Lyme disease in dogs – tick repellents, prevention and other tick borne diseases

lyme disease in dogs

Lyme disease is an infectious disease caused by bacteria called Borrelia burgdorferi. The bacteria are most commonly carried by the blacklegged tick. Not only humans are at risk of contracting Lyme disease. Dogs can contract Lyme disease and other tick borne diseases as well.

A tick bite can spread Lyme disease to your dog. A tick needs to be attached for approximately 12 hours before it can transmit the disease to your dog. Young dogs appear to be more susceptible to Lyme disease than older dogs. In general Lyme disease leads only to symptoms in a minority of the dogs that become infected.

Tick prevention in dogs

Our pets are constantly playing in conditions that are conducive to tick exposure. Once a dog is infected with one of these organisms the chance is that dog is infected for life. Prevention is therefor critically important.

Occasionally a dog can pick up hundreds of ticks on a single outing. If a dog walks through a place where ticks are molting into nymphs you can find two hundred tiny ticks on your dog.

It is a misconception that ticks die in the winter. Ticks hunker down and wait for warmer days. This can relax your awareness and tick prevention which is a risky thing to do. All you need is one warm day and the ticks are out. Year round diligence and protection is essential.

Lyme disease used to be a Northeast and Midwest phenomenon in the United States but this is no longer the case. It’s all over the United States, Canada and Europe. Leading veterinarians are of the opinion that dogs should be tested annually for Lyme disease.

Tick checks

If possible avoid your dog from roaming in tick invested environments. Check your dog’s coat and skin daily and remove ticks properly to prevent the transmission of tick borne infections. It is more difficult to check for ticks on dogs than humans. Some dogs have thick coats and ticks can hide deep in the fur. Consider clipping the coat of your dog if it has long hair during the months that ticks are most active. This makes ticks easier to spot.

Start at the head and run your hands over your dog’s body. Check under the collar and use your fingers like the teeth of a comb. Check behind the ears, the toes, under the tail, and around the anus. Ticks are drawn to dark, hidden areas on the body. Check the skin for areas that appear red or irritated and watch for signs of excessive scratching or licking in particular areas. This can be a sign the tick has attached itself in this spot. Ticks can be the size of a flea and are easily missed. Daily checking increases the chance of finding the tick before it has been able to harm your dog’s health.

preventing ticks on your dog

Tick removal

Upon discovering a tick on your dog your first instinct might be to pull it off immediately with your bare hands but that is not a good idea and does more harm than good.

You may wear a pair of disposable gloves when handling ticks. Use tweezers or special tick removal tools but make sure you grab the tick behind the head as close to the skin as possible to avoid squeezing its body and accidentally causing the tick to vomit its content (including the bacteria it carries) into the blood stream of your dog.

After removing the tick you can kill it by putting it in rubbing alcohol and flushing it down the toilet.

Tick repellents for dogs

There is a Lyme vaccine; there are tick collars and there are monthly topical and oral repellents. No one method is 100% effective and all methods have their pro’s and con’s. Either way it remains important to check your dog for ticks on a daily basis.

There are many products available to repel or kill ticks. Some of the more popular products have been available for many years now and this causes the emergence of resistant ticks. Therefor newer products might be more effective.

Some of the available prevention products don’t actually repel the ticks of your dog’s body. Most of these products don’t prevent the tick from walking onto your dog or biting your dog. These products kill the tick after it has bitten. This is perfectly fine. Tick that are killed within the first 24 hours of being attached to your dog cannot transmit disease.

A downside to this is that dogs can still hitch ticks into your house and this can be a threat to your own health and that of your family members. In contrast with the oral medications a tick collar physically repels ticks. If your dog wears a tick repellent there is also a chance that the ticks instead climb on you or your kids. Thus there are pro’s and con’s to both methods.

It is generally not a good idea to combine products. So you use either a collar, a topical or oral preventative option but you do not combine them because these products are toxic. Discuss with your veterinarian which tick repellent is best for your situation.

Topical tick repellents

1. Frontline Plus

  • Active ingredient: fipronil
  • Duration of protection: 1 month

Fipronil collects in the oils of skin and hair follicles and is released onto the skin and coat. This results in long-lasting activity.

2. Advantix

  • Active ingredient: permethrin, imidacloprid
  • Duration of protection: 1 month, can be administered weekly.

Advantix kills and repels ticks without the tick having to bite the dog. Toxic to cats.

3. Tick collars

Tick collars contain organophosphates which are potentially toxic. The collar is less effective in dogs that swim.

Small dogs need a different collar than large dogs. Large dogs have a different body composition and have a higher tolerance for the chemicals used. Smaller dogs need less chemicals for effective protection.

Oral tick repellents

Some owners are concerned at the increased risk of toxicity with oral products. There is always a risk of your dog reacting to anything synthetic or natural. Both Nexguard and Bravecto have been associated with the death of dogs. We don’t recommend the use of these products. These drugs are only available by prescription. If your dog had side-effects from these products please reach out for assistance and support at the Bravecto and Nexgard Facebook groups.


Nexguard is only available by prescription.

