I would like to introduce you to Spot. Spot is a lovely dog that recently came in for her first appointment after being fostered and adopted by her new family. She is a sweet dog that just wants to sit and rest her head on your knee. You can look into her eyes and see she is tired. Upon examination she has an ulcerated mass on her belly, some scars, and large nipples that indicate she has had at least one litter of puppies. Spot’s new family has graciously allowed us to follow Spot’s story.
What you can’t see is that Spot is very sick. She is infected with both Ehrlichiosis (a disease carried by ticks) and heartworm disease (a disease carried by mosquitoes). The saddest part is that both of these diseases can be prevented with properly administered medications. We don’t know Spot’s history, just that she came from Georgia. We have started treatment with doxycycline (an antibiotic to treat both the Ehrlichiosis and start the process of treating the heartworm) and have gotten her started on heartworm preventative as well – this is used to help kill off some of the “baby” stages of the heartworms and to prevent reinfection. Both of these treatments are just the beginning of the long road to recovery. Once mom gets enough money put together, we will remove the mass on Spot’s belly to make sure that it is not cancerous, then we will move onto the next stages of treatment for heartworm disease.
What is Ehrlichiosis?
Technically speaking, “Ehrlichiosis is the general name used to describe several bacterial diseases that affect animals and humans. Human ehrlichiosisis a disease caused by at least three different ehrlichial species in the United States: Ehrlichia chaffeensis, Ehrlichia ewingii, and a third Ehrlichia species provisionally called Ehrlichia muris-like (EML). Ehrlichiae are transmitted to humans by the bite of an infected tick. The lone star tick (Amblyomma americanum) is the primary vector of both Ehrlichia chaffeensis and Ehrlichia ewingii in the United States. Typical symptoms include: fever, headache, fatigue, and muscle aches. Usually, these symptoms occur within 1-2 weeks following a tick bite. Ehrlichios is is diagnosed based on symptoms, clinical presentation, and later confirmed with specialized laboratory tests. The first line treatment for adults and children of all ages is doxycycline. Ehrlichiosis and other tick borne diseases can be prevented.” (http://www.cdc.gov/ehrlichiosis/)
Dogs can’t tell us in words that they have a headache, fatique, or muscle aches, but, with a simple blood test run in many veterinary offices, you can have a positive test for exposure in 8 minutes. Due to some other blood test results, Spot’s symptoms, and cost we did decide to treat for the disease without doing some more advanced testing. Ehrlichiosis, and other tick borne diseases, can be prevented using medications, checking people and pets for ticks daily and removing any ticks found, and decreasing the risk of ticks in your yard.
What is heartworm disease?
Heartworm disease (dirofilaria immitis) is carried by mosquitoes. Adult female heartworms place their young (microfilariae) into the bloodstream of animals. Mosquitoes ingest the young while feeding on animals. The microfilarae then grow into the infective larvae stage over the next 10-14 days inside of the mosquito. When the mosquito then feeds on the next animal(s), the larvae are injected into the new animal. Over the next 6-7 months, the larvae become adult heartworms. At this point, they can start creating more microfilariae, although these microfilariae have to go through another mosquito before becoming adults themselves. This is where preventative medications come into play. Most heartworm preventatives are taken by mouth and the kill the larvae so if your dog or cat is bitten and has larvae injected into it, the medication kills it before it matures. In areas of the world where heartworm is present, your veterinarian may recommend treating all year round – this is because of the life cycle of the heartworm and trying to kill off the larvae before they become adult worms. Microfilaria in a heartworm positive dog (video courtesy of Richelle Ackerman, DVM)
Infected dogs may not show any symptoms at first, but as the worm burden grows dogs can develop a cough, exercise intolerance, inappetence (not wanting to eat), and weight loss. These signs can indicate severe heart and lung disease.