Royal Canin U. S. A. v. Wullschleger
The Supreme Court ruled unanimously that a plaintiff who rewrites her complaint to remove all federal claims after her case was transferred to federal court is entitled to have the lawsuit sent back to state court.
The decision resolves a split among federal appeals courts and establishes that federal courts must assess their authority based on the current complaint — not the one that existed when the case first arrived — and that this rule applies equally whether the case originated in federal court or was moved there from state court.
“Once the plaintiff has ditched all claims involving federal questions, the leftover state claims are supplemental to nothing—and §1367(a) does not authorize a federal court to resolve them.”
The Court's plain-English statement of why supplemental jurisdiction evaporates when all federal claims are removed from the complaint.
How it got here: Wullschleger sued in Missouri state court; Royal Canin removed the case to federal court; after she amended to delete all federal claims, the district court denied her remand request; the Eighth Circuit reversed; the Supreme Court took the case to resolve a split among the federal appeals courts.
The Case in Depth
What happened
A Missouri woman sued a premium pet food company, alleging it falsely marketed prescription-only dog food as if the prescription requirement reflected a medical necessity, when in fact the food contained no special medication and the prescription was used only to charge higher prices. Her original complaint included both Missouri consumer-protection and antitrust claims and a claim under a federal food-safety law. The company used the federal claim to transfer the case to federal court. She then rewrote her complaint to delete every reference to federal law, keeping only state claims, and asked the court to send the case back to Missouri.
The question before the Court
After a defendant moves a lawsuit from state to federal court, can the plaintiff force the case back to state court by rewriting the complaint to remove all federal legal claims?
The Court's answer
Yes — when a plaintiff amends her complaint after a case has been moved to federal court, and that amendment removes every federal claim, the federal court loses its authority over the case and must send it back to state court.
The central statute is 28 U.S.C. § 1367, which allows federal courts to hear state-law claims that are closely related to a federal claim already properly before the court — a power called "supplemental jurisdiction." That power is derivative: it requires an active federal claim as its anchor. Once the plaintiff deletes all federal claims through an amendment, the state claims become supplemental to nothing, and § 1367 no longer authorizes the federal court to hear them. The Court also rejected the dog food company's argument that two earlier Supreme Court decisions had established an exception for cases removed from state court, finding that both relied-on passages were non-binding side comments that could not override the statute's plain text or the Court's own core rule that jurisdiction follows the current, operative complaint.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Plaintiffs who prefer state court can now reliably secure a return there by dropping federal claims from an amended complaint after removal. Defendants who use a federal legal claim as a hook to move cases out of state court lose that advantage if the plaintiff simply amends those claims away. Lower courts that had relied on a contrary rule drawn from a Supreme Court footnote must now apply this clearer, uniform standard.
What changes now
The pet food lawsuit returns to Missouri state court, where Wullschleger will litigate her state consumer-protection and antitrust claims against Royal Canin. Nationwide, the decision settles the law for federal courts that had been following the now-repudiated Rockwell footnote: once a plaintiff amends away all federal claims after removal, remand to state court is mandatory, not discretionary. The decision is final on this jurisdictional question; the underlying merits of the dog food marketing dispute remain to be decided.
What this does not decide
The ruling does not decide whether Royal Canin's marketing of prescription dog food was actually deceptive — that merits question goes back to state court. The Court also left open what happens in a removed diversity case (based on parties from different states) when a plaintiff amends to add a non-diverse party, rather than to remove federal claims.
How the Court got there
The legal reasoning, step by step
- The Court began with the text of 28 U.S.C. § 1367(a), which grants federal courts supplemental jurisdiction — the power to hear state-law claims closely related to a federal claim already in the case. The statute's language requires the case to be one 'of which the district courts have original jurisdiction,' meaning an active federal anchor. The Court read this to mean supplemental jurisdiction disappears the moment no federal claim remains.
- A critical textual clue came from § 1367(c), which lists three situations where federal courts may decline to exercise supplemental jurisdiction even when they have it — for instance, when all federal claims have been dismissed. The Court reasoned that if § 1367(a) still granted supplemental jurisdiction after a plaintiff voluntarily deleted all federal claims, those leftover state claims would obviously belong on § 1367(c)'s list of candidates for remand. Because they aren't there, § 1367(a) simply doesn't cover them at all.
- The Court invoked its prior ruling in Rockwell Int'l Corp. v. United States (2007), which held that in cases originally filed in federal court, courts 'look to the amended complaint to determine jurisdiction' — meaning an amendment stripping all federal claims defeats the court's power. Because § 1367(a) draws no distinction between cases filed originally in federal court and cases removed there, the Rockwell rule applies equally to both. Since Royal Canin conceded Rockwell controlled for original cases, § 1367(a) had to reach the same result here.
- The Court also identified a broader statutory pattern: Congress regularly treats amendments as capable of wiping the jurisdictional slate clean and requiring fresh analysis. Multiple federal statutes allow an amendment to bring a case newly within or newly outside federal jurisdiction. Under that framework, § 1367 was read to require a fresh jurisdictional look whenever an amended complaint is filed — and if the amended complaint contains no federal claims, the court lacks any basis to retain the case.
- Royal Canin pointed to a passage in Carnegie-Mellon Univ. v. Cohill (1988) and a two-sentence footnote in Rockwell that appeared to say the opposite — that amendments in removed cases generally do not defeat jurisdiction. The Court called both passages non-binding side comments (technically 'dictum'): Cohill was about a different question entirely (whether to dismiss or remand, not whether to keep the case), and the Rockwell footnote was an unexplained, off-topic observation written in a case that had nothing to do with removed suits. 'Drive-by jurisdictional rulings' without analysis carry no precedential weight and cannot override the statutory text or Rockwell's own core insight.
Doctrinal impact
Cases affected by this decision
Reaffirms Rockwell Int'l Corp. v. United States (549 U.S. 457)
Its core rule — courts look to the amended complaint to decide jurisdiction — is reaffirmed and extended to removed cases; its contrary footnote 6 is stripped of any precedential weight.
Distinguishes Carnegie-Mellon Univ. v. Cohill (484 U.S. 343)
Cohill asked only whether to dismiss or remand, not whether to keep the case; its passing suggestion that retention was possible is dismissed as non-binding dictum.