Heartworm Update - Day 8

I have learned an awful lot about heartworms this week.  I learned that the treatment plan goes by days. Day 1 was last Sunday, the day Lakota was diagnosed.  Today is day 8.  We dropped Lakota off at the vet today for x-rays and more blood work.  It broke my heart to leave her there because she fought the technician who was trying to take her back, running back towards us.  My husband had to walk in the back with them just to get her into the clinic.  The purpose of the tests today was to determine what class (how advanced) Lakota's heartworms are.  The lower the class, the less chance of complications during treatment.  Below is a list of the classes of heartworms from the LSU School of Veterinary Medicine:

http://www1.vetmed.lsu.edu/VTHC/Shared%20Services/Cardiology/Cardiac%20Diseases%20and%20Conditions/Acquired%20Cardiac%20Diseases/item41535.html

Clinical Signs and Stages 

Heartworm disease has four distinct clinical stages and treatment is initiated specifically for the stage diagnosed:    

•    Class 1 heartworm positive animals have a positive antigen test but are generally asymptomatic. They cough rarely and may show slight exercise intolerance. They may have very mild changes evident on thoracic radiographs. Blood work is normal other than a positive heartworm antigen test.

•    Class 2 heartworm positive animals also have a positive antigen test but have clinical signs associated with moderate disease. Clinical signs can be occasional coughing, exercise intolerance and fever. A split 2nd heart sound may be heard on physical examination due to delayed closure of the pulmonic valve compared to the aortic valve due to pulmonary hypertension. Blood work may reveal a mild anemia and urinalysis may show mild to moderate protein loss. Thoracic radiographs may reveal moderate disease such as dilated pulmonary arteries and right heart enlargement.  

•    Class 3 heartworm positive animals also have a positive antigen test but have clinical signs associated with severe disease. Clinical signs include difficulty breathing without exercise, frequent cough, weight loss, inappetance, lethargy, coughing up blood and abdominal distension due to ascites. Blood work can show a moderate to severe anemia and urinalysis can show severe protein loss. Thoracic radiographs show signs of severe disease with tortuous and dilated pulmonary arteries, enlarged right heart and other pulmonary parenchymal changes such as an interstitial pattern from allergic pneumonitis or pleural effusion secondary to right heart failure. A split 2nd heart sound may be heard on physical examination due to delayed closure of the pulmonic valve compared to the aortic valve due to pulmonary hypertension.  

•    Class 4 A syndrome called Caval Syndrome defines Class 4 heartworm positive dogs. Clinical signs include a very sick patient that can be weak or collapsing due to shock. All clinical signs of a class 3 heartworm dog can be present. In addition, urinalysis will reveal a dark brown urine signifying hemoglobinuria secondary to red blood cell lysis from the shearing forces as blood is forced across the tricuspid valve which is entangled with worms. Thoracic radiographs are similar to class 3 animals. Echocardiogram can reveal the presence of many adult heartworms in the right heart and pulmonary artery. A loud systolic murmur heard best of over the right apex can be present due to tricuspid valve regurgitation. A split 2nd heart sound may be heard on physical examination due to delayed closure of the pulmonic valve compared to the aortic valve due to pulmonary hypertension.  

Based on Lakota's x-rays and blood work, the vet determined she is between class 1 and 2, although she is classifying her as a 2 because her lungs showed inflammation and although her heart looked good, the vessels were inflamed.  I was shocked, once again.  Lakota has not coughed at all this week, and rarely has coughed since the episode a little over a month ago.  She does not have weight loss (she actually gained a little weight), her abdomen is not distended, her heart sounds normal (to the vet), she doesn't have fever, and although I definitely see some lethargy, she seems like a healthy dog.  Ironically, just like our other dog, her liver enzymes were elevated.  I am now going to give both dogs a SAMe milk thistle supplement to see if it brings those enzyme levels down.

The next step is to continue on the antibiotic for 20 more days, and finish up the prednisone (now at every other day for a few more days).  The vet said that if Lakota starts coughing or shows other issues like diarrhea, vomiting or not eating, we will have to continue the prednisone for the next few weeks.  We also have to give her Heartguard on the first of each month, following our normal heartworm prevention schedule.  

On day 60, Lakota will have her first injection of melarsomine, the arsenic based product.  We are slated to do this on or around April 15.  I am actually hoping to schedule this on a Friday (either April 10 or 17), so I can be with her during the entire weekend.  This will be the time when she cannot have any exercise or get too excited.  When I talked to the vet today, she said that if Lakota is not used to being caged, caging her may actually make her more stressed.  If we can keep her calm at home around the house, this would be much better for her.  Someone is home most of the time, so I think this will be feasible.  If we leave the house, I will put her in our guest room, which has her favorite couch and a window that while she can see out, she can't see people or dogs walking by (something which always gets her excited and barking).  I can leave her favorite toys with her, too.

Days 90 and 91 (around May 15) will be the final two Melarsomine injections, followed by complete rest for at least another month.  Around day 120 (June 15), she will have a full assessment of her health, emphasizing how the heart and lungs are faring.  Hopefully she will be doing well enough to resume her walks and build up to our normal hyper puppy again.

One thing I failed to mention in my previous post is how much this is costing us.  I am keeping a running tab, so I will know the final amount we spent.  So far, in 8 days time, we have spent $383.  It will likely cost at least another $700 or more for the 3 injections, medications and follow up exams.  

I will keep updating any time there are changes and treatments.  For now, Lakota is happy to be back home, in her favorite spot under a dining room chair.  

Until next time,

Lakota's Mom