Probiotics for Dogs Side Effects

Written by
James Patel
Published on
March 20, 2016
Updated on
June 22, 2024

Probiotics are live bacteria presented in capsule or liquid form that provide numerous benefits to a dog’s overall health. Bacteria species found in most canine probiotics include Lactobacillus, Bifidobacterium and S. thermophilus, all gram-positive bacteria that colonize within a dog’s gastrointestinal system, eliminate harmful bacteria and restore optimal levels of “good” gut microbiota.

Probiotics are typically given to dogs suffering GI tract illnesses, chronic diarrhea or diarrhea associated with antibiotic use. However, probiotics are like “super” vitamins that improve all aspects of a dog’s health, ranging from enhancing immune system functioning to supporting intestinal absorption of nutrients necessary for keeping all dogs fit, happy and disease-free.

Do Probiotics Cause Side Effects in Dogs?

Any substance that contains ingredients capable of effecting changes with a living organism is going to produce side effects of varying degrees. Some of these side effects won’t manifest themselves enough to be physically experienced because they occur at the cellular level. Other side effects may extend beyond the cellular level in reaction to the dog’s body chemistry, which may be abnormal due to illness, hormonal irregularities or a compromised immune system.

Probiotic supplements are complete safe to give to dogs since they contain nothing but natural ingredients, i.e., probiotic bacteria that already exist in the canine GI tract. If side effects do occur after giving probiotics to a dog, they are usually associated with digestive issues, such as excess gas, constipation or diarrhea (if you are not already treating the dog for diarrhea). In addition, the dog’s health problems may worsen a bit before completely clearing up as the GI tract adjusts to the sudden influx of “good” probiotic bacteria.

Side Effects Resulting from Weakened Immune Systems in Dogs

Research into lactobacillus included in probiotic supplements has found that L. bacillus may thrive too much in a dog’s immune system weakened by disease, malnutrition or even old age. Although a rare occurrence, overgrowth of lactobacillus may allow bacteria to spill over into the dog’s bloodstream and produce a systemic infection or inflammation.

Allergic Reactions to Probiotics

Experts estimate that only one in a million dogs and people could have an allergic reaction to probiotics for reasons that have yet to be identified. Signs that a dog may be suffering an allergic reaction to one or more of the live bacteria composing probiotic supplements are intense “all over” itching, difficulty breathing, swelling of the tongue and lips and unsteady gait. Dogs exhibiting these symptoms after being given probiotics should be taken to a veterinarian as soon as possible for supportive care.

Low Quality Probiotics May Cause Side Effects

Probiotics manufactured by inferior companies do not care about your dog’s healthy. They are only in the business to make a profit and produce cheap, unstable probiotics that quickly degrade in the dog’s stomach before reaching the intestines. Unless probiotic bacteria reach the dog’s intestines in tact and still retaining all their beneficial properties, they are essentially useless and may even be harmful to the dog once “seeded” in the GI tract.

Another problem with low quality probiotics is that they may labeled “for dogs” but are, in fact, meant for humans. Nearly all bacteria are host-specific, meaning that some bacteria are designed to exist in dogs and some specific to humans. Giving dogs human probiotic supplements may cause side effects that include vomiting, severe diarrhea and dehydration.

Canine-specific bacteria are:

  • Bifidobacterium animalis
  • Lactobacillus acidophilus
  • L. rhamnosus
  • L. fermentum
  • L. reuteri
  • L. salivarius

Every one of these bacteria can be found in high-quality probiotics formulated especially for dogs. In addition, superior canine probiotics will offer the correct CFU, or “colony forming units”, beneficial to your dog’s health. A probiotic formula’s CFU is the total amount of bacterium in the formula. Some formulas combine all bacteria strains into one CFU count while others will list each strain of bacteria on the label, along with its unique CFU.

How Many Probiotic CFUs Do Dogs Need?

This depends on the type and severity of the dog’s health condition. Owners who put their dogs on canine probiotics should closely monitor the dog, observe their eating and sleeping habits, determine whether the dog’s energy level has increased and decide (with helpful input from a veterinarian) if the dose should be adjusted.

Depending on how much your dog weighs, a total CFU of one to four billion is extremely effective in restoring your dog’s health. To minimize the risk of side effects, dogs under 50 pounds should be given between one and three billion CFUs of probiotics for the first few days. Dogs weighing more than 50 pounds can handle between two and five billion CFUs per day. It’s also a good idea to divide dosages into two parts to be given at mealtimes.

Advantages of Probiotics for Dogs Clearly Outweigh the Minimal Risks

In addition to antibiotics causing GI tract disorders, chronic diarrhea, flatulence and appetite loss, other factors such as poor diet, stress, environmental changes and non-antibiotic prescription drugs can also deplete beneficial bacteria in the dog’s intestines. Probiotics not only promote growth of “good” bacteria in your dog’s intestines but will also:

  • Improve digestive processes by facilitating breakdown of consumed food, absorption of vitamins and minerals and removal of toxic waste products
  • May help reduce minor food intolerances and their side effects
  • Reduces inflammation in the GI tract to relieve diarrhea or constipation
  • Increases energy levels by eliminating some chronic health conditions
  • Promotes manufacturing of folic acid, biotin and B vitamins
  • Stimulates and regulates all components of the canine immune system
  • Helps degrade and neutralize food toxins and carcinogens
  • Keeps hormone levels balanced and regulated
  • May reduce the risk of female dogs suffering urinary tract infections

Love Your Best Friend with Probiotics

Side effects of probiotics in dogs is minimal to none and should never deter a dog owner from giving their dog the great health benefits of safe, high-quality probiotics.

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