Pet Diseases and Parasites | Winnipeg Humane Society
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Pet Diseases and Parasites

Signs, symptoms and prevention strategies:

Lyme Disease

Lyme disease is a bacterial infection that is carried and spread by the deer tick (pictured here). The bacterium is found in mice, deer, and other wildlife. When a tick feeds on an infected animal, the tick transfers the bacteria to the next animal it feeds on. This disease can affect your pets, as well as you; however, you can only catch the disease if you’re bitten by the tick itself, NOT by contact with your pet.

Lyme disease is found in Canada, and the highest incidences occur in North West Ontario along the Manitoban border, however, it can also be found in British Columbia, Quebec, and New Brunswick.

How do I know if my dog has Lyme disease?

The most common symptom of Lyme disease infection in dogs is arthritis, which causes inflammation, pain in joints and lameness. Other signs can also be dehydration, loss of appetite and weight, inactivity and swollen lymph nodes. Signs of the disease usually develop 2-5 months after the infection, with the period of lameness lasting for 3-4 days.

Most dogs exposed to the Lyme bacterium, do not get ill. Also, some dogs require treatment, however, many infections resolve on their own.

Diagnosis is made by a blood test that detects exposure to the bacterium in conjunction with symptoms. The test will also identify a dog that was exposed to the bacterium but did not become ill; therefore, interpretation of a positive result is important.

How can I protect my dog?

  • Prevention – Early removal of ticks by carefully inspecting your dog’s ears, tail area, elbows and between toes. This should be done daily, as it takes the tick about 48 hours to infect your dog.
  • Tick control – Use tick repellant sprays weekly, and apply them before going into tick infested areas.
  • Vaccination – This is also available, but has a high rate of side effects.


Heartworms are blood parasites that pose a dangerous and even fatal condition to your dog. Immature heartworms are spread by mosquitoes and are passed along into the bloodstream of the dog. They travel to the right side of the heart where they can grow and reproduce, resulting in blockage of the arteries. Adult heartworms can grow to the length of 15-30cm, and in severe cases, a dog can be infested with hundreds of them.

What are the symptoms?

Symptoms of heartworm disease depend on how many worms the dog carries, and how long they have been carried. Unfortunately, most symptoms are detectable only after much damage has been done to the internal organs, which can be irreversible.

Signs include intolerance to exercise, chronic cough, listlessness, labored breathing, weight loss, fainting, chest bulging, and abnormal heart and lung sounds. Worms in the heart decrease the amount of oxygen rich blood, and increase the work load, causing liver and kidney problems, and heart failure.

What are the treatment options for this disease?

Preventing heartworm disease is easy! There are monthly medications that are available at your local vet. The heart worm prevention program in Manitoba starts on June 1st- Nov 1st. Every dog should be on heartworm prevention.

How can I protect my dog?

Since Southern Manitoba is one of the areas in Canada that is endemic, and the disease is transmissible in warmer seasons, protecting your dog from heartworms is important. Once-a-month tablets are available to prevent the growth of heartworms into adult ones, as well as solutions that can be applied directly to the skin in mosquito season.


Blastomycosis is a fungal infection caused by a fungus, which grows as a mould in moist, warm, acid and sandy soils. Dogs often get the infection after inhaling in the spores from the soil and into their lungs, but can also occur through contact with exposed skin (e.g. wounds).

This fungus is found in the Canadian provinces of Manitoba, Ontario, as well as Quebec, and can be fatal if untreated. Once the fungus is in the body, it multiplies rapidly and can spread from the lungs where it creates a pulmonary lung infection, to other parts of the body such as eyes, bones, brain and urogenital system

What are the symptoms of Blastomycosis?

  • Respiratory tract problems such as difficulty in breathing and harsh lung sounds
  • Coughing
  • Exercise intolerance
  • Anorexia and weight loss
  • Depression and lameness
  • Fever that does not respond to antibiotics ( 103 degrees or higher)
  • Eye problems such as redness, pain, swelling, excessive tearing, clouding of the cornea, and in extreme cases, blindness.
  • Blood in urine
  • Draining skin lesions and forming ulcers on skin
  • Enlarged lymph nodes

To diagnose Blastomycosis, a sample is taken from the infected tissue. A chest x-ray can also be taken for respiratory disease.

