What Are Symptoms of Black Mold in Dogs?

By Bethney Foster

Black mold, also known as Stachybotrys chartarum, lurks in dark corners and hides in cabinets in the days, months and even years after a house has been flooded by water. While it's been known for many years that black mold causes respiratory problems and pulmonary hemorrhage in humans, the first documented case of it causing illness in pets didn't come until 2005. Before then, black mold had not been associated with disease in pets.



The first documented case of toxic black mold and its effects on pets came when two Himalayan cats were undergoing a routine dental cleaning at Marathon Veterinary Hospital in Florida. The two brother felines were under anesthesia when the veterinarian saw blood forming in the tubes that provided the anesthesia during the procedure. One of the cats died the next day and the other died two weeks later. The veterinarian, Dr. Douglas Mader, stated that what happened was abnormal because anesthesia doesn't cause pulmonary hemorrhage. The veterinarian, after talking to the cats' guardians, learned that they lived in a home that had sustained water damage in a hurricane a couple years earlier. Black mold was found in the home after the cats' deaths.


Black mold grows in areas with high humidity. Homes that have been flooded or suffered other major water damage are particularly susceptible. The spores of black mold contain different kinds of mycotoxins that are dangerous to the health of people and animals.


The effects of black mold poisoning can range from mild respiratory disease to lung trauma. The black mold poisoning causes weakening of the capillaries in the lungs and when the capillaries are stressed, they burst and bleed. Complications from the hemorrhaging of their lungs is what killed the two Himalayan cats.


While little information is yet available on black mold and pets, veterinarians are urging pet guardians to exercise caution if their companion animals must undergo anesthesia and there is a chance they have been exposed to black mold. Guardians should tell their veterinarians about their pet's possible exposure and veterinarians should ask more questions of pet guardians to determine if their patients might be at risk.


If your pet does undergo anesthesia and complications arise that suggest your dog or cat may be poisoned by black mold, such as a bloody respiratory discharge during the procedure, the anesthesia should be stopped immediately. Initially your pet will be treated with corticosteroids to try to stabilize the capillary epithelium. Your pet will then likely be given antibiotics to help prevent bacteria growth which could lead to secondary pneumonia.