Manganese is an interesting conundrum. Why are raw diets low in it and where do dogs normally source it from?
Some weeks ago we were discussing cruciates in dogs and how to avoid a cruciate tear – the main points being
- Get them lean, no fat dogs, ever, these are long distance runners, for the most part
- Feed them raw dog food
- Don’t neuter when young before growth plates are set
- Reduce over-exuberant, possibly guilt-laden exercise of fatties not properly warmed up when you come from work.
But during the discussion on our Facebook page, an interesting one popped up, the crucial role of manganese. This was news to me I have to admit (every day’s a school day) and it’s why I love this subject, always throwing up interesting little factoids to look into. Some result in dead-end myth but others have weight. It’s clear this manganese tip is in the latter group.
There are a few studies out there showing how important manganese is to healthy cruciates and joints (here’s a great video of Dr Karen Becker discussing the role of manganese in avoiding soft tissue injury in your pet). Furthermore, Becker and Brown did a nice piece that compared two raw diets, one with veg and one without, to show absent manganese can be from non-veg containing raw dog food, highlighting the potential for using some veg ingredients in the dog’s diet, though there are a few more reasons you might feed veg to dog.
So there’s definitely something to this manganese thing.
The daily manganese requirements of dogs are, apparently, 2.3 mg of manganese daily for every pound of dog food they eat (on a dry matter basis, NRC requirements). If we divide this figure by three (as fresh food contains say 65-80% water), that’s still 0.7mg of manganese per pound (454g) of fresh raw.
I did a search for how we raw-feeders get manganese into the diet and I literally couldn’t find a land-based meat source of any real value. There’s not a lot in bones, fat or meat in anywhere near the degree that the dog requires. The highest I could find was liver where 100g of raw liver contains 0.35mg of manganese per 100g, everything else paled in comparison.
As most raws are made on the 80:10:10 principle (80% meat, 10% bone, 10% organ) then these products might contain between 5-10% liver, or 25-50g raw liver, which would leave the dog wanting in the extreme for manganese.
Animal Wellness Magazine does a nice piece highlighting the issue. They verify my findings above, stating:
A prey model diet of “80/10/10” lean beef supplies 0.22 mg manganese per 1,000 kcal (and that figure is even lower if the meat is less than 90% lean). An 80/10/10 prey model diet using chicken supplies 0.12 mg Mn per 1,000 kcal. This is even more deficient in manganese than AAFCO’s too-low recommended minimums found in processed foods.
They go on to cite there is ten times more manganese in hair, fur and feathers than organ meats (the best meat source of this ingredient) although, while interesting, the figures are unreferenced and I can’t find anything solid that has been done here, so I can’t be sure that’s a solution. As most raw feeders and indeed raw products exclude these pieces it’s a moot point for now. The AWM piece is great though and ends with foods that contain a nice whack of manganese, including:
- Raw spinach / mussels (43mg per 1000kcal)
- Blackberries (23mg)
- Pumpkin seeds (6mg)
- Spirulina (5mg)
- Raw beef liver (2mg)
So, make sure some of these are going into your dog when you can. Organic spinach is an easy one. You can use them frozen in those little cubes and pop into the bowl now and again. However, spinach is also quite high in oxalic acid which can sort of cancel out the good effects if used too much. Sweet potato is another good plant source of manganese (with skin on, boil up some cubes and feed, great for fibre too) though not everyone wants to give their dogs carbs. Lastly, I love pumpkin seeds as they’re also antihelminthic, keeps the worms away (blitz in a food processor).
However, far better you feed mussels. Best you pick them up frozen in the supermarket, raw if you can though most are cooked. Luckily manganese is fairly resistant to the cooking they get so don’t worry. The second best option is pick up some mussels in a tin (best find the ones in freshwater or brine and pour off the excess juice though veg oil will do if no alternative, we just want to feed as little cooked veg oil as possible to dogs).
You’ll rarely if ever see me recommending a nutrient supplement for pets (or you). It’s a really poor way of your body getting what it needs. Most bits can be sourced from the diet. However, in this case, you can always pick up some chelated (bound to a protein, a good thing for crappy supplements) manganese on Amazon if worried, particularly if you’re really working those joints but again, mussels are easier, likely cheaper and more nutritious.