Understanding Blastomycosis in Dogs – Key Insights

Blastomycosis is a serious infection in dogs caused by a fungus found in soil. It occurs in places like the Mississippi and Ohio River valleys. Dogs get it by breathing in fungus spores. At first, it affects the lungs but can move to other body parts.

This disease hits young, male, hunting dogs the hardest, especially those roaming free in certain areas. Signs of the disease include coughing, trouble breathing, fever, not eating, and losing weight. Catching and treating it early is key to helping your dog recover¹.

Key Takeaways:

• Blastomycosis is a systemic fungal infection caused by Blastomyces dermatitidis.
• The infection starts in the lungs and can spread to other organs, leading to a disseminated infection.
• Blastomycosis is more common in young, male, hunting dogs in endemic areas.
• Clinical signs include coughing, difficulty breathing, fever, loss of appetite, and weight loss.
• Prompt diagnosis and treatment are crucial for successful management¹.

Symptoms of Blastomycosis in Dogs

Blastomycosis symptoms in dogs differ with the organs it affects and how severe it is. Dogs may show many signs:

• Coughing: Roughly 85% of dogs start with a dry cough, which can become wet as the infection gets worse².
• Difficulty breathing: Dogs with this infection might breathe fast or struggle to breathe due to their lungs being affected³.
• Fever: High body temperature is often seen in dogs with this condition³.
• Loss of appetite: Infected dogs may not feel like eating and ignore their food³.
• Weight loss: Dogs can lose weight without any clear reason if they have this disease³.
• Skin lesions: About half of the dogs show skin bumps filled with pus³. These can appear on their body or legs and might also cause hair loss².
• Ocular problems: Dogs might squint, have red eyes, or be sensitive to light².
• Neurological symptoms: Though rare, this disease can impact a dog’s brain, leading to seizures or a head tilt².
• Lameness: When it infects bones, dogs might limp and have trouble moving².

It’s crucial to remember these signs could hint at other health issues. Only a vet can give a clear diagnosis and the right treatment².

Diagnosis of Blastomycosis in Dogs

Figuring out if a dog has blastomycosis is tough due to vague symptoms. But, getting details about the dog’s time in places where blastomycosis is common helps. Tests to find antibodies against the Blastomyces dermatitidis fungus might help, but they’re not always right, particularly early on.

To confirm blastomycosis, doctors must find the fungus in tissue from biopsies or skin nodules. They look at these samples under a microscope and grow the fungus to be sure it’s Blastomyces dermatitidis.

“Blastomycosis is most reliably diagnosed by demonstrating the organism in cytologic or histologic samples from infected tissues. Cytologic evaluation of lymph nodes and skin lesions can yield positive results in a high percentage of cases. Cytologic examination of lung samples can assist in diagnosing pulmonary blastomycosis, with transtracheal wash samples showing organisms in 69% to 76% of cases.”⁴

Treatment of Blastomycosis in Dogs

Treating blastomycosis in dogs often means using antifungal medicine for a long time. Doctors choose the drug based on how sick the dog is. Amphotericin B is given through the veins first. Then, medicines like ketoconazole, itraconazole, or fluconazole are given by mouth. These medicines fight the fungus well. Yet, they might hurt the kidneys and liver. So, checking the dog’s blood often is key to keep them safe.

Treatment might last many months to over a year. It depends on how well the dog responds to the medicine. In one study, dogs took 170 mg itraconazole every 12 hours for three days. Then, they took it once every 24 hours for seven days⁵. This plan worked well against blastomycosis.

It’s important to watch how the dog does and change the medicine as needed. Vets keep an eye on the dog’s symptoms and do lab tests over and over. They also make sure the dog eats well, drinks enough water, and is comfortable. All this helps the dog get better.

The cost for finding and treating blastomycosis can be high. Just the test to find blastomycosis can cost up to $250⁵. But finding the disease early is key to picking the best treatment.

Success of Treatment:

Studies show that treating blastomycosis in dogs with itraconazole works really well. In one research, a test for blastomycosis was right 93.5% of the time⁵. Another study found it was 100% accurate at diagnosis⁵. This shows how good the test is at finding the disease and seeing if treatment is working.

All 4 animals with a certain test reading got better with itraconazole⁵. This proves itraconazole is a strong choice for fighting blastomycosis.

Seeing the vet regularly while treating blastomycosis is a must. This helps track the dog’s improvement and checks if symptoms are going away. With the right care, most dogs beat the disease. They end up healthier and happier.

Prevention of Blastomycosis in Dogs

Blastomycosis is a common fungal infection in dogs. It’s a big health risk, especially in wet areas where the Blastomyces fungus lives⁶. Even though we don’t have a vaccine, dog owners can still do a lot to keep their dogs safe from this infection.

