Can a dog survive a fungal infection

Identifying and Treating Fungal Infections in Dogs

By Reyna Gobel

Bacteria and viruses are what typically spring to mind hen pet parents think infection, but fungi can also be to blame. While not as common as bacterial or viral infections, fungal infections can be just as serious. Dogs can contract fungal infections from other animals, from the environment, or as a result of the overgrowth of fungi that are naturally present on their own bodies. Every pet is potentially at risk for contracting a fungal infection, and an accurate diagnosis is necessary before appropriate treatment can begin. Read on to learn more about fungal infections in dogs.

Fungal Skin Infections

When your dog starts scratching himself more than is normal, it can be hard to tell whether its because of an allergy, flea bites, infection, or something else. Excessive itching can be quite worrisome, especially if your dog develops bald spots or damages his own skin as a result.

One telltale sign of fleas is the presence of flea dirt (small black clumps of flea feces) on your dogs skin and fur. If you see flea dirt or actual fleas, treat him right away. But if fleas or ticks arent to blame, dont self-diagnose or rely on Dr. Google, warns Dr. John DaJong, a veterinarian at Newton Animal Hospital in Massachusetts. After performing a complete physical exam, your veterinarian can conduct specific tests to help diagnose the problem and identify whether a fungal infection is to blame.

Lets look at two common types of fungal infections that affect the skin of dogs and how to treat them.

Ringworm

Ringworm is a common fungal infection in pets. It can affect a dogs skin, fur, and also the nails. Common symptoms include hair loss, itching, flaky or crusty skin, and misshapen or brittle nails. While you should treat any infection as soon as possible, time is of the essence with ringworm because it can easily spread to other household animals and humans, says Dr. Andrew Rosenberg, a veterinarian at Riverdale Veterinary Dermatology clinic in Riverdale, New Jersey.

To diagnose ringworm, your veterinarian will perform a fungal culture of hair or skin cells or a microscopic examination of a hair sample. Depending on the severity of the infection, ringworm may be treated with medicated baths and dips and/or oral antifungal medications. Vacuuming and disinfecting the house will also help lessen the chances that ringworm will spread between pets and people.

Yeast Infection

Overgrowth of yeast on a dogs body can lead to irritating yeast infections, commonly affecting the skin, paws, and ears. These infections can be extremely uncomfortable for dogs, says Rosenberg. Theyre generally secondary to allergies or other conditions that disrupt the skins ability to control the yeast that normally live there.

If I suspect a dog might have a yeast infection, I take an impression smear of the area that might be infected and look at it under a microscope, Rosenberg says. When the slide is stained, the yeast look like little purple peanuts.

Treatment normally involves an antiseptic or antifungal drug applied to the skin. Oral medications may be necessary in severe cases. Unlike ringworm, yeast infections arent contagious to other pets or people. To prevent yeast infections from recurring, its important to treat any underlying conditions as recommended by your veterinarian.

If your pet is constantly itching and scratching, schedule an appointment with your veterinarian. Unfortunately, not all conditions can be solved with one visit. Sometimes it could take several visits to pinpoint the cause of your dogs itching or require a visit to a veterinary dermatologist, Rosenberg says.

Systemic Fungal Infections

Fungal infections on the surface of the body are bad enough, but those that invade deeper structures can have even more serious consequences. Lets look at several common types of systemic fungal infections in dogs and how to treat them.

Blastomycosis

Blastomycosis is most commonly diagnosed in dogs that have spent time in Mississippi, Ohio, Missouri, Tennessee, the St. Lawrence River valley, the mid-Atlantic, and around the Great Lakes because the types of soil that are typically found in these areas support the growth of the fungus. Dogs that spend time sniffing around in the dirt are at risk for inhaling fungal spores, which can lead to a lung infection, says Dr. Jennifer Coates, veterinarian and author of Dictionary of Veterinary Terms, Vet-Speak Deciphered for the Non-Veterinarian. From there, the organism can travel almost anywhere in the body. According to Coates, common symptoms include poor appetite, weight loss, coughing, difficulty breathing, limping, eye problems, skin lesions (particularly around the toenails), enlarged lymph nodes, and fever. If the disease is caught early enough, treatment with an oral anti-fungal medication can be curative.

