Doggie Business

Nominated Best San Francisco Dog Walker! | Since 2007

← Back to Blog

The Dangers of Eating Things They Shouldn't

Posted by The San Francisco Dog Walker

Dog eating food outdoors

By far the most common concern I see in the spring and summer months involves pets that eat things they shouldn't. This can happen any time of the year, but when the weather is nice and the ground is warm and moist, it becomes a perfect incubator for viruses, bacteria, and parasites.

After 19 years of professional dog walking in San Francisco, I've seen nearly every type of eating-related emergency imaginable. The good news is that most of these dangers are preventable with awareness and vigilance. Here's what every San Francisco dog owner needs to know.

Common Hazards in San Francisco

Our beautiful parks and beaches hide some specific dangers:

The Mushroom Menace: A Special Danger for Puppies

San Francisco's fog and moisture create perfect conditions for mushrooms, and they pop up everywhere—in parks, on lawns, in yards, and along trails. While any dog can be at risk, puppies are particularly vulnerable to mushroom poisoning because they explore the world with their mouths and are naturally curious about these strange objects growing in the grass.

The problem is that identifying toxic mushrooms is extremely difficult, even for experts. What looks like a harmless mushroom could be a deadly Amanita (Death Cap or Destroying Angel), which are common in the Bay Area and can cause fatal liver failure. Other toxic species can cause severe vomiting, diarrhea, seizures, and organ damage.

Why Puppies Are at Higher Risk

Puppies are mouthy by nature—they investigate everything by picking it up, chewing it, and tasting it. A mushroom is the perfect size and texture for a curious puppy to grab. By the time you notice what they're doing, they may have already swallowed pieces of it.

Additionally, puppies don't have the learned caution that older dogs might develop. They haven't yet figured out what's food and what's not, making them indiscriminate about what they put in their mouths.

Mushroom Safety

If Your Dog Eats a Mushroom

If you see your dog eat a mushroom, this is serious - toxic mushrooms can cause severe damage or death:

  1. Try to retrieve a sample: If possible, collect the mushroom (or remaining pieces) for identification
  2. Consider calling your vet: Time is critical with mushroom poisoning, and they can advise you on next steps
  3. Watch for symptoms: By the time symptoms appear with toxic mushrooms, serious damage may already be done, which is why early intervention can be important
  4. Induce vomiting only if directed: Your vet may tell you to induce vomiting, but only do this if they specifically instruct you to

Time is critical with mushroom poisoning. The sooner treatment begins, the better the chance of survival.

Fresh-Cut Grass Clippings: A Tempting but Dangerous Treat

Here's a problem that catches many San Francisco dog owners by surprise: grass clippings. Several times a year, the parks department mows the grass in our parks and leaves the clippings out on the lawns. To dogs, these fresh grass clippings are absolutely irresistible—the smell is enticing, the texture is appealing, and many dogs will enthusiastically gobble them up.

The problem is that grass clippings spoil quickly, especially in warm weather or when they're left in piles. Within hours, they can begin to ferment and develop harmful bacteria and molds. When dogs eat these spoiled clippings, they typically develop gastrointestinal upset that can range from mild to severe.

Why Dogs Love Grass Clippings

Fresh-cut grass has a strong, sweet smell that many dogs find irresistible. The soft, moist texture is also appealing, and dogs who normally graze on grass find the clippings easy to eat in large quantities. Unlike standing grass that they have to nibble, clippings are right there in convenient piles, making it easy for a dog to consume a significant amount in a short time.

Why Grass Clippings Make Dogs Sick

Several factors make grass clippings problematic:

Signs Your Dog Has Eaten Spoiled Grass Clippings

Common symptoms include:

Prevention Strategies

When to Call the Vet

Most cases of grass clipping ingestion result in mild, self-limiting stomach upset that resolves within 24 hours. However, call your vet if:

The best approach is prevention. When you see freshly mowed grass in your neighborhood park, take a different route for a day or two until the clippings have been cleared or have dried out completely.

