Bilateral Exclusion Pet Insurance: The Second Knee

Twelve words carry the whole thing: "even if the opposite side had no clinical signs of being affected or involved."

They close exclusion E on Nationwide's My Pet Protection Plus coverage form, VS-G-16(6-24), read 22 August 2026. In full:

Any veterinary services or veterinary expenses related to a bilateral condition that is found to be a pre-existing condition, any veterinary services or veterinary expenses related to the opposite side shall be excluded, even if the opposite side had no clinical signs of being affected or involved. For example, if cruciate ligament disease affecting or involving the left hind leg was present prior to the policy effective date, we will not pay for any veterinary services or veterinary expenses related to cruciate ligament disease in either the left or the right hind leg. This exclusion for bilateral conditions supersedes all Optional Coverages to this policy.

Credit to the drafters for the worked example; most carriers make you assemble that inference yourself out of two definitions three pages apart. And read the last sentence, because it catches people who bought protection specifically for this: Nationwide sells an optional Cruciate coverage, available only "for enrollment 12 months after the initial policy inception date," and the bilateral exclusion overrides it.

Whether the trouble in the second knee is the same condition as the first is a veterinary question and belongs to the veterinarian who examined the animal. Everything below is about the document.

The numbers the underwriter is looking at

A retrospective study of 511 dogs treated for cruciate rupture at the Royal Veterinary College's Queen Mother Hospital for Animals between March 1998 and March 2007, published in VCOT in 2011 (PMID 21327290), found bilateral cranial cruciate ligament rupture in 38.7% of them — 198 of 511 — with a mean of 57.9 weeks between the first side and the second, and a range from 3 weeks to 260. A later cross-sectional study of 831 dogs that were at least 8 years old and at least 15 kg at first rupture, published in VCOT in 2024 (PMID 37487534), put the contralateral rate at 19.1%, a median of 12.9 months afterwards.

Fifty-seven point nine weeks is just over thirteen months. That is not an actuarial curiosity, it is the shape of the whole problem: the second knee usually turns up in the second policy year, long after anyone is still thinking about what the enrolment-era medical records said.

What it costs when it turns up is a separate figure. Veterinary Surgical Solutions in Austin, Texas publishes a surgery price sheet with low and high estimate columns. Read 22 August 2026: TPLO is $3,000 to $3,155 for a dog under 60 lb and $3,785 to $4,079 for one over 130 lb, each row annotated "Includes radiographs, epidural and 6 rehabilitation sessions," with lateral suture at $1,714 to $1,808. One clinic, one metro, and the page calls these "general estimates only." Use it for scale: a denied second knee is that whole number, arriving a second time.

Four carriers, four widths, and a clause that avoids the word

These clauses are not variations on a theme. They are different mechanisms with different reach.

Four forms, chosen for one reason: each publishes its complete policy wording as a public PDF that can be downloaded and quoted line by line. Several of the largest carriers do not, so read what follows as four contracts read in full on 22 August 2026, not as a survey of the market. Where a carrier is absent below it is because its contract wording could not be retrieved, and nothing should be inferred either way about what its clause says.

Nationwide's is the widest by category. Paired organ system, with kidneys named. Set it beside the same form's definition H — "Cranial cruciate ligament disease is a progressive, degenerative, bilateral condition causing rear limb lameness, pain, or joint effusion in the knee(s)" — and the contract has already settled that a cruciate problem is bilateral by nature, before any particular dog walks in.

The AKC Pet Insurance Oregon form, underwritten by Independence American, is tighter in structure but its examples travel further. Cruciate ligament, cherry eye, and lameness. Lameness is a sign, not a condition, and it is the word most likely to be sitting in a general practice note from four years back. Bound that one carefully, though. Its number ends 1120 and the others here end 1024, 0724 and 6-24, so the convention is month and year: this document dates to November 2020, and it is an Oregon form. Five years older than everything else in the table, and good for one state.

Spot's Illinois accident-and-illness form, on the insurer's sample policy page, splits the job so that neither half looks like much. The definitions page carries a bland one-liner, "Bilateral Condition: A condition that affects both sides of the body," and then ten entries later does the actual work under a heading nobody would think to search: "Ligament and Knee Conditions: Conditions involving a ligament, patella, meniscus or soft tissue disorder of the knee. These are considered bilateral conditions and related, regardless of cause; meaning an occurrence on one side of the body affects both sides of the body." The exclusion that picks that first term up, on the page the form numbers 5 of 8, is five words long. "Bilateral conditions of pre-existing conditions." Twelve letters further down the same list, exclusion (o) does the same job without needing any of it: "Ligament and knee conditions, if any ligament and knee condition occurred prior to the first effective date of the applicable coverage or during a waiting period."

Figo keeps that second mechanism and throws the first one away. Its Washington policy defines Bilateral Condition at item 6 and Ligament and Knee Conditions at item 24. The phrase "Bilateral Condition" then appears nowhere else in the document — not in the conditions, not in the exclusions, not once. What denies the second knee is exclusion 4, and the word bilateral is not in it: "Veterinary Expenses or Treatment for any ligament and knee condition, if any ligament and knee condition occurred at any time prior to the Pet's Original Start Date or prior to the end of any applicable Waiting Period."

