Whole Herring

Herring is caught for seafood and animal feed. Small fish are difficult to fillet, and some catch unsuitable for the seafood trade goes to animal food. Keeping it whole retains the frame.^4,7,10

1. 01 // Source Landed herring The catch includes small fish that are difficult to run through commercial filleting equipment.
2. 02 // Process Kept whole Fish selected for whole use retain the flesh, skin and frame that filleting would separate.
3. 03 // Process Kept cold Whole fish is chilled or frozen for storage; fish ingredients usually travel to pet food plants in refrigerated trucks.
4. 04 // Output Whole herring The fish reaches the plant as a wet ingredient before the recipe is mixed, cooked and dried.

1. 01

   Adds fish protein

   Flesh supplies protein while the frame contributes mineral-rich material. The fish enters the recipe wet, so its listed weight overstates its share of dried kibble.^4,7,9

2. 02

   Brings marine fat

   Oil extracted from whole herring contains EPA and DHA. Their amount in finished kibble depends on the fish, the recipe and storage, so the ingredient name is not a dose.^5,6,7

3. 03

   Uses more catch

   Fillets with skin yield about 53% of ungutted landed weight. Whole-fish use keeps material otherwise trimmed away and gives small, hard-to-fillet herring an animal-food outlet.^4,7

How much Ingredient lists rank by weight, and one measured whole herring sample was 76.6% moisture, so its rank can hide a small dry-matter share.^4,9

1. Brands say

   Whole herring supplies protein and fat

   Evidence

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

   A measured whole-fish sample contained 47.1% protein and 26.6% fat on a dry matter basis. Those are real contributions, though its wet weight gives no measure of how much remains in finished kibble.^4,9

2. Owners say

   Herring has less mercury than tuna

   Evidence

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

   FDA's commercial fish data report average mercury of 0.078 ppm for herring and 0.350 ppm for canned albacore tuna. The comparison holds for those samples; it does not measure a particular pet food batch.⁸

3. Brands say

   Herring improves itchy skin and coat

   Outruns the evidence

   Evidence

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

   In a controlled trial involving 29 dogs, fatty acid supplements improved clinical skin scores while placebo did not. The trial tested supplements for atopic dermatitis, not whole herring in kibble or a cosmetic coat benefit.¹

4. Brands say

   Whole herring relieves arthritic joints

   Outruns the evidence

   Evidence

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

   A placebo-controlled dog trial reported better joint outcomes with fish-derived EPA and DHA at an average of 69 mg/kg daily. It tested a measured supplement dose, not whole herring at an undisclosed kibble inclusion.²

5. Brands say

   Whole fish bones balance the minerals

   Outruns the evidence

   Evidence

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

   The whole-fish sample contained 12.9% ash, showing that minerals contribute to its dry weight. That measurement does not give the food's calcium-to-phosphorus balance; formulators must assess the complete recipe.⁴