The Science of Cross-Species Formulation

Why one supplement can be safe and effective for both cats and dogs.

Portrait of Dr. Sarah Wooten, DVM, CVJ
Veterinary Author

Written by Dr. Sarah Wooten, DVM, CVJ

Veterinarian, certified veterinary journalist, international speaker, and widely published pet health writer. Dr. Wooten is recognized for making complex veterinary topics clear, practical, and trustworthy for pet parents.

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Pet parents often hear that “cats are not small dogs,” and while that is true in many important ways, it can also lead to unnecessary confusion. From a veterinary science standpoint, cats and dogs share a deep foundation of cellular biology that behaves far more similarly than differently. Marketing sometimes exaggerates this divide, but biology tells a more unified story. Many of the core processes that influence wellness, cellular balance, and visible traits like skin and coat function in remarkably similar ways across both species.

Cross-species formulation is based on this biological reality. It recognizes the shared physiology that makes a combined product possible, while equally respecting the differences that matter for safety. When companies design conservatively, use comparative physiology as the guide, and scale serving amounts thoughtfully, a single supplement can support both cats and dogs without compromising safety or quality.

This article explores the underlying science, where the similarities end and the differences begin, and how thoughtful formulation bridges the gap.

Shared Physiology, Shared Cellular Science

Much of the fundamental biology inside dogs and cats works in remarkably similar ways. They rely on comparable systems for energy, detoxification, antioxidant balance, and cellular repair. These shared processes form the foundation that makes cross-species formulation possible, as long as the formulation respects the differences we will explore later.

Here are a few major examples of where dogs and cats share physiology relevant to supplement science.

Image credit: Dr. Wendy Bautista, MD PhD, Barrow Neurological Institute.

1. Oxidative stress and antioxidant balance

Both species generate free radicals as natural byproducts of metabolism. Their cells rely on antioxidant pathways to maintain balance. Supportive ingredients, when used responsibly, can help maintain normal oxidative balance in similar ways across cats and dogs because the underlying chemistry is nearly identical.

mitochondrial dysfunction 12 hallmarks of aging in dogs 10

Image Credit: Canva Pro Licensed Asset

2. Mitochondrial function

The mitochondria, often called the powerhouses of the cell, operate similarly in both species. These structures help generate cellular energy. Many compounds that support normal mitochondrial activity have comparable safety considerations across cats and dogs when used within normal ranges.

inflammaging 12 hallmarks of aging in dogs 3

Image Credit: Sanjay Mukhopadhyay. Public domain.

3. Inflammatory pathways and cellular resilience

Cats and dogs share many of the same immune signaling routes. Inputs that influence normal inflammatory balance often act on overlapping internal chemical pathways. This allows for cross-species supplement design that supports general wellness rather than addressing specific disease conditions.

Image Credit: Louisa Howard, Dartmouth Electron Microscope Facility. Public Domain.

4. Tissue structure and turnover

Skin, coat, and nail cells in cats and dogs rely on the same structural proteins, fatty acids, vitamins, and trace minerals. The way these tissues grow and renew is similar enough that certain nutrients or bioactives can be formulated for both species with proper serving sizes.

These examples illustrate why the idea of “cats need X while dogs need something totally different” can be misleading. Many of the building blocks of life, and the molecular routes that keep cells functioning normally, are shared across most mammals.

Key Differences That Matter in Responsible Formulation

Shared biology creates the foundation, but the differences are where safe cross-species formulation becomes a science rather than an assumption. The most important distinctions involve metabolic pathways, essential nutrients, and upper limits.

1. Feline detoxification pathways

Cats have unique liver metabolism compared to dogs. They process certain compounds more slowly because some of their liver enzymes function differently. Cross-species formulations must avoid ingredients known to stress feline natural detoxification pathways or must be used well within safety margins supported by existing research.

