Tick-borne diseases are one of the biggest threats to dogs. Very dangerous pathogens, bacteria, viruses, nematodes or protozoa can be present in the tick's saliva. Some ticks do not have any pathogens, and others can transmit one or more pathogens. In this case, your dog may experience a variety of symptoms, making it difficult to make a correct diagnosis. In the case of the most dangerous tick-borne diseases, the dog can die within a few days. Therefore, it is very important to properly protect your dog against ticks. But which tick remedy is effective and safe?
Disclaimer: The text of this post is based on my experience with tick remedies and on available scientific research and FDA and EMA communications and does not constitute a recommendation. Be sure to consult with your veterinarian before using any anti-tick agent.
In the case of tick-borne diseases, you should act quickly. Every hour can decide whether our black terrier will survive or not. Two of my black terriers had a tick-borne disease and I saw how quickly their condition worsened. The illness came completely unexpectedly. I was returning with Antonov and Allegra from an exhibition in Romania, it was early spring and there was still snow in the meadows. On our way back home, we stopped for a quick walk in a meadow somewhere in Hungary. My dogs were not protected against ticks, because it was snowing, because it was still cold, because there were no ticks yet... Soon after returning home, Antonov began to behave strangely, and soon Allegra began to have similar symptoms. Antonov very quickly became so weak that he could not stand on his feet. Despite the night hours, I immediately grabbed the phone and started calling all possible veterinarians to find someone who would take me in right away. A quick diagnosis and I already knew that both of my dogs had babesiosis. Fortunately, we managed to find a drug in the area that was immediately administered. Later, a few sleepless days and nights, a dozen or so liters of drips, some nerves and the illness subsided. However, it was very dangerous, the dogs were weakening at a rapid pace and if left untreated, they probably would not have survived.
In order to prevent tick bites and injections of saliva with pathogens, it is necessary to protect our black terriers with anti-tick agents. Here, however, the matter becomes more complicated, because while tick-borne diseases are very dangerous and can cause the death of a dog, anti-tick agents can also be very dangerous and also in some cases can cause the death of a dog or cause very serious neurological problems, seizures, epilepsy, etc. and in extreme cases, even death. Why is this so, if these are remedies for treating dogs? In this article, I will describe the tick and flea remedies available on the market and describe their advantages and disadvantages. Some of these drugs can be really dangerous for our black terriers. If you want to find out what anti-tick agents I recommend to the owners of my puppies and why, I invite you to read the article.
Overview of available solutions
There are various forms of protection against these parasites available on the market:
- Anti-tick collars – e.g. Bayer Foresto.
- Topical remedies with active ingredients such as fipronil.
- Oral tablets – e.g. Bravecto, Simparica, Nexgard.
Each of these methods differs in its mechanism of action, length of protection, potential side effects and method of application. Below is a more detailed description of their advantages and disadvantages and a comparative analysis.
How do tick and flea pills work and what side effects can they cause?
The active ingredient of the most popular remedies against ticks and fleas are very strong pesticides. The three most commonly administered anti-tick tablets, i.e. Bravecto, Simparica and Nexgard, contain pesticides from the isoxazoline group as active substances. These are afoxolaner (Nexgard), fluralaner (Bravecto) and sarolaner (Simparica).
Let's take a closer look at the three anti-tick agents above. The active substance used in them, or rather its antiparasitic properties, was discovered during the synthesis of bisbenzamidine isoxazolines by Dupont Pharmaceuticals in 1995. The aim of these activities was to create anticoagulants, but during the research it turned out that the synthesized agents also have parasitic effects, which was described in 2014 in the journal Veterinary Parasitology https://www.sciencedirect.com/journal/veterinary-parasitology.
Isoxazolines work by blocking GABA receptors, which leads to a disturbance in the functioning of the nervous system of parasites and their death. For those interested, I include a link to a detailed description of the effect of isoxazolines on the nervous system of arthropods in the sources.
In theory, isoxazolines have a targeted effect, have a very strong effect on the nervous system of fleas and ticks, and have only a minimal effect on the nervous system of mammals, providing a large margin of safety. In theory and in pre-marketing studies, the tests were successful and the side effects that the manufacturers described in detail in the drug information leaflet were not dangerous. But the number of animals on which drugs are tested before they are introduced to the market is not large, so serious neurological problems began to come to light only after the drugs were introduced to the market. Reports from owners began to show that isoxazolines used in the most popular tick tablets can be toxic not only to the nervous system of ticks and fleas, but also to the nervous system of mammals, including dogs and cats. Dog owners began to describe seizures, epilepsy and even deaths of dogs and cats after being given isoxazoline tablets. There is even a group on the social network Facebook called "Does bravecto kill dogs and cats?" https://www.facebook.com/groups/fb.comgroupsdoesbravectokilldogsandcats/ where the owners published videos and reports about seizures, epilepsy and other reactions after administering anti-tick and flea tablets. A petition was created on the Internet www.bravectopetition.org to withdraw Bravecto from the market, which was signed by over 100,000 people.
Soon, the media became interested in the problem. The German television RTL made a report about the possible harmfulness of Bravecto, which can be viewed here: https://www.youtube.com/watch?v=Sh8zMmwdi2w . And here you can watch a documentary that was made in the Netherlands "Bravecto, is it safe or not?" https://vimeo.com/205048944 .
