Lyme Disease in Dogs
Lyme Disease in dogs is named after the town of Lyme, Connecticut, where an outbreak of arthritis was first reported in children. The disease was caused by a corkscrew-shaped bacteria from the family Borrelia, hence its other name: Canine Borreliosis. These days, Lyme Disease in dogs is thought to be the most common disease transmitted by insects or arthropods in the United States.
The bacteria are carried by adult and nymph Ixodes ticks: dogs (and people) become infected when they are bitten by one of these insects. Ticks need to have been attached to a dog and drinking their blood for 24-48 hours before infection occurs. This means that infection is more likely to be spread by nymphs as they are smaller and harder to find on your dog.
Because Lyme Disease in dogs is spread by ticks, it is diagnosed most frequently in those areas where these ticks are common, and in the seasons when they are most active. In the United States, these areas are those states on the Pacific Coast, the Atlantic Coast and in the Midwest. There are other species of ticks in the country, but they don't transmit Borrelia. Spring is peak season for Lyme Disease as this is when adult ticks lay their eggs. Newly hatched ticks feed on infected rodents and pick up the bacteria; they are then able to infect other animals, including our dogs, when they have a blood meal.
The CDC reportst that 95% of Borreliosis cases happen in 12 states. Those are Pennsylvania, New Jersey, New York, Massachusetts, Conneticut, Wisconsin, Maryland, Minnesota, New Hampshire, Delaware, Maine, and Virginia.
Symptoms of Lyme Disease in Dogs
Before we look at the signs of Lyme Disease in dogs, we need to keep in mind that 95% of dogs who are infected with Borrelia will not show any signs of illness at all. If your dog does develop Lyme Disease, they may show signs of inflammation in their joints, heart and kidneys. These usually appear 2-5 months after they have been bitten by an infected tick.
Lyme arthritis is the most common consequence of Borrelia infection. Symptoms include joint swelling, lameness and fever. Often, the joints nearest to the tick bite are more painful than the others. The lymph nodes, or glands, near affected joints are usually enlarged and may also be painful. It can be hard to tell which leg is sore, because your dog will appear to limp firstly on one leg, then on another.
Borrelia can also affect the heart muscle, leading to abnormal heartbeat rhythms and fainting. Dogs that develop this condition will probably need a pacemaker inserted in their heart at some time in the future, to control their heart rhythm. Fortunately this complication of Lyme Disease is extremely rare; very few dogs have heart problems associated with Borrelia infection.
One of the most serious effects of Lyme Disease is a type of kidney failure, known as protein losing nephropathy. Affected dogs vomit, lose weight and drink lots of water. Unfortunately, almost all dogs that develop kidney failure associated with Lyme Disease will die.
Diagnosis of Lyme Disease
It is not easy to accurately diagnose Lyme Disease in dogs.
Antibodies are part of a dog's immune system, and they are produced by white blood cells to circulate in the bloodstream, and fight infectious organisms. They are also produced after vaccination. Testing for Lyme Disease involves examining your dog's blood to see if they have any antibodies against Borrelia. However, these antibodies will be present in dogs that have been infected sometime in the past, or have had a vaccination against Lyme Disease. It doesn't really confirm infection.
These days, a more useful test is available, which looks for specific antibodies to the C6 peptide on the bacteria's body. Only those dogs who have been infected with Borrelia will have antibodies to this, so it will differentiate between those dogs with antibodies due to vaccination, and those due to actual infection. Still, the test only shows that a dog has been exposed to Borrelia at some stage. Again, a positive test doesn't mean your dog currently has an active infection.
The Idexx SNAP 3Dx Test is done in the veterinary clinic to test for Lyme Disease in dogs. Your veterinarian may also choose to send blood work out to Idexx to perform the Lyme Quant C6 Test which is a way to monitor how your dog is responding to treatment.
There are other diagnostic techniques that may be useful, such as microscopy and culturing bacteria from tissue cells taken from an affected dog. However, all of these techniques have their limitations and aren't routinely used.
Ultimately a diagnosis of Lyme Disease in dogs usually based on clinical signs, the results of their blood tests and a history of being in a tick area or having had ticks on them.
Treatment of Lyme Disease
The most important part of treating Lyme Disease in dogs is to give them doxycycline antibiotics for up to 6 weeks to kill the Borrelia bacteria
Anti-inflammatory drugs can be given for dog pain relief but these may have adverse effects on affected dogs' kidneys. Before any pain relief is prescribed, these organs must be checked to make sure they are functioning normally.
This treatment usually results in your dog feeling better very quickly, but there is a chance they may develop symptoms again in the future. Nobody is sure why this occurs. Many researchers believe that dogs infected with Borrelia are infected for life, and this is why repeat episodes of arthritis can occur.
If blood tests indicate that the kidneys have been affected by Lyme Disease, treatment includes intravenous fluids and medication to support them while they heal. A prescription Renal Diet and omega fatty acids are also beneficial, however the prognosis is very poor.
Prevention is Better than Cure
Given that Lyme Disease in dogs can be so serious, it makes sense to do whatever you can to stop your dog picking up a Borrelia infection. There are two ways of doing this: keep your dog free from ticks, and vaccinate them against the disease.
The main part of preventing Lyme Disease is to stop ticks from feeding on your dog. Tick control is simple and affordable. Apply Frontline or Advantix to your dog every two weeks to kill ticks before they get the chance to feed. Some people don't like to have chemicals on their dog's skin and coat because they don't like the smell, and don't want to touch it when they cuddle them. Tick collars containing amitraz or deltamethrin are a good choice under these circumstances.
Just as important as chemical insecticides is checking your dog every day for ticks, and killing any that you find. A bottle of Frontline spray is handy for this; one squirt onto the tick, and it is soon dead. The reason this works is that you'll be able to remove the ticks within that 48 hour window of opportunity before they start transmitting Borrelia to your dog. Although it sounds time consuming, it's not – use it as an opportunity to spend quality time cuddling and stroking your four legged best friend.
Lyme Disease Vaccine for Dogs
A vaccine is available to protect dogs from Lyme Disease, but its use is controversial. Most veterinarians will only recommend it for dogs that live in well known tick areas. Some veterinarians aren't in favor of vaccinating dogs even if they are in a Lyme Disease region because they aren't sure how protective the vaccine is. Also, most dogs aren't affected at all by infection with Borrelia, and there is always the risk of a vaccination reaction.
When it comes to dog vaccination
, each pet should be treated as an individual, and you must take into consideration where they live, and their lifestyle when deciding whether or not to immunize them. For example, an indoor dog has a very low risk of picking up a tick compared to an outdoors dog that enjoys hunting or camping with their owners.
Merck/InterVet/Schering Plough is the maker of the Nobivac Lyme vaccine for dogs. It contains two inactivated strains of Borrelia.
Lyme Disease is a real challenge for veterinarians and dog owners. Diagnosis is difficult, treatment doesn't always work, and no vaccine is 100% effective.
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