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A reader recently asked me about the supplements I give my dogs; two in particular: Olewo carrots and spirulina. She wondered if the combination of these two supplements would lead to Vitamin A toxicity.
One of the things I love about being in charge of my dogs' nutrition is all the things I learn. Something new comes to my attention weekly, and I dig into it with gusto to try and figure out the answer. This week, I have to ask if I'm killing my dogs with too much vitamin A.
Benefits of Vitamin A for Dogs
Vitamin A is a fat soluble vitamin that is stored in the fat surrounding the liver until needed. This is a great vitamin for puppies because it supports growth; but that's not all.
- Vitamin A promotes healthy skin and coat for dogs.
- Vitamin A supports the liver, lung, and kidney health for dogs.
- Vitamin A supports healthy eyesight for dogs.
- Vitamin A supports healthy nerves and muscles for dogs.
Where Does a Dog Get Vitamin A
If we're going to supplement our dog's diet with vitamin A, it's best to look for a natural source and not synthetic. Not only are synthetic vitamins difficult to digest and utilize – causing a dog's system to do a lot of work to convert them into something useful – it's not always clear where the vitamins are sourced.
Another downside to synthetic vitamins is that they usually are only one vitamin, which is why there is a risk of vitamin toxicity. When we feed our dogs vitamins from whole food sources, the nutrients are working together and our dogs' systems will discard what they don't need. Ideally, our dogs should be able to get everything they need from a raw diet, however, we understand that this isn't always the case because it depends on what we're feeding, the sources, and a basic understanding of what our dogs need.
If you are concerned about your dog gaining enough nutrients, I suggest speaking with a holistic veterinarian that is knowledgeable about raw feeding. I'm also working on a nutrient spreadsheet that is helping me understand what my dogs need – you're more than welcome to check it out and use it for your dogs.
Natural Sources of Vitamin A Include:
I did some research and found that I was feeding my dogs plenty of food that is rich in Vitamin A; but am I feeding too much? Are my dogs at risk for vitamin A toxicity?
- Eggs – I feed our dogs an egg once or twice a week
- Sardines – I feed our dogs a couple of sardines (canned in water / low sodium) once a week.
- Liver – this is a regular in our dogs' raw food diet
- Apples – my dogs love snacking on apples
- Carrots – our dogs get 1 tbsp of Olewo carrots 5 mornings a week
- Celery – this is an ingredient in my veggie mix
- Spinach – this is an ingredient in my veggie mix
- Green Beans – great to help a dog that needs to lose weight feel more full when you cut back her servings
- Seaweed, Kelp, Spirulina – added as a supplement or when making my veggie mix
- Goat's Milk – nearly every morning and when not goat's milk, fermented cow's milk aka kefir.
Other sources of vitamin A include sweet potatoes, pumpkin, and cod liver oil. If you do a Google search for foods that are high in vitamin A, you'll find various lists. I have yet to find two sites that agree completely.
Vitamin A Toxicity in Dogs
Although I'm feeding my dogs several different sources of vitamin A, I'm not worried about vitamin A toxicity. After an evening of reading several articles, I realized that my dogs aren't getting enough vitamin A to reach toxic levels.
According to PetEducation.com, dogs require a minimum of 2272 IU (international unit) per pound of food consumed; this amounts to 50 IU per pound of body weight according to VetInfo.com. To reach a toxic level, a dog would need to consume between 2500 IU and 113,600 IU per pound of food consumed fed daily for months or years.
If your brain is melting when you see the “IU”, and you're wondering “what the hell?,” you're not alone. I still don't have a proper grasp of this. However, I'll try and explain. IU is how vitamins are measured. The milligrams (mg) that make up a vitamin's IU depend on the potency/concentration of the vitamin. If you want to dig deeper, there are IU to mg calculation sites.
The more I read, the more confident I became that my dogs are doing fine. Vitamin A toxicity usually happens if a dog dines on a bottle of spilled vitamin A supplements – not through a balanced raw diet. Toxicity can also occur if we feed our dogs too much cod liver oil (I prefer Bonnie & Clyde fish oil, hemp oil, and camelina oil) or too much liver. I'm careful about the amount of liver in my dogs' diet because too much will throw their diet out of balance and lead to diarrhea and, apparently, vitamin A toxicity.
How Much Vitamin A is In…
I found the following information by Googling “how much Vitamin A is in a carrot.” Google provided a drop-down menu that allowed me to check various foods. Keep in mind that this isn't from a veterinarian.
|Food||Amount||IU/Pound of Food Consumed|
|Eggs||1 large||270 IU|
|Sardines||1 cup, drained||161 IU|
|Liver||3 oz||15,297 IU|
|Apples||1 medium||98 IU|
|Carrots||4 g||668 IU|
|Celery||1 stalk||180 IU|
|Spinach||1 cup||2,813 IU|
|Green Beans||10 g||938 IU|
|Seaweed, Spirulina||1 tbsp||40 IU|
|Seaweed, Kelp||2 tbsp||12 IU|
|Raw Goat's Milk||1 cup||400+ IU (estimate)|
|Sweet Potatoes||1 cup||18,869 IU|
|Pumpkin||1 cup||9,875 IU|
If the above information is correct – Google, don't let me down – then my dogs aren't at risk of Vitamin A toxicity through their diet.
Signs of Vitamin A Toxicity
Whenever I start reading up on a potential health issue, I swear that I see it in my dogs. I'm always wrong, but that doesn't stop me from panicking for a day while I closely monitor (aka creepily stalk) my dogs to see the warning signs.
Symptoms of Vitamin A Toxicity in Dogs:
- appetite loss
- bone spurs
- weight loss
If you're concerned about your dog's condition and nutrition, I recommend reaching out to your vet immediately. Treatment varies depending on the level of toxicity, the source of the vitamin A, and how recent the dog consumed the vitamin A (if it's your vitamins).
At this time, adding Olewo carrots and spirulina to my dogs' meals will not bring about a toxic level of vitamin A. Our dogs get Olewo carrots five days a week and spirulina is added to their veggie mix when I don't have kelp. I think they're doing great!
I'm still going to bring this up at their next wellness check.