Macadamia nuts and avocado get filed together because both sit on the same party platter, but they fail in different ways. Macadamias produce a nerve and muscle syndrome that looks alarming and usually resolves in 24 to 48 hours. Avocado mostly delivers a fat load, a 3 to 5 cm pit, and a mild upset stomach. Three measured checks in the first 24 hours separate the two, and each one takes under 2 minutes.
Why 0.7 g per kg is the macadamia number
Reported cases of macadamia toxicosis cluster around 0.7 g of nut per kg of body weight, with signs appearing 1 to 12 hours after ingestion and most animals improving within 24 to 48 hours without specific treatment. A whole nut weighs about 2.5 g, so a 5 kg dog crosses that line at roughly 1 to 2 nuts, a 20 kg dog at 6. Assess the nut, not the bag: salted, roasted, and chocolate-covered nuts all count, and the chocolate adds a second problem. Cats are less often affected in reports, but there is no reason to assume they are protected.
Check 1: the back legs and the jump
The signature sign is hind-limb weakness, sometimes with a stiff, swaying gait, tremors, or an inability to jump onto a 30 cm surface the animal cleared easily yesterday. Ask the pet to walk 10 steps on a non-slip floor and watch the hips. Knuckling, dragging, or a wide stance counts as abnormal. Most dogs stay bright and hungry through the whole episode, which is exactly why owners underestimate it. Weakness that reaches the front legs, or a pet that cannot stand for 10 seconds, moves the case from observation to a clinic visit.
Check 2: vomiting, stool, and water
Gastrointestinal signs are common and usually mild: 1 to 4 vomits in the first 12 hours, soft stool within 24 hours. What matters is the count and the fluid going in. A 10 kg dog needs roughly 500 to 700 ml of water a day; if vomiting passes 3 episodes in 12 hours or the dog refuses water for 6 hours, dehydration is building faster than the syndrome itself. Photograph each vomit with a coin beside it, and note whether any nut fragments came back up, because that answers the dose question better than any estimate.
Check 3: temperature and breathing at rest
Macadamia cases can run hot. Normal rectal temperature is 38.0 to 39.2 C; above 39.5 C with panting at rest is a reason to cool the animal with room-temperature water on the paws and belly and call the clinic. Resting respiratory rate should sit at 20 to 30 breaths per minute in a dog and 20 to 30 in a cat; count for 30 seconds and double it. A rate above 40 at rest, or gums that look muddy rather than pink, ends the observation phase.
How much nut is on the table
| Body weight | Nuts at 0.7 g/kg | Usual onset | Observation window |
|---|---|---|---|
| 5 kg | 1 to 2 nuts | 3 to 6 hours | 12 hours |
| 10 kg | 3 nuts | 3 to 6 hours | 12 hours |
| 20 kg | 6 nuts | 1 to 12 hours | 24 hours |
| 30 kg | 8 to 9 nuts | 1 to 12 hours | 24 hours |
| 40 kg | 11 nuts | 1 to 12 hours | 24 hours |
These are the amounts at which signs have been reported, not a guarantee of safety below them. A 3 kg cat that eats 1 nut is already at 0.8 g per kg, which is why cats get the same call as dogs.
The 3 checks on one page
| Check | Normal | Call the vet | How often |
|---|---|---|---|
| Walk and jump | 10 steady steps, jumps 30 cm | dragging, knuckling, cannot rise | every 2 hours |
| Rectal temperature | 38.0 to 39.2 C | above 39.5 C or under 37.5 C | every 4 hours |
| Resting breathing | 20 to 30 per minute | above 40 per minute | every 4 hours |
| Vomiting | 0 episodes | more than 3 in 12 hours | log every event |
Avocado is a different file
Avocado flesh is roughly 15 to 20 g of fat per 100 g, so one medium fruit with 150 g of flesh delivers about 25 to 30 g of fat and 240 kcal. That load is a pancreatitis risk for a small dog, and a 4 kg dog eating a whole avocado is eating the fat equivalent of 6 tablespoons of oil. Persin, the compound behind avocado toxicity in birds and rabbits, causes only mild stomach upset in dogs and cats in most reports, and the flesh carries far less of it than the skin, leaves, and pit. The pit is the mechanical problem: 3 to 5 cm across, too large to pass a small dog's pylorus, and a classic obstruction that shows up as vomiting 6 to 24 hours later.
Chocolate, salt, and other add-ons
Chocolate-covered macadamias combine two toxicities, and the chocolate usually decides the outcome. Salted nuts carry 150 to 250 mg of sodium per 30 g, which matters for a pet with heart or kidney disease. Macadamia butter is the sneakiest form: 2 tablespoons is 30 g of nut, comfortably past the 0.7 g/kg line for a 5 kg dog. Read the label for 3 words: macadamia, chocolate, salted. The label guide on the toxin page covers the rest of the platter.
When to stop watching and drive
Go now for tremors that repeat every few minutes, a temperature above 40 C, vomiting more than 6 times, a distended abdomen with unproductive retching, or a pet that cannot stand. Bring the nut shells if you have them, and say how many nuts the bag held before and after. Do not induce vomiting at home: a nut that comes back up into the airway costs more than 1 hour of observation. A vet who knows the nut count, the body weight, and the hour of ingestion can usually skip the guesswork and go straight to supportive care.
5 steps for tonight
- Weigh the pet, count the nuts, and write both numbers with the time on one sheet.
- Clear every nut and avocado from surfaces under 120 cm, including the bin lid.
- Run the 3 checks at 2 to 4 hour intervals and write the numbers down rather than remembering them.
- Offer water in small amounts every 30 minutes, and record what is drunk.
- Call the clinic if any check crosses its line, and take the log with you.
Keep the household toxin checklist on the fridge for the next platter, and check the same page before you decide that a 1 nut snack is too small to matter.
Frequently asked
How long do macadamia symptoms last in a dog?
Signs usually appear 1 to 12 hours after ingestion and resolve within 24 to 48 hours with supportive care only. Weakness and tremors are the common pattern. Watch for a temperature above 39.5 C and repeated tremors, both of which justify a clinic visit rather than another hour of waiting at home.
Is avocado actually toxic to dogs and cats?
The flesh is low risk in most reports and causes mild stomach upset at worst. The real hazards are the fat load, roughly 25 to 30 g per medium fruit, and the 3 to 5 cm pit, which can obstruct a small dog within 6 to 24 hours. Birds and rabbits are a different story and should never be given avocado.
Do I need to see a vet for 2 macadamia nuts?
For a 5 kg dog, 2 nuts is about 1 g per kg, above the 0.7 g per kg level at which signs have been reported. Call the clinic, then run the three checks every 2 hours. Most cases need no treatment, but a temperature above 39.5 C or tremors that repeat every few minutes change that answer.