In a study published in November, 2015, BMC Veterinary Research concluded that lysine supplementation is not an effective treatment for feline herpesvirus 1 infections. The study also states that lysine is ineffective when it comes to preventing the infection from occurring in cats.
As the basis of its study, BMC Veterinary Research sent surveys to 68 veterinary practices located in three countries, the United States, Australia and the United Kingdom. BMC Veterinary Research received replies from 23 of the treatment centers. After confirming that the animal hospitals treat cats on a regular basis, BMC Veterinary Research inquired about whether they recommend lysine supplementation to treat cats infected with feline herpesvirus 1 and if pet owners are able to buy lysine directly from them.
Based on the responses it received, BMC Veterinary Research determined that 91 percent of the veterinary clinics recommend lysine supplementation for cats who are infected with FHV-1. BMC Veterinary Research also determined that 87 percent of the same clinics sell lysine supplements.
Given that lysine is so widely used to treat FHV-1 in felines, BMC Veterinary Research used data provided by NCBI’s PubMed database to evaluate the effectiveness of lysine supplementation in treating and preventing FHV-1 in cats. The data BMC Veterinary Research analyzed to reach the conclusions outlined in its recently published report included seven studies on lysine and feline FHV-1 and ten publications that discussed lysine and human herpesvirus.
After analyzing the data mentioned above, BMC Veterinary Research determined that lysine is not effective to treat or prevent FHV-1 in cats. While lysine doesn’t have antiviral properties, the supplement is thought to lower arginine levels which is believed to be effective at preventing the FHV-1 virus from replicating itself. According to BMC Veterinary Research’s study, however, there is no evidence that reduced intracellular levels of this amino acid stop the virus from replicating. The study also states that an arginine deficiency can lead to hyperammonemia, a condition that can result in death.
BMC Veterinary Research also concluded that lysine itself does not inhibit the replication of the FHV-1 virus. Even more alarmingly, BMC Veterinary Research’s report revealed that certain previous studies concluded that lysine is not only ineffective in the treatment or prevention of FHV-1 in cats, the supplement can actually increase the frequency of infection and worsen the severity of the disease in felines treated with lysine.
If you have a cat who suffers from FHV-1 and are treating your pet with lysine, BMC Veterinary Research recommends that stop administering the supplement immediately and consult your veterinarian for alternative treatments. BMC Veterinary Research makes this recommendation due to the “complete lack of any scientific evidence for its [lysine’s] efficacy.”