Got distracted going through some old threads tonight. Moved some. Didn't find what I wanted may have been lost in the trim years ago.
Anyway found some diet info I forgot I had.http://www.sciencedirect.com/science/ar ... 9188902246
Fennec fox captive blood levels and diet intake
Retinol Diet 0.89mg/day - Blood Mean 1.7mg/l range 1.5-2.1mg/l
Vitamin E 5.8mg/d alpha-Tocopherol(E) blood Mean Average 6.7mg/l range 5.8-7.7
The above would be more meaningful if they had tested animals in the wild.
Here's a bit you can see cal/phos for red fox http://www.nap.edu/openbook.php?isbn=030903325X
That is interesting really as it mentions a sign of deficiency is walking on the pasterns which some have had with their red fox kits but "grew out of it" probably then from a better home diet than the store/breeder gave. But that was red kits kinda putting it here just for future easy-to-find-ness.
But using red fox info as general all fox requirements for lack of other species specific info:
cal/phos rang of 1/1 to 1.7/1http://www.rodentpro.com/qpage_articles_03.asp
whole prey rabbit
Cal/phos 3/2.25 or 2/0.64
Adding veggies will effect the ratio a we bit, insects a bit more depending on how much added. Since veggies have phos it would kick the ratio to about right.http://www.nap.edu/openbook.php?isbn=030903325X
it goes into vitamins requirements. For Vitamin A it says 100IU of retinol or 600IU of carotenes, that is per KG of body weight. 200IU per gram shows signs of making them ill and it began being stored in the liver between 50 to 100IU per KG. Using 100 as the goal per kg as max, about 450 grams per pound so a 3 pound fennec being 1350grams, 1.35kg is 135Iu per day. Geez that's not much.
1.5 cups of food is roughly 3/4's of a pound(13oz). So 135 per 13 oz of food for a fennec which is what they would eat in a day(3/4 cup's twice). Or to make things simpler for comparing 367IU/kg of food.
Smith1947 showed 25IU per KG body weight in growing pups was the minimum.
So 25-100 IU per KG body weight is the acceptable range in red foxes less than that could cause problems but red foxes tolerate more well but they did not test deeper than visual like x-rays.
(of interest in that is that fox, at least red fox, can turn beta-carotene into retinol. Cats and ferrets can not because they are designed to eat only animal matter which has only retinol and no beta-carotene. Plant matter does have bate-carotene and obviously a foxes body can digest it since it absorbs it and can turn it into retinol though is not as efficient at doing so as a more omnivorous animals like rats and humans.)
Now since they can turn carotene into retinol you don't have to worry if retinol might be a bit low they can turn the carotene from their veggies into retinol if they need it but the body wont if it doesn't need it. This is one reason why bright orange things like squash and sweet potato are good for the veggie portion of their diet.
Rabbit, domestic - 6,200IU/kg Retinol roughly 2,282IU/368g(13 OZ)
Lizard, anolis - 4,880IU/kg 1,795IU/386g
Rat Neonatal, <10 g - 21,333 iu/kg 7,850IU/268g
I'll just skip the rest they are all obviously too much remember we are looking for 135iu 13 OZ of food(a days worth of feed) per fennec assuming red fox levels
Chicken - 35,600IU/kg
Rat Adult or >50g - 151,389IU/kg
Adult Mouse Mouse, domestic 578,272IU/kg
Yep that even means rabbit is too high but it's the lowest whole prey source I could find. To remedy this feed some rabbit without organs to lower the retinol and more insects as they are also much lower. The veggies only take away about 24 iu or so. In fact feeding one rabbit with organs and one without would is still 2,113.6 per 1.5 pound for combined 1 with and one without. So actually if you had one in 10 rabbits with organs that would take it down to 422.7 per 1.5 pound/day. So maybe give 1 in 25 with organs and the rest without as that's 169IU per 1.5 pounds and some veggies will knock it down to about right.
That may seem a bit baffling but rabbits, mice ect have a much richer diet than their wild counter parts so their livers store up a bunch for retinol. Wild ones as I showed before with mice have much less than their domestic cousins. Insects the fennecs main diet is even lower in retinol.
Mice and other feeders could be rendered safer to eat by gutting them and removing their livers before feeding.
So there you go more scientific info showing dietary need for retinol is low in foxes in general.Wait
lets look at the lowest kibble
it lists 22,000iu/kg. Now a 1.5 cups(3/4's twice) of kibble is 0.225kg(225g) a lot less that a half cup of "Real" moist food. So one and a half cups of the kibble would be 4,950iu
One last note too much retinol can weaken bones, could possibly be implicated(in part) in their high incidence of bone breakage.https://books.google.com/books?id=YmgrA ... es&f=false
Here's a study on red fox that found the fox to be eating about 80% animal matter and 20% vegetation, though I rounded them off a wee bit.http://ilacadofsci.com/wp-content/uploa ... -print.pdf
I wish there were something like that on fennecs. I'd probably say 20% max for reds and 10% max for fennecs as an educated guess but 10% for reds and 5% for fennecs as ideal vegetation intake as other studies show varied amounts in reds depending on what's available.
Another interesting note from that and pretty much every other study I found on reds is that their main diet is rabbits and hares but they fall back on other prey when rabbit is not as available.