The Serious Problem of Feces in San Francisco Parks

This is an unfortunate reality of urban dog ownership in San Francisco, and it's important to address it directly. Feces—both animal and human—pose serious health risks to your dog, and the problem is more prevalent in our city than many people realize.

Dog Feces: Not All Dogs Are Healthy

Many people don't pick up after their dogs in San Francisco parks and on sidewalks. This isn't just an aesthetic problem—it's a health hazard. Dogs who eat feces from other dogs (a behavior called coprophagia) can contract:

You can't tell by looking at feces whether the dog who left it was healthy or sick, vaccinated or unvaccinated, parasite-free or infected. Every pile of dog waste is a potential disease transmission point.

Human Feces: A Dangerous Urban Reality

Unfortunately, some San Francisco parks and areas have problems with human feces due to homelessness and drug use. This creates an even more serious danger for dogs. Human feces can contain:

Critical Urban Danger: Some San Francisco parks have human feces from drug users. If your dog eats this contaminated waste, they may ingest illegal drugs like fentanyl or methamphetamine and can overdose. This is a life-threatening emergency.

Horse Manure: Another Attractive but Dangerous Hazard

Golden Gate Park and Fort Funston both allow horseback riding, which means you'll encounter horse manure on trails and paths in these areas. To many dogs, horse manure is absolutely irresistible—they're drawn to the smell and will enthusiastically roll in it or eat it given the chance.

While horse manure might seem more "natural" or less concerning than other types of feces, it poses real health risks to your dog. The primary danger is Giardia, a parasitic infection that causes severe, persistent diarrhea and intestinal problems. Horses can carry Giardia without showing symptoms, and their manure can transmit it to dogs who eat it or even just get it on their paws and then lick themselves.

Why Dogs Are So Attracted to Horse Manure

The smell of horse manure is apparently intoxicating to many dogs. It contains undigested plant material and has a strong, earthy odor that dogs find fascinating. Some dogs will eat it, while others will roll in it thoroughly—coating themselves in the stuff as if it were the finest perfume. Either behavior can lead to Giardia infection.

The Giardia Risk

Giardia is a microscopic parasite that lives in the intestines and causes a condition called giardiasis. Symptoms include:

Giardia can be persistent and difficult to treat, sometimes requiring multiple rounds of medication. It's also contagious to other dogs and can even infect humans, making proper hygiene critical if your dog contracts it.

Protecting Your Dog in Golden Gate Park and Fort Funston

High-Risk Areas for Feces Contamination

While this problem can occur anywhere in the city, be especially vigilant in:

Local Warning: Be especially careful in Golden Gate Park and Buena Vista Park, which are notorious for feces contamination. Buena Vista Park has a significant drug problem and no bathrooms. Golden Gate Park and Fort Funston also have horse manure that can cause Giardia. Keep your dog on a short leash and watch constantly for what they're investigating on the ground.

Protection Strategies

If Your Dog Eats Feces

If you see your dog eat feces, particularly in an area where human feces or drug use is a concern:

  1. Note what they ate and where: This information may be helpful if you need to contact your vet
  2. Watch for signs of drug ingestion: Extreme hyperactivity, seizures, collapse, difficulty breathing, dilated or constricted pupils, disorientation
  3. If your dog shows signs of drug toxicity: This is serious - seizures, extreme agitation, or collapse mean you should get to a vet right away
  4. Monitor for gastrointestinal symptoms: Vomiting, diarrhea, loss of appetite over the next few days - contact your vet if these develop

Drug toxicity from contaminated feces can progress rapidly. If your dog shows neurological symptoms (seizures, extreme agitation, collapse) after eating feces, getting veterinary care quickly is important.

