Mycetomas In Dogs
It is a general disease characterized by the formation of tumors and lesions on the skin. If it is caused by fungus, it is called eumycotic mycetomas. Many different types of fungi are known to cause mycetomas. When the fungus that has infected the dog multiples in the skin lesions, they form granules. The size and color of the granules may differ according to the fungal species responsible for them.
Mycetomas of fungal origin are usually localized on the skin and the underlying tissue, but in some cases, the lesions that appear on the skin may have originated from a fungal infection deep in the dog’s abdomen. The lining of the abdomen may be inflamed, or abnormal masses may be seen in the abdomen, in such cases. White-grain mycetomas are examples of this. On the other hand, black-grain mycetomas are nodules developing on the skin. They are usually found on the dog’s face or on its limbs. When they develop on the limbs, the infection can penetrate into the bones below.
Mycetomas that originate in the skin are not potentially fatal, but they can be disfiguring. Anti-fungal treatments are not very effective in many cases, and surgery may be necessary to remove the growths. If the bones are involved, the limb may have to be amputated. In the case of mycetomas resulting from abdominal infection, the infection may be too extensive for surgical excision, and the outlook may not be very good.
North American blastomycosis In Dogs
This fungal infection caused by Blastomyces dermatitidis is confined to certain areas of the United States, hence the name. The humid and damp areas around the river basins of Missouri, Mississippi, Ohio, and Tennessee rivers and St.Lawrence Seaway, as well as the Great Lakes, play host to the this fungus that thrive in acidic soil and decomposing vegetation. Beaver dams offer the right conditions for their growth and multiplication. They are present in the droppings of bats and pigeons too.
Blastomyces dermatitidis that occur in nature in the mycelial form is highly infectious, and causes disease in both animals and humans. But the same fungus found in the tissues of infected animals is in a non-contagious yeast form. The infection usually originates in the lungs. But it spreads to the blood, and then to the other parts of the body through the blood. It is more common in people or animals that have a weak immune system. Infection can originate in the skin too, but the transmission to other parts is usually from an infection in the lung.
Among dogs, hunting breeds and young males are more prone to developing blastomycosis as they are more likely to be exposed to moist soil contaminated by fungal mycelia. The disease may affect the eyes and bones of the dogs too.
The typical symptoms are respiratory difficulties accompanied by fever and cough. The dog may have difficulty in exercising, and may develop breathlessness. Lack of appetite as well as weight loss is common. The lymph nodes found in the neck, knee and shoulder area may be swollen. If bones are affected, the dog may have pain while moving, and it may become lame due to that. When the eyes are involved, they may become sensitive to light. Glaucoma or blindness may result too. Bloody urine is a sign of urogenital tract infection. Male dogs may have infection in the prostate gland. Infection in the skin produces nodules that drain pus.
Blastomycosis is treated with one or more antifungal medications which have to be taken for a couple of months or more. They will remove the active disease from the body, even if complete eradication of the fungus is not always possible. 20% recurrence is observed in dogs that have been treated with the antifungal drugs, but repeat treatments are effective. Other medications may be necessary to tackle the problems caused by the infection to different organs like the eyes and the lungs. The outcome of the treatment may not be good in case of extensive damage to the lungs. It is extremely poor if the disease has affected the brain or the nerves.