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Urgent care is for pets who are unwell, in discomfort, are in urgent situation or are not acting like themselves and should be assessed within 24 hours.
Wellness, routine, or general care is for pets needing vaccines, preventive care, or ongoing monitoring who can safely wait at least 24 hours.
This page focuses on urgent assessment. Routine wellness exams, preventive care, and monitoring of stable conditions are provided through scheduled general wellness appointments.
Dog Drank Blue-Green Algae Water
Cyanobacteria exposure can range from mild digestive upset to rapid, life-threatening toxicosis depending on the type of toxin and amount ingested.
Definition
This condition occurs when dogs or cats ingest water contaminated with toxin-producing cyanobacteria, commonly known as blue-green algae. It is not an infection or contagious disease — it’s a toxic reaction. Cyanotoxins can severely affect the liver, nervous system, or gastrointestinal tract depending on the strain. Exposure often occurs when pets drink from or swim in stagnant lakes, ponds, or slow-moving streams during warm seasons.
Toxin levels can vary, and pets may show signs within minutes to hours. While public awareness is growing, most lakes and ponds are not routinely tested for toxins.
Who This Page Is For
• Dogs that swam in or drank from ponds, lakes, or rivers and are now acting off
• Sudden vomiting, diarrhea, weakness, or collapse after outdoor water exposure
• Cats exposed to contaminated water bowls or puddles near algae bloom runoff
• Dogs that began seizing or drooling excessively after a hike or swim
• Pets showing yellow gums or abnormal bruising after outdoor water play
• Any pet with recent recreational water access and sudden unexplained illness
Who This Page Is Not For
• Pets who simply got wet but didn’t swallow water or show signs afterward.
If you are unsure whether this is significant, that uncertainty itself warrants veterinary assessment.
Related Urgent Symptoms
• Dog Vomiting
• Dog Diarrhea
• Bloody Diarrhea or Blood in Stool in Dogs & Cats
• Dog Lethargic and Weak
• Seizures or Convulsions
• Heatstroke or Heat Exhaustion
• Pale Gums (Emergency)
• Toxin Exposure in Dogs and Cats
What This Can Look Like at Home
• Vomiting or diarrhea shortly after a swim or outdoor drink
• Weakness, staggering, or sudden collapse
• Pale or yellow gums
• Excessive drooling or panting
• Seizure-like activity
• Sudden death in extreme exposures
Why This Can Be Hard to Judge
Some dogs drink contaminated water and show no signs for hours, while others collapse minutes later. Not all cyanobacteria strains are toxic, and toxin concentration can vary even within the same pond. Cats may be exposed via paws or water bowls rinsed outdoors. Owners may assume the signs are from heat or overexertion when they’re actually toxin-related.
The Improvement Trap
Temporary improvement does not equal resolution. Pets with toxin exposure may vomit once, appear to recover, then rapidly deteriorate as liver or neurologic damage progresses internally. A pet that seemed “off” then perked up may still be in early toxicosis. This is especially dangerous with liver-targeting strains.
What Is Easy to Miss at Home
• Slight yellowing of gums or eyes
• Weakness mistaken for fatigue
• Drinking pond water without being seen
• Early vomiting or diarrhea that seems mild
• Bruising or bleeding under skin
• Quiet behavior after swimming mistaken for tiredness
• Drooling or panting that seems normal at first
• Exposure from grooming algae off fur
Even mild signs may represent early stages of internal toxicosis.
When This Can Be an Emergency
Cyanobacteria toxicosis can be rapidly fatal in some cases. Seek same-day urgent care if your pet shows:
• Seizures or tremors
• Weakness or inability to stand
• Sudden vomiting or diarrhea after water exposure
• Yellow gums or bruising
• Sudden collapse
• Pale or blue gums
• Excessive drooling or panting
• Unresponsiveness or confusion
• Any sign of illness after drinking from natural water sources
How Veterinarians Assess This
Veterinarians cannot diagnose cyanobacteria toxicosis by physical exam alone. A pet that appears “off” may already be experiencing internal organ damage. Objective testing helps identify toxin effects on liver function, neurological status, and internal bleeding or clotting issues.
