A spot-on treatment or a flea collar works based on chemicals. Some of these are known for their toxic effects, such as fipronil. Side effects that can occur with chemical flea control include:

• Vomiting and nausea
• Diarrhea
• Excessive salivation (after licking the product)
• Itching, bald spots, skin ulcers, and color changes in the coat
• Lethargy
• Nervousness
• Neurological symptoms such as ataxia (loss of muscle control) or trembling, and in severe cases, even seizures.

It appears that smaller dogs are more sensitive to these occasional side effects than larger animals. The severity of the side effects can vary, and not every dog will experience them. Consult your veterinarian for advice if you want to use chemical products to control fleas.

Environment

Another reason to reduce the use of chemical flea collars, spot-ons, and similar products is their impact on the environment. For example, if your dog loves to swim, the chemicals from its coat can enter the water, which is harmful to aquatic life. It also means you need to reapply the treatment more frequently to control fleas.

Natural Remedies

Fortunately, there are several alternatives to chemical flea control products. You can use essential oils, lemon, or vinegar. To keep your home and your dog's surroundings flea-free, table salt is a very handy remedy. Additionally, there are dietary supplements that make your dog less attractive to fleas, so they are less likely to settle on your dog and bite less frequently.