Lyme disease in dogs - just one bite, long-term consequences
Borrelia are bacteria that are transmitted from ticks to dogs – and our canine friends can encounter ticks almost year round. However, dogs with strong immune systems very rarely contract Borrelia infections (Lyme borreliosis). Learn what Lyme disease is and what you can do to prevent you dog from contracting it here.
What are Borrelia bacteria?
The pathogen that causes Lyme disease was first detected in ticks in 1981 by the American bacteriologist and parasitologist Willy Burgdorfer, and named Borrelia burgdorferi in his honour. Borrelia burgdorferi are large, screw-shaped bacteria. They are classified as spirochetes, which can move like corkscrews through tissue. There are 19 species in all, three of which can be hazardous for dogs. The pathogens inhabit the intestines of genus Ixodes ticks (hard ticks). These include the castor bean tick and the hedgehog tick, both found throughout Europe. Ticks are infected by Borrelia bacteria when they attach to an infected wild animal (mice, hedgehogs, or wild ruminants). According to studies, in Germany alone, between 5 and 35 percent of all ticks are infected with Borrelia.
How do dogs pick up Borrelia?
When a tick feeds on the dog's blood, the Borrelia bacteria become active in the tick’s intestine and migrate into its salivary glands. From there, the bacteria need at least 16 hours to move into the dog’s skin – with exceptions, as transmission time may be shorter if, for example, the tick changes host when the pathogens are already in its saliva.
Dogs can only contract Lyme disease from infected ticks. Transmission between dogs or from dogs to humans (or vice versa) is not possible.
What happens in a Borrelia infection?
After an infected tick bites the skin, the pathogens begin to spread from there. In humans, this causes a local inflammatory reaction, recognisable by the typical “bull’s eye” ring around the bite. This symptom (Erythrema migrans) does not appear in dogs. A dog may experience a temporary, mild reddening of the skin after being bitten, but this is rarely detected under its coat.
The good news: only 5 to 10 percent of infected dogs develop symptoms. In most cases, the dog's immune system reacts to the Borrelia bacteria in the skin by producing antibodies. However, when the immune defence is weakened by stress or other infections, the bacteria slowly start to reproduce through division and spread in the body. At this stage, they "outwit" the immune system by altering their surface proteins and actively invade collagen tissue, joints, and the connective tissue layers that surround the central nervous system. There they can survive in a dormant state and are not affected by medications. If the disease is not fully treated, the bacteria can survive in the dog’s body tissues and cause new episodes throughout the dog’s life. With dogs, the time from incubation period until a borreliosis outbreak is between two and five months.
What are the symptoms in a dog with Lyme disease?
Unfortunately, Lyme disease symptoms in dogs are not always clear. In the early stage of infection, the dog may seem tired and have a fever. This is followed by an asymptomatic phase which can last several weeks, or even months. Afterwards, often the dog will first display lameness for a few days; this often subsides without treatment.
Typical symptoms of Lyme borreliosis include:
- Loss of appetite
- Swollen lymph nodes
- Shifting lameness of various degrees
As the disease progresses, some dogs develop heart disease or neurological symptoms.
In rare cases, a serious kidney disease called Lyme nephritis may occur, characterised by excessive excretion of protein through the urine, leading to kidney failure. A higher risk of kidney damage due to Borrelia has been observed in certain breeds of dogs including Labrador Retrievers, Golden Retrievers, Shelties, and Bernese Mountain Dogs.
How is borreliosis diagnosed in dogs?
Borreliosis can be difficult to diagnose due to its various and changing symptoms. If you suspect a Borrelia infection, first determine if the dog has come into contact with ticks and, if bitten, if there are any changes to the skin. The dog may have already been treated with antibiotics for one of the symptoms, resulting in short-term improvement but not a complete cure. Before starting treatment, the pathogens must be identified in laboratory tests in order to exclude other causes for the symptoms.
How is borreliosis diagnosed?
There are various procedures for determining a Borrelia infection.
An ELISA test is used to examine the total antibodies against Borrelia in the serum. It cannot determine an exact differentiation of the antibodies, i.e., whether the dog is currently suffering from an acute Borrelia infection, has already recovered, or has been vaccinated against borreliosis. Smaller amounts of antibodies may not be detected.
A Western blot test, for which proteins are transferred to a carrier medium in order to detect specific antibodies in the serum, will yield more accurate results.
Another option involves detection of the pathogen via PCR (polymerase chain reaction) or through a bacterial culture that is grown on sample material for up to six weeks. In this process, Borrelia antigens are amplified from tissue samples and then made visible by various markers. The PCR test and the bacterial culture sometimes yield false-negative results because often there is little to no bacteria present in the tissue at the time of collection, which can be the case in chronic Lyme disease especially. A positive result, however, is proof of infection. In practice, a reliable diagnosis is usually obtained through a combination of ELISA test and Western blot test.