Diagnostic testing may include:
• Complete Blood Count (CBC) – evaluates red and white blood cells, clotting, and signs of bleeding
• Serum Chemistry Panel – assesses liver enzyme elevation, kidney function, and overall organ health
• Electrolyte Testing – detects dehydration or toxin-driven electrolyte disturbances
• Coagulation Profile – checks clotting ability in cases of liver involvement or internal bleeding
• Blood Glucose Testing – detects drops linked to liver failure or systemic shock
• Abdominal Ultrasound – may identify liver enlargement, fluid accumulation, or internal bleeding
• Urinalysis – screens for bilirubin, hematuria, or toxin-induced kidney changes
Additional disease-specific testing (such as toxin panel, liver bile acids, blood lactate, or serial clotting profiles) may be considered based on the overall clinical picture.
Veterinary Differentials - Serious / Must-Rule-Out First
• Cyanobacteria Toxicosis
Toxin-producing algae ingested during outdoor water exposure can rapidly affect the liver, nervous system, or blood clotting.
Tests may include CBC, chemistry panel, clotting profile, glucose, and abdominal ultrasound.
• Heatstroke
Overheating during outdoor activity may mimic or worsen cyanotoxin symptoms.
Tests may include temperature measurement, CBC, chemistry panel, electrolytes, and clotting profile.
• Rodenticide Toxicosis
Exposure to certain toxins (including cholecalciferol or anticoagulants) can resemble algae poisoning.
Tests may include clotting times, calcium/phosphorus levels, kidney panel, and abdominal ultrasound.
• Acute Liver Failure
Toxins or infections can trigger sudden hepatic collapse.
Tests may include liver enzymes, coagulation profile, bilirubin, bile acids, and imaging.
• Addisonian Crisis
Adrenal failure can cause collapse, vomiting, and abnormal electrolytes.
Tests may include electrolyte panel, ACTH stimulation test, and baseline cortisol.
Veterinary Differentials - Common / More Typical
• Gastroenteritis from Ingesting Contaminated Water
Dogs and cats often vomit or develop diarrhea after drinking stagnant or bacteria-rich water.
Tests may include CBC, chemistry panel, fecal testing, and abdominal ultrasound.
• Dietary Indiscretion
Eating spoiled material near the shoreline can cause GI upset without true toxicosis.
Tests may include CBC, chemistry, pancreatic testing, and fecal analysis.
• Leptospirosis
Bacteria in standing water can cause vomiting, liver damage, and kidney injury.
Tests may include leptospirosis serology, CBC, chemistry panel, and urinalysis.
• Pancreatitis
Vomiting and systemic illness may follow ingestion of rich food or toxin.
Tests may include pancreatic lipase, CBC, chemistry, ultrasound.
• Parvoviral Enteritis (in unvaccinated dogs)
Vomiting and diarrhea after outdoor exposure can mimic early toxicosis.
Tests may include parvo SNAP test, CBC, glucose, and imaging.
Safety, Psychology, & Peace of Mind
Because outward signs may not reflect internal damage, diagnostic testing offers the clearest path forward. It rules out time-sensitive conditions like liver failure or coagulopathy that can worsen quickly. Early intervention guided by test results may prevent progression to irreversible injury or death. Even if symptoms seem to fade, internal toxin effects may persist. Testing replaces guesswork with answers — and gives you clarity when your pet needs it most.
Frequently Asked Questions
Is blue-green algae poisoning always an emergency?
Not always — but it can become life-threatening very quickly. Some dogs recover after mild symptoms, while others collapse or die within hours, depending on the toxin type and amount. Because the toxin effect is unpredictable, any exposure followed by vomiting, weakness, or collapse warrants same-day urgent care.
My dog just vomited once after swimming — could it still be serious?
Yes. Even a single vomit after water exposure can be the first sign of dangerous internal toxicosis. Symptoms like weakness or quietness may be overlooked but still serious. “Apparent normalcy after vomiting does not rule out toxin exposure."
If my pet seems better, is it safe to wait and watch?
No. Temporary improvement after toxin exposure can be misleading. Cyanotoxins, especially those that damage the liver, can continue causing harm even if vomiting stops. “Pets may seem better, then suddenly crash — waiting risks irreversible progression.”
Why are so many tests needed?
Because physical signs don’t reflect internal damage. Toxins may silently affect liver, brain, or clotting — only diagnostics reveal the true impact. “Testing identifies whether the condition is mild or life-threatening and guides appropriate care.”
What should I do if I think my dog drank from a toxic pond?
Seek veterinary care the same day if your pet drank from a lake or pond and is vomiting, drooling, or acting off. These signs may indicate serious toxin effects even if mild at first. Bring a photo of the water if possible. “Don’t wait — toxin signs may escalate fast and unpredictably.”