The Deadly Danger of Dead Seals and Sea Lions

This deserves its own warning because it's so common on San Francisco beaches and so potentially deadly. Dead seals, sea lions, fish, and marine birds regularly wash up on Ocean Beach, Fort Funston, Baker Beach, and other coastal areas. To your dog, these are irresistible—the smell is intoxicating, and the urge to chew on, roll in, or eat parts of these carcasses is nearly overwhelming.

But here's the critical danger: these dead animals can carry leptospirosis, a serious bacterial infection that can be fatal to dogs. Leptospirosis is transmitted through the urine and bodily fluids of infected animals, and it thrives in marine mammals. Your dog doesn't even need to eat the carcass—simply chewing on it, rolling in it, or even sniffing around it closely can expose them to the bacteria.

Serious Health Risk: If your dog chews on or rolls on a dead seal, sea lion, or other marine mammal, they may be exposed to leptospirosis. Watch for symptoms and contact your vet if your dog becomes ill.

What Is Leptospirosis?

Leptospirosis is a bacterial disease that affects the kidneys and liver. Without treatment, it can lead to kidney failure, liver failure, and death. Even with treatment, some dogs suffer permanent organ damage. The bacteria can also infect humans, making this a serious public health concern as well.

Early symptoms include:

Prevention Is Critical

On San Francisco beaches:

The Leptospirosis Vaccine: Essential but Not Perfect

If your dog lives in San Francisco or frequents beaches and parks, the leptospirosis vaccine is a MUST-DO. This is not an optional vaccine for city dogs—it's essential protection against a potentially fatal disease.

However, here's the critical limitation: the vaccine doesn't protect against all strains of leptospirosis. There are many different serovars (strains) of the bacteria, and the vaccine typically covers only the four most common ones. The strain your dog encounters in a dead seal or contaminated water may not be one of the strains covered by the vaccine.

Important Vaccine Information: Just because your dog has the leptospirosis vaccine does NOT mean they are fully protected. The vaccine doesn't cover all strains. You must still avoid dead animals and contaminated water, even with vaccination.

Think of the vaccine as a seatbelt—it significantly reduces your risk and can lessen the severity of the disease if your dog is exposed, but it's not a guarantee of complete protection. You still need to practice prevention by keeping your dog away from dead animals and contaminated water.

That said, vaccinated dogs who do contract leptospirosis often have milder cases and better survival rates than unvaccinated dogs. The vaccine is absolutely worth getting—just don't let it create a false sense of security.

What to Do If Exposure Occurs

If your dog has contacted a dead seal or sea lion:

  1. Bathe your dog: Use gloves and wash thoroughly to remove any bacteria from their fur
  2. Wash your hands thoroughly: The bacteria can infect humans too
  3. Monitor closely: Watch for any signs of illness over the next week - fever, lethargy, vomiting, loss of appetite
  4. Contact your vet if symptoms develop: If your dog becomes ill, let your vet know about the exposure

The smell of dead marine animals is irresistible to many dogs. Stay alert and use training to help keep your dog away from carcasses when you spot them on the beach.

General Signs of Gastrointestinal Distress

If your dog has eaten something they shouldn't have, watch for:

If your dog shows any of these symptoms after eating something questionable, contact your vet. When in doubt, err on the side of caution—what seems like minor stomach upset can quickly become serious.

The Broader Solution

While you can't control what others do or what hazards appear in our parks and beaches, you can protect your own dog through vigilance and training. After 19 years of walking dogs in San Francisco, I can tell you that the most important thing is constant awareness of what your dog is investigating.

The "leave it" command is worth its weight in gold. Train it, practice it, and use it consistently. Combined with scanning ahead for hazards and staying aware of what your dog is investigating, this simple command can prevent most eating-related emergencies.

Unfortunately, these dangers are part of the reality of urban dog ownership in San Francisco. The good news is that with awareness and proper precautions, you can keep your dog safe even in challenging environments. Stay vigilant, trust your instincts, and don't hesitate to call your vet when something seems wrong.