Giardia is a microscopic intestinal parasite that dogs and cats pick up by drinking or licking water and ground contaminated with infected stool. Puddles, creeks, muddy yards and shared bowls are common sources. Typical signs are soft, greasy, foul-smelling stools and on-and-off diarrhoea, often without a fever. A faecal exam is the next step.
How Dogs and Cats Pick Up Giardia Around East Abbotsford
Giardia spreads through hardy cysts that are shed in the stool of infected animals, including dogs, cats, wildlife and livestock. Those cysts are already infective the moment they are passed, and they survive for weeks in cool, damp conditions. That combination is why a single contaminated spot in a park or a back garden can affect several pets over a season.
Most pets are exposed in ordinary, unremarkable ways. Common routes in our part of the Fraser Valley include:
- Drinking from puddles that collect on trails, gravel lots and driveways after rain
- Lapping from slow creeks, agricultural ditches and roadside runoff along the Whatcom Road area and the Sumas Prairie flats
- Sharing communal water bowls at dog parks, patios, trailheads, daycare and boarding facilities
- Walking across contaminated ground and grass, then grooming mud off paws, legs and coat at home
- Direct contact with the faeces of another infected pet, which is why multi-pet households often see more than one animal affected
Cats are exposed less often outdoors, but they are not exempt. Indoor cats can be affected through shared litter boxes, contaminated soil tracked in on shoes, or grooming a housemate that has been outside. Because only a small number of cysts is needed, a brief drink from the wrong puddle is enough.
Why Late Summer Standing Water Raises the Risk
By August, creeks and ditches across the Fraser Valley have dropped. Fast-moving water becomes a chain of warm, shallow, stagnant pools, and anything washed into them stays put instead of flushing downstream. Standing water that sits for days is a very different proposition from a running stream.
Warm weather also changes your dog’s behaviour. A hot dog on a trail at Sumas Mountain or along the Matsqui Trail dyke paths will drink from whatever is closest, and a shared bowl left in the sun outside a shop or at a trailhead can be used by dozens of animals before anyone rinses it. Late summer is also when yards stay muddy in shaded corners and irrigation runoff pools along field margins.
You cannot sterilize a trail, but you can reduce exposure. Carrying fresh water and a collapsible bowl on every outing, discouraging drinking from puddles and stagnant water, and rinsing muddy paws and hindquarters after a walk all lower the number of cysts your pet takes home.
The Signs Owners Notice First
Giardia rarely announces itself dramatically. The classic picture is a pet that seems well in themselves but has stools that are just not right. Signs that warrant an exam include:
- Soft, greasy or pale stools with a strong, unusually foul smell
- Mucus in the stool, and sometimes streaks of fresh blood
- Intermittent diarrhoea that clears for a few days and then returns
- Weight loss or a dull coat and poor condition despite a normal or even hearty appetite
- Excess gas, gurgling, urgency or accidents in a previously reliable pet
- Slower growth in puppies and kittens, who are hit hardest
- Usually no fever, and often a bright, playful animal
That last point is what delays many visits. Owners expect a sick pet to look sick, so a happy dog with a soft stool gets watched for weeks. Nutrient absorption is affected the whole time, which is why weight can slip while the food bowl empties normally.
These signs overlap with dietary indiscretion, food sensitivity, other intestinal parasites and chronic conditions such as inflammatory bowel disease, so they point to testing rather than to a conclusion. If your pet is also vomiting repeatedly, becoming lethargic, passing significant blood or showing signs of dehydration, that is a same-day concern and our urgent care team should hear from you rather than waiting for a routine appointment.
Why One Negative Faecal Test Does Not Rule Giardia Out
Infected pets shed cysts intermittently. A sample collected on a low-shedding day can genuinely contain none, even while the parasite is present and causing signs. A single negative result lowers the odds; it does not close the file.
Sample quality matters too. Cysts are unevenly distributed through a stool, the tested portion is small, and a sample that has dried out or sat warm for hours is harder to read. This is why your veterinarian may ask for samples collected over two or three consecutive days, may repeat a test after a fortnight, or may pair a flotation test with an antigen test that looks for the organism a different way.
Our in-house diagnostics allow much of this work to be handled quickly, and results are interpreted alongside your pet’s history, weight trend and physical exam rather than in isolation. If you are collecting at home, take a fresh sample, seal it, keep it cool and bring it in the same day.
