In the United States, animal vaccines are not regulated by the FDA. They fall under a separate agency — the USDA Animal and Plant Health Inspection Service (APHIS), Center for Veterinary Biologics (CVB) — through the Virus-Serum-Toxin Act of 1913, one of the oldest federal drug-regulation statutes still in force. Every licensed veterinary vaccine, bacterin, antitoxin, diagnostic kit, and antibody product sold in the US must be produced at a USDA-approved establishment, tested batch-by-batch for purity, safety, potency, and efficacy, and assigned a unique product code.

The CVB publishes a quarterly Product Code Book listing every licensed and permitted veterinary biological product. This article analyzes the April 2026 edition of that catalog — 1,199 licensed product codes from 69 parent companies covering 386 distinct disease or antigen groupings. Every number below is computed directly from the USDA APHIS Veterinary Biologics product catalog (analysis run date: 2026-06-10).

Three things these numbers do not mean

Before the data, three important caveats:

1. Product codes are not the same as marketed products. A single brand-name vaccine may appear under multiple codes (different strains, formulations, or combinations), and some codes may not currently be in commercial distribution. The catalog is a regulatory listing, not a sales database.
2. The catalog covers only USDA-regulated biologics. Pharmaceutical drugs for animals (NSAIDs, antibiotics, parasiticides) are regulated by the FDA Center for Veterinary Medicine and do not appear here. The boundary matters: a killed-virus vaccine is USDA, but an antiparasitic tablet is FDA.
3. "For Further Manufacture" products are intermediates. The catalog includes 145 product codes for biological materials (master seeds, antigen preparations, bulk antibodies) that require further processing before becoming finished products. These are excluded from the main analysis unless stated otherwise.

The product mix: vaccines dominate

Of the 1,054 finished veterinary biological products (excluding intermediates), vaccines and combination vaccine products account for two-thirds:

Grouping these into broader categories makes the picture clearer:

• Vaccines and combination immunologicals (standalone vaccines + combination vaccines with bacterins/bacterial extracts/toxoids): 708 products — 67.2% of the entire catalog.
• Bacterins, toxoids, and bacterial extracts: 214 products — 20.3%. These are killed bacterial preparations, often targeting clostridial diseases in livestock.
• Diagnostics, antibodies, antitoxins, and miscellaneous: 132 products — 12.5%.

The US veterinary vaccines market was valued at $4.39 billion in 2025 and is projected to reach $6.50 billion by 2031, growing at 6.8% annually, according to MarketsandMarkets. The breadth of the licensed catalog — 708 vaccine and combination products — reflects that commercial scale.

What species the products target

Species assignment is approximate because many products carry claims for multiple species, and the product name does not always specify a species. Based on the disease and antigen names in the catalog:

(Note: products targeting multiple species appear in multiple rows; percentages exceed 100%.)

Several observations:

Food-producing animals drive the catalog. Avian, bovine, and porcine products together account for roughly half of all licensed codes. This reflects both the economic scale of livestock production and the regulatory structure — the USDA's mandate historically centered on protecting agricultural herds and flocks.

Clostridial products inflate the ovine/caprine count. Many clostridial bacterin-toxoids (targeting Clostridium perfringens, C. chauvoei, C. novyi, C. septicum, C. sordellii) carry claims for both cattle and sheep, which inflates the sheep-specific count relative to products primarily developed for that species.

Companion animals are a minority by product count. Dogs and cats together represent about 11% of the catalog. However, companion-animal products tend to have higher per-unit revenue, and the segment is growing faster than livestock in dollar terms.

Aquatic products are a niche. Only 29 codes target fish — vaccines for diseases like furunculosis (Aeromonas salmonicida), vibriosis, and enteric septicemia of catfish. Aquaculture vaccine development is a relatively young field in the US compared to Norway and Chile.

Disease categories driving the catalog

The 386 unique product names in the catalog map to the following disease and antigen categories (products can appear in multiple categories):

Clostridial products are the single largest cluster — 146 codes across standalone bacterins, bacterin-toxoids, toxoids, and combination products. This reflects the wide range of Clostridium species that cause economically significant disease in cattle, sheep, and goats (blackleg, enterotoxemia, tetanus, botulism, malignant edema), the availability of well-characterized antigens, and the longstanding practice of routine clostridial vaccination in livestock operations.

Avian products are the second-largest cluster. Poultry production's scale — over 9 billion broilers produced annually in the US — and the rapid population turnover in commercial flocks drive continuous demand for both core and emerging-disease vaccines.

Who holds the licenses

The catalog lists 76 unique licensee or permittee numbers, consolidating to approximately 69 distinct parent companies. But the distribution is sharply concentrated:

The top three companies hold 49.1% of all licensed product codes. Boehringer Ingelheim, Zoetis, and MSD Animal Health collectively license 670 of the 1,366 product–license entries in the catalog. The top five control 62.1%, and the top ten control 77.2%.

This concentration mirrors the broader animal health industry. Zoetis, the animal-health spinoff from Pfizer, is the world's largest animal health company. Boehringer Ingelheim acquired Merial's veterinary portfolio in 2017. MSD Animal Health (known as Merck Animal Health in the US) maintains the Intervet legacy portfolio. These three companies have the largest portfolios across livestock, companion-animal, and avian species.

