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Modesto, CA Animal Ordinances: Mandatory Spay/Neuter (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Breeding without permit
Unlawful under §5-4.503(a)
Permit issuer
Stanislaus County Animal Services, annually
Litter cap
1 litter per animal per permit year (§5-4.503(d)(1))
Uncorrected violation penalty
$500 fine (§5-4.504(a))
Offspring transfer age
Not before 7 weeks old (§5-4.503(d)(2))
Public sale of unaltered pets
Banned under 6 months without permit (§5-4.505(b))

Summary

Modesto does not force every dog or cat to be fixed, but Code Section 5-4.503(a) bars anyone from breeding a dog or cat within the City without an annual litter permit from Stanislaus County Animal Services. Unaltered dogs also carry a higher license fee under Section 5-4.506 to push owners toward spaying or neutering.

(a)No person shall cause or allow any dog or cat owned, harbored or kept within the City of Modesto to breed without first obtaining a litter permit. The term litter permit means a written authorization, issued annually by the Stanislaus County Department of Animal Services Director or his/her designee, giving its lawful holder permission to breed a dog or a cat.(b)Each litter permit shall be valid for one (1) year from the date of issuance, and may be renewed annually before its expiration date. Each applicant for a litter permit shall pay an annual fee, as prescribed by the City Council and set forth in Section 5-2.201 of this title. ... (2)No offspring may be sold, adopted, bartered, or otherwise transferred, whether for compensation or otherwise, until it has reached the age of at least seven (7) weeks and the offspring have received its first immunization against common diseases.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 71).

Full Breakdown

501 lay out the policy: pet overpopulation drives mass euthanasia and rising shelter costs, so the ordinance's fix is to require all dogs four months or older to be licensed and altered, unless the owner buys a litter permit for the privilege of keeping the animal intact and breeding it, and to raise the license fee for unaltered dogs as a financial nudge toward spay and neuter. 503(a) puts that into operative language: no dog or cat may be bred within the City without a litter permit issued annually by the Stanislaus County Department of Animal Services.

503(d)(1) caps breeding at one litter per animal per permit year, with a one-time exception if a veterinarian verifies a health-based need or a prior litter had to be euthanized. 503(d)(3)-(4), with records of buyers kept for three years. 505(b) separately bars publicly selling, bartering, or offering for adoption any unaltered dog or cat under six months old, in places like sidewalks, parks, flea markets, and in front of businesses, without a litter permit, though government agencies, registered nonprofits, and licensed pet stores selling in-store are exempted. 503(e).

Violations & Fines

If Stanislaus County Animal Services or Modesto Animal Control finds a breeding violation, the owner has 30 days from notice to correct it by obtaining the required permit; failing that, Section 5-4.504(a) imposes a $500 penalty that cannot be waived even if the animal is later transferred or abandoned, and if the animal still is not fixed, microchipped, or permitted within another 15 days, the continuing violation becomes an additional prosecutable infraction. A litter permit can also be revoked under Section 5-4.504(b) for violating City or County animal ordinances or state health and safety law, with revocation appealable to Animal Court within five working days. Separately, failing to display a litter permit number in advertising or on a sale receipt is its own infraction under Section 5-4.505(g), fined $100 for a first occurrence, $200 for a second, and $300 for each occurrence after that, with each day counted as a separate violation.

Frequently Asked Questions

Does Modesto require every dog or cat to be spayed or neutered?
No, there is no blanket mandate. Section 5-4.503(a) instead requires anyone who wants to breed a dog or cat to first obtain an annual litter permit from Stanislaus County Animal Services; owners who don't intend to breed can keep an unaltered pet, but pay a higher license fee under Section 5-4.506.
What happens if I breed my dog or cat without a litter permit?
Animal Services gives the owner 30 days from notice to correct the violation by getting a permit. If it isn't corrected, Section 5-4.504(a) imposes a non-waivable $500 penalty, and the violation becomes an additional infraction if the animal still isn't fixed or permitted within 15 more days.
Can I sell puppies or kittens at a flea market or on the sidewalk?
Only with a litter permit. Section 5-4.505(b) bans publicly selling, bartering, or offering for adoption any unaltered dog or cat under six months old in public places like sidewalks, parks, and flea markets unless the seller holds a valid litter permit.
Does an unaltered dog cost more to license in Modesto?
Yes. Section 5-4.506 sets a standard annual license fee for every dog, but unaltered dogs that don't qualify for a listed exemption, such as working ranch dogs or registered show dogs, pay the higher unaltered rate, an incentive tied to the pet overpopulation findings in Section 5-4.501.

Sources & Official References

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