  • Active ingredient: afoxolaner
  • Duration of protection: 1 month


Bravecto is only available by prescription.

  • Active ingredient: fluralaner
  • Duration of protection 3 months
IngredientProductSide Effect
ImidaclopridK9 Advantix, Seresto Flea and Tick collarsApathy, labored breathing, incoordination, staggering, spasms, anemia, hormone disruption
FipronilFrontlineSkin irritation, lethargy, incoordination, dilated pupils, convulsions, potential carcinogen
PyrethrinsK9 AvantixVomiting, seizures, heart failure, brain damage, hormone disruption
FluralanerBravectoVomiting, lethargy, seizures, death
AfoxolanerNexguardVomiting, lethargy, seizures, death

Natural tick repellents

If you are seeking natural repellent options you can consider Neem Oil sprays. These may repel but do not kill ticks. There is no data on their effectiveness and devices which send out sound waves to repel ticks are a scam.

Cedar, Rose Geranium and Lavender oil have also been suggested as effective tick repellents for dogs. There is some data that suggests that Rose Geranium is as effective as DEET in repelling ticks.

For most of the marketed essential oils there is no data on their effectiveness or the frequency it needs to be applied for optimal protection. Effectiveness can differ between brands.

Remember that just because essential oils are ‘natural’ that doesn’t mean they are automatically safe. There are at least 30+ essential oils known to be potentially toxic to dogs.

Lyme disease Vaccine

There is a Lyme vaccine for dogs available but it is only moderately effective. It only seems to prevent Lyme disease in 60-86% of the vaccinated dogs. Vaccinations can be administered at twelve weeks of age; require two shots, three weeks apart and yearly boosters.

lyme vaccine for dogs

  • Less than 5% of the dogs develop signs attributable to Lyme disease. If you use proper tick control a vaccine is usually unnecessary.
  • There are concerns that the Lyme disease vaccine for dogs causes Lyme nephritis and auto-immune arthritis due to the presence of the OSP-A antigen in the vaccine.
  • The Lyme disease vaccine produced more post-vaccine adverse events than any other canine vaccine.
  • It is only moderately effective and prevents Lyme disease in only 60-86% of the vaccinated dogs


Lyme disease symptoms in dogs

In humans the Bull’s Eye rash is the most well-known Lyme disease symptom. If a human gets treatment at that point there is a chance the infection is killed before it becomes a systemic infection. In dogs the first signs are pain, lameness and fever. By the time you spot the symptoms of a tick borne infection in your dog he is already systemically infected.

Lyme disease symptoms in dogs can also mimic other conditions. Lameness can be easily mistaken for an injury. If your dog is limping you might assume that he is injured. The joints may be swollen, warm and painful.

If the lameness comes on suddenly and moves around from one leg to another this is a sign it might be caused by Lyme disease. The lameness can also be mistaken for arthritis but lameness from arthritis comes on more slowly over a long period of time and affects the same joint consistently.

Some dogs develop kidney problems. Lyme disease can inflame and cause dysfunction of the blood filter in the kidneys. Kidney failure may set in and can be accompanied by vomiting, diarrhea, lack of appetite, weight loss, increased urination and thirst and abnormal fluid buildup.

  • Lameness
  • Swelling of the joints
  • Sensitivity to touch
  • Difficulty breathing
  • Fever
  • Lack of appetite
  • Lethargy/depression
  • Swollen lymph nodes


The veterinarian will ask for a thorough history of your dog’s health and its activities. If he suspects your dog has Lyme disease he will recommend testing your dog for Lyme disease and a number of other common tick borne infections such as ehrlichiosis, anaplasmosis, Rocky Mountain spotted fever and babesiosis.

The test used most often is called an antibody test. It detects antibodies created by the dog’s immune system as a response to exposure to Lyme disease. This test can be false negative:

  • recently infected and antibodies are not yet developed
  • suppressed immune system causing a failure to develop antibodies
  • been infected for a long time there may no longer be sufficient antibodies present

The tests used to diagnose Lyme disease are called the C6 and Quantative C6 test (QC6). The C6 is a preliminary test that looks for antibodies against a specific protein called C6. This protein is unique to the Lyme bacteria and the presence of antibodies against the C6 protein suggests exposure to the infection. The C6 antibodies can be detected 4 weeks after the dog has been bitten by an infected tick.

When antibodies are found with the next step is the QC6 test which determines if antibodies are high enough to justify treatment. If the value of the QC6 test is high enough and the dog shows clinical symptoms antibiotic treatment is considered.

Your veterinarian may also recommend other tests:

  • To evaluate organ function (kidneys, liver, pancreas)
  • Complete blood count (to assess for blood related conditions)
  • Electrolyte tests (to ensure your dog isn’t suffering from dehydration)
  • Urine tests (to look at kidney function)
  • Thyroid test (to see if the thyroid is producing enough thyroid hormone)
  • ECG (to screen for abnormal heart rhythm)


If the antibody levels on the QC6 test are high enough and your dog shows clinical symptoms and/or has abnormal levels of protein in his urine the veterinarian prescribes antibiotics. When a dog tests positive for Lyme disease but is otherwise appearing healthy it may be unnecessary to treat it with antibiotics. However, Labradors and Golden Retrievers are predisposed to developing serious complications from Lyme disease. Any dogs of these two breeds that test positive for Lyme disease should be treated with antibiotics immediately.