Read it twice. It is not side-to-side, it is condition-to-condition. A luxating patella noted at a puppy exam is a ligament and knee condition, and the clause then excludes any ligament and knee condition after it, in either leg. Searching your PDF for "bilateral" sails straight past it, and past Spot's (o) as well. Two of these four forms can deny a second knee through a sentence the word does not appear in.

The direction of travel is not all one way. Because Spot and Figo declare the two knees to be one condition "regardless of cause," a second rupture on a policy where the first was covered is the same occurrence rather than a new one, and that cuts in two directions at once. A deductible or copay charged per condition is met once instead of twice. A payout cap charged per condition or per incident is shared across both surgeries instead of resetting for the second — Figo's form defines a Covered Incident Limit as "the maximum amount We will reimburse You per Covered Incident," sitting alongside a separate annual deductible. Which of those two you get is on your declarations page, not in the definitions.

Eleven defined terms, and this is not one of them

I searched the full text of the NAIC Pet Insurance Model Act (#633), Summer 2022 edition, on 22 August 2026. The word "bilateral" is not in it.

That absence does work, because of what the preamble to Section 3 does: "If a pet insurer uses any of the terms in this Act in a policy of pet insurance, the pet insurer shall use the definition of each of those terms as set forth herein and include the definition of the term(s) in the policy." Eleven terms are standardised that way, one of them "Orthopedic," which the act defines to include "ruptured cranial cruciate ligaments." So the model reaches all the way to the knee and then stops one step short of the clause that empties it. The same section says out loud that nothing in the act "shall in any way prohibit or limit the types of exclusions pet insurers may use in their policies."

Disclosure has the same edge. Section 4(A)(1) requires an insurer to disclose that a policy excludes pre-existing conditions, hereditary disorders, congenital anomalies or disorders, and chronic conditions. Everything else is handled by 4(A)(2), one sentence: "Other exclusions may apply. Please refer to the exclusions section of the policy for more information." Washington enacted that structure at RCW 48.205.040, effective 1 January 2024, and reproduced that fallback sentence word for word at (1)(b).

One filed document shows the result cleanly. The Washington Insurer Disclosure of Important Pet Insurance Policy Provisions that Independence American files for Figo, form IAIC FPI ML NOTICE 0124 WA, lists ten policy definitions and three named exclusions. Bilateral Condition is not among the definitions. Ligament and Knee Conditions is not among the definitions. Exclusion 4 is not among the three named exclusions. The form is complete and compliant, and someone who read only that form before buying would have no way to know the knee rule exists. That is not an insurer misbehaving. It is the disclosure list doing precisely what it says.

Which of these rules binds your policy is a state question — the model act is a model, not a law, and states adopt it in pieces or not at all. Your state insurance department's site will say whether a pet insurance chapter was enacted and what went into it.

Five searches that find the clause in your own PDF

Open the policy document, not the plan summary, and run these in order. Two minutes, and an inference becomes an answer.

1. bilateral — may return nothing at all in the operative sections, as with the Figo form. Nothing found is not an answer.
2. knee and ligament — this is what catches the clauses that avoid the first word, and two of the four forms above hang the denial here rather than on "bilateral." Watch for a defined term headed something like "Ligament and Knee Conditions," then check whether an exclusion repeats the phrase in lower case.
3. opposite and both sides — these catch the operative sentence when the definition itself is bland and elsewhere.
4. paired — catches the organ-system wording, which is what stretches the rule to eyes, ears and kidneys.
5. cured — find the cured-condition paragraph and read its carve-out list. Whether knees sit inside or outside that list decides whether the exclusion can ever expire.

Then check one date. If your form carries a pre-existing waiting period, as the AKC Oregon form's 365 days does, the bilateral exclusion inherits that clock. If your form says knee conditions are "not considered curable," as Figo's Washington form does, it does not. Those two forms read almost identically on the definitions page and behave in opposite directions in year three.

If a denial has already landed, the clause number quoted in the letter is the first thing to check against the policy you were actually issued — same form number, same state of delivery — and the rest of that process is in reading the denial letter and writing the appeal. Almost every one of these denials runs through the pre-existing definition rather than around it, so what an old chart note does governs the outcome as much as the bilateral wording. And if the animal is a breed whose orthopedic risk was the reason you insured in the first place, the multi-year arithmetic changes once you assume one side may be uninsurable, which is the same pressure that bends the ten-year hip dysplasia curve.

What to have in front of you before arguing with anyone

Five documents and two clause references. Assemble them first; the argument mostly writes itself.

• The full policy form for your state, with the form number visible. Not the benefits summary. Strings like PET-P-20000-IL-1024 or VS-G-16(6-24) confirm you are reading the contract you actually bought.
• Your state's Insurer Disclosure of Important Pet Insurance Policy Provisions, where the state requires one. Ask for it by that name; it is a filed form, not a brochure.
• The definition of "Bilateral Condition" and of any knee- or ligament-specific defined term, quoted with page numbers.
• The exclusion the denial actually relies on, by letter or number, together with the cured-condition or pre-existing waiting-period paragraph sitting near it.
• Complete medical records for the years before enrolment — exam notes and results, not invoices. The record entry naming the first side is the only evidence the exclusion runs on, and building the claim packet around that is what stops a records request from restarting everything.
• The date of the first side's earliest recorded sign and the policy effective date, written next to each other. Which side of that line the note falls on is the entire dispute.