Alternaria Tenuis in Dogs

by Betty Lewis
Alternaria tenuis is happy in the woods amongst the decomposing leaves.

Alternaria tenuis is happy in the woods amongst the decomposing leaves.

David De Lossy/Photodisc/Getty Images

Alternaria tenuis is mold that can trigger allergies in people and pets. Also known as alternaria alternata, the mold is commonly found on a wide variety of plants and in environments both indoors and outdoors. If your pup has an allergic reaction to this mold, it will likely show up on his skin.

The Mold and Its Haunts

Alternaria tenuis thrives outside on vegetation, but it can grow in other places. Compost, old leaves, soil, rotten wood and some forest plants provide great breeding grounds for this mold, which prefers damp spots. It also grows in condensed water on windows and is common in dust found in buildings. When spores of this mold are found indoors, it's likely that they came from an outside source.

Developing an Allergy

The first time Pal inhales alternaria tenuis spores, if he's sensitive to them, his immune system will produce antibodies that attach to the spores to neutralize them. The reaction is known as sensitization, and it happens just the first time, or first season, a dog encounters the allergen. If sensitization doesn't occur, the dog has no allergy. This is the most common type of allergy in dogs, referred to as atopy or atopic dermatitis. The next time the allergic dog encounters alternaria tenuis spores, his immune system will quickly produce large amounts of antibodies, which release histamines from his mast cells, resulting in the allergic reaction.

Itchy Scratchy

Your first clue that Pal is suffering from an allergic reaction will be his increased scratching. His skin may become moist, red or scabbed if he scratches excessively. The dog's face, feet and armpits are the most likely spots for him to suffer intense itching. Because he's so itchy, he may bite, rub, lick or chew his skin, and his eyes may be itchy and runny. In most cases, a dog will show signs of allergy in his skin, but occasionally he may sneeze and experience diarrhea and vomiting.

Adapting to Allergies

Pal will need to visit the vet for an exam if he's scratching excessively. The vet will perform a skin test and will want to know when your pup started experiencing his symptoms. Generally, the reaction becomes worse each season the dog's exposed to the airborne mold. Other testing may include stool sample, allergy testing and fungal tests. Medication, such as steroids and antihistamines, can provide relief; if Pal has developed an infection from his intense scratching, he may need an antibiotic. You'll need to pay attention to your surroundings to determine if your pup frequents an environment infested with alternaria tenuis. The spores can travel great distances, so they may be unavoidable. Look for potential areas for mold growth that will trigger Pal's reaction. Regular dusting and thorough housecleaning will help, particularly if you have houseplants and carpeting. Work to reduce moisture in the air during humid weather, and consider getting a HEPA filter to capture potential allergens.

Photo Credits

  • David De Lossy/Photodisc/Getty Images