Parasites and Prevention – What You Need to Know!

Parasites and Prevention – What You Need to Know!

If you’ve been noticing the positive temperatures and thinking it may be parasite season, you’re right! Here’s all you need to know about which parasites to be concerned about this year and what to do to protect your furry family members (and your human family members too)!


Ticks 1st Photo

Ticks have been making the news for some years now because of their prominence across Canada. Our last two newsletters reported on ticks and the diseases they carry (you can read these articles here and here). Unfortunately, in Ontario, tick-borne diseases have gone from being rare cases to being fairly common. In fact, one of the most reputable laboratories across Canada reported a 382% increase in Lyme disease, 1017% increase in Anaplasma-positive cases, and 1660% increase in Ehrlichia-positive cases from 2012 to 2017! And while we once thought ticks only resided in densely forested areas, our clinic has confirmed cases (specifically Lyme and Anaplasma) where the dogs did not walk through any forested areas. After all, as ticks spread their geographical territory, their only true necessity is a blood-meal from any warm-blooded animal. As ticks hitchhike on birds and other mobile animals, ticks have been able to achieve far-reaching territories that we once thought safe. Also, because our cats and dogs are a main vector to bring ticks into our homes, there is a risk that ticks may choose the relatively hairless humans instead.

Ticks 2nd Photo

It was also once thought that ticks are only active between 4-24°C; however, recent research indicates ticks maintain activity as low as 0°C, which means ticks may be active all winter long. So how do we protect our pets and ourselves? The only proven (through extensive research) and safe (through extensive testing) methods are veterinary-grade tick preventatives. Other tick preventatives have not undergone the rigorous research and testing that verifies the quality and safety of the product. There are no “natural” tick preventatives that work; in fact, these treatments generally provide consumers of a false sense of security but with essentially zero protection. Tick preventatives come in either monthly topical treatments or chewable tablets that may be given monthly or every three months. There are significant benefits to topical treatments, as they provide a “force field” of protection, which cause most ticks to die off very shortly after coming into contact with our furry family members. Topical tick prevention is also a mosquito repellent. Chewable options work once the ticks attach and feed, which causes the tick to ingest the toxin in the preventative and die. How long our pets need protection really depends on the weather. As ticks are active at cooler temperatures than we expected, it is recommended that you follow the temperatures closely and treat your pet as often as needed (and this may mean you’ll be using preventatives all year round). Please contact us today to talk about which options would be best for your furry companion!


Heartworm 1st Photo

Heartworm disease is also sadly also increasing in prevalence – it is endemic in Ontario and other places in Canada. We have been reporting on heartworm disease in previous newsletters and you may read about exactly what heartworm is and how it effects our canine companions here. The number one question we’re asked is how pet parents know whether their dogs contracted heartworm disease (without doing blood screening) and the answer is you wouldn’t! At least not until heartworms invade a significant portion of the heart and greater blood vessels of the lungs. Once the disease reaches this point, treating the condition is extremely difficult, expensive and often and can leave our pets with permanent cardiovascular damage. Heartworm disease is insidious – even with excellent screening methods, heartworm disease isn’t generally detectable on a blood test for six months after a dog is infected.

Heartworm 2nd Photo

Luckily, our clinic has caught all our cases of heartworm disease on routine, annual heartworm screening, which has allowed us to intervene quickly and save our patients’ lives.  For this reason, we strongly recommend each dog undergo annual blood testing in the months of April or May. Because heartworm disease is spread through infected mosquitoes, every dog that goes outdoors – even for a quick bathroom break – needs to be on heartworm prevention monthly, starting from June until November (or throughout winter if you’re traveling with your pet to a warmer climate). Much like veterinary-grade tick prevention, veterinary-quality heartworm prevention products have undergone rigorous research and testing to ensure its efficacy and safety. Heartworm preventatives are available in topical and chewable formulas, so please give us a call today to discuss which options are right for your pet!




