Infectious Diseases

By | 2011-05-09

Herbs For Infectious Diseases

Herbs can deactivate viruses, bacteria, or fungi directly (this may involve altering membranes or enzyme systems) and are considered to be antimicrobial or to have antiseptic action. Others act indirectly via stimulation of phagocytosis, natural killer cells, lymphocytes, or other immune cells. For example, Andrographis (Andrographis paniculata) was originally thought to have direct antibacterial activity but was later found to exert its effect though immune stimulation. On the whole, treatment for infectious diseases is symptomatic. Apart from feline interferon-omega, there are currently no antiviral medications registered for veterinary use. Human antiviral drugs are available but are largely uneconomical or untested and complete elimination of virus is also not usually achieved. Herbal medicine management offers great potential to provide strategic immune modulatory action for infectious diseases. Herbs can also provide antiviral, antibacterial, antifungal, and antiprotozoal activity as well as symptom support for various infections.

Some general principles apply with any infectious disease. Provide conventional therapy as required and according to the severity of the symptoms. Support the immune system with immune-enhancing herbs. Provide systemic support. Focus particularly on the digestive system, which aids immune regulation via gut activated lymphoid tissue (GALT). Consider bitter herbs and alteratives that support elimination. Use adaptogens, particularly because stress can be a contributing or compounding problem associated with infectious diseases. Support the particular organs or systems affected by the infection. For example, Milk thistle is an obvious choice as a hepatoprotective herb in liver infections. Consider Golden seal (Hydrastis canadensis) for the gastrointestinal system and Uva ursi (Arctostapbylos uva-ursi) for the bladder. Use organ-specific antimicrobial, antiseptic, antifungal, antiprotozoal, or antiviral herbs.

Herbs With Immune-Modulating Activity

Coronavirus Infections

Coronavirus infections are most often associated with acute, self-limiting, enteric, and respiratory infections, but they can become chronic in infected animals. The low virulence enteric coronaviruses in cats and disease-causing feline infectious peritonitis are closely related and may represent differences in virulence. Coronaviruses do not usually cause disease in adult dogs but can cause mild gastrointestinal disease in puppies unless there is concurrent infection with parvovirus occurs.


Use immune-supporting herbs such as Echinacea (Echinacea spp.) or Astragalus (Astragalus membranaceus). Use adaptogenic herbs such as Withania (Withania somnifera), which also assists gastrointestinal function. For mild gastrointestinal disease consider the gastrointestinal herbs that can be used to alleviate symptoms; alternatively, consider the respiratory herbs if that system is affected. St. John’s wort (Hypericum perforatum) has activity against coronaviruses.

Canine distemper

Canine distemper virus (CDV) is a morbillivirus, which induces multifocal demyelination in the central nervous system in dogs. Part of the pathogenesis includes noninflammatory demyelination and viral-induced immunosuppression.


Use immune-supporting herbs such as Echinacea (Echinacea spp.) and Picrorrhiza (Picrorrhiza kurroa). Use adaptogenic herbs such as Withania (Withania somnifera), which is also a relaxing nervine. For neurological disease consider the neurological herbs that can alleviate symptoms and neurorestorative herbs such as Dan shen (Salvia miltiorrhiza). St. John’s wort (Hypericum perforatum) also has activity against morbillivirus. Also consider Thuja (Thuja occidentalis) for immune stimulation and antiviral effects.

Distemper in dogs is considered to be a model for multiple sclerosis. Medical cannabis is often used by patients with multiple sclerosis (MS) for muscle spasm and pain, and in an experimental model of multiple sclerosis low doses of cannabinoids alleviated tremor.

Feline Upper Respiratory Tract Infections

Feline upper respiratory disease (FURD) complex may be caused by viral or bacterial organisms, or concurrent infections of calicivirus, herpes virus, chlamydia, borde-tella, and mycoplasma. Treatment is mainly supportive (a high level of nutrition, adequate hydration, and good nursing care). Herpes virus 1 (rhinotracheitis) and calicivirus are the most common viral causes of upper respiratory tract infection in cats, and can be recurrent and chronic with or without secondary bacterial infection. There are no consistently effective treatments in conventional medicine. Lysine at 250 mg PO BID may be beneficial but is unproven, and interferon may help some cats with suspected herpes virus 1 infection, but neither are likely to cure the disease. Anti-inflammatory medications such as piroxicam can assist with chronic lymphocytic-plasmacytic rhinitis but side effects are possible. Herbal medicine rarely cures chronic disease but can reduce severity and increase disease-free periods, in the author’s experience.


