Can Dogs Get Sick from the Rain?

There is something special about taking your dog for a walk after a good rainstorm. The air smells amazing, the ground looks freshly washed, and best of all you get to spend time in the great outdoors with your favorite canine friend. While this might seem like a great time to get out and about, you need to exercise a lot of caution when it comes to letting him splash around in the puddles, as you never know what might be in the water.

Fortunately, since most humans are smart enough not to drink from the rainwater puddles, they don't pose quite as much of a health risk to them. But at the same time, pools of standing water can contain some pretty serious health hazards for your furry friend.

Can Dogs Get Sick from the Rain?


Depending on where you live, it is possible for your dog to get sick from the rain. The water that gathers into puddles on the ground can contain a variety of biological and chemical hazards that can be harmful and even kill your dog.

Does My Dog Have Rainwater Poisoning?

While you may think this sounds a bit odd, your dog could end up being exposed to Leptospira bacteria, Giardia, and even antifreeze in those fun-to-splash-in puddles. Both Leptospira and Giardia come from animal waste, the first from urine and the second from feces. All three contaminants cause similar symptoms, including:

  • Diarrhea

  • Vomiting

  • Loss of appetite

  • Lethargy

Leptospirosis and antifreeze can also cause kidney failure, and ingesting antifreeze can also lead to seizures and coma.

The most common causes of rainwater poisoning are other animals--or at least the urine and feces of other animals--as the bacteria responsible for leptospirosis and the Giardia protozoa live in these waste products. Rain water helps to disperse them over a larger area and collect in puddles. When your dog drinks the water or licks himself clean after your walk, he can ingest them at which point, they get to do their job of making him ill.

With antifreeze, it only takes a minute amount of the highly toxic chemical ethylene glycol to have a devastating effect on your dog's health.

If your dog begins to act sick shortly after a walk through the rain puddles, take him to see his vet a soon as possible. The vet will perform a series of blood, urine, and stool sample tests to diagnose his condition. It is important that you realize many dogs who ingest antifreeze don't survive even after receiving aggressive treatment.

How Do I Treat My Dog's Rainwater Poisoning?

How your dog is treated for his exposure to rainwater will depend heavily on what particular condition he has contracted. Both giardiasis and leptospirosis are treated with IV fluids and antibiotics.

Your vet should immediately place your four-legged friend on IV fluids to help flush out the organism or chemical responsible for the problem.

The next step for leptospirosis and giardiasis is to start a regimen of antibiotics such as metronidazole or fenbendazole,  which are commonly used.

In the case of antifreeze poisoning, the vet may induce vomiting before adding sodium bicarbonate to his IV along with fomepizole. If it has been more than four hours since he ingested the antifreeze, it will have most likely passed into his kidneys, requiring aggressive treatments in an attempt to correct the acid/alkaline balance.

Providing you seek timely treatment, most cases of leptospirosis or giardiasis will clear up within a few days after beginning the appropriate treatment. The prognosis for these medical conditions is considered very good, and a little more care with walking in the rain can help prevent recurrence. There is a vaccination for leptospirosis that is known to be quite effective.

On the other hand, unless you take your dog to the vet within the first four hours after he consumes even a small amount of antifreeze, the prognosis is not good. Ethylene glycol causes renal failure that is often irreversible and will lead to death. Even with proper treatment, there is still a chance he may not do well.

How is Rainwater Exposure Similar in Dogs and Cats?

Cats may not enjoy going out in the rain or walking in the puddles in the same manner as dogs, but they will drink the water. This can lead to the same basic medical conditions with similar side effects that require treatment. These can include

  • Leptospirosis – a bacteria that can cause vomiting, diarrhea, lethargy

  • Giardiasis – protozoa that can cause diarrhea, vomiting, lethargy

  • Antifreeze poisoning – can lead to kidney failure and death

How is Rainwater Exposure Different in Dogs and Cats?

Cats are more sensitive to the cold and to becoming wet than dogs. In fact, if a cat's temperature drops below 100 degrees Fahrenheit, it can lead to frostbite and death if left untreated. The big difference is that in most cases, it takes far less time for this to happen to a cat than it does in a dog, due to body mass.

At the same time, most cats tend to avoid water, which in turn reduces their chances of becoming "poisoned" by rainwater. But at the same time, when thirsty enough, cats are just as likely to drink from a puddle as any dog. In turn, this exposes them to the same bacteria, protozoa, and chemicals. Being a smaller animal may result in more devastating effects from lesser exposure.

Case Study

You and your furry friend took a nice long walk just after the rain storms passed. While you never actually caught him drinking from the puddles, he definitely had fun splashing around in them. A few hours after getting him home, he started vomiting and couldn't wait to get outside because of diarrhea.

You rush him to the vet for a checkup, taking a stool sample with you. The vet examines your dog and the sample and then tells you Fido has giardia and must be treated. He starts an IV to replace lost fluids and gives the dog the first in a series of antibiotics.

By following the treatment plan, your dog should make a full recovery within just a few days and be back to his normal happy and playful self, ready to go walking once again.

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