Fungal Rhinitis In Dogs – Symptoms And Treatment

Fungal rhinitis (often being used interchangeably with ‘aspergillosis’) is a growth, allergic response, or infection caused by opportunistic pathogens called Aspergillus fungus, Penicillium spp., and Cryptococcus neoformans. These funguses grow on compost piles, decaying stored grains, dead leaves, bird droppings, or other decomposing vegetation.

Aspergillus species has more than 180 types of lacy, fluffy molds that occur extensively in the outdoor and indoor environment.

Viewed under the microscope, Aspergillus looks like a fine-looking flower. The fungus sheds microscopic spores (called conidia) that float in the air to infect a host when inhaled or colonizing organic matter.

There are two common types of canine Aspergillus infection:

• Nasal (most common form - usually caused by Aspergillus fumigatus)
• Systemic (travels to other organs via the bloodstream - caused by Aspergillus terreus)

Meanwhile, there have been up to eight genotypes recognized of Cryptococcus, including Cryptococcus neoformans and Cryptococcus gattii. VN I, a type of c. Neoformans are the type that most commonly infects dogs.

Dogs contract infection after breathing in the infective spores of fungus in the environment. After infection, the organism transforms to yeast at normal canine body temperature and begins to infect the lungs, and spread systemically.

• Creamy or green/greenish-yellow nasal discharge. Blood can sometimes be seen within the nasal discharge
• Sneezing
• Ulcers around the nostrils
• Nose bleeds (epistaxis)
• Visibly swollen nose
• Hypopigmentation/ depigmentation of the nasal planum(Dudley nose- Pale discoloration of areas of the front of the nose)
• Signs that the dog is becoming head-shy
• Discomfort on palpation of the nose
• Reverse sneezing

Treatment of nasal aspergillosis:

1. Topical antifungal agents such as bifonazole 1% solution with clotrimazole or enilconazole (1% solution), are imparted inside the nostrils using a Foley catheter. After incubated for 1 hour, the solution enters all of the areas in the sinuses. After 1 hour, the remaining content is drained out or suctioned through the nostrils.
2. When the infection has infiltrated the brain, oral antifungals like fluconazole (Diflucan), terbinafine (Lamisil) or itraconazole (Itrafungol, Sporanox) is provided. Treatment is of longer duration and reportedly it has a 60% success rate.

Treatment of Cryptococcus neoformans:

This requires long-term medications (2-6 months in most cases).

Amphotericin B (Abelcet -The Liposome Company) is the "gold standard" of antifungal drugs.

ketoconazole (less expensive than the other azole antifungals) or a combination of medications may also be used in certain cases.

1. Relieve your dog’s nose with natural, organic ingredients found in Nozzle Nectar of Snout Soother.
2. Flush your dog’s sinuses with a saline flush to flush out mucus. This allows your dog to breathe easier.
3. Run a humidifier or place a vaporizer in the area your dog has to increase air moisture and humidity.
4. When you take a hot shower, you can bring your dog into the bathroom.
5. Use a bulb syringe or nasal aspirator to softly suck out or remove excess mucus inside of your dog’s nose.
6. Check with your vet for antihistamines usage (like Benadryl and Zyrtec) to help alleviate your dog’s runny nose.

• Check and dispose of overflowing waste bins and trash in the backyard carefully
• When going for walks, keep your dog away from rotting plant matter, dead leaves, and other decayed substances in the woods
• Maintain your lawn or garden. Keep it neat and clean to avoid unwanted pests
• Ask your vet for good quality flea and tick preventatives
• Feed a high-quality food and exercise regularly

All breeds are susceptible although highly prevalent in ‘dolichocephalic’ dogs (dogs with long noses).

Long nose: (e.g., Greyhound, Dachshund, Collie).

Retrievers and rottweilers also showed higher numbers.

Aspergillosis is rare in dogs under the age of 1 year.

Cryptococcus neoformans:

• Young, large-breed dogs especially Sporting dogs, hound breeds, and hunting dogs.
• Proximity to water bodies is a significant risk factor for affected dogs.

1. Causes:

• Aspergillusis considered an opportunistic pathogen, and dogs that have suppressed or compromised immune systems are highly susceptible.
• Aspergillusfungi shed microscopic spores (conidia) that float in the air and when inhaled, they sometimes avoid or sidestep a dog’s defensive respiratory mechanisms and can cause disease.
• Cryptococcus neoformans: This occurs more frequently in cats and the disease is rarely reported in dogs. The tendency for the dogs to poke their noses in the soil or follow a scent trail may play a role in infection. Airborne fungal spores of contaminated soil get disturbed and the dog inhales the spore. Cryptococcosis from dogs to humans is not yet reported.

2. Types:

• Aspergilloma: (referred to as a 'fungal plaque'), a relatively rare and less invasive form of nasal aspergillosis that produces an accumulation of fungus and mucous.
• Systemic (disseminated aspergillosis): Aspergillus terreus fungus enters the respiratory tract and via the bloodstream, transports to other organs producing a more severe systemic or generalized fungal infection. German Shepherd Dogs are overrepresented.
• Nasal aspergillosis: The most commonly diagnosed form of aspergillosis. Most cases of nasal aspergillosis are invasive which means the funguses damage the delicate bones of the sinuses.

3. Mortality:

Fungal rhinitis is not a lethal disease but it leads to long-term complications. If the central nervous system is involved, the mortality rate will be higher.

4. Diagnosis:

• Blood and urine cultures
• Specific blood tests to detect Cryptococcus
• Skin lesions biopsy
• A culture of eye/nose discharge
• Spinal tap- if pets show neurologic signs
• X-rays, ultrasound, or CT scan

5. Prognosis:

The prognosis for fungal rhinitis is really good and it depends on the age and overall health of the dog. For cases with localized nasal aspergillosis, the prognosis is generally good.

The prognosis for systemic aspergillosis varies inversely with delay in detection, severity, and evidence of sinus destruction.

It’s better to set up an appointment with your veterinarian if you notice:

• Nasal discharge - thick, green, yellow, or bloody
• Draining skin lesions
• Nose bleeds

Foods to avoid:

• Luncheon meat, bacon.
• Bread and baked goods.
• Sour cream, soft cheese, and Yogurt.
• Peanut butter, nuts, and legumes.
• Jams and jellies.
• Highly processed pet food.
• Starch as an additive or binding agent.
• High fructose corn syrup additives.

What to feed?

• Whole, unprocessed foods.
• Fresh food.
• Low-carb dog food.
• Probiotics and digestive enzymes.
• Fresh, lean protein.
• Add oregano or basil to their diet.
• Animal Essentials Detox Blend: (combination of herbs suspended in glycerine).
• This will help your dog detox.
• The raw diet, Semi-Homemade Food (commercial homemade diet with a dehydrated formula), or home-cooked meals.

Generally, the diagnosis of fungal rhinitis could be confusing considering the symptoms are similar to a sinus infection. Treatment of fungal rhinitis is dependent on proper identification. For cases with localized infections by Cryptococcus neoformans, the prognosis is generally good. About 25% of affected dogs relapse once treatment is finished.