Time and again, I’m asked which herb is best for treating worms. Time and again, I give an answer that surprises many of my clients: If your pet has serious parasite problems and you’re serious about treating them, don’t use herbs. Use commercial drugs instead—they’re more effective.
This is not to say that herbs can’t help. After chemical deworming, an herbal program can enhance your pet’s ability to avoid worm infestations. In certain mild cases, I suggest no treatment at all, other than allowing the animal’s own healing abilities to take over, perhaps with an herbal boost to help. For example, a healthy puppy or kitty’s natural immune system will eliminate adult roundworms as the animal matures, and tapeworms are really more unsightly than they are a problem to your pet’s overall health.
I see dozens of different parasites in the animals I treat. The most common types are tapeworms, roundworms, hookworms, whipworms, heartworms, coccidia, and giardia. Each has its own life cycle, and how they are contracted and treated varies widely. Early infestations cause vague and nonspecific symptoms: general loss of vigor, lusterless fur, dull eyes, weight loss, and depression. Heavier loads of parasites can eventually kill the infected animal. To effectively diagnose the problem, your veterinarian will need to look at a fresh fecal sample and examine your pet’s blood.
Herbs: Not a cure-all
Over the years, I’ve tried several commercial herbal parasite remedies on pets in my practice. The problem is that they don’t meet the twin criteria that veterinarians use to evaluate any remedy: safety and efficacy. In almost all cases, these herbs cause side effects when used in doses strong enough to fight parasites. If you want to risk using them—and I recommend doing so only in mild cases—be alert for adverse reactions, especially in cats.
Although some herbal preparations are moderately effective against tapeworms and roundworms (the relatively mild guys), none are very effective against the more severe species of internal parasites such as heartworms or hookworms, which can be lethal even in small numbers.
• Garlic stimulates the immune system, kills many bacteria and fungi, and has some apparent effectiveness against parasites—especially roundworms. However, recent reports show that it may cause abnormal blood cells and result in anemia. Cats are more susceptible to the blood problems than dogs.
• Wormwood (Artemesia absinthium) contains thujone, a toxin that stuns roundworms, which are then expelled through the normal action of the intestines. Folklore abounds about wormwood’s usefulness against parasites, especially roundworms and pinworms. But repeated infusions of thujone can cause diarrhea, and high doses taken for a long time may cause liver problems. Wormwood as a flavoring agent is considered Generally Recognized As Safe (GRAS) in the United States, but only if it’s free of thujone.
Wormwood is extremely bitter, which makes it difficult to get your pet to take it. This bitter quality may further explain its reputation; bitters stimulate movement in the intestines, which may dislodge those parasites not firmly entrenched.
Other artemesias—including southernwood (A. abrotanum), mugwort (A. vulgaris), and sweet Annie (A. annua)—also contain thujone and have been mentioned in the literature for their apparent effectiveness against parasites.
• Black walnut is a common component of many herbal wormers. Based on my personal experience, black walnut produces fewer adverse side effects than do the artemesias.
• Pumpkin seed has a couple of qualities that may explain its reputation as an herbal wormer. When inside the intestine, the sharp edges of the freshly ground seeds may cut into parasites, injuring or killing them. And one of pumpkins seed’s bioactive ingredients also arrests cellular division; this may in some way inhibit the growth of parasites.
I’ve seen no toxicity using pumpkin seed for pets, but reports exist about other animals (cattle, sheep, poultry, and ostrich) that, when fed large amounts of pumpkin seed, develop a kind of drunkenness that becomes habit forming, and may cause withdrawal symptoms.
Herbs as support
A word of caution: Don’t let the remedies above give you a false sense of security. Some of my clients will see gobs of tapeworm segments in the feces right after their pet takes an herb, and they’ll think it has done a whale of a job. In reality, the remedy has caused only the tapeworm’s terminal segments to be passed, leaving behind the worm’s head, which is still embedded deeply in the gut wall, alive and well and ready to begin producing more segments. Or my clients will see roundworms—but what they don’t see are the worm’s larvae, either migrating throughout the pet’s body or encysted in tissue. These larvae may produce another infestation, or they may stay dormant until the animal becomes pregnant, when they can be passed on to puppies or kittens in the uterus.
Even though modern commercial drugs kill the whole tapeworm and wipe out roundworm larvae, holistically minded pet owners may still feel strongly that they want to use a natural remedy. But when it comes to the health of your pet, a severe parasite infestation can cause more harm than any product available from your veterinarian or local pet store. It’s much better to give your pet’s immune system a fighting chance by knocking out the infestation with the commercial drug. Then you can use the herbs listed in the box on page 30 to keep your pet in prime health.
If you have concerns or questions, discuss the situation with your veterinarian. And please, remember to request a fecal sample and blood test every year. Your pet will appreciate the results.