: Rated 4.7/5 stars . Owners appreciate that it is odorless and tasteless, making it easy to hide in wet food without their cats noticing. Where to Buy : Found at NOW Foods , Walmart , and Target Tomlyn Immune Support Powder

: Available at VetRxDirect , UPCO Pet Supplies , and Chewy.com NOW Pets L-Lysine Powder

Lysine is a popular amino acid supplement widely recommended by veterinarians—with a in some surveys—primarily to manage symptoms of Feline Herpesvirus-1 (FHV-1) such as sneezing, watery eyes, and congestion. While many pet owners report positive results in clearing up respiratory issues, scientific studies provide conflicting evidence regarding its actual efficacy in preventing or treating the virus. Top-Rated Lysine Supplements

: A highly palatable maple-flavored gel that contains 500mg of L-lysine per serving.

Pet owners generally prefer products that are easy to administer and highly palatable to cats. Vetoquinol Viralys Oral Gel