Cryptococcosis

While cats are more commonly infected with the fungus Cryptococcus, Coates says dogs tend to develop a more severe form of the disease. The fungus is present in soils world-wide but may be especially prevalent in areas where pigeons and other birds congregate. As is the case with blastomycosis, dogs typically inhale the Cryptococcus fungus, leading to a lung infection. It can then spread almost anywhere in the body, which can cause symptoms ranging from lethargy, coughing, nasal discharge, eye problems, skin lesions, and even seizures and other neurologic abnormalities. Coates warns that treating cryptococosis can be difficult. Oral antifungal medications may need to be given for a year or more and some dogs will still succumb to the disease.

Coccidioidomycosis

Dogs can get coccidioidomycosis (also known as Valley Fever) from inhaling dust or dirt that contains coccidioides fungal spores,says Dr. Carol Hillhouse, a veterinarian in Panhandle, Texas. It tends to grow in desert areas with little rain and sandy soil, such as California, Nevada, Arizona, New Mexico, and Texas, she says. Strong winds, earthquakes, construction areas, and even crop harvesting can stir up the spores into the air.

Once the spores are inhaled, the fungus may simply cause a chronic cough, Hillhouse says. In other cases, especially if immunosuppressed, the dog may develop pneumonia or the fungus can spread to other areas in the body, such as bone or the eyes, she says. It can be difficult to diagnose, and usually requires radiographs, blood, and cell testing. Valley fever requires long-term treatment with oral antifungal medications, but the prognosis is pretty good if caught early, she says.

Histoplasmosis

Another soil-borne fungus, Histoplasma, prefers the temperate climates of Ohio, Mississippi, and Missouri River Valleys, Hillhouse says. This fungus grows best in nitrogen-rich soil, such as bird and bat excrement, and is usually acquired by inhalation of the organism from the environment.Infected dogs can show weight loss, fever, cough, eye inflammation, vomiting, and diarrhea, she says. Often, a combination of blood and urine tests, as well as radiographs, are used to make the diagnosis. Sometimes biopsies are required as well. Treatment involves long-term fungal medication, but prevention is best by restricting access to soil that is contaminated with bird or bat droppings.

Aspergillosis

Infections with Aspergillusfungus are usually limited to a dogs nasal passages. Aspergillosis can affect dogs residing in almost any part of the country since the fungus is present in most soils. Treatment typically involves anesthetizing the pet and infusing his nasal passages with a liquid anti-fungal medication. Most dogs will recover if treated appropriately, although a second treatment may be necessary in some cases.

Preventing Fungal Infections in Dogs

Fungal infections in dogs range from localized annoyances to potentially fatal systemic diseases. Prevention is not always possible, but common sense measures can help. If you live in an area where a certain type of fungal infection is endemic, avoid high risk environments. Pets with ringworm should be isolated to limit the spread of the disease to people or other animals. Finally, appropriately manage any underlying health problems that increase your dogs risk for developing a fungal infection.

Fungal Infections in Dogs: Signs, Causes & Treatment (Vet Answer)

The information is current and up-to-date in accordance with the latest veterinarian research.

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A number of fungal infections can affect our canine companions. Some of these fungal infections are superficial or local diseases, such as ringworm and yeast dermatitis, which are problematic but not life-threatening. Other fungal infections, such as Aspergillosis and Cryptococcosis, can involve multiple internal organs and are much more serious.

This article will explore common fungal infections in dogswhat they are and watch to watch for, as well as how they come about and how they can be treated.

What Are Fungal Infections in Dogs?

Fungi are parasitic microorganisms that produce spores. While many people think of mushrooms when they think of fungi, the fungi that produce disease in dogs are generally tiny microorganisms that require a microscope to be seen. Fungi are abundant in the environment (particularly in soil), but only a few are capable of causing disease. This article will focus on four common causes of fungal infections in dogs. It helps to categorize fungal infections as localized, meaning the fungi are confined to the skin or external features, and systemic, meaning major body systems are involved:

The 2 Types of Fungal Infections

1. Localized Fungal Infections

Dermatophytosis (Ringworm). Ringworm is an extremely contagious disease-causing fungus that is common across the world. It is spread through direct contact between dogs, though it can also jump across species from people or cats. Ringworm causes skin disease and hair loss that is generally mild and treatable.

Fungal Dermatitis. This is also referred to as yeast dermatitis or, in vet circles, Malassezia dermatitis. Yeasts are a type of fungus, and in dogs, Malassezia pachydermatis is the yeast normally responsible for this disease. While it is normal for dogs to have this yeast on their skin, some dogs are prone to an overgrowth of the yeast, resulting in inflammation of the skin.

