Animal Plasma

Plasma comes from meat packing. Blood collected at slaughter is split into red cells and plasma, and the plasma is dried into a protein powder used first in piglet feed and now in pet food.^2,8

1. 01 // Source Slaughter blood Blood from pigs, cattle or poultry is collected and mixed with an anticoagulant, usually sodium citrate, so it stays liquid.
2. 02 // Process Chilled and spun The blood travels in a refrigerated truck at 3 to 5°C, then a centrifuge separates the red cells from the plasma.
3. 03 // Process Spray-dried The plasma is sprayed under high pressure into hot air and reaches about 80°C throughout as it dries.
4. 04 // Process Held before sale Makers store the packed powder at room temperature for at least 14 days, a step shown to inactivate certain pig viruses.
5. 05 // Output Plasma powder A dry powder under 10% water and about 75 to 79% protein, shipped to pet food plants.

1. 01

   Binds wet food

   Heated, plasma proteins unfold and set into a stable gel that holds water and fat. That is why wet foods and toppers use it to hold chunks and loaves together.²

2. 02

   Protein without fat

   At about 75 to 79% protein and 1% fat, a few percent lifts protein without adding fat. Diets with it digested protein at about 85 to 88% in dog trials.^1,2,5

3. 03

   Coats finished kibble

   Dry foods can dust it on after extrusion, along with fat and flavor. One trial fed a 4% coating alongside diets that mixed plasma into the base before extrusion, to compare the two methods.¹

4. 04

   Priced above common meals

   It is not the budget protein. A 2023 review notes that cost pushes feed makers toward cheaper fish meal or whey powder with similar properties.²

How much Dog trials have fed 1 to 12% of the diet, with intake unaffected at 2 to 8% though dogs preferred a plain diet over one coated with 4%.^1,3,4

1. Brands say

   Highly digestible protein that shrinks stool volume

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A 22-dog APC-authored trial found 2% plasma raised DM digestibility 3.2% and cut fecal output 15%. A 2025 trial in 12 dogs at 8% found no change in digestibility (84.5 to 85.9%) or fecal output (145 to 160 g per day).^1,3

2. Brands say

   Plasma supports gut health and immunity

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   A 12-dog trial at 8% raised fecal IgA about 40% and fecal short-chain fatty acids, with no change in stool score or calprotectin. Those are markers, not fewer illnesses, and a plasma maker sponsored it.¹

3. Brands say

   Plasma eases arthritis in older dogs

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   One 42-day trial in 24 senior dogs with arthritis saw lameness scores of 3.13 at 4% plasma against 3.70 on control. It is a single study with plasma-maker co-authors and no replication.⁵

4. Brands say

   Plasma makes food taste better to dogs

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Adding up to 3% did not change intake in 22 Beagles. In a 2019 preference test, dogs chose food without plasma over food coated with 4%, and the authors warned plasma compromised palatability. Only cats preferred it.^2,3,4

5. Critics say

   Blood products are cheap filler

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Plasma powder is about 75 to 79% protein, and in a 36-dog study diets with it digested protein at 85 to 87%. A 2023 review notes cost pushes feed makers toward cheaper fish meal or whey instead.²