1. Avoid High-Risk Areas

Dogs get blastomycosis by breathing in fungus spores from the soil⁶. It’s smart to stay away from places with a lot of fungus. Think about avoiding wet soil near rivers, lakes, and wetlands loaded with organic stuff⁶. By doing this, you can cut down the risk of your dog meeting the nasty fungus spores.

2. Be Mindful of Outdoor Activities

Be careful when you’re outside with your dog, especially if they like to dig⁶. Activities like camping, hiking in moist areas, or swimming can put your dog at risk if the area has blastomycosis fungus⁷. Watch what they do closely and try to keep them away from soil that might have the fungus.

3. Early Diagnosis and Treatment

Spotting blastomycosis early can make a huge difference in how well your dog recovers⁶. It’s key to watch out for signs and get help from a vet fast if you think your dog might be sick. Tests like X-rays, blood checks, and samples can confirm if your dog has the infection⁶. Once you know, a vet can start treatment which usually involves medicine for a few months⁶.

4. Regular Monitoring

Dogs that aren’t very healthy or have weak immune systems are more likely to get blastomycosis. They should really stay away from areas where the fungus is common⁶. It’s vital to watch your dog closely outside, especially if they’re the type to dig around a lot⁶.

“To prevent blastomycosis in dogs, avoid fungus-heavy areas and keep a close eye on your pets outdoors, particularly if they dig.” – Statistical Data⁶

In summary, protecting dogs from blastomycosis involves several steps since there’s no vaccine. Dog owners can play a big role in prevention. Just avoid places where the fungus spreads, watch your dogs’ outdoor play, get them checked if they show signs of sickness, and always keep an eye on them. This way, your furry friends can stay safe from blastomycosis.

Genetic Diversity of Blastomyces dermatitidis

Blastomyces dermatitidis, the fungus behind blastomycosis in dogs, shows lots of genetic variety. Research has found genetic differences between the types found in animals and humans¹.

Dog-related strains have more genetic types, or alleles, than those in humans¹. This genetic variation helps shape the fungus’s genetics and affects its growth and disease-causing abilities¹.

Also, the genetic types of B. dermatitidis can vary between animals and humans¹. This means the fungus might interact differently with its hosts depending on their genetics¹.

Epidemiology of Blastomycosis in Dogs

Blastomycosis is a major health issue for dogs, mainly in places where it’s common. It’s among the top systemic fungal diseases affecting dogs in North America⁸. This disease often hits young, male dogs, especially those from hunting breeds who enjoy the outdoors.⁹ While dogs get blastomycosis more often than humans, cats rarely get this disease⁸. Dogs usually catch this disease by breathing in fungus spores from the environment⁸.

In dogs, the disease often spreads throughout the body, more so than in humans. Dogs may show general symptoms like tiredness, lack of appetite, and fever. They might also show symptoms that signal problems in specific organs⁸. The disease is found more in some places than others, with certain areas seeing over 100 cases in 100,000 dogs⁹.

A study in Michigan shed light on how this disease affects dogs there. It found most cases came from the Upper Peninsula or a dense area in the northern Lower Peninsula⁹. Moving or living north of the 45th parallel increased the risk of getting the disease⁹. The study mapped high-risk and low-risk locations based on where dogs lived or traveled⁹. Blastomycosis was found year-round, peaking in summer and fall⁹.

This Michigan research aimed to understand how common blastomycosis is in dogs and pinpoint risk factors. Over 200 vet clinics and specialty centers contributed data for the study⁹. Its findings help both human and animal health professionals. They offer insights into where blastomycosis is most common in Michigan and aid in improving how we diagnose and treat it⁹.

Besides dogs, other animals can get blastomycosis, though it’s rare. For instance, there have been a few cases in ferrets¹⁰. Passing the disease from animals to humans is unusual, but a few cases have been noted¹⁰. Dogs with this disease often have lower levels of a certain nutrient in their blood. Those with very low levels have a higher risk of dying during treatment¹⁰.

Clinical Manifestations of Blastomycosis in Dogs

Blastomycosis is a fungal infection in dogs caused by Blastomyces dermatitidis. It shows up with different signs depending on which organs it affects. Dogs may have a hard time breathing, cough, or not handle exercise well if their lungs are hit. If the eyes get involved, your dog might squint a lot or not like bright lights. Problems like seizures or a tilted head can show up if it spreads to the brain.

