Avocado Toxicity

An owner called the hospital today and wanted to know if avocado is poisonous. Specifically, she wanted to know if avocado is poisonous to dogs.

Short answer - no. Dogs can eat quite a bit of avocado without problem. The pits are mainly a problem if they are swallowed whole and end up becoming and obstruction. Too much avocado = bad diarrhea.

Here's a quote from Dr. Mark Grossman:
Avocado does contain the toxin persin. The leaves, fruit, bark, and seeds contain the toxin. In dogs and cats however, it does not seem to be as much of a problem as in cattle, horse, goats, rabbits, birds and fish.
Signs including vomiting, diarrhea, death, inflammation of mammary glands of rabbits, goats, cattle, and horses are seen. As well as cardiac failure in goats with respiratory distress, generalized congestion, fluid accumulation around the heart.
A few cases of dogs becomming sick exist but they have to consume large amounts.

In other words - don't feed your goat avocado! Dogs - OK.

This has also come up because of a popular new food called Avoderm. Dasuquin also has avocado in it. It's OK. By all measurements, Avoderm appears to be a good food. Don't let the avocado part of it worry you.

Dr. H-

Follower Question - Hyperthyroid Feline and Proper Drug Choice

Hello Dr. Herndon,
I've seen it mentioned a couple times in a couple places that injectable and/or all benadryl should be used with caution/not used at all in a hyperthyroid cat. But, I can't find out why or what to look for. Also can't find any info on benadryl's effects on CRF cats. [I have a 16yr old CFR (+peri-renal cysts)/hyperthyroid female that has some serious sinus issues, among other things.

My vet and I have been trying to find ways of dealing with it that don't torture the cat. She severely hates Afrin nasal spray. Saline drops don't seem to accomplish much. Today I stuck her in a cage "next to" a steam vaporizer for 1/2 hr--that seemed to help a little... At any rate, she has been on injectable benadryl since 6/20 at 0.05-0.07 mL/dose. Most days she only got 1 dose. On 7/4 she went off her food--nauseated style. Today received an anti-nausea and pepsid in the AM. She finally ate cat food around 5:30pm after the vaporizer session. She has other issues too so this could very well be unrelated to the benadryl, but wanted to check.]
Thank you so much for your time, Kelly S


I can't think of any good reason not to use Benadryl in a well controlled hyperthyroid cat. No worries there at therapeutic doses. It MIGHT cause the heart rate to increase a little. A cat in out-right heart failure might not do well with it, but I think you'll be fine.

Cats with upper respiratory congestion are difficult to treat. When a cat can't smell, a cat won't eat. When a cat don't eat, a cat gets worse. You're doing the right stuff. Here's a couple of suggestions to bring up to your doctor:

1) Consider having a PCR run to check for herpesvirus, calicivirus, and mycobacterium (PCR is a very sensitive test looking for virus or bacteria DNA). If this is viral, it may be smart to consider using an antiviral up the nose. There is an antiviral drug called idoxuridine that is sometimes used in the eye - I've used it once in the nose instead. If it's herpes, then you can also add the amino acid lysine to the diet - that helps slow the virus down. The other anti-herpesviral medications used in people don't work well in cats (acycolvir/valcyclovir).

2) I've sometimes used atropine ophthalmic drops in the nose (cats HATE THIS!) but that helps dry it up. I'll also mix atropine with an ophthalmic antibiotic drop. The antibiotics can sometimes help with secondary infection.

3) I've worked with a compounding pharmacy to have an antihistamine made in a trans-dermal gel. Transdermal gels are a substance you would smear on the inner surface of the ear. The drug then absorbs across the ear skin. Not all chemicals/drugs can do this, but the pharmacist can help your doctor find out what drugs might be worth trying.

Humid air helps - you are trying to break up the debris in the nose so the kitty will eat.

A 16yr old kitty with several major health issues is not an easy task. If she's feeling nauseous I'd have some bloodwork run. When the renal values get too high the toxins will cause upset stomach and mouth ulcers. Worth a check.

Dr. H