How is borreliosis treated in dogs?
To completely eliminate the Borrelia bacteria, the dog must be given antibiotics for at least four weeks. There is a risk of recurrence if treatment is interrupted or discontinued prematurely. Painful symptoms like lameness are also treated with pain-killing medications until the symptoms subside.
Dogs suffering from joint problems should respond to the therapy within a few days. However, scientific studies have shown that treatment with antibiotics does not eliminate infection in 100% of cases, and that Lyme disease can become a chronic ailment.
Longer rounds of antibiotics also upset a dog's stomach. The chemical preparations kill the Borrelia, but they also destroy the beneficial bacteria strains living in the dog's digestive tract. High doses of medication can also be damaging to the stomach lining, so many vets additionally prescribe a gastric protector.
You can also prevent canine stomach problems through herbs.
- Liquorice protects the mucosa and is anti-inflammatory.
- Marsh-mallow contains mucilaginous substances that act as a protective film over the stomach lining and soothe irritated mucus membranes.
- Camomile soothes irritation and is anti-inflammatory.
- Yarrow stimulates digestion and has soothing effects on dyspeptic ailments and stomach cramps in the abdominal area.
- Lavender is relaxing and soothing.
- Walnut leaves contain tannins that have astringent and anti-inflammatory effects.
- Speedwell is anti-inflammatory and is used in folk medicine to treat digestive complaints.
Should my dog get vaccinated against Lyme disease?
Since the 1990s there have been vaccines available which protect dogs against Borrelia infections. They work directly on the bacteria in the tick's intestine and inhibit their migration into the tick's salivary glands. Vaccination can also prevent new infections in dogs that have already had Borrelia infections. However, because it is rare for dogs to suffer from severe cases, the benefits of vaccination are disputed. Vaccination is recommended for dogs that spend lots of time off-leash outdoors, such as hunting dogs. Basic immunisation must be followed with annual boosters. For older dogs that have already had contact with ticks, a rapid test for Lyme disease antibodies is carried out before vaccination.
How can I protect my dog from ticks?
If you and your dog spend lots of time in the great outdoors, you should make sure he has effective protection against ticks. Ticks are not found exclusively in forests, and they don’t fall from trees, but rather lurk in bushes and high grass where dogs like to sniff around – even in residential areas. Preparations like spot-ons or tablets that control ticks can be obtained from your vet.
Alternative plant-based or EM products should only be used if you can examine your dog’s body from snout to tail for ticks and you are one hundred percent certain that you have found every tick. The risk of harming your dog with chemical preparations is lower than the risk of your dog contracting a tick-borne infection.
As warm winters are becoming more common in our latitudes, ticks are now active almost year round. Ticks do not go into dormancy until temperatures drop below 7 °C. If you are worried about long-term tick control with chemicals, you can use herbal cures to promote the detoxification of your dog’s organism. A liver-kidney cure can increase your dog's well-being after a round of strong antibiotics as well.
There are several herbs can help to take strain off of the liver and kidneys.
- Milk thistle fruits can boost liver regeneration and protect the cell membranes of the liver from cytotoxins.
- Artichoke promotes liver and bile function.
- Goldenrod has diuretic and detoxifying properties.
- Dandelion and birch leaves have mildly diuretic effects.
Caution: To not feed diuretic herbs to dogs with Lyme borreliosis-related kidney disease!
Help, I found a tick on my dog!
If you find a tick that has attached itself to your dog, remove it as soon as possible. Borrelia bacteria need between 16 and 65 hours to enter the dog's skin via the tick's salivary glands. Never apply oil, alcohol, glue etc. to the tick or squeeze a tick to remove it, as it will secrete large amounts of saliva when fighting against suffocation. Ideally, remove the tick quickly with tweezers or special tick tweezers. Make sure that the head isn’t left in the skin. Afterwards, disinfect the bite area and dispose of the tick. Practical tick removal tools such as tick tweezers and tick lassos are available at pet shops or vets. Treat mild skin irritation or itching with a wound cream that contains zinc or skin-soothing chamomile oil.
What can I do to prevent Lyme borreliosis?
You can support your dog's immune system with herbs:
- Echinacea is a valuable herb for strengthening the immune system and stimulating the body’s natural defences against bacteria.
- Sea-buckthorn and rose hips are both high in vitamin C and promote a strong immune response.
- Siberian ginseng has adaptogenic properties and strengthens the organism’s natural defences.
- Hawthorn strengthens the cardiovascular system.
- Common nettle helps the body to eliminate toxins.
A strong canine immune system can deal with Borrelia before it starts to spread in the body and do harm.