Lyme disease on Island veterinarian warns after six confirmed cases in dogs

MANITOULIN—The Expositor recently learned of an unusually high number of Lyme disease cases in dogs on Manitoulin this summer and fall.

“Lyme disease is present on Manitoulin Island,” Doctor Janice Mitchell, a veterinarian at both the Island Animal Hospital and Scott Veterinary Services in Mindemoya, told The Expositor. “This summer, five cases have been confirmed at Scott Veterinary Services and one case at the Island Animal Hospital, with five of the six dogs never having left the Island. The dogs were from Gore Bay, Birch Island, M’Chigeeng, South Baymouth (a Hurricane Katrina dog), Mindemoya and Evansville.)”

“This past summer, an eight-year-old spayed female golden retriever was presented at one of the Island veterinary clinics with a complaint of lameness,” Dr. Mitchell said of one case. “She has a fever, and was sore in three of her limbs. Bloodwork revealed a high white blood cell count and a positive antibody tied to Borrelia Burgdoferi, otherwise known as Lyme disease.”

Dr. Mitchell said this is high for Manitoulin and that traditionally Lyme disease in Ontario has been seen in pocketed areas at Rondeau Provincial Park, Point Pelee, Long Point and the Kingston/Gananoque region.

“However, ticks are on the move, at 46 km per year to be exact, and the tick that is responsible for transmitting the Lyme is the deer tick, known as ixodes scapularis,” added Dr. Mitchell. “We are just seeing more and more ticks in the area, they are moving north. Typically we find that there will be a bad tick year, but with climate change and deer and humans colliding more, we are seeing a rise.”

“Lyme disease (named for the Connecticut town of Lyme) is caused by a bacterial organism called Borrelia Burgdoferi,” Dr. Mitchell said. “It is transmitted to mammals through a blood sucking vector, the deer tick. The deer tick is a three host tick which means that each growth phase (larva, nymph, adult) will molt off the host between their requisite blood meal on three separate mammals. A female tick will lay approximately 2,000 eggs in spring, at temperatures four degrees Celsius and above. The six legged larva hatches and attaches to a host as soon as it is able—usually a mouse. If the mouse is infected with the Lyme disease bacteria, the larva will be infected. It takes up to one year to molt into an eight legged nymph. In spring, the nymph may seek another mouse or a larger host such as a human or dog. It has its blood meal and then drops off until late summer when it molts into an adult. The adult then seeks a larger host, hence its name the ‘deer tick.’ At any phase in its development, the tick can transmit the Lyme bacteria during the blood sucking phase on its host. This process of transmission can take 24-48 hours, which means that if the tick is removed in this window, the bacteria cannot be transmitted.”

Dr. Mitchell said that Lyme disease manifests itself differently in dogs compared to humans.

“After being bitten by an infected tick, 80-90 percent of humans are likely to develop the disease, where dogs are five to 10 percent likely (even less in cats),” she said. “In those canines that do develop the illness, it doesn’t manifest for weeks or months after infection at which point arthritis signs are noticed. Sometimes there is a fever, and in longer standing untreated cases, kidney damage can occur. Dogs do not develop the classic bull’s eye rash as is noted with humans.”

Luckily, Dr. Mitchell said testing for Lyme disease in dogs is simple and quick. “The same test for heart worm, 4DX, also tests for Lyme disease and two other tick diseases. It is a 10 minute blood test that detects antibodies against the organism. Once positive and if showing clinical signs, treatment consists of an inexpensive course of proper antibiotics.”

The Lyme disease incidents on the Island will be reported to the Ontario Animal Health Network, but the incident isn’t directly reported to the Sudbury and District Health Unit (SDHU).

The Expositor contacted the SDHU to see if there was a corresponding high number of humans diagnosed with Lyme disease this fall and if the public should be concerned.

“We haven’t had any confirmed black legged ticks (deer ticks) on Manitoulin this fall,” said Jon Groulx, an environment support officer with the SDHU. “There have been no confirmed human cases of Lyme disease on Manitoulin, though there have been confirmed black legged ticks and humans with Lyme disease in the SDHU catchment area.”

When asked if the high number of dog cases has led to concern at the SDHU, Mr. Groulx said, “We regularly educate the public about how to prevent ticks and how to remove one.”

He said that they also do tick dragging to determine if there is an issue in an area, but that now isn’t a prime time to do so.

Mr. Groulx confirmed that there had been an increase of black legged ticks submitted for testing with the SDHU, but said he couldn’t speculate on this being due to a high number of ticks or people being more vigilant.

People can submit ticks to the SDHU (locally in Mindemoya) to test if it is a deer tick. If it is confirmed as a deer tick (black legged tick), it is sent for further testing to see if it has the Lyme disease bacteria.

“To help prevent ticks and Lyme disease, we recommend people check for ticks when they come in from outdoors,” said Mr. Groulx. “We also suggest people wear long sleeves and tuck their pants into their socks and wear Health Canada approved bug spray.”

To prevent ticks from biting dogs, Dr. Mitchell suggested considering a veterinary approved safe treatment against ticks.

“There are several that are being prescribed in the Canadian veterinary field and exist as a pill or topical treatment administered monthly to every three months. Also, it is wise to go through your dog’s coat with a fine tooth comb, a flea comb, after any outdoor hikes to look for ticks and remove promptly,” said Dr. Mitchell. “The sooner you remove, the less time for Lyme transmission. To remove a tick, simply grasp it with tweezers close to its attachment to the skin and gently twist until the tick dislodges. Your must make sure that the entire tick, head and body is removed. Finally, for dogs visiting endemic areas of Lyme disease in Ontario, there are newer vaccines that have emerged.”

Ms. Mitchell recommended visiting www.oahn.ca for more information bout the prevalence on Lyme disease in Ontario and also noted that any questions will be welcomed at either vet clinic on the Island.