Tick Protection for Pets - How it Harms the Environment

There are a variety of tick-borne diseases, most notably Lyme disease, which can seriously affect pets as well as humans. This has to be taken seriously as these diseases can often be hard to cure completely, and may result in life-long complications, or in the worst-case could even be fatal. In the case of Lyme disease, this mainly affects dogs, as well as humans - cats seem to be less susceptible. It must be noted that the effects in humans are more severe than for animals. It can be generally expected that dogs will be completely cured after a course of antibiotics, whereas in humans it is difficult to cure completely, and symptoms can be persistent and even life-long.

 

A topic of serious concern, however, is that some of the current best methods of tick control for pets, mainly dogs, are entering our natural water systems in large amounts, and having a significant impact on aquatic life. Tick, as well as flea and lice control, are often controlled using topical pesticides. While killing these insects helps to prevent the infection and spread of diseases, releasing large amounts of pesticides into the environment is having unintended consequences, and is damaging our natural environment.

 

Ticks harbour the Borrelia bacterium, which results in Lyme disease, in their gut and salivary glands. When ticks bite and extract blood, the bacterium enters the human or animal, infecting them. In the wild, the bacterium is transmitted between ticks and host animals such as rodents and birds. 

 

These are the current available methods to combat ticks, lice and fleas, or the diseases that they carry:

 

Vaccination and oral medications, in the form of pills or chewable tablets, are contained within the animal’s body, as opposed to a topical treatment. Vaccination creates antibodies, which attack the lyme disease bacteria once they end up in the body, or even while they are in the tick from the blood that the tick has extracted. Oral medication absorbs into the bloodstream and into the skin - when a tick bites, the medication is transferred to the tick, which dies before being able to transfer the bacteria. Both of these methods are only effective once the tick has bitten, and does not prevent a bite. 

 

Topical treatments and collars use pesticides on the surface of the skin and hair to control ticks, lice and fleas. The two most widely-used pesticides against ticks are fipronil and imidacloprid. These are applied to the hair and skin of your pet. They eventually wash off, either by swimming in natural bodies of water, or by washing at home, which washes the pesticides down the drain. The pesticides are not able to be filtered out of water treatment plants, and are washed back into natural bodies of water. There is growing evidence that these pesticides, as well as the forms that they become after breaking down over time or in the sun, are highly toxic to a range of aquatic life, from small invertebrates to fish. 

 

 

 

 

A study in the UK analysed 20 English rivers between 2016-18 Fipronil was detected in 99% of samples and a highly toxic breakdown product called fipronil sulfone was found in 97%. The average concentrations were 5 and 38 times higher than their chronic toxicity limits, respectively. The UK and EU have no official limit for these chemicals so the scientists used a 2017 assessment produced for a water quality control board in California. Imidacloprid was found in 66% of the samples and was above toxicity limits in seven of the 20 rivers. The researchers found the highest levels of the pesticides downstream from water treatment plants, showing that urban areas were the main source of these pesticides (1) A similar study with similar results was conducted in the netherlands (2)

 

Fipronil was banned from use on farms in 2017 in the EU due to its impact on bees, but remains allowed as a non-agricultural pesticide, which is up for renewal in September 2023.  (3)

 

Imidacloprid, one type of neonicotinoid class of pesticides, was banned in 2018 for use on farmland in the EU due to its impact on bees.(4,5) Imidacloprid is however still used in greenhouses, as well as to treat farm and domestic animals, including fish. While the amount of pesticide remaining in consumed food is regulated (6), there is no current regulation concerning the amount of Imidacloprid or Fipronil in surface or groundwater - it is not included in the list of priority substances in the field of water policy (7). One possible explanation for why these pesticides were left out of the latest list of water priority substances is that “the Union is to take account of available scientific and technical data, environmental conditions in the various regions of the Union, the potential benefits and costs of action or lack of action as well as the economic and social development of the Union as a whole and the balanced development of its regions”. The EU parliament has asked the EU commission to urgently reconsider limits for Imidacloprid considering its impact on aquatic life (8). 

 

The EU reacted commendably to ban pesticide use on fields which were strongly linked to loss of bees, has determined maximum residue limits (MRLs) allowed in food consumption, but is delaying acting to restrict other forms of releasing pesticides into the environment, which ultimately has a severe impact on aquatic life.

 

Taking one brand of highly-rated topical tick protection as an example, it contains 400mg of Imidacloprid to be applied every 4 weeks. There are currently around 10 million dogs in Germany (9). If 50% of dog owners are assumed to apply a topical tick protection as regulated this would result in 2000kg - 2 tons - of Imidacloprid applied to dogs and later washed into our water systems per month - or 24 tons per year. 

 

Any improvement in reducing pesticides in the environment can help. By avoiding topical pesticides for ticks, fleas and lice which contain pesticides, this can help reduce the overall amount of pesticides entering our environment.

 

 

 

 

Natural tick repellents can be used to complement vaccination and oral medication, in an attempt to naturally repel ticks and to try to avoid a bite altogether. The only option which is backed by a scientific study is the use of lauric acid (10). Coconut oil contains around 50% lauric acid. The study showed that a concentration of 10% lauric acid protects between 81% and 100% of the time, showing coconut oil to be an effective method to prevent tick bites.

 

Always check yourself and your dog if you have been in an area which has ticks. Checking your pet at least once a day for ticks is an added layer of prevention.