What are the treatment options for Blastomycosis?

It can take weeks or even months for any signs of Blastomycosis to appear, but sometimes, the dog’s immune system can fight off the infection if relatively small amounts were inhaled. However, if the dog is not able to fight of the fungal infection, oral antifungal drugs are available.

How can I protect my dog?

Unfortunately, there is no other way to protect your pet other than to avoid the areas with high Blastomycosis population. If you are out for the weekend in your cottage, ensure that your dog is not digging beneath the cottage or in wet, damp, moldy areas such as beneath rocks that are close to the water. Be aware of the symptoms, and take immediate actions if you think that your dog may have Blastomycosis.


Tapeworms are an intestinal parasite that can affect dogs (and cats). They attach themselves to the wall of the small intestine with their hook-like mouth. They are flat and segmented, white in color and can grow to the length of several feet. As the tapeworm matures, those small segments break off the tail part of the worm and pass into the stool, while new segments are formed at the neck area. These segments are about the size of a grain of rice and are mobile when first passed. There are several types of tapeworms that infect pets.

How would my dog or cat get infected with tapeworms?

Tapeworms are spread by eating infected, fleas, rodents, or fish. Your pet can ONLY get tapeworms this way, not from another pet.

  • By swallowing a flea that has tapeworm larvae (from other animal’s feces) while grooming
  • When they eat a rabbit, rodent, or such that is infested with the tapeworms

What are the signs and symptoms of the infection?

Often, you may be able to see dried segments of the tapeworm around the pet’s anus (they resemble rice grains), or even moving segments in their feces.

Usually, infections are not very harmful to your dog, but heavy infections can be. The tapeworms feed off the nutrients of the dog, and therefore can cause malnutrition and a dull looking coat. Other symptoms may include inflammation of the intestine, diarrhea, vomiting, and weight loss.

The infection is usually diagnosed when the white moving parts are seen crawling on the dog, or in their feces, however, they are often not detected in the routine fecal examination.

How can I protect my dog?

  • Prevention by regular de-worming with medication able to get tapeworms.
  • Flea control and elimination
  • Do not allow hunting of wild animals and rodents or eating raw fish.
  • Treatment is simple and effective. Drugs are available at your vet clinic and can kill the tapeworms.


Roundworms are the most common intestinal parasites found especially in young puppies and kittens. Adult roundworms are slender, spaghetti-like bodies, white-ish-to-cream colored and can grow up to several inches. They move against and feed on the food ingested by the dog.

How would my dog get infected?

  • During embryonic development, larvae can be passed to the puppy or kitten (most puppies are infected that way)
  • Milk from an infected mother
  • Swallowing worm eggs from the soil in the environment (from self grooming or soil)
  • From eating an infested animal such as a rodent or a rabbit

What are the signs and symptoms of an infection?

  • A pot-bellied appearance to the abdomen especially in puppies
  • Coughing and Vomiting
  • Dull hair coat and weight loss
  • The presence of worms in the stool or vomit of the dog
  • In serious cases, anemia and pneumonia due to the worm’s presence in the respiratory system

Note that the younger the puppy, the more symptoms it will show. Older dogs may not show any outward symptoms at all.

Are roundworms transmittable to humans?

Yes they are, however, humans are not the usual hosts for these parasites and the worms can get “lost” in the human body. If larvae enter the eyes, blindness can result. Young children are most vulnerable to roundworm infections because of their habits to put things in their mouth. If a human ingests roundworm eggs, they will become infected. Deworming your pet will help keep people safe.

How can I protect my dog and my family?

  • All puppies need to be given a monthly dewormer against all the major intestinal parasites by the age of two weeks
  • Routine fecal testing
  • Immediate feces pickup to eliminate any possible larvae