Sometimes, the infection can make dogs limp or feel pain in their bones. They might also get skin sores that drip or ulcerate. How bad the disease is can change, from not very serious to very dangerous.¹¹

Dogs can catch blastomycosis easier than people or cats can. It’s more usual to see it in certain parts of the U.S., like the Midwest and Southeast. Out of dogs that catch it, about 50% to 60% really show signs that they’re sick. Most of them, around 75%, will have trouble with their lungs. Big dogs, like Labrador Retrievers and Pointers, often get sicker than others. The chance of not surviving ranges from 10% to 50%, depending on how fast they get help.¹¹

Quickly figuring out if a dog has blastomycosis is super important. This means starting the right treatment fast. This disease can affect many parts of the body, from lungs to bones to the brain. Having regular check-ups by the vet is key, especially for dogs in places where this fungus is common. This helps catch the disease early and treat it effectively.

Complications and Prognosis of Blastomycosis in Dogs

Blastomycosis in dogs can lead to various issues, depending on the affected organs. When lungs get badly involved, it may lead to a dangerous condition known as acute respiratory distress syndrome (ARDS). This condition can be deadly.

The infection might also move to other organs, like the kidneys, eyes, and brain. When it hits the eyes, dogs might need special eye drops or even surgery to remove the eye that’s affected.

When the disease affects three or more organs, dogs usually don’t do well². If it reaches the brain, dogs can have seizures that are hard to control. This also usually means the outlook isn’t good².

Dogs with severe blastomycosis can get sick again, mostly within the first six months after being treated². It’s very important for these dogs to see their vet often. This helps keep them healthy and stops the disease from coming back².

If dogs with blastomycosis get help quickly when symptoms start, and they get the right medicine, they have a good chance of getting better². Dogs that get diagnosed early and have a mild form of the disease are likely to do better than those with a widespread illness².

Remember, even though dogs can get over blastomycosis, they might not be totally safe from getting it again².

Summary of Complications and Prognosis of Blastomycosis in Dogs

Note: The table demonstrates the various complications associated with blastomycosis in dogs and the corresponding prognosis. It serves as a summary of the information discussed in this section.

Research and Genetic Studies on Blastomycosis in Dogs

Studies on dog blastomycosis have opened our eyes to the diversity of Blastomyces dermatitidis genes. There have been insightful investigations into the genetic makeup of this fungus, through work on both pets and humans¹². These efforts show various genetic lineages, enhancing our grip on its history and harmfulness.

This research also found similar genetic markers in both humans and dogs, hinting at possible infections across species¹². Continuing these studies is key to unlock how blastomycosis works genetically. It will aid in better diagnoses and treatments.

Conclusion

Blastomycosis in dogs is a crucial fungal infection caused by the fungus Blastomyces dermatitidis. It leads to a variety of symptoms, depending on which organs are affected. Symptoms include breathing issues, eye problems, neurological symptoms, and bone infections. Recognizing and treating this infection early is key for helping dogs get better.

Genetic research on Blastomyces dermatitidis offers insights into the fungus’s genetic diversity. This knowledge helps us understand the disease better. Continuing this research will help us improve ways to prevent, diagnose, and treat blastomycosis in dogs.¹³Statistical data shows the survival rates for dogs with blastomycosis. Rates are as follows: at discharge (87%), 1 week (85%), 2 months (74%), and 6 months (69%). Dogs with lower levels of Blastomyces in urine and mild breathing issues fare better than those with high levels and severe issues.

The Blastomyces antigen test is reliable, with urine test sensitivity between 93% and 100%, and serum test sensitivity at 87%. The test is very specific for healthy dogs or those with nonfungal lung disease, showing 95% to 100% specificity. But, its specificity drops to 25% when it comes to histoplasmosis.

Historically, 53% to 75% of treated dogs overcome blastomycosis. Sadly, many dogs pass away within the first week of treatment. And, 20% to 26% of dogs see a return of the disease.¹⁴

Blastomycosis is indeed a tough and complicated disease in dogs. But, with ongoing research into its genetics and medical traits, we can get better at preventing, recognizing, and curing it. This will hopefully lead to better lives for affected dogs.

Source Links

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3637404/
2. https://www.petmd.com/dog/conditions/respiratory/c_multi_blastomycosis
3. https://www.rivergateveterinaryclinic.com/site/blog/2023/07/15/blastomycosis-dogs
4. https://www.dvm360.com/view/canine-blastomycosis-review-and-update-diagnosis-and-treatment
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5432155/
6. https://clarionanimalhospital.com/blastomycosis-in-dogs/
7. https://www.webmd.com/pets/dogs/what-to-know-about-blastomycosis-in-dogs
8. https://pubmed.ncbi.nlm.nih.gov/16317913/
9. https://pubmed.ncbi.nlm.nih.gov/31732747/
10. https://www.sciencedirect.com/science/article/pii/S1096286705000575
11. https://www.hillspet.com/dog-care/healthcare/blastomycosis-in-dogs
12. https://pubs.usgs.gov/publication/70173503
13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4895520/
14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7995372/