Seasonal Information


Heartworms are bloodworms transmitted from dog to dog by mosquitoes. Heartworms live in your dog’s blood vessels, eventually reaching a length of 15-30 cm. All dogs, regardless of age, sex or breed are at risk wherever mosquitoes are present.

Heartworm disease can be fatal. Adult heartworms can block blood flow, damage the lungs and cause other health problems. It takes only one infected mosquito to infect your dog.

Wellness Testing

Through a special arrangement with our lab, we will be offering Wellness Testing for your dog when done in conjunction with a heartworm test. The following are some options:

  • Heartworm Test Only
  • Wellness Profile 1: Recommended for young dogs to profile individual baseline data that your veterinarian can use later as a reference. Includes a heartworm test, 14 biochemistries, and a complete blood cell count.
  • Wellness Profile 2: Recommended for dogs over 8 years of age to monitor vital organ function and detect disease before symptoms appear. Includes a heartworm test, 18 biochemistries, electrolytes, and a complete blood cell count.

Frequently Asked Questions About Heartworm

During the mosquito season once monthly from June 1st to November 1st. The medication works retroactively. For example; the June 1st dose prevents heartworm disease from developing as a result of mosquito bites during the month of May.

Your dog should have a negative heartworm test for 2 consecutive years before switching to alternate year testing.

If you have a puppy that was born after September 1st last year they will not need a heartworm test because they have not been exposed to mosquitoes. They will still require preventive medication for the upcoming season.

If your dog missed a dose of preventive medication last year then they will need a test this year.

If you have traveled south over the winter to the United States or other heartworm prevalent areas with your dog then they should be tested this year because risk of heartworm exposure is greater in the United States.

If your dog vomited any of last year’s doses then they will need a test this year.

If you have faithfully given all of your preventive medication last year after doing a test, then you may choose to skip this year’s test.

Although heartworm preventive medications are very reliable, no medication is 100% effective. We suggest at least testing every other year as a precaution to ensure your dog has not contracted heartworm disease.

If your dog does not receive the full 6 doses then he will be tested next year even if he was tested this year.

If you start on June 15th then you should give the medication the 15th of each month.

Medication does not need to be given after November 15th since mosquitoes do not pose a threat after that date.

If you forget a dose of medication then give the dose when you remember and that day each month afterwards.

You should also have your dog tested next spring to ensure he or she wasn’t exposed to heartworm.


Ticks have become increasingly common even in Oakville in recent years. Some ticks have the ability to carry and transmit infectious diseases, such as Lyme disease, to dogs and to humans.

Ticks are most numerous in the spring and fall but can be acquired anytime from March to December. There are some very effective products available to help protect your pet against infestation with ticks.


Nexgard is a prescription medication formulated into a flavoured tablet that will kill fleas and ticks for one month following administration. It can be used in combination and given simultaneously with any heartworm preventive medication.

K9 Advantix

K9 Advantix is a topically applied medication that will kill fleas and ticks for one month following application. It can be used in combination with any heartworm preventive medication. When used along with Advantage Multi, they are applied alternately once every 2 weeks. K9 Advantix (

Regardless of which tick and flea medication is used, because ticks become active at temperatures of 4 degrees Celsius and higher, in some cases it is wise to initiate preventive medication starting in March.

If you would like more information about Lyme disease, please see:

Ticks and Lyme Disease


Fleas continue to be an extremely common warm weather skin parasite of dogs and cats. In an allergic pet, even one flea can cause severe dermatitis, itch and discomfort.

Fleas become active outdoors when the temperature rises above freezing in the spring, with the peak in flea numbers occurring in August and September. Winter weather provides some relief by reducing the outdoor flea population but fleas will thrive indoors over the winter months if allowed.

Fortunately, there are several flea control products available for dogs and cats that are very effective, very safe, and very simple to administer. Some of these products also provide protection against other parasites, such as heartworms, intestinal parasites, mites and ticks. Please ask us which flea control product best suits your pets needs.

Products Recommended for Dogs:

K9 Advantix:
Advantage Multi:

Products Recommended for Cats:

Advantage Multi:


If you would like some answers to commonly asked questions about rabies, please see:

Rabies Q&A