Update on Parasites and Your Dog
Our clinic’s mission statement is “Excellence in Care for Pets and Their Families”. One of the ways we strive to provide excellence in care is through client education.
This is a detailed update for those who are interested- if you are short on time; please skip to the important summary at the end.
We attended a conference in January of 2017 on the increasing presence of ticks in Canada, and thought we should share this information with you.
There are a number of parasitic diseases that are of concern in Southern Ontario. These are internal parasites such as roundworm, hookworm, whipworm, heartworm and giardia, and external parasites such as ticks, fleas and mosquitoes. The most potentially impactful of these parasites over the last several years is ticks, more specifically the Black Legged or Deer tick that can carry Lyme disease and Anaplasmosis. In dogs, Lyme disease is the most common, and can cause problems with the joints and kidneys, but if caught early, can often be helped with treatment. Unfortunately, even with treatment, dogs are not “cured” but go into remission and need ongoing monitoring.
Lyme disease incidence has significantly increased in southern Ontario over the last several years. Dogs can be carrying Lyme disease and not be showing clinical signs, therefore testing is very important. Anaplasmosis is much less common, but can cause fever, muscle pain, and serious changes in the blood. Fortunately, it is a treatable disease if caught early.
The tick population in southern Ontario is rapidly increasing. The best approach to tick borne disease is to treat for ticks before they can transmit the disease. Ticks start to look for a blood meal when it is above the freezing mark (0 degrees Celcius), and therefore during our increasingly mild winters, each month can have had a period of time where ticks could be active. The white-tailed deer is an important part of the Black Legged tick’s life cycle, and therefore areas where there is an established deer population would have more concerns for Lyme disease. However, other intermediate hosts for the Black Legged or Deer Tick can include mice, rabbits, raccoons, and coyotes. These animals can come into our suburban areas and can therefore bring ticks carrying Lyme and other diseases into our backyards. Even birds flying overhead can drop ticks into our back yards, meaning that even dogs that do not go out for a lot of walks in wilder areas are still potentially at risk.
Many of the parasite increases that we are seeing in Ontario can be attributed to global warming. There is truly a benefit to the cold Canadian winters we used to have, since many parasites cannot survive severe cold. It has been noted that by 2050 with our current rate of global warming, our climate here in Southern Ontario is predicted to resemble that of Tennessee. Apparently southern Ontario also has a “mosaic” countryside (lots of fields with woods interspersed in between), which is exactly the environment that ticks enjoy. When combining this with decreased pesticide use in Ontario, warmer winters, and a thriving white tail deer population, it is understandable how the tick population and risk of Lyme disease is increasing dramatically.
For a number of years, we have been recommending parasite treatment year-round as our gold standard for dogs and outdoor cats. This recommendation is now stronger than ever, because ticks and their associated disease risks, continue to increase in southern Ontario.
We are recommending Interceptor tablets, combined with a tasty Simparica chew taken orally both given once a month. This combination of Interceptor and Simparica will provide extremely effective control of the higher risk parasites in Ontario. Interceptor is the little brother of Sentinel (which we have used for many years), and when taken orally once a month, effectively controls roundworm, hookworm, whipworm and heartworm. However, Interceptor does not have a flea control ingredient. Therefore, the Interceptor should be combined with Simparica, a highly effective flea AND tick control product. It works very specifically on the nervous system of the fleas and ticks, and does not affect the nervous system of mammals at all, so is a very safe product.
If your dog is indoors virtually all of the time, and only goes out to urinate and defecate, then you could potentially use Sentinel without Simparica as your year-round parasite control program, since your dog will be at lower risk for ticks. However, it is rare to have a dog at no risk for acquiring ticks, simply due to the fact that almost all dogs go outside to eliminate.
And please don’t forget the human risk of Lyme disease. In general, more mature ticks will attach more readily onto dogs, and the younger, smaller nymph form will attach onto humans. If a tick latches on to us for a blood meal, then we are also potentially at risk for Lyme disease and other diseases as well. Please be sure to contact your physician if you find a tick attached to you, and of course let us know if you find a tick on your dog.
