To the Editor:
The CVMA (Canadian Veterinary Medical Association), in partnership with Merck Animal Health, declared March as National Tick Awareness Month and for the second year is promoting awareness for pets and people with the help of veterinary clinics. Lyme is a true zoonosis (Zoonoses are diseases that can be transmitted from animals to humans by either contact with the animals or through vectors (vector, an organism, typically a biting insect or tick, that transmits a disease or parasite) that carry zoonotic pathogens from animals to humans.) The emergence of this problem is real and escalating in most of Canada.
Studying ticks helps us have an idea of the geographic risk. There was a passive tick surveillance program in Nova Scotia where various groups and individuals were able to send in ticks found on themselves or their pets; that program ended in 2011. Passive surveillance is not for clinical management as results are not available in a timely manner.
There is also active surveillance where suspect areas are dragged looking for ticks or where rodents are trapped/inspected and tested for pathogens. A new surveillance method is being explored called E-tick where pictures of ticks would be sent in for identification.
Tick numbers are always greater than seen. Areas that are hot spots likely were problem areas for at least two to three years before being recognized. It can take two to three years for the tick to complete its life cycle and for an area to be deemed endemic all stages of the life cycle must be found. These ticks from established areas can spread out by piggy backing on mice, deer and birds, at a rate of 35-55 kilometres per year with an average of 46 kilometres.
Nothing short of an ice age will stop the expansion of these ticks.
The focus of Tick Awareness Month is on prevention. Identification of ticks is important and there are aids available to help. A new book, The Handbook to the Ticks of Canada, is available online; it can also be purchased in hard copy. The hope is that veterinarians can identify and help their clients learn the basics of tick identification. There is about a 50-plus percent chance in Nova Scotia that the tick you find is a blacklegged tick Ixodes scapularis with the wood/dog tick Dermacentor variabili being the next most common tick found; there are also other species of ticks.
Education is important for protection of pets and people. A tick check is the number one approach in helping prevent disease. Ticks can be active anytime the temperature is above 4 degrees C. In Nova Scotia, there are many days in the winter months that are above this temperature. It can be said that while there is not risk 365 days of the year, that there is risk of being bitten by a tick in every month of the year. So do tick checks daily when ticks are active and your pet and family members have been in an area that would sustain ticks.
The use of preventatives such as repellents and monthly topical (on skin) is next in trying to help control ticks on your pet. There is a vaccine available for dogs but it is important to note that it is only effective against Borrelia, ie Lyme, and there are many other co-infections being carried by the blacklegged tick. The most effective way of battling ticks and preventing disease is to use the three prong approach: body checks, preventatives and vaccination if in high risk areas, noting that no approach is 100 percent. Veterinarians have an in-clinic test for dogs for tick-borne diseases.
The longer the blacklegged tick is attached the more likely it is to transmit disease. How do you know how long the tick was attached? There is controversy about time of attachment required to transfer pathogens that cause disease. Infection can be transferred in as little as a few hours for Borrelia and in minutes for other pathogens. I feel any blacklegged tick bite is cause for concern. Recent literature claims that approximately 85 percent of dogs exposed to Borrelia burgdorferi will not develop clinical signs of Lyme disease (versus >90 percent of exposed humans WILL develop clinical signs).
In some recent studies it has been found that the blacklegged tick’s like leaf litter better than long grass and are prevalent along edges of property/trails. Ticks are not on cut lawns but in transition areas or trails animals travel.
Nova Scotia, Ontario and Quebec are the provinces with the highest number of Lyme cases.
We cannot stop the ticks but we can change our perception. Education is KEY!