Nancy Heigl, co-founder of the Jason Debus Heigl Foundation, was in Louisiana last month on business and during her stay in New Orleans rescued a Miniature Schnauzer called Cici! Weighing in at a tiny 13lbs and approximately 5 years old, CiCi had been used for breeding all of her life before being heartlessly dumped at the side of the road.

Cici

"I heard about her via a rescue group near Baton Rouge. They were going to have to euthanize her because she is heartworm positive and they didn’t have the money to pay for her treatment," Nancy explains. "So I decided to just take CiCi, get her treated and add her to my Schnauzer pack."

Describing the latest addition to her four-legged family as "very, very sweet but quite timid," Nancy kept CiCi with her for a few weeks in New Orleans before flying back home to Utah to continue the veterinary treatment. We are all very hopeful that the adorable pup will make a full recovery!

Heartworm is a very serious but preventable disease, as our resident expert Dr. Stan Kunin explains.

Heartworm

Article By Dr. Stan Kunin In Collaboration With Diana Kunin

Heartworm is spread by mosquitoes. For instance, if a dog is infected with the heartworm disease and a mosquito bites that dog, then that same mosquito bites an unaffected dog who is not on heartworm prevention, that dog will contract this disease. A rough idea of how this parasite manifests itself inside the dog, is described by the following steps. A dog with a mature heartworm is bitten by a mosquito. The larvae from that worm (microfilariae) are sucked up by the mosquito and mature into the infective larval stage within the mosquito. After that, the mosquito bites another dog, and the infective larvae enter the dog through the bite wound. A dog cannot get heartworm until after the larva has developed into this stage inside the mosquito. Once the mosquito bites the second dog and has transmitted this larve (microfilaria) into the dog’s circulatory system, it takes about 6 months inside that dog before the microfilaria grows into an adult worm. This worm grows inside the heart, the pulmonary artery, and sometimes, but not often, in the vena cava.

Heartworm used to be found only in the southern and eastern parts of the United States and in Hawaii. However, there now are heartworm cases in all 50 states and the numbers are continuing to rise. There are many reasons for these increased incidences. Some of these reasons include the transportation of dogs from a heartworm infested area and introduced into non-infested area. For example, dogs who were evacuated from areas affected by Hurricane Katrina. Dogs who were not on preventative heartworm medication, and were relocated to other states, spread this disease. Another example for the spread of heartworm is the fact that many parts of the country are being urbanized. This change in habitat opened the door for infected mosquitoes to move in and breed. New buildings created new sources of stagnant water where the mosquitoes most frequently lay their eggs. In addition, the urbanization of homes in coyote territory brings the coyote into closer contact with domesticated dogs. Many coyote are carriers of heartworm and those dog living near coyote country could be susceptible to becoming infected with this parasite.

In the early stages of heartworm disease, many dogs show no symptoms. It is not until the disease is in an advanced stage that it is evident there is something wrong. The clinical symptoms include difficulty in breathing and exercise intolerance. When the heartworm makes its home in the heart and the surrounding circulatory areas, it causes a series of circulatory blockages and inflammation which leads to heart failure. A diagnosis is made through a specific blood test and is then further scrutinized through chest x-rays or an ultrasound. Once the diagnosis has been made, then determining the proper protocol therapy which is best for the patient is put into action. Therapy has evolved from a once dangerous drug to a new updated drug, Melarsomine (Immiticide). This drug, although much safer, still needs to be used with caution. There are a few different protocols for treating heartworm with this medication. One example is that one injection is given in the muscle, then the second is given 4 months later, with an additional injection given one month later. The purpose of giving these injections far apart is to minimize killing the heartworm too quickly. Killing the worm too quickly would cause a blockage in the circulatory system. When the worm dies it lets go of the site where it has attached itself. This can lead to a circulatory blockage. Furthermore, during heartworm treatment, the dog must be kept in confinement and on a very strict no exercise schedule to help reduce the possibility of the dead worm dislodging itself or any of its fragments (thromboembolism). Confinement must continue for at least one month after each injection of Melarsomine. Additional drugs may be needed, such as steroids to reduce inflammation. It has been found recently that a bacteria, Wolbachia, can coexist with the heartworm thereby complicating this disease. In this case, an antibiotic, such as Doxycycline, should be used at the same time. Because the Melarsomine does not kill the microfilariae, the microfilariae has to be controlled to prevent them from developing into an adult heartworm. There are many products available to rid the body of these microfilariae. One of these products is called Heartgard. If given monthly, it will prevent microfilariae from making its home in the dog. Ideally, a heartworm test should be performed prior to beginning Heartguard in order to rule out an existing infestation. This test is especially necessary for dogs that are from an unknown background (ie: rescue, pound, etc.) or dogs coming in from a heartworm infested area and are not on preventative medication.

Heartworm is a preventable disease. Most veterinarians agree that all dogs, especially young ones, should be on a monthly anti-parasite therapy like Heartguard. This drug can not only help to prevent heartworm but it can also prevent other parasites such as roundworms and hookworms. Indoor dogs are just as susceptible to these parasites. Point in fact, heartworm infected mosquitoes can exist inside the home, and in addition, dogs can be introduced to roundworms and hookworms during their daily walks, especially in parks, where they are exposed to fecal matter on the ground and in the grass. Fecal matter is easily picked up and deposited on the dogs paws and in their hair. It is then ingested and introduced to the body when the dog licks itself.

Although Southern California and some other areas may have lower incidences of heartworm, it is still important to prevent dogs from contracting these parasites. It is very important from a public health perspective as some of these worms can be transmitted to humans, especially to children or people with weaker immune systems.

See your veterinarian to discuss which products they recommend as an important element of the monthly routine care for your dog. This is essential because heartworm and other parasites can be prevented. However, if contracted, it can be devastating; and even with the expensive and potentially dangerous treatments, the outcome is not always positive. Further information can be found at the Heartworm Society.

About Dr. Stan Kunin

Stan Kunin DVM graduated from UC Davis in 1978 and has had his own practice in Woodland Hills, California since 1986. Dr. Kunin is a special veterinarian who was born 80% deaf, but the weakness in his hearing has helped to give him a 6th sense about animal care and the wellbeing of his patients.

In a regular series of articles for the Jason Debus Heigl Foundation, Dr. Kunin shares his thoughts, opinions and advice on animal matters.