Much like ticks, fleas are considered an external parasite because they do not enter the body. We’ve previously reported on fleas and their effect on our furry family members here. Fleas can be more than a mere annoyance that keeps your pet up all night itching away. Fleas can harbour disease (after all, they’re the main vector for transmitting the Bubonic Plague) and their biting behaviour can cause serious infections. Fleas become active as soon as the weather becomes warm and readily spread to cats and dogs, even after very minimal exposure to the outdoors. Once fleas lands on our furry family members, they breed and lay thousands of eggs very quickly. Flea infestations often happen very quickly and often take three to six months (or longer if there are other pets in the home) to fully eradicate in the home. The good news is, most good-quality tick and heartworm preventatives have flea protection built in!


Intestinal Parasites

Intestinal Parasites - 1st Photo

The term “intestinal parasites” covers many different species of organisms that take up a home in the intestines of its host. We’ve covered intestinal parasites in last year’s newsletter and you can read more about it here. There are, however, some new developments in the parasite world! Firstly, there is a deadly and fatal tapeworm that has become a well-established parasite in southwestern Ontario and you can learn more about it here. In addition, our clinic has experienced a recent but exponential increase in the number of two particularly nasty intestinal parasites – whipworm and hookworm.

Intestinal Parasites - 2nd Photo

Whipworm is a type of intestinal worm that literally looks like a microscopic whip. These types of worms spread through the ingestion of eggs through oral contact with feces, contaminated dirt, improperly washed/cooked fruits and vegetables, and ingesting infected animal tissue. The worst part about your pet contracting this parasite is the fact that whipworms can dwell dormant deep within soil and can easily cause re-infection for up to five years! If your pet contracts this parasite and uses your back and front yard to defecate, it is recommended that six inches of the top, contaminated soil be removed and disposed! This is often completely unfeasible for most people, so the next best recommendation is to have your furry companion remain on deworming agents for five years, allowing the parasite to die off due to its natural lifecycle. The main signs of this parasitic infection are non-specific, intermittent but slowly worsening diarrhea.

Intestinal Parasites - 3rd Photo

Hookworms are another intestinal parasite we’ve seen with increasing frequency. These particular intestinal worms are very dangerous and often cause a lot of damage to the intestinal tract of the host in which it sets up a home. The name hookworm is very fitting because these parasites infiltrate the gut with their three pairs of teeth! Imagine the act of sewing a garment with a needle and thread. In this analogy, the garment is the intestines and the needle and thread are the hookworms. The damage sustained by the intestinal lining can be immense. Without prompt treatment, these parasites can cause significant blood loss and permanent damage to the intestines, leading to inflammatory bowel disease. As you can probably imagine, this parasitic infection can be very serious, especially if it happens to puppies/kittens or weakened senior pets.

Intestinal Parasites - 4th Photo

So what can we do about preventing these parasites? Fortunately, most good-quality heartworm preventatives have excellent anti-parasitic properties, which help avoid these parasites from moving beyond their infantile life stages. This helps to ensure true infections are kept to a minimum. Also, because parasites can be contracted by mere contact with the outdoors (after all, fecal residue can be anywhere!), we recommend annual fecal testing to search for any parasite eggs that point toward an infection. This is particularly important, as many intestinal parasites can be transmitted from our furry family members to our human family members, particularly young children and those with compromised immune systems. If you have any questions or concerns about how parasites effect your pet, please contact us today!



Leptospirosis - 1st photo

Though this disease is technically caused by bacteria, it’s an infection that is typically contracted in spring and fall. We’ve reported on this condition in several newsletters and you can read more about it here and here. Because this bacterium is spread from infected wildlife urine, Leptospira can found anywhere outdoors. Anywhere from infected soils and grass, to puddles and lakes, Leptospira bacteria are deadly and lead to an infection that causes the kidneys and liver to fail. Sadly, many cases of leptospirosis are fatal, especially if not treated right away. There are many different types of Leptospira bacteria that cause disease but, luckily, there is a vaccine that can prevent many common types! For the other strains that aren’t covered by the vaccine, there is a body of research that shows dogs vaccinated for leptospirosis have some cross-protective immunity. Unfortunately, this disease may be transmitted to humans, so it’s important to vaccinate your canine companion against this terrible disease annually. If you have any questions about your pet’s vaccine status, please contact us today!

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