In cats, use medicinal mushrooms, particularly Reishi (Ganoderma lucidum), Maitake (Grifola frondosa), Cordyceps (Cordyceps sinensis), and Shitake (Lentinula edode) combinations, to support immunity and help treat respiratory infection. Echinacea (Echinacea spp.) is ideal for respiratory tract infections. For nonsymptom periods consider Astragalus (Astragalus membranaceus) as a preventative. For herpes, consider herbal steam nebulizers to deliver St. John’s wort (Hypericum perforatum), or for calcivirus use Astragalus or both as teas to deliver direct activity to the nares and mucosal membranes. Consider the respiratory demulcents to reduce inflammation in the mucous membranes; Marshmallow (Althaea officinalis) is ideal in cats. If using conventional anti-inflammatory medications consider herbs that reduce the potential for side effects such as renal protective herbs (Astragalus is ideal).

Carrier status is common and stress induces disease; therefore, adaptogens play an important role in prevention.


Canine Infectious Hepatitis

Acute canine infectious hepatitis has been associated with canine hepatitis virus (canine adenovirus type-1), Helicobacter canis infection, leptospirosis, Rocky Mountain spotted fever, and other agents. Infections can lead to chronic liver disease.


Use immune-stimulating herbs. Andrographis paniculata is immune stimulating and has been used to treat leptospirosis. In people with infective hepatitis a majority of 20 patients showed marked improvement after the equivalent of 40 grams of andrographis were given each day for an average of 24 days. Overall, 80% were cured and 20% improved. Picrorrhiza kurroa may be valuable in viral hepatitis. In clinical trials using Picrorrhiza to treat infectious hepatitis, rapid decreases in bilirubin and quick clinical recoveries were observed. Echinacea is another good choice. Use adaptogens. If the patient is not excessive, consider Panax ginseng, which aids liver regeneration and hepatic function. Herbs that support liver function, including Milk thistle (Silymarin marianum), and in combination with Picrorrhiza are particularly well suited to the treatment of infectious or immune-mediated liver damage.

Feline Herpes: Stomatitis, Keratitis, Corneal Ulcers

The ocular syndromes caused by herpes in cats include ophthalmia neonatorum in the newborn, bilateral keratoconjunctivitis in young cats, and ulcerative keratoconjunctivitis in young and adult cats. Topical medications with specific antiviral activity such as Trifluridine may be beneficial. L-Lysine (500 mg twice daily) may also help.


Consider the options under Feline Upper Respiratory Tract Infections. Consider the options under herbs for eye and ear disorders. Use immune-supporting, adaptogenic, antiviral, and symptom-alleviating herbs. Topical herbal teas may be helpful. Teas should be made daily with boiled water to which 2 teaspoons of herb and 1 teaspoon of salt have been added. The tea should be filtered through a coffee filter to remove impurities that could irritate the eye. Lemon balm (Melissa officinalis) is the tea of choice for cats. It has topical efficacy against human herpes virus (Gaby 2006). Consider adjunctive care and pain-relieving herbs if blepharospasm is evident.

Parainfluenza/Infectious Tracheobronchitis

Infectious tracheobronchitis (ITB) is often a mixed infection (viral, bacterial, mycoplasma). Canine parainfluenza virus, canine adenovirus-2, and Bordetella bronchiseptica are considered to be primary pathogens. Other bacteria and Mycoplasma spp. may be primary or secondary. Paroxysmal coughing can be hacking, dry, or productive, but is usually self-limiting. Complicated cases may benefit from antibiotic therapy to treat or prevent secondary infections.


