Pet Points: Lyme disease up among pets here
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Millie was a 16-month-old spayed Bernese mountain dog who bounded into the veterinary examination room and greeted our staff with her wagging tail and bubbly personality. Her coat was sleek, her eyes were bright and her physical examination was normal.
She tested negative for internal parasites and was at her ideal weight. She was in perfect health -- or so we thought.
Millie was ready to go home when our veterinary technician noted her snap 4DX test was positive for Lyme disease. How was that possible? The owner had done everything recommended to protect her by applying monthly tick protection; in fact, her owner was the veterinarian.
Lyme disease is increasing in Western Pennsylvania. Veterinarians are seeing more ticks on local dogs now than in previous years. Some are deer ticks that are infected with Borrelia burgdorferi, a spirochete bacterium that causes Lyme disease.
If vets are seeing Lyme in their four-legged patients, then humans are also at risk. There is significant debate about how harmful Lyme disease is in dogs, but the disease is severe in people and precautions need to be taken.
The life cycle of the deer tick (Ixodes scapularis) is a complicated two-year process. Larva hatch from eggs laid by the adult and feed on a small host, often a mouse. If the host is infected with Lyme disease the larva will also become infected. After a year, the larva molts to a nymph that again will feed on a host such as a mouse, dog or human. The disease can spread at this point. Nymphs molt to adults and find a variety of hosts to feed on, such as dogs, humans and often deer. Deer do not show any signs of Lyme disease but are often carriers. Birds also can contribute to the spread of ticks and tick-borne diseases. People get a bull's-eye rash from the tick bite, and 80 percent of humans can become ill if infected.
People should contact a physician immediately if an attached tick is found on them. Likewise, pet owners should contact their veterinarian for advice and assistance on how to safely remove embedded ticks from their pets. It is very important that the entire tick be removed.
A great deal of controversy exists surrounding Lyme in the veterinary field. Experts have different opinions regarding the significance of a positive test in a healthy animal, and about the value of vaccinating against Lyme. They all agree that good tick control is fundamental to prevent the harmful bite and the spread of Lyme disease. Professional topical products are available from veterinarians to kill and repel ticks.
Dogs infected with Lyme may show a fever, lameness and joint swelling. Symptoms will resolve within days of starting treatment with an antibiotic. In some areas of the state, particularly eastern Pennsylvania, 80 percent of dogs could test positive. A simple blood test should be performed during a pet's annual visit to check for tick-borne diseases as well as heartworms.
Lyme experts agree that preventing tick bites is the key to preventing Lyme disease. Certain dog breeds, such as beagles, are less likely to become infected when exposed. However Labrador and golden retrievers and Shetland sheepdogs are more at risk. All dogs that test positive should be checked for protein in their urine. Lyme nephritis is a serious complication of the kidney in infected dogs and can lead to kidney failure. Vaccination for Lyme disease is available, but again there is controversy whether it's beneficial. The inoculation can prevent the disease but could pose additional risks, such as vaccine reaction and damaging circulating immune complexes.
Because Millie's infection was detected and treated early she is now free of the disease and will not have to endure the chronic debilitating effects of Lyme disease. Dog owners should discuss the risk factors with their veterinarian to develop a testing and prevention program.
In future articles we will present opinions from the local veterinary community on a wide range of topics.
First Published November 13, 2010 12:00 am