Summer Damp Heat Causes Gastrointestinal Distress and Skin Infections

Hot, damp weather can aggravate existing problems in the gut, as well as the skin and urinary tract. Pets prone to inflammatory bowel disease, recurring bouts of diarrhea, or recurring cystitis (bladder inflammation) will have more flares during hot, humid late summer months. It can also cause dogs with syringomyelia (SM) to become more symptomatic. Our Cavalier King Charles Spaniel, Shayna, struggles to walk when the temperatures soar and the humidity is high. The pressure builds in the syrinx in her spinal cord causing pain when there are atmospheric pressure changes. Horses living in hot, humid areas can suffer from anhidrosis (inability to sweat).

TCVM Explanation for Summer Damp Heat

Heat and Dampness are two of the six ‘pernicious evils’ in Traditional Chinese Medicine. Too much heat outside can aggravate Heat inside the body. External Dampness (humidity or rain) can make internal Dampness worse. Internal Dampness occurs when the Earth element (Spleen/Stomach) is damaged.

Excess dampness and heat also affects Lungs and Large Intestine (Metal element). That’s because dampness tends to accumulate in the Lungs. When the Lungs are saturated with dampness, coughing and phlegm may occur. Eating cold foods, cow dairy products, or fried foods may also affect Large Intestine. When this happens, loose stools or diarrhea may occur.

Summer and late summer are prime times for Heat and Dampness to cause increased problems for pets and people who already suffer from one or more symptoms like:

  • Acid-indigestion or regurgitation
  • Inflammatory Bowel Disease
  • Red-toned skin eruptions or rashes
  • A tendency to be more irritable or cranky in hot, humid weather
  • Concentrated, dark urine or burning urinary tract infections
  • A tendency to be thirsty, especially for cool or cold fluids
  • Bloody or mucoid diarrhea
  • Swelling in the extremities
  • Lung and sinus infections

Chronic inflammation, poor diet, eating cold foods, and excess work can lead to excess Damp Heat. The tongue in Damp Heat will be red and may have a yellow greasy coating. 

Traditional Medicine Studies Have Shown Similar Results

Several studies have linked excessive summer heat exposure to worsening stomach problems which could lead to diarrhea. In one of the studies, it was found that human patients with inflammatory bowel disease (IBD) got worse during periods of prolonged heat waves to the point of requiring hospitalization. The study showed that a seven-day heat wave led to a 4.6 percent increase in risk of people needing to be hospitalized with a relapse of inflammatory bowel disease for every additional day that a heat wave lasted. One possible reason for the one-week delay in IBD flares is that heat waves change the bacterial composition of the gastrointestinal tract. But this change in gut bacteria takes time, which may explain the seven-day time lag in developing intestinal symptoms. Providing a good probiotic with herbs to soothe the intestines may help prevent this change in gut flora during times of heat stress. 

Treatment Options 

For Summer Damp Heat causing bloody or mucoid stools and diarrhea: Coptis root or Pulsatilla root - These are very bitter, strongly detoxifying and drying herbs, necessary when there is a great deal of mucous, foul and burning stool, and fever or infection. They have a broad antibacterial and anti-inflammatory action, and are generally used for a short time to subdue a severe and acute flare of symptoms. These herbs have shown as much benefit as metronidazole in human studies, without the side effects that can be seen when using metronidazole (Flagyl). 


For Damp Heat causing red, ulcerated skin, the herbal formula Si Miao San (also known as Four Marvels) can be very beneficial. The herbs in the formula clear heat and resolve dampness. This can also be beneficial for Damp Heat in the urinary tract. The four ingredients include:

  • Huang Bai (phellodendron bark)
  • Yi Yi Ren (coix seed)
  • Cang Zhu (atractylodes rhizome)
  • Huai Niu Xi (achyranthes root)

These ingredients are highly anti-inflammatory and often this formula can take the place of prednisone for inflammatory disorders but without the side effects.


Diet Matters

Foods that contribute to Dampness include cold raw foods (animals on a raw diet should be served food that is warmed to room temperature), cow dairy products (goat milk and goat cheese are not as heavy), and greasy foods. Foods that contribute to Heat include highly processed foods, foods cooked at high heat, and foods that are energetically hot. Avoid feeding dry kibble, starchy vegetables and grains, chicken, corn-fed beef, lamb, and goat during Summer Heat. Add cooling foods to the diet such as watermelon, celery, and cucumber. Rabbit, duck, alligator, cod, and clams are good protein sources that are Yin tonics (cooling). Drain Damp using celery, mushrooms, radish, asparagus, and turnips.

Proactive Care

By changing your pet's diet as soon as the temperatures begin to rise, adding cooling treats, cooling mats, and air conditioning, you can help avoid Summer Damp Heat issues. Exercise your pet outside early in the morning and late in the evening. Reduce stress by keeping your pet entertained inside with puzzle games, search games, grooming, and belly rubs. Regular grooming and bathing will help you detect any signs of inflammation or infection in the skin. Learn the signs of heat stroke so you can intervene before the situation becomes dire.

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