

Can support
Continued use of an older record when key specifications remain aligned.
Stop transfer when
A current official source changes or omits a property that controlled the original compatibility reason.
Time anchor

Save source date and package evidence

Can support
A historical result for the formula verifiably sold during the report period.
Stop transfer when
The transition date between old and new packaging or formula cannot be established.
Evidence state

Downgrade unresolved matches to Unknown or Estimated

Can support
Transparent retention of the older record without presenting it as current proof.
Stop transfer when
Visual similarity or a retailer-merged listing is used to bridge an unresolved formula change.

Published boundary

What Litter-Robot actually says

These statements describe classes and limits. They are not PawExact tests and do not automatically approve every product using the same marketing term.

OfficialLitter-Robot 4
“We recommend a high-quality, standard-weight, clay-based clumping litter”
Official source
OfficialLitter-Robot 4
“Alternative, plant-based litters typically do not work with Litter-Robot as these may not be filtered properly through the sifting system.”
Official source

Exact-product records

Products that show why the class label is not enough

These records show common transfer traps: same-family weight variants, separate Boxie formulas, and grain-specific World’s Best outcomes.

Single report1 public report

Free & Clean Unscented Clumping

Purina Tidy Cats

Material
Clay
Clumping
Clumping
Weight
Standard

The accepted standard-weight report cannot transfer to Free & Clean Lightweight.

Likely compatible

Read exact record
EstimatedClass rule only

Free & Clean Lightweight Unscented

Purina Tidy Cats

Material
Clay
Clumping
Clumping
Weight
Lightweight

Compatible with conditions

Read exact record
Single report2 public reports

BoxiePro Deep Clean Probiotic

Boxiecat

Material
Clay
Clumping
Clumping
Weight
Standard

Not recommended

Read exact record
Single report1 public report

BoxiePro Bot Clumping Clay

Boxiecat

Material
Clay
Clumping
Clumping
Weight
Standard

Bot and Deep Clean Probiotic are separate formulas with separate reports.

Not recommended

Read exact record
Single report1 public report

Low Tracking & Dust Control

World's Best Cat Litter

Material
Corn
Clumping
Clumping
Weight
Lightweight

The large-granule formula has a different screening signal from Multiple Cat Unscented.

Not recommended

Read exact record

Before a larger purchase

A small, observable first-use check

This is not a controlled test protocol. It is a way to notice an obvious mismatch before treating one successful cycle as proof.

  1. Check 1Photograph front, variant name, weight claim, and ingredient or material panel.
  2. Check 2Save the current official product URL and verification date.
  3. Check 3Compare exact names and key specifications with the evidence record.
  4. Check 4Downgrade to unknown or Estimated when the current formula cannot be confirmed.

Known limits

What the current evidence cannot prove

  • Packaging changes do not always reveal whether the formula changed.
  • Retailer listings can lag behind current manufacturer pages or combine variants.
  • Without dated package evidence, PawExact cannot identify when a report stopped transferring.

Evidence readiness

What this guide can support today

This checkpoint separates a useful answer from claims the current official rules and exact records still cannot support. It is an editorial evidence review, not a PawExact test.

Question scope
This guide answers when an older compatibility record stops transferring to a current bag. It does not claim that every packaging change means the formula changed.
Direct official boundary
Current manufacturer specifications remain the reference for material and behavior. A shared brand or family name cannot bridge a changed weight, grain, scent, formula, or unresolved current specification.
Exact-product evidence
The current examples document standard-versus-lightweight, separate Boxie formulas, and grain-specific World’s Best records. They demonstrate transfer traps, not confirmed reformulation timelines.
Remaining gap
Packaging transitions and effective dates are often unavailable, and retailer listings may merge variants. Without dated package evidence, the exact point when an older report stops transferring remains unknown.

Intent boundary

Keep the next question narrower

Use this page when the historical report and today's bag may not be the same formula. It determines whether evidence can transfer; the switch checklist instead records what happens after a confirmed product change.