Common Liver Toxins

Dogs and cats are exposed to many toxic substances that harm the liver. Because a healthy liver is essential for life, pets should avoid liver toxins. This list details some common liver toxins and describes how pets might be exposed to them.

Acetaminophen or Tylenol
Pain & arthritis medication frequently used in humans. Some folks give this medication to pets to help their pain. It kills cats and harms dogs.

Aflatoxin
Aflatoxin is a toxin produced by Aspergillus mold. Because Aspergillus is present in the soil, crops are often infected. Although minute quantities of aflatoxin are allowed in crops, the molds grow to produce toxic amounts of aflatoxin when crops are stressed by bad weather. Plants commonly infected with Aspergillus mold that produces aflatoxin include: corn, maize, sorghum, millet, rice wheat, peanuts, soybeans, sunflower, cotton, almonds, and walnuts.

Aflatoxin is unrecognizable in the food because it doesn’t have an odor or an appearance that we recognize as moldy. For example, the FDA finds that aflatoxin is present in minute quantities in all commercial peanut butter. Aflatoxin is also present in packaged food containing grains and oils, such as dog kibble. Although we cannot recognize the toxin, many dogs and cats know it’s in the dog food and are reluctant to eat it.

Blue-green algae
Blue - green alga produces cyanotoxins and can be found in abandoned swimming pools and ponds full of nitrate fertilizer run-off. This is different than the algae we use to keep pets healthy, such as Spirulina.

Clay pigeons
Clay pigeons that are used for skeet and trap shooting are toxic to pets. Shooters don’t go out into the fields and pick up the busted clay pigeons, so they litter fields and can impact soil, wildlife, and pets used for hunting. Poisoning is caused by pitch that contains cresol and phenol. Pitch serves as a binder in clay pigeons, but non-toxic clay pigeons made without pitch are available.

Creosote
Roofing tar, tar paper, and wood preservatives contain creosote as a preservative. Pets that sleep on treated decks, in treated dog houses, or that crawl over tar paper rooms are affected. Creosote causes liver disease.

Copper
Pet supplements are often fortified with copper. For some dogs this is not a problem, but for others, even small amounts of copper are toxic. This occurs because these dogs have genetic predisposition that allows them to store copper but not to move it out of the liver. Thus, toxic levels of copper build up although the pet is receiving only a small amount of copper in the supplement. We cannot always tell a pet has a copper overload because blood tests don’t tell us what is stored in the liver, only what is carried in the blood. Some dogs prone to develop copper toxicosis are Bedlington Terriers, West Highland White Terriers, Labrador Retrievers, and Doberman Pinschers.)

Cycad palms
Cycads are palm plants with large seeds that grow where it’s warm, either in the sun or in the shade. The cycad palm nut contains a toxin that animals eat. Wild animals then become poisoned and carry the toxic substance in their fat. Dogs and cats that eat wild cycad-poisoned wild animals may also be poisoned. Some indigenous tribes use cycad nuts for food, but they soak the nuts so that much of the toxin is stripped from the nut.

Iron
Pet supplements are often fortified with iron, and iron is also present in some fertilizers and pesticides. Some dogs have genetic predisposition that allows them to store iron but not to move it out of the liver. Thus, toxic levels of iron build up although the dogs are ingesting only a small amount of iron in the supplement. We cannot always tell this is happening because the blood tests don’t tell us what is stored in the liver or bone marrow, only what is carried in the blood.

Lantana
Lantana is a flowering shrub that is so highly toxic that it is considered one of the ten most noxious weeds in the world. Usually, Lantana poisons grazing ruminants such as cattle and sheep, but it can be grown as a flower in shady, moist residential areas where it would be toxic to dogs and cats.

Mushrooms
Amanita and psilocybin mushrooms contain toxins that harm the liver and can cause death. Humans may use these mushrooms for mystical religious experiences because they cause profound central nervous system changes and hallucinations. Pets are already mystical. No mushrooms necessary.

Phenolics
Phenolics are chemical compounds that harm the liver and are found in everything from mouthwash to coal tar:
· creosol wood preserver
· coal tar,
· BHT food preserver,
· thymol in mouthwash,
· xylenol in antiseptics and disinfectants,
· cannabis found in marijuana,
· propofol an anesthetic,
· methyl salicylate found in oil of wintergreen.

Pyrrolizidine plants
Pyrrolizidine is toxic to the liver. Groundsel, rattlebox, and comfrey are plants containing pyrrolizidine. For pets, exposure to pyrrolidine is most often through comfrey used in wound and joint salves. Comfrey salves are OK for external use but are not OK if the pet licks the salve off.

Protect your pet
Unfortunately, liver disease is too common. Sometimes the effects of disease are subtle and difficult for us to detect, and other times, such as when exposed to high levels of aflatoxin in dog food, the effects are sudden and profound. Help protect your pet’s liver by avoiding toxins.