Internet chatter about tick-borne illnesses, especially Lyme disease, increases every spring and summer. Lyme disease can be a problem all year round for those who live in the Northeast, Mid-Atlantic or upper Midwestern states.
Lyme disease is the most common cause of Lyme in dogs and humans. The spirochete Borrelia Burgdorferi is transmitted by the black-legged ticks that are infected. These ticks stay attached to their hosts for at least two days. When a tick is a B. burgdorferi carrier, it usually begins transmitting bacteria to its host 24 to 48 hour after becoming attached.
Lyme disease symptoms in dogs
Lyme disease symptoms will only appear in 5% to 10% dogs that have been infected by B.burgdorferi. Most of these dogs will develop Lyme disease. This is characterized by acute lethargy and lameness of one or more legs, fever, swollen or enlarged joints, or lymph nodes. They are drained of energy, and have little desire to eat.
Infected dogs are less likely to develop Lyme nephritis, an inflammation of the kidneys. Lyme nephritis can cause chronic weight loss in dogs, as well as lethargy and vomiting. They urinate and drink more water over the course of two weeks or longer. Dogs may experience edema in the advanced stages.
Dogs do not get a bullseye rash from a tick that has transmitted B. burgdorferi. After being bitten either by black flies, mosquitoes or ticks, dogs may develop a small, bulls-eye rash. The lesion is caused by the bite of the tick, and not by the disease transmitted through the tick.
Treatment of Lyme Disease in Dogs
Dogs who have Lyme arthritis will be treated for 30 days with doxycycline, an antibiotic. Gabapentin or another analgesic may be prescribed for joint pain. Most dogs respond quickly to doxycycline therapy, showing improvement in their symptoms within 24 to 72 hour of starting the drug.
A complete course of Doxycycline might not be enough to remove all the Lyme bacteria. B.burgdorferi is very adept at evading your immune system. It can hide in certain body tissues even years after treatment.
The cause of Lyme nephritis remains a mystery. In a valiant effort to rid the body of B. burgdorferi, it is believed that the immune system damages the kidneys irreparably. The glomerulus, the filtration unit in the kidney, is the part of the kidney affected. This condition is known as immune-complex glomerulonephritis.
The treatment for dogs with Lyme nephritis is the same as any other dog that has ICGN. Hospitalization may be required with intravenous fluids and medication for high blood-pressure, protein loss from the kidneys, nausea and vomiting, as well as treatment with an immunosuppressant and doxycycline. The prognosis is not good for dogs suffering from Lyme nephritis.
How Lyme Disease is Diagnosed
The diagnosis of Lyme is difficult. B. burgdorferi can travel through a dog’s skin, as well as other tissues like joints and tendons. B. burgdorferi is rarely found in bloodstreams, but this does not seem to be the preferred way for it to travel through the body.
B.burgdorferi rarely appears in the bloodstream. Therefore, blood tests for Lyme measure the dog’s antibodies against B.burgdorferi. A positive “Lyme” test, or more precisely, a B.burgdorferi antigen titer, tells us if the dog was exposed to B.burgdorferi, and developed antibodies against that bacteria. However, it does not tell us whether the dog’s symptoms were caused by Lyme.
Another type of test is designed to detect B. burgdorferi. The bacteria is found in the tissues of a dog, such as skin, joints and tendons. A PCR test can be used to detect B. burgdorferi genetic material in a sample of tissue. These samples are collected in a more invasive manner than blood. This involves obtaining a joint fluid sample or a skin biopsy. The site of the tick bite is where you should take a skin biopsy sample. It may be difficult to determine where a sample of skin should come from, as many tick bites are not detected. You can obtain joint fluid from the sore, swollen joint. Positive PCR results confirm a diagnosis of Lyme.
Most veterinary clinics use rapid blood tests to diagnose Lyme disease. The results are available in 10 minutes. These tests detect antibodies your dog has developed against B. burgdorferi. Your veterinarian may prescribe doxycycline if your dog tests positive for Lyme disease symptoms and the rapid blood test. If your dog’s symptoms disappear within 24 to 48 hours after starting doxycycline treatment, they were probably caused by Lyme.
If your dog’s symptoms persist – he does not improve within 72 hours after taking doxycycline-, then it is possible that a different reason for the symptoms exists. If the positive test shows that your dog has been exposed to B. burgdorferi at some point and mounted an immunity to this infection, then it is likely that something else is causing his symptoms. Your veterinarian may want you to have your dog re-examined and ordered additional diagnostics.
Many ticks are known to carry multiple bacteria that can cause disease. Talk to your vet if your dog’s test for Lyme disease is positive. They can also check for other tick-borne diseases in your area.
