Last week, we covered a few common toxicities I see in cats and dogs. Not all animal toxins are as obvious as recreational drugs or medications from our own medicine cabinets. Some are hiding in your pantry or growing in your garden. Dogs and cats metabolize foods differently than humans, and many things that are safe for us can be dangerous to our furry companions. Sharing grapes or macadamia nuts with your dog during a picnic may feel generous, but it could be unknowingly exposing them to severe organ damage.
Grape and raisin ingestion is one of the most common toxin triage calls I receive. Dogs are the only species reported to be susceptible to grape and raisin toxicosis. The exact toxic principle remains uncertain; however, tartaric acid (found in grape leaves) appears to play an important role. Dog kidneys seem uniquely sensitive to tartaric acid, and large exposures can lead to renal tubular necrosis, or kidney failure.
The amount of tartaric acid varies considerably depending on the ripeness of the fruit, which may explain why toxic doses are so unpredictable. Frustratingly, there is no clearly established toxic dose. Even a few grapes or raisins in a small dog have caused acute kidney injury. Some dogs never develop clinical signs despite eating large quantities, while others progress to kidney failure within 24 to 72 hours.
Because this toxin is so unpredictable, veterinarians must assume the worst-case scenario whenever a dog ingests grapes or raisins. The best course of action is to induce vomiting as quickly as possible before the fruit leaves the stomach. Your veterinarian will check their kidney values to obtain a baseline and may recommend intravenous fluids for 24 to 72 hours depending on the case. In my clinical experience, most of these patients make a full recovery when treatment begins before kidney injury develops.
While cat kidneys are not known to be sensitive to grapes or raisins, they are extremely sensitive to lilies. Species belonging to the Lilium and Hemerocallis genera are highly nephrotoxic to cats, even in very small amounts. Every part of the plant is toxic, including the leaves, pollen and flowers, although the exact mechanism remains unknown.
Lily ingestion causes severe damage to kidney cells and can quickly lead to acute kidney failure. Cats may initially also experience GI upset (vomiting, diarrhea, abdominal pain) shortly after exposure. Without treatment, kidney failure can develop within 24 to 72 hours, and death may follow within three to five days. Immediate veterinary care is crucial. Treatment is similar to grape toxicosis in dogs. Early decontamination, intravenous fluids and close bloodwork monitoring are the priorities. Most of the lily exposures I see involve indoor cats chewing on flower bouquets, but some of these lily species are native to Colorado, so outdoor cats can also be at risk.
The garden holds other dangers as well. Mushrooms are another major concern for our pets. As with humans, many mushrooms are harmless, but certain species can be highly toxic or fatal. Most mushroom-related fatalities are linked to Amanita phalloides, commonly known as the deathcap mushroom, which fortunately is not native to Colorado. However, several dangerous species do grow here, including Amanita gemmata (“jeweled deathcap”), Amanita muscaria (“deadly agaric”), Galerina marginata (“deadly Galerina”) and Gyromitra species (“false morel”). Mushroom identification can be extremely difficult, and dogs are notorious for swallowing something before their guardian can identify it. If your dog ingests a wild mushroom, contacting your veterinarian immediately is the safest choice. Your veterinarian may consult with a toxicologist or mycologist because toxicity varies dramatically between species.
Treatment includes rapid induction of vomiting and supportive care. Clinical signs are usually present within six hours of ingestion and can include GI upset (vomiting, diarrhea), liver failure, kidney injury or even neurologic symptoms such as tremors or seizures.
Wild mushrooms are not the only fungal danger to dogs. Pets can also ingest psilocybin-containing mushrooms left behind after outdoor concerts or music festivals. While humans can describe psychedelic experiences in vivid detail, our four-legged companions cannot tell us whether they, too, are “seeing the universe.” What we do know is that affected dogs often appear distressed. They may have GI upset, vocalize excessively, stumble, seem disoriented or develop other neurologic changes within 30 to 60 minutes of ingestion. In my experience, they do not seem to be having as good of a time as your friends did at the concert, so it’s best to avoid exposure all together.
Dr. Kelly Voss is a veterinarian at Aspen Animal Hospital, where she practices small animal medicine and surgery. She has a background in emergency and critical care and is passionate about bringing high-quality veterinary care to the mountains. Have a question for the column? Email her at dr.kellyvoss@gmail.com.