2. Systemic Fungal Infections

Aspergillosis. This is a variety of fungi found in soils across the world. It commonly infects the nasal passages of dogs, and this is termed Nasal Aspergillosis. While generally limited to the nose and the sinuses, it can damage the bones of the nasal cavity. Less commonly, this fungus causes a more generalized and life-threatening disease, called Disseminated Aspergillosis, in which the fungus enters the bloodstream. This tends to be seen in German Shepherd dogs.

Cryptococcus fungus. While this is more prevalent in cats, dogs can also become infected with the Cryptococcus fungus. It can cause lung infections if inhaled, but it can also reach the eyes, skin, and nervous system. Cryptococcosis is more common in areas where birds such as pigeons gather in large numbers.

The Signs of Fungal Infections Based on the Fungus Type

The signs of fungal infections in dogs depend on which fungus is involved, and if the disease is localized or systemic.

• Ringworm: Ringworm is generally not an itchy condition in dogs. It causes patches of hair loss, circular skin lesions, flaky skin, and brittle nails.
• Fungal Dermatitis: This is generally confined to the skin, ears, and paws. Red/inflamed skin, itchy skin, scabby lesions, yeasty-smelling skin, and ear infections are all common signs.
• Aspergillosis: Nasal AspergillosisThis causes lethargy, bloody or snotty nasal discharge, sneezing, pain around the nose, and loss of pigment around the nose.
• Disseminated AspergillosisLethargy, limping, loss of appetite, weakness, vomiting, and swollen lymph nodes.
• Cryptococcosis: Lethargy, coughing, labored breathing, eye problems, and seizures are all possible signs.

What Are the Causes of Fungal Infections in Dogs?

Fungi are everywhere in the environment. There are three main ways dogs become infected with a fungus.

Firstly, the fungus can be inhaled or picked up in the environment, as in the case of Aspergillus and Cryptococcus. This is generally considered an accident and can occur in otherwise healthy dogs.

Secondly, fungal infections can be transmitted from one dog to another. This is what happens with contagious fungal infections such as ringworm. Other dogs infected by ringworm are immunocompromised, meaning they have a weakened immune system. This occurs with sick dogs and young puppies.

Lastly, fungal infections can be caused by an overgrowth of fungi that naturally exist in small numbers on the skin; this is the case with yeast dermatitis. Most dogs have a few Malassezia yeast on their skin, causing no issues at all; but some dogs with allergies develop unhealthy, inflamed skin, allowing the yeast population to flourish and cause dermatitis.

How Do I Care for a Dog with a Fungal Infection?

This should always begin with a consultation with a veterinarian, so that a diagnosis can be reached, and treatment options discussed. Treatment for dogs with fungal infections varies based on what fungus is present, and how severe the signs are. Generally, localized fungal infections are treated with topical creams and shampoos, and sometimes tablets. Dogs infected with ringworm should be kept away from other dogs to minimize the chance of the fungus spreading.

Systemic fungal infections require more aggressive treatment, often involving a period of hospitalization and very long courses of antifungal tablets. Some dogs with Nasal Aspergillosis benefit from a surgical procedure under anesthetic.

Frequently Asked Questions

What Is the Prognosis for Dogs with Fungal Infections?

This depends on the specific fungal infection. Localized fungal infections are generally treatable, with a very good prognosis for full recovery, but systemic fungal infections can be much harder to treat.

How Are Fungal Infections in Dogs Diagnosed

Most localized fungal infections, which are confined to the skin, can be diagnosed by fairly simple and non-invasive tests. This might include taking skin samples for analysis under the microscope, as well as fungal cultures and biopsy. Systemic fungal infections may also require fungal cultures and biopsy; however, advanced imaging such as an MRI or CT scan may be required to establish a diagnosis.

Conclusion

Fungal infections in dogs can cause a wide variety of signs. While systemic fungal infections are very hard to prevent and treat, localized fungal infections can generally be managed with good skin hygiene, isolation from other dogs, and fairly simple at-home treatments.

The above list is not exhaustive but rather focuses on the most common fungal infections in dogs. If you have any concerns about your dog, or if you have noticed any of the signs outlined above, dont hesitate to contact your veterinarian.

Featured Image Credit: Nathalie Marran, Shutterstock