What happens if your dog’s rapid blood test results are positive, meaning they have antibodies against B. burgdorferi but no symptoms? Most dogs exposed to B. burgdorferi have subclinical Lyme Disease. They may not show any symptoms, but still test positive for their annual heartworm/tick combination test.
It is controversial to treat a nonsymptomatic, seropositive dog with a course doxycycline. There is no consensus among veterinarians on whether this treatment is beneficial or if it is a waste of antibiotics which can lead to resistance. Discuss the pros and cons with your vet if your dog fits this description.
Black-Legged Tick Life Cycle
The black-legged spirochete, Borrelia Burgdorferi, which causes Lyme, is transmitted by the feeding and biting of the tick. The black-legged tick comes in two different species. Ixodes Scapularis transmits Lyme disease in the Northeast, Mid-Atlantic and Upper Midwestern States. Ixodes Pacifica is responsible for Lyme disease in the Pacific Coast States.
The life cycle of black-legged ticks is two years long and consists of four stages. In the first year, an adult female tick lays the egg. Each egg hatches into a larval mosquito that is hatched in the summer. The larval tick stage is about the size and shape of a poppyseed, with six legs.
The tick is “questing”, hanging on grass and waving his front legs while waiting for a passing animal that it can grab. Photo by kmatija. Getty Photos.
To complete the transition from larval to adult ticks, they need to feed on blood. Ixodes larval ticks of both species feed on birds, mice, squirrels and shrews. Ixodes larval ticks feed also on lizards. The bacteria Borrelia Burgdorferi is found in the white-footed mice. Larval ticks infected by B.burgdorferi become carriers and infect other white-footed mice.
After a larval tick has eaten blood, it will transform into a nymph between the fall and spring of the first year. Nymphs grow to about twice the size as larval ticks. The nymphs have eight legs.
The nymph tick needs a blood meal in order to transform into an adult tick. Therefore, they are looking for larger animals, such as dogs, cats and humans. The nymph can pass B. burgdorferi on to its new host if it picked up B. burgdorferi as a larval.
In the second year, nymphs transform into adult ticks. Adult ticks are approximately twice as large as nymphs. Before winter, they look for a suitable host to feed on (such as dogs, deer or humans). If the adult tick had B.burgdorferi in its nymph stage, it can also transmit B.burgdorferi into the new host.
In the spring, adult ticks mate on deer. After mating, the male tick dies. The female tick leaves her deer host to lay thousands of eggs. After laying the egg cache, the female tick dies.
In the winter, both nymphs and adults will hide in leaf litter and shady areas, or under snow. When the temperature is above 37 degrees Fahrenheit, and the snow shelters are melted, adult and nymph ticks will seek out a host to feed on blood in winter.
How to Prevent Lyme Disease
You cannot prevent your dog from getting Lyme disease. You can lower the chances of your dog being exposed to B. burgdorferi by following the three-pronged strategy:
All year round, use a quality flea/tick prevention. Check your dog for ticks every night. Nymphs and adults can be active during winter if the temperature is higher than 37 degrees Fahrenheit. If you remove ticks within 24 hours after they attach to your dog, the risk of burgdorferi transmission is reduced. Talk to your vet about vaccinating for Lyme disease in your dog if you reside in an area where Burgdorferi can be found. The majority of Lyme vaccines prevent Lyme disease with a 90% effectiveness rate. Like most vaccines, the effectiveness of Lyme vaccines can diminish over time.
Lyme disease and other tick-borne illnesses are here to remain. We can reduce our exposure to Lyme disease, for both ourselves and our dogs.
What Ticks do to your dog (and you)?
Remove ticks as soon as they bite or before your dog bites. This will help reduce the risk of infection by B. Burgdorferi. Contrary to popular belief ticks don’t fly or jump from trees. They are found on grass blades, the tops of leaves, and the tips of shrubs. The frogs hold onto the vegetation with their back legs, and then wave their front legs as they wait for a suitable host. This is known as questing.The tick will grab your dog or you with its front legs when you brush up against their hangout. The tick will then spend 30 minutes to 2 hours walking around the body of their new host, searching for the best spot to insert its mouth parts and start taking blood. It is usually in a warm area of the body such as the armpits or groin.Wearing clothing treated with permethrin will help to prevent ticks from attaching themselves to you or your dog. Permethrin can cause ticks to develop a condition known as “hot-foot”. Permethrin causes a tick’s legs to burn and run as fast as they can.
Lyme Disease Whole Dog Journal
Did you miss our previous article…