Cats and Lysine

By Michael Ephraim Vergara, DVM

Cat population has slowly risen in numbers the past few years here in our country. The common notion is that, with the increase in number of condominiums in the metro, living with a cat is more acceptable that living with a dog.

But of course, this is not the sole reason as there are families not living in condominium units but in houses who are also into cats nowadays. Their reasons range from cats being sweet to cats being little more independent at times. With all these coming together, products and other necessities for cats have grown as well and are now being available in the market.

cat 1


But one thing that has been there for cats and has actually been through scrutiny is lysine. Some have studied on lysine and shown the importance and great effects it gives to cats while for some, they can go as blunt as saying lysine is unnecessary for cats.

Lysine is an essential amino acid that serves as a building block for protein, which plays a key role in carrying out many different bodily functions. Lysine is not only for pets as it can be given as a supplement as well for humans.1

In cats, various references have mentioned the role lysine plays. One reference says lysine helps cats produce antibodies and enzymes that support the immune system. It also mentioned that lysine promotes healthy skin.2 Also, lysine is said to be helpful for calcium absorption, which supports strong bones.

But it is important to note that a cat’s body does not make lysine on its own. With the many functions it does and lysine being essential for their health, cats should receive outside sources of this amino acid through food supplements.1 Supplementing cats with lysine doesn’t have to be difficult especially this time that various supplements with lysine are available in the market and they come in various dosage forms like in gels and syrups.

Lysine supplements are commonly used in preventing herpes in kittens in the same way that in humans, lysine is often used to treat cold sores because it seems to stop herpes virus from growing. In kittens, lysine is given up until the time they get their protection from vaccines. Also, lysine is part of the regimen in treating upper respiratory infections in cats.2

Lysine is also beneficial, as per a write-up from one internationally known feline practitioner Dr. Susan Little for chronic rhinosinusitis (CRS) wherein cat will show frustrating symptoms of chronic sneezing and nasal discharges. CRS is also known as ‘chronic snufflers’ or chronic cat flu and is commonly associated with a viral infection. But a thorough diagnostic work-up is necessary to identify this and may suggest as well a life long treatment so part of proper client education for this disease is setting realistic expectations.3

CRS in cats would typically appear as sneezing as mentioned earlier and noisy breathing, serous or mucopurulent nasal discharges if secondary bacterial infections were present. Some cats with CRS have a history of infection with feline herpesvirus (FHV1) or feline calicivirus (FCV) at young age.3





Diagnostic plan for this disease as per Dr. Susan Little can be thought of in phases:

Phase 1 (initial presentation): thorough physical examination, good medical history, minimum database collection, and therapeutic trials.

Phase 2 (when initial findings indicate further investigation or failure to respond to therapeutic trials): oropharyngeal exam under sedation, skull imaging (radiography, CT, MRI), rhinoscopy with collection of samples for histopathology and cultures, viral isolation or PCR.3

With CRS, resistance to therapy may be often, so therapy would mean controlling clinical signs rather than cure. Antibacterials are suggested to prevent secondary bacterial infections. If cats have a history of FHV1, therapies include lysine, antivirals and 

Lysine, as mentioned in references, is beneficial for cats from being a simple preventive supplement to being a supportive therapy for complicated cases. With various references saying differently as to the benefits of lysine in cats, for us the more important thing is that lysine is first and foremost is an amino acid, building block of protein which is a nutrient needed by anyone. As in any nutrient, it is vital for growth and in life, and if not given or supplemented it may lead to anyone not maximizing their potentials or may lead them to have diseases and health problems. So in the end, we say, this is lysine and we should let this nutrient in.




Published by: plaridel
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