Uncomplicated infectious tracheobronchitis can be treated symptomatically using respiratory herbs, mainly antitussives. Use preventative measures for dogs that are in contact with one another; for example, oral doses or nose drops of Astragalus (Astragalus membranaceus) decoction protected mice from parainfluenza virus type 1 infection. Use immune-supporting herbs such as Echinacea (Echinacea spp.), Astragalus (Astragalus membranaceus), or Holy basil (Ocimum sanctum). Chronic upper respiratory infection in dogs may benefit from Echinacea. In an open, multicenter trial, 41 dogs not previously treated that had various conditions including kennel cough, bronchitis, pharyngitis, and tonsillitis were given powdered Echinacea purpurea root extract (1:3). Although there was no proof of diagnosis or control in this trial, 92% of the dogs had a good or very good improvement at 4 weeks and 95% showed the same results at 8 weeks. Use adaptogenic herbs such as Siberian ginseng (Elutherococcus senticosus), which is particularly indicated for infections due to stress that may occur in boarding situations. Note that it should not be used in acute infections. Use respiratory herbs such as demulcents, antitussives, and respiratory antimicrobials.

Canine Parvovirus And Feline Panleukopenia

These infectious diseases lead to hemorrhagic diarrhea and mucosal sloughing with breakdown of the gastrointestinal mucosal barrier. This in turn can lead to bacterial translocation and endotoxemia, as well as sepsis, which is made worse by a concurrent neutropenia. Antibiotics are indicated in these patients, along with fluid therapy, pain relief, and supportive nursing. Vomiting may preclude treatment with herbal medicine but gastrointestinal herbs should be used when recovering, or administered via enema using teas in the hospital. During the acute phase, if possible administer Slippery elm (Ulmus rubra) powder, which acts as a mucilage and demulcent and nutritive herb.

Herbs such as Agrimony (Agrimonia eupatoria) and Tormentil (Potentilla erecta) contain tannins, which can denature surface proteins and lead to reduced pain and bleeding. However, they must to be given orally, which may be counterproductive in the acute phase. Berberine-containing herbs such as Golden seal (Hydrastis canadensis) can reduce endotoxemia.

In the recovery phase, probiotics are important to help gastrointestinal repair. Also consider glucosamine, glutamine, and fructooligosaccahrides. Once vomiting has stopped consider formulas presented under gastrointestinal herbs. Three to 4 weeks of gastrointestinal repair should be expected. Herbs such as Meadowsweet, Marshmallow, Dandelion, and Withania (Witbania somnifera) may be helpful.

In one report by Jones (1995), 2 veterinarians treated 15 dogs with parvovirus using Cat’s claw (Uncaria tomentosa) as a distilled preparation (1 mL/kg twice daily). They reported that 10 of the 15 dogs recovered.

Tick-Borne Diseases: Lyme, Ehrlichiosis, Rocky Mountain Spotted Fever

Tick-borne diseases should be treated conventionally with appropriate antibiotics and supportive therapy. Depending on the diagnosis and signs, more than 1 disease-causing agent may be present at the same time. The spirochete Borrelia burgdorferi is responsible for the clinical syndromes of Lyme disease, which include arthritis, nephritis, carditis, and neurological changes. Canine ehrlichiosis is an acute to chronic disease characterized by infection of monocytes and lymphocytes, with anemia, lucopenia, and thrombocytopenia as common sequelae. Secondary immune-mediated hemolytic anemia may also be triggered by infection. In the chronic stage, pancytopenia and lymphocytois may occur. Rocky Mountain spotted fever is caused by Rickettsia rickettsii, which invade vascular endothelium and cause necrotizing vasculitis and petechiae, ecchymoses, and edema. Respiratory and neurological signs and lymphadenopathy may be seen. Conventional therapy may also include whole blood transfusions, fluid therapy, and sometimes corticosteroids. Herbs can be used to support the patient during the acute stages but are more strongly indicated for convalescence and for chronic disease. Herbal treatment is based on the individual patients and their symptoms.


Fundamentally immune-enhancing herbs are the most important part of treating these infections, acute or chronic. Prescribe herbs to support the organs and tissues affected by the infection; herbs that treat anemia may be useful. Provide herbs that alleviate symptoms such as nervines and musculoskeletal or respiratory herbs as needed. Consider restoring bowel flora following antibiotic therapy, particularly if extended treatment is needed.

Traditionally, spirochete infections (syphilis) in people were treated with Sarsparilla (Smilax ornata), Stillingia (Stillingia sylvatica), and Guaiacum resin (Guaiacum officinalis), and may have applications in the treatment of persistent Lyme disease.