And finally ticks can also occur on cats. Luckily cats are relatively resistant to tick borne diseases (unlike humans and dogs). But if you do not like having your outdoor cat getting tick bites please call to discuss tick prevention options for cats, there are some new products coming.
There has also been an increase in the population of the Texas Lone Star tick in southern Ontario, although luckily these are far less common than the ticks that carry Lyme disease. The Texas Lone Star Tick carries Rocky Mountain Spotted Fever, which is a potentially fatal disease in dogs if untreated, and can affect humans as well. It can also carry Ehrlichia, which can cause some dangerous changes in the blood, and although treatable, like Lyme disease it is never completely eliminated from the body. Simparica is recognized as the most effective tick control for the Texas Lone Star Tick out of all currently available tick products.
With respect to other parasites, studies have shown dogs can be carriers of raccoon roundworm (Baylisascaris), a parasite which can be dangerous and even life threatening to humans, especially children. Interceptor and Sentinel are highly effective against this roundworm. Other internal parasites such as Giardia or Coccidia must be diagnosed through analyzing the stool (feces) of the dog at least once per year.
We must not forget that heartworm disease is still present in Canada, with southern Ontario having the highest density of cases. Rescue dogs that were brought to Canada after hurricane Katrina, and that continue to be brought in from warmer climates, unfortunately can contribute to our heartworm problem, since many are not properly treated prior to arrival. The wild dog population (i.e. coyotes) can also harbor heartworms and can spread the disease. As you may know, heartworm disease is spread by mosquitoes. With our mild winters, we are seeing mosquitoes much earlier than before, with a resulting longer season where heartworm is transmissible. This is another reason to administer year-round Interceptor since the same compound that is in Sentinel and Interceptor which treats roundworm, hookworm and whipworm, also effectively controls heartworm.
We are fortunate to have a vaccine against Lyme disease if you wish to be very certain your dog is protected. Humans are not so lucky yet, although there are potential vaccines on the horizon for us. There is currently no vaccine for Ehrlichia or Anaplasmosis, but if caught early these diseases can be helped with treatment.
We recommend a yearly blood test for every dog called the 4DX test. This test screens for heartworm disease, Lyme disease, Ehrlichia and Anaplasmosis, it is recommended as our gold standard once yearly even if your dog is not showing any signs of problems, since all of these diseases can hide for periods of time before causing clinical signs.
Gold Standard for Parasite control in Ontario dogs:
- Current physical exam- must have been seen within the year to dispense prescription product
- Remove/avoid tall grass and leaf piles to minimize tick environment
- Fecal Analysis yearly
- 4DX blood test yearly along with wellness testing to screen for organ disease
- Interceptor tablet once monthly year-round
- Simparica chew (orally every month year-round)
- Lyme vaccine
What To Do If You Find a Tick on Your Dog
- Use tweezers to grasp the tick by its mouthparts closest to the skin and pull gently away from, and out of the dog
- Do not use your hands to remove tick since this may squish the body of the tick and encourage it to regurgitate its digestive contents into the animal, which would then increase the chance of disease transmission. Also many of the diseases transmitted from ticks can be passed to humans, so using a tweezer and plastic disposable gloves will minimize this risk.
- Do not stun the tick with alcohol first since this may encourage the tick to regurgitate into the animal and increases the potential risk of transmission of disease.
- Once the tick is out, please dispose of it in a small jar of rubbing alcohol to kill it and the diseases it may contain. Squishing it to kill it can cause dispersal of diseases, so this is discouraged. You can also use regular alcohol like rum or scotch in a pinch.
- Ideally a 4DX blood test should be performed on your dog 1 month after a tick bite, and 4 months after a tick bite. This will check for any transmission of disease. However, testing will depend on if your dog has been on a preventative tick medication and if your dog has been vaccinated against Lyme disease, so will be discussed with you to determine the best approach for your dog.