Monday Medical: Avocados - poison or pet food additive?

Does your pup look forward to Mexican Fiesta night at your house? Does he lick his lips when you break out the guac and chips?

image courtesy Wikimedia Commons

Or maybe it's your kitty, who always has an eye out for the finer things in life. After all, what's tastier than a rich, creamy guacamole dip with avocados, cilantro, lime juice, some onion and tomato....

There are a few reasons - in the form of ingredients - that your pet shouldn't indulge in this delicious treat.  Onions and avocados.

We covered the toxicity of onions and related edibles a few weeks ago, and you can read about it here. Interestingly enough, the issue of avocado toxicity isn't so cut-and-dried. You see, there are actually some pet foods that use avocado in their ingredients.

The 4-1-1 on avocados

image courtesy Wikimedia Commons

Avocados are incredibly rich in all sorts of good things, like essential fatty acids, niacin, potassium, and vitamins A, B, C, D,  E and B6.

Sounds fabulous, doesn't it? No wonder a pet food manufacturer would want to use it!

There's just a teesny problem. There's a fatty acid derivative in the avocado, as well, called persin. Persin is found in every part of the avocado plant - in its leaves, bark, the monster seed in the middle, and even the fruit.

The good news is that there's very little persin in the actual fruit, compared to concentrations found in leaves, bark and the pit. The bad news is what persin can do to an animal if enough is ingested.

For dogs and cats, it's more of a mild nuisance than a deadly toxin. If enough avocado is ingested, it'll cause diarrhea, possibly vomiting. And cats are more sensitive to persin than dogs are.

For other pets such as birds, horses and rodents, it's another matter. For birds in particular, like parakeets or cockatiels, persin can cause respiratory distress, fluid around the heart and, if enough is ingested, eventually death.  In sufficient quantity, it can cause colic in horses and, without veterinary intervention, death.

Yet both avocado oil and meal are found in both dog and cat food. Specifically, in the brand Avoderm. In fact, the company derives its name from the avocado. How can this be good for dogs and cats?

It turns out that most avocado toxicity can be traced to a specific strain of avocado - the Guatemalan variety. The type of avocado used by Avodern, the company states on its website, is not Guatemalan. Nor does it use the bark, leaves or pits in its formulation. The fruit pulp is screened before use, and the company requested a toxicology review from the Environmental Toxicology Department at UC Davis to determine its safety.

The report concluded that the avocado used in Avoderm pet food is not toxic and the company feels its inclusion in their pet food formula is especially beneficial to animals who suffer from skin and coat problems.

Ultimately, the decision is yours as a responsible pet owner. But ASPCA veterinary outreach director Dr. Tina Wismer admitted that there were no reliable reports of poisoning in dogs, cats or ferrets. The biggest danger by far for such animals is the choking hazard presented by the avocado pit.

One last thought to leave you with: as with humans, it's always wise to use everything in moderation. A lick of guac now and again for your dog or cat probably won't cause tummy upset. And it's just common sense to throw the pit away. Though it might be fun to bat it around, it's not a toy.

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Next week: 
Can Cats & Dogs
Suffer From Breast Cancer?

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sources:
http://www.pawnation.com/2010/02/04/are-avocados-bad-for-pets/
http://www.petpoisonhelpline.com/poison/avocado/
http://www.aspca.org/pet-care/poison-control/people-foods.aspx
http://en.wikipedia.org/wiki/Avocado#Toxicity_to_animals
http://www.breeders-choice.com/about/
http://www.breeders-choice.com/cat_products/avocadosafety.htm

Monday Medical - Onions: Toxic to Pets?

So…are onions really all that dangerous if your pet eats them? Well, it depends.

There’s no doubt onions are toxic to both dogs and cats. It’s the amount and concentration of it – as well as its availability – that you need to consider.

onion harvest: Wikimedia Commons

Onions are in the allium species of plants, and all these plants (around 95 varieties in all) are toxic to pets. That includes leeks, chives, garlic, shallots, scallions and your basic onion.