The Reinfection Cycle and Why Yard Hygiene Matters
The frustrating pattern with giardia is the pet that improves, then relapses. Because cysts are infective immediately and cling to fur, bedding, bowls and soil, an animal can re-expose itself from its own environment as soon as a course of treatment ends. Breaking that loop is as much a housekeeping job as a veterinary one.
- Pick up stool from the yard promptly and daily, and bag it rather than composting it
- Wash bedding, blankets and soft toys on a hot cycle and dry them thoroughly
- Wash food and water bowls daily, and stop sharing bowls between households while a pet is affected
- Bathe or at least rinse the hind end and coat toward the end of a treatment course, so your pet is not carrying cysts on its fur
- Hard surfaces such as patios and kennel runs can be cleaned properly; grass and soil rely mostly on sunlight, drying and removing faeces quickly
- Ask about testing housemates, since an untreated pet in the same home keeps reseeding the environment
Your veterinary team can advise which cleaning products are appropriate for your surfaces and safe around your pets. Never give a medication of any kind, human or leftover animal product, without direction from your veterinarian.
Can People Catch Giardia From Their Pet?
This is the first question most owners ask, and it deserves a straight answer. Giardia exists as several genetic groups, and the ones that most often affect people are not usually the ones carried by dogs and cats. Most human infections are linked to contaminated drinking water, untreated surface water and travel rather than to a household pet.
Transmission from a pet is considered uncommon, but it is not impossible, so sensible hygiene is worth the effort while a pet is affected. Wash hands after handling stool, litter or bedding, supervise young children around the pet’s rear end and bowls, and skip face licking until the all-clear. Any questions about human symptoms belong with your family physician or local public health, not with a veterinary team.
When to Book a Faecal Exam
Book when the pattern is more than a one-off. Soft stool lasting more than two or three days, diarrhoea that keeps coming back, weight loss alongside a normal appetite, or a puppy or kitten that is not thriving all justify a stool check. So does a recent stay in boarding or daycare, a summer of creek walks, or a new pet joining the household.
Routine faecal testing during annual visits catches quiet infections in pets that never looked unwell, and is part of the same preventive picture as year-round deworming. You can read more in our guide to parasite prevention across the Fraser Valley. Where the picture is more complicated, or where diarrhoea has become a long-running problem, our gastrointestinal care workup looks past the immediate result to the underlying cause.
Frequently Asked Questions
How soon after exposure would my dog show signs?
Signs typically appear about one to two weeks after exposure, though some pets shed the parasite without ever looking unwell. That delay is why owners often cannot connect a soft stool to a specific walk or puddle. Bring the timeline anyway, since recent boarding, daycare or creek access is useful context for your veterinarian.
Can an indoor-only cat get giardia?
Yes, though it is less common than in dogs. Indoor cats can be exposed through a shared litter box, contaminated soil or plant material brought inside, standing water in a saucer or planter, or grooming a housemate that goes outdoors. Any cat with recurring soft stools is worth testing regardless of lifestyle.
Will giardia clear up on its own?
Some healthy adult pets do clear it without help, but many continue shedding and reinfecting themselves for months. Waiting also means ongoing poor nutrient absorption in a growing puppy or kitten. A faecal exam gives you an answer rather than a guess, and your veterinarian can then discuss whether treatment is warranted.
Can my dog swim in Fraser Valley creeks again?
Swimming and drinking are two different risks, and it is the drinking that matters most here. Bring fresh water on every outing so your dog has a better option, steer them away from stagnant pools and ditches, and rinse them off afterward. Ask us about your dog’s specific routine and exposure level.
Do I need to test my other pets if one is positive?
Often yes, because an untreated housemate can keep reintroducing the parasite to the shared environment. Some pets carry giardia with no visible signs at all. Your veterinarian will weigh the number of pets, their ages and their health status before recommending testing or treatment across the household.
Book a Faecal Exam at Alpha Animal Hospital
Has your dog or cat had loose or greasy stools since the summer walks started? Bring a fresh stool sample to our Whatcom Road clinic and let our veterinarians take a proper look. Call (604) 859-6322 or explore our pet care services to arrange a visit six days a week.
Published by the team at Alpha Animal Hospital.
This article is provided for educational purposes only and is not a substitute for an in-person veterinary exam, diagnosis or treatment. If your pet is unwell or you have an urgent concern, please contact Alpha Animal Hospital or your nearest emergency veterinary hospital right away.
Alpha Animal Hospital
2362 Whatcom Rd, #125, Abbotsford, BC V3G 0C1
(604) 859-6322
Monday to Friday: 8:00am – 8:00pm
Saturday: 9:00am – 5:00pm
Sunday: Closed
STAT: Closed