2. Essential nutrient requirements

Cats are obligate carnivores. They require specific nutrients, such as taurine and preformed vitamin A, which dogs can synthesize or convert differently. This does not prevent cross-species formulation, but it means that a product intended for cats cannot rely on a dog-only nutrient assumption. Formulas must remain neutral, safe, and supportive for both species.

3. Metabolic rate and sensitivity

Cats are generally more sensitive to higher amounts. They often have lower safe upper limits for certain nutrients or bioactive compounds. Designing for the stricter species, in this case the cat, ensures safety across both. This is one of the most important principles in making a shared product truly cross-species.

4. Palatability differences

Cats tend to be more selective about taste and smell. While this is not a safety issue, it can be a formulation challenge. Cross-species products must retain flavors and textures that appeal to both species without using ingredients that might be inappropriate for cats.

These differences highlight a central truth: cross-species formulation is not about “one size fits all.” It is about building from the shared biology while using cat physiology as the limiting factor, creating room to serve both species safely.

How safe cross-species formulation works

Responsible cross-species design is based on a few guiding principles that come directly from comparative physiology and veterinary science. When these principles are applied consistently, one supplement can support both cats and dogs without compromising safety or quality.

1. Design to the stricter species

If cats have a lower tolerance for a specific nutrient or compound, the formula is built around the feline limit. Dogs then receive an amount well within normal safety ranges. This approach is central to cross-species safety.

2. Use serving-size-to-weight logic

Cats and small dogs typically receive smaller amounts, while medium and large dogs receive more. Weight-based serving size is well established in veterinary medicine and is a reliable way to scale a cross-species supplement so that each pet receives an appropriate amount.

3. Exclude species-specific risks

Certain ingredients are safe for dogs but not for cats, or vice versa. A responsible formulation simply omits those ingredients or uses alternatives with documented cross-species safety. It is a conservative approach designed to avoid avoidable risks.

4. Focus on universally relevant pathways

Some cellular pathways are shared across mammals. When a formulation targets these universal systems, it makes cross-species design more intuitive and safer. These include pathways linked to energy metabolism, antioxidant defenses, fatty-acid balance, and structural protein synthesis.

5. Keep the formula non-therapeutic

A cross-species supplement should be positioned as supporting normal biological function, not as a treatment or cure. This is key for both scientific accuracy and regulatory compliance. When the intent is supportive and general, cross-species design fits naturally within that scope.

Example of Cross-Species Formulation from La Petite Labs

In cross-species design, examples can help illustrate how targeting universal pathways works. The following mentions are educational only and are not included as promotional claims or health promises. They simply demonstrate how a formulation can be built around the shared biology of cats and dogs.

1. Hollywood Elixir™ and cellular wellness pathways

Some emerging formulations explore nutrient combinations that interact with cellular energy routes and pathways studied in longevity research found across mammals. In a cross-species context, this kind of design looks at supporting normal cellular housekeeping functions and energy balance in both species. Hollywood Elixir™ sits within this scientific framework by supporting broad cellular systems that behave similarly in cats and dogs.

2. Pet Gala™ and shared skin, coat, and nail biology

Cats and dogs both grow hair, skin cells, and nails with the same proteins, fatty acids, and micronutrients. When a formula is designed to support normal skin and coat appearance, it often draws on shared biology. Pet Gala™ illustrates how a single blend can be designed for dogs and cats around these common needs through careful ingredient selection and usage.

These examples show how cross-species design can work when the pathways are universal and the formulation relies on strict safety benchmarks.

Pulling it Together: The Logic Behind Cross-Species Formulation

When you focus on the biology rather than marketing categories, designing a supplement for both cats and dogs becomes much more straightforward. They share core cellular systems, metabolic routes, and tissue structures. Their differences can be fully respected through conservative serving amounts, exclusion of species-specific risks, and formulating to the more sensitive species.

Cross-species formulation is not about treating cats like small dogs or vice versa. It is about grounding decisions in comparative physiology and designing with intention.

“Cross-species formulation works when it is guided by comparative physiology, built to the more sensitive species, and rooted in shared cellular biology rather than convenience.”