And you need to know that it includes over 80 varieties of ornamental plants, as well.

As far as amount? The ASPCA’s Animal Poison Control Center and the DVM 360 web sites tell us that if your cat ingests as little as 5 grams per kilogram of body weight, it can have an impact. For dogs, it’s as little as 15 grams per kilogram of body weight.

That can be kind of hard to envision, so I did a bit of calculating.

For a cat Allie’s weight, she’d have to eat almost an ounce of onion, the equivalent to about a tablespoon of chopped onion, for it to have an effect. Probably not going to happen.

BUT. As I stated in the beginning, amount is only one of three factors you need to consider.

one ounce of onion - enough to impact a cat

Now let’s talk concentration. Cooking any of these – onion, leek, shallot, etc – does nothing to lessen its impact. Neither does processing them down into a powder, like the onion or garlic powder so frequently used in cooking.

These are concentrated amounts and so it will take much less than a tablespoon to impact our Allie!

sauteed onions: Wikimedia Commons

And consider how many packaged foods you buy at the grocer that contain these ingredients.

Pasta sauce, salsas, Hamburger Helper (not that we eat that - just sayin’ ;-), flavored potato and tortilla chips (!), even some crackers contain either garlic or onion powder.

Honestly, it hadn't occurred to me how ubiquitous onion and garlic powder can be in packaged foods.

Be aware of the cumulative effect that foods like this may have on your pet if she’s fed table scraps.

Finally, let’s talk availability for a moment.

In places all over the world, you’ll find wild onions, leeks and chives growing.

I once made the mistake of buying a garlic chive plant and am still trying to weed it out of my yard. That thing is resilient and pops up everywhere!

Allie sits in front of chives in one of our gardens

And wild onions? Had them in the fence line of my previous home.

With the love many pets have of noshing on green things outdoors…be aware of what might be within their reach.

Here’s what these plants can do to an animal: The main cause for concern is anemia, followed closely by impaired oxygen transport to the tissues.

All living things require oxygenation of the tissues to survive. (It was brought dramatically home to us when Ryker suffered the blood clot that so quickly took him from us. The emergency vet immediately put him in an oxygen tent to try to supply much needed oxygen to his legs past the blood clot blockage.)

Additionally, active agents in some of these plants, such as garlic, are potent muscle relaxers and in studies inhibited the heart’s ability to contract properly. It also inhibits an animal's ability to contract the windpipe, affecting their ability to cough.

If you’re looking for signs that your pet has eaten one of these plants, you may be waiting a while, as the effects can take a few days after ingestion to begin to surface. Because of this, if you suspect your pet may have eaten onion, garlic or any of the other plants mentioned above, it’s always best to err on the side of caution and seek veterinary medical attention.

Staffordshire Bull Terrier: Public Domain

Diagnosis is usually made from observation of clinical signs as well as microscopic confirmation that Heinz bodies are found in your pet’s blood. Heinz bodies indicate anemia and changes in the hemoglobin inside red blood cells.

Your vet will most likely induce vomiting, then administer activated charcoal to absorb the toxins that might already be in your pet’s system (this is a universal antidote used in animal poisoning cases). They might also give your pet a blood transfusion or oxygen therapy if the symptoms are severe.

Bottom line, the best way to treat onion toxicity (and that of all onion and garlic-type plants) is to ensure your pet avoids them! And please…be sure to read food labels before offering any from-the-table treats.

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Next Week: Avocados - poison or pet food additive?

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sources:

Veterinary Medicine DVM 360: Toxicology Brief: Allium species poisoning in dogs and cats
VPI Pet Insurance: Pets and Onions: Each Layer Can Poison Your Pets
MEDLINE, May-June, 1991: Direct relaxant effects of garlic juice on smooth and cardiac muscles
food.com forum: products that contain garlic and onion