The antibiotic of choice is usually doxycycline but depending on your dog’s clinical signs and circumstances the veterinarian can choose another antibiotic. The recommended length of treatment is at least 4 weeks but has to be longer in some individual cases. Improvement of your dog’s condition may be noted after 3-5 days of treatment.

Antibiotic treatment does not always completely eliminate the Lyme bacteria from the dog’s body. Once a dog is infected with Lyme disease some dogs will always have the Lyme disease bacteria. Therefore relapses are possible and pet owners should consult their veterinarian when the dog develops unexplained fever, swollen lymph nodes, and/or lameness after initial treatment for Lyme disease. The development of kidney disease in the future is always a worry. In those cases re-treatment is recommended.

Other tick borne diseases in dogs


Anaplasmosis is a tick-borne disease caused by the bacterial organism Anaplasma phagocytophilum. Anaplasma has been reported worldwide in a wide variety of animals.

Most dogs have symptoms for 1-7 days. Some will have only minor symptoms. Clinical disease is often mild. Some dogs develop bruising or bleeding. Dogs with anaplasmosis often have many of the same symptoms as those with Lyme disease. Infection with both bacteria (co-infection) is not uncommon.

Symptoms: lameness, joint pain, fever, lethargy, anorexia, vomiting, diarrhea, coughing, labored breathing. Rarely neurological signs such as seizures are reported.


  • Doxycycline, treatment generally lasts 4 weeks. It is well tolerated with minimal side effects.


The organism responsible for this disease is a rickettsial organism called Ehrlichia. Rickettsiae are similar to bacteria. The disease seems to be particularly severe in German Shepherd Dogs and Doberman Pinschers.

Signs of ehrlichiosis can be divided into three stages: acute (early disease), sub-clinical (no outward signs of disease), and clinical or chronic (long-standing infection). In the acute stage the dog develops fever and other symptoms. This stage lasts 2-4 weeks and in that time some dogs eliminate the bacteria or develop a subclinical phase. Sometimes a dog will pass through the acute phase without apparent symptoms or signs of illness. These dogs may progress to a next stage of clinical ehrlichiosis or eliminate the organism.

Symptoms: fever, swollen lymph nodes, respiratory distress, weight loss, bleeding disorders (spontaneous hemorrhage or bleeding), eye problems (including hemorrhage and blindness), neurological disturbances such as meningitis and if the bone marrow is infected the dog can develop blood disorders.


  • Dogs experiencing severe anemia or bleeding problems may need a blood transfusion.
  • Doxycycline, treatment generally lasts 4 weeks. It is well tolerated with minimal side effects.


Babesiosis is caused by a tick borne parasite called Babesia. Babesia invades red blood cells and causes anemia. It is considered a serious threat to racing greyhounds and pit bull terriers.

Dogs infected with Babesia may present with a wide variety of clinical signs ranging in severity from a sudden collapse with systemic shock, to a hemolytic crisis or a subtle and slowly progressing infection with no apparent clinical signs.

Hemolysis happens when the immune system identifies the red blood cells that are infected by Babesia and destroys them. If large amounts of infected red blood cells are destroyed the dog can develop anemia.

Neurological symptoms can develop when Babesia enters the central nervous system and there can be lung injury. If the acute infection is not lethal a chronic infection develops which usually does not produce symptoms but relapses can occur with stress.

Symptoms: fever, weakness, pale mucous membranes, lethargy and depression, swollen lymph nodes, enlarged spleen and dark urine.


  • Imidocarb, it creates remission but does not clear the infection. A single dose is usually effective but two injections are needed for some forms of Babesiosis. Side effects are muscle tremors, drooling, elevated heart rate, shivering, fever, facial swelling, tearing of the eyes and restlessness. Pre-treatment with atrophine helps alleviate these symptoms.
  • Azithromycine + atovaquone, stops the reproduction of Babesia and gives the immune system a chance of clearing the infection. Side effects are few or none.

Rocky Mountain Spotted Fever

Rocky Mountain Spotted Fever is a disease caused by the bacterial organism called Rickettsia rickettsii. The disease occurs in North, South, and Central America as well as east of Saskatchewan in Canada.

In dogs, the signs of Rocky Mountain Spotted Fever can be vague and non-specific. Because the organism damages the walls of small blood vessels, clinical signs develop throughout the dog’s body. The clinical signs can be vague and mimic other disease processes which may delay diagnosis and the start of treatment.

Symptoms: poor appetite, muscle- or joint pain, fever, cough, abdominal pain, vomiting, diarrhea, swelling of face or legs, lethargy or depression, hemorrhages in the eyes and gums, nosebleeds, neurological disturbances such as wobbling when walking or painful hypersensitivity


  • Doxycycline, treatment generally lasts 7-21 days.
  • Two other antibiotics that can be used are Enrofloxacin and Chlooremphenicol for similar durations.