Daily doxycycline (10 mg/kg PO Q 24 H for 24 weeks of a 36-week study) reduced heartworm burden by 78% after 9 months of therapy as compared to control dogs.
Doxycycline not only has effects on adult worms but also decreases numbers of microfilariae and prevents development of heartworm in subsequently infected dogs.
For a few decades now, the slow kill method has been used as an alternative option for treating heartworms. It involves long-term use of only a monthly heartworm prevention plus an antibiotic called Doxycycline.
Melarsomine dihydrochloride (available under the trade names Immiticide and Diroban) is an arsenic-containing drug that is FDA-approved to kill adult heartworms in dogs. It's given by deep injection into the back muscles to treat dogs with stabilized class 1, 2, and 3 heartworm disease.
A combination of doxycycline and ivermectin is adulticidal in dogs with naturally acquired heartworm disease (Dirofilaria immitis) Vet Parasitol.
The above-mentioned results suggest that the combined use of ivermectin and doxycycline can be useful in controlling the severity of the infection, as both drugs act synergistically in producing antiviral effects. Furthermore, doxycycline will provide the additional benefit of reducing the cytokine storm.
This means that if one opts to treat a heartworm positive dog with an ivermectin heartworm preventive only, one can expect the dog to remain heartworm positive for a good 2 years and the heartworm disease will be progressing during that 2 years.
No one wants to hear that their dog has heartworm, but the good news is that most infected dogs can be successfully treated. The goal is to first stabilize your dog if he is showing signs of disease, then kill all adult and immature worms while keeping the side effects of treatment to a minimum.
Prognosis: heartworm treatment success rates
With the three-dose adulticide protocol described above, in conjunction with doxycycline and macrocyclic lactones as recommended by the American Heartworm Society, 98% of dogs will be cleared of heartworm infection.
Dogs that have a high number of heartworms often develop symptoms such as pronounced and persistent coughing, difficulty breathing, and exercise intolerance. In more severe cases, dogs may also experience fainting or collapse, pale mucous membranes, weakness, elevated heart rate (tachycardia) and severe lethargy.
The length of time your dog stays on doxycycline, depends on the condition being treated. For gum disease and moderate infections, doxycycline is used for 5 to 7 days. But in some other conditions, such as respiratory infections or tick-borne disease, treatment may last 30 to 45 days.
Stage 4. There is a large mass of worms which physically blocks the blood flowing back to the heart. This stage is life-threatening and requires quick surgical removal of the heartworms. However, surgery is risky and even with surgery, most dogs in this stage die.
They can be controlled naturally with citrus oils, cedar oils, and diatomaceous earth. Dogs needing conventional treatment may benefit from herbs such as milk thistle and homeopathics such as berberis; these minimize toxicity from the medications and dying heartworms.
How long does it take doxycycline to work? Doxycycline starts working in as little as 2 hours after taking it. But depending on the infection you have, it may take up to 24 to 48 hours (1 to 2 days) to start seeing its effects.
Slow Kill Method
While not generally recommended, another method of handling heartworms is to only attack the microfilaria, leaving existing adult heartworms to die of natural causes. This is known as the slow kill method. It's cheaper and does not require a rest period and debilitating adulticide.
Signs of heartworm disease may include a mild persistent cough, reluctance to exercise, fatigue after moderate activity, decreased appetite, and weight loss. As heartworm disease progresses, pets may develop heart failure and the appearance of a swollen belly due to excess fluid in the abdomen.
Dogs can live for at least six to seven months after becoming infected with heartworms. This is because it takes that long for adult heartworms to grow.
The average lifespan of heartworms in untreated pets is 5-7 years in dogs and 2-3 years in cats. Virtually 100% of dogs exposed to infective heartworm larvae become infected; in cats, this number drops to 61% to 90%.
Rarely, cases may be so advanced that it is safer to treat organ damage and keep the dog comfortable than it is to risk negative effects associated with killing the heartworms. Dogs in this condition are not likely to live more than a few weeks or months.
Frequent Vomiting. Finally, frequent vomiting usually goes along with heartworms. Dogs who cough often may cause themselves to vomit as a result of their extensive coughing. Some dogs may feel nauseated from their heartworms as well, and may vomit often just because they feel so sick with the disease.
Is heartworm painful? - Animal Hospital of Statesville. It's not painful, per se, but they feel sick, uncomfortable, and they're likely having difficulty breathing. They're not perfusing very well, so they don't feel well.
Because heartworms must be eliminated before they reach this adult stage, it is extremely important that heartworm preventives be administered strictly on schedule (monthly for oral and topical products and every 6 months or 12 months for the injectable).
Some breeds of dogs (e.g., collies, sheepdogs, and collie- or sheepdog-cross breeds) are more sensitive to ivermectin than others. This is typically due to a specific genetic mutation (MDR1) that makes them less able to tolerate high doses of ivermectin.
Heartworm disease is dangerous and isn't something to treat by yourself. You can treat your dog at home, but make sure you get help from a holistic vet or herbalist. You can find a holistic vet at ahvma.org or a homeopathic vet at theavh.org.
The exercise restriction during melarsomine treatment is so important. As the heartworms die, they float around in the bloodstream and lodge in the walls of blood vessels. If your dog exercises too hard, the fragments can get shoved into narrowing blood vessels potentially causing a blockage/embolism and even death.