However, all these are opinions and descriptions of private people and journalists that can be questioned. So let's look at the side effects of anti-tick pills in a more formalized way. Research methodology requires that data for research be collected in a verifiable, formalized, and reliable way. These can be reports from professional entities, polls, surveys, etc. So let's check what formal sources say about the side effects of tick pills.
The world's two most important drug regulatory bodies, the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA), have the largest sets of adverse reactions after drug administration.
In addition to FDA and EMA statistics, we will look at the results of a survey conducted between August 1 and August 31, 2018 among veterinarians and dog owners by a group of scientists studying the side effects of tick pills. More about the survey here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738705/
Below is a summary of the reports of adverse side effects for Bravecto, Simparici, and NexGard. There are several types of side effects in FDA and EMA reports, but we will focus on the most severe of them, i.e. cases of epileptic seizures and death.
Officially documented cases of epilepsy and death after administration of Bravecto, Nexgard and Simparici.
In the table above, I have listed only the most serious side effects after the administration of tick pills. In addition to the above, there are many other side effects, such as seizures, problems with maintaining balance, internal bleeding, behavioral problems, vomiting, diarrhea and others.
Bayer Foresto (or Seresto) – anti-tick and flea collar
How does Bayer Foresto work?
The Bayer Foresto collar is one of the most popular anti-tick and anti-flea products for dogs. It contains imidacloprid and flumethrin, active substances that act on contact, which means that parasites do not have to bite the dog to suffer toxic effects.
- Imidacloprid mainly acts on fleas, destroying their nervous system.
- Flumethrin has a strong anti-tick effect, paralyzing ticks and preventing them from attaching to your dog's skin.
The collar provides protection for up to 8 months.
Advantages of the Foresto collar
- Long-lasting protection – works for up to 8 months.
- Easy application – just put the collar on, which eliminates the need for frequent injections.
- Contact action – parasites do not have to bite the dog, which reduces the risk of disease transmission.
- Water resistance – the collar is waterproof, so you can leave it on your dog while bathing.
Disadvantages of the Foresto collar
- Possibility of allergies and skin reactions – some dogs may experience skin irritation.
- Risk of mechanical damage – the collar may break or get lost.
- Restrictions in puppies and small breeds – Foresto may not be safe for dogs under 7 weeks of age and dogs weighing less than certain values.
- Risk of access for children – Children may come into contact with the collar, which can lead to a risk of exposure to chemicals.
Side effects and statistics
Although Foresto is widely used, some dogs may experience side effects such as:
- skin irritation,
- itching and redness,
- loss of hair around the neck,
- rare: neurological problems (tremor, clumsiness).
According to medical reports, tick collars can cause side effects in less than 5% of users, but depending on the sensitivity of the dog, reactions can vary.
- Fipronil agents (e.g. Frontline)
How does fipronil work?
Fipronil is an ingredient used mainly in topical preparations, applied directly to the animal's skin, usually around the neck. This agent accumulates in the sebaceous glands and spreads over the surface of the skin, forming a protective layer that is toxic to fleas and ticks. Parasites must come into contact with the animal's skin to be rendered harmless.
Advantages of fipronil products
- Easy to apply – the preparation is applied topically, which minimizes the risk of accidental eating.
- Availability in many forms – fipronil remedies are widely available, often over-the-counter.
- Fast action – parasites usually die within 24-48 hours of contact with the agent.
- Protection against fleas and ticks for up to a month.
Disadvantages of fipronil
- Parasites have to bite the dog – which increases the risk of disease transmission.
- Shorter duration of action – the agents usually work for about 4 weeks, requiring regular application.
- Side effects in sensitive animals – in rare cases, skin irritation, itching, muscle tremors, or even neurological reactions may occur.
Side effects and statistics
Fipronil is relatively safe, but about 2–4% of animals may show mild allergic reactions. Less commonly, especially in dogs with neurological sensitivities, more serious effects such as tremors or balance disorders may occur.
What are safe tick remedies?
Now think about what you want to achieve by administering a tick repellent. You want an anti-tick substance to be on your dog's skin. There are two ways to do this:
1) administer directly to the skin, i.e. to the target area (fipronil drops, Foresto/Foresto collar),
2) administer a very strong pesticide, e.g. afoxolaner (i.e. the active ingredient Nexgard) into the mouth of your black terrier, your dog will eat this very strong pesticide, from his digestive system the pesticide will be distributed through the circulatory system to the tissues, so that at the very end a certain amount of this pesticide will end up on the dog's skin.
Isn't it better to just apply the pesticide directly to the skin instead of letting it circulate all over your black terrier's body, at the risk of wreaking havoc on the internal organs? If you're still not convinced, if you haven't been convinced by videos of dogs that had severe neurological reactions, seizures, epilepsy after being given tick pills, then think that these dogs were healthy and active before the pill was given. Of course, thousands/millions of dogs in the world get these pills and nothing happens. But what happens when your black terrier is in the few percent that experience side effects? What happens when he gets epilepsy? I saw a video of a black terrier who had dozens of seizures a day (!!) after taking an anti-tick pill. This dog had to be euthanized. Of course, there are different opinions. Some people believe that the Foresto or Fipronil collars are not as effective in the fight against ticks as the tablet. Tick-borne diseases are really nasty and some people would rather take the risk of a tick pill than risk fighting a tick-borne disease if a Foresto or Fipronil collar doesn't work. The choice is yours and your veterinarian, but I hope that after reading this article and realizing that an anti-tick pill is not such a simple and obvious choice, you will be able to make a decision more consciously.