Among companion-animal (canine/feline) products specifically, the concentration is even higher:

The top four companies hold 194 of the roughly 280 companion-animal product entries — approximately 69%.

IDEXX Laboratories' presence is notable because it is primarily a diagnostics company. Its 58 product codes are overwhelmingly diagnostic test kits (antibody test kits for avian mycoplasma, PRRS, pseudorabies, and other diseases) rather than vaccines — a reminder that USDA-licensed "biological products" include diagnostics as well as immunologicals.

Vaccine technology platforms

The catalog's 708 vaccine and combination products break down by technology:

Live and modified-live vaccines remain the backbone of veterinary immunology, accounting for just over half of all licensed vaccines. Killed and inactivated products represent nearly a third. Newer platforms — vectored vaccines using fowl pox, Marek's disease virus (serotype 3 HVT), or baculovirus as vectors, plus DNA and RNA products — are still a small share of the catalog but are growing, particularly for emerging diseases like avian influenza where traditional platforms face manufacturing or regulatory challenges.

The first USDA-licensed RNA veterinary vaccine was approved in 2012. The first plant cell-derived product and first live-vectored chimera vaccine were both licensed in 2006. These milestones are recent relative to the VSTA's 1913 origin, and the platform diversification is accelerating.

Conditional licenses

Approximately 25 of the 1,054 finished products carry a conditional license designation. Conditional licenses are issued under 9 CFR 102.6 when a product meets purity, safety, and potency standards but efficacy data are still being gathered — typically for emerging diseases or emergency situations where waiting for full efficacy data would delay availability. Products like avian influenza vaccines and some autogenous products frequently operate under conditional licenses.

What this means for veterinary practice

Several patterns in the data are practically relevant:

The livestock vaccine catalog is deep and competitive. With 146 clostridial products, 78 bovine respiratory products, and 254 avian products, food-animal veterinarians have substantial choice. This competition means generic and private-label alternatives are available for many core antigens, and price pressure is real.

Companion-animal innovation is diversifying beyond traditional vaccines. The antibody products section now includes anivovetmab (a monoclonal antibody from Elanco), and products like Cytopoint (lokivetmab) and Solensia (frunevetmab) — though regulated by FDA as drugs rather than by USDA as biologics — represent a broader trend toward biologic therapeutics in companion animals. The USDA antibody products section also includes polyclonal antibody preparations for bovine coronavirus, Escherichia coli, and Rhodococcus equi.

Diagnostics are a separate licensing track. The 42 licensed diagnostic products — antibody test kits, antigen test kits, DNA test kits, tuberculin — are a distinct category. IDEXX dominates with test kits for avian mycoplasma, PRRS, and pseudorabies. Thermo Fisher Scientific (Tetracore) holds licenses for nucleic acid test kits. The distinction matters for practitioners: USDA-licensed diagnostics must meet CVB standards for sensitivity and specificity, but they are not FDA-cleared devices.

Autogenous vaccines are a significant and growing category. Products labeled "Autogenous Vaccine" — custom-made from pathogens isolated on a specific farm or operation — appear across multiple sections. They are licensed to a range of companies including Cambridge Technologies, Hennessy Research Associates, BioStone Animal Health, and others. Autogenous products fill gaps where no licensed commercial vaccine exists for a particular strain or serotype, especially in livestock and aquaculture.

The regulatory split between USDA and FDA matters. Vaccines, bacterins, toxoids, antibody products, antitoxins, and diagnostic kits that act through immunological mechanisms are USDA. Drugs, including monoclonal antibodies for osteoarthritis (bedinvetmab, lokivetmab, frunevetmab), parasiticides, antibiotics, and NSAIDs, are FDA. Practitioners reporting adverse events need to know which agency has jurisdiction — USDA adverse events go to APHIS, FDA adverse events go to the CVM.

Sources

• USDA APHIS Center for Veterinary Biologics. Current Veterinary Biologics Product Catalog (April 1, 2026). https://www.aphis.usda.gov/veterinary-biologics/licensed-products
• USDA APHIS. Product Code Book, April 2026. https://www.aphis.usda.gov/sites/default/files/currentprodcodebook.pdf
• USDA APHIS. About the Center for Veterinary Biologics. https://www.aphis.usda.gov/veterinary-biologics/about-cvb
• USDA APHIS. Veterinary Biologics — Licensed Product Information. https://www.aphis.usda.gov/veterinary-biologics/licensed-products
• JAVMA. Review of updated regulations and product license categories for veterinary vaccines in the United States. https://avmajournals.avma.org/view/journals/javma/257/11/javma.2020.257.11.1142.xml
• FDA. Animal Biologicals — jurisdiction between USDA and FDA. https://www.fda.gov/animal-veterinary/products/animal-biologicals
• Sidley Austin LLP. Veterinary Biologics and Biosimilars: Routes to Approval and Commercialization in the US, EU, and UK (February 2026). https://www.sidley.com/en/insights/newsupdates/2026/02/veterinary-biologics-and-biosimilars-routes-to-approval-and-commercialization-in-the-us-eu-and-uk
• MarketsandMarkets. US Veterinary Vaccines Market Report 2026–2031. https://www.marketsandmarkets.com/Market-Reports/us-veterinary-vaccines-market-128182859.html