Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Iguanid Herpesvirus IgHV-1

©2000 Melissa Kaplan

Herpesviruses are found throughout the vertebrate animal kingdom, including many strains associated with reptiles, including IgHV-1 - iguanid herpesvirus, 1 (meaning that, so far, there is only one known strain, or species, of iguanid herpesvirus; to put this into perspective, only within the last few years have new human herpesviruses been found and identified - HHV6-9).

To be able to determine whether an animal has an HV infection, electron microscopy must be done on tissue samples taken from skin or organs. Histology and electron microscopy evaluations can also be done on negatively stained bodily fluids, such as saliva, urine and vesicular fluid.

Typically, as with the human herpesvirus H. simplex (HSVI; infection remains dormant in body; when activated, causes cold and canker sores in mouth and elsewhere on face, and in some cases elsewhere on the body; is different than HSVII, the HHV that causes genital herpes), the virus is dormant for long periods of time during which the host is active and healthy. Acute environmental and/or psychosocial (including work-related) stress can compromise the body's immune system function and result in the herpesvirus becoming active again.

Acyclovir (brand name Zovirax) is available as a topical ointment, in pill and in parenteral (injectible) form; of the first two forms, it is most effective and more quickly effective in pill form. This antiviral is specifically for HV (HSVI and HSVII, and H. zoster [shingles]) infections, as well as Epstein-Barr virus (EBV) and cytomegaly virus (CMV). It works not by killing the virus but by disrupting the virus's DNA, preventing it from replicating. The flare subsides as the immune system is supported in other ways, and the lesions heal and disappear, the virus dormant again until the next flare.

A review of what little literature there is finds nothing to indicate that IgHV-1 is any more serious than H. simplex in humans, meaning that while an otherwise healthy body may occasionally go through a reactivation of the usually dormant virus, immune support and the use of acyclovir (which does not have harmful or serious side effects) to stop the reactivated virus from replicating. In humans 70% of the drug is eliminated in the urine (making it a damned expensive one, if you think about how much gets flushed down the sewer system!); this means that, like all drugs, it is being processed through the liver and kidneys, so, as with antibiotics, you need to make sure a reptile on acyclovir is getting extra fluids while actively taking the drug and for a week or so after the prescribed dose has been completed. Other side effects are rare.

If your iguanid lizard has IgHV-1, you might want to talk to your vet about the use of oral or injectible acyclovir. You may want to encourage your vet to contact one of the consulting vets on the Consulting Veterinarians list to discuss IgHV-1 and the use of acyclovir for reactivations.

It is unknown just how viruses are transmitted between reptiles. To reduce the risk of infecting other reptiles including other iguanid lizards, an iguana who tests positive for IgHV-1 can go to a home where he or she will be, for the rest of his or her life, the only reptile.

I have seen no data on iguanid infection rate, but estimates are that H. simplex, for example, is already found in at least 50% of the human population in most areas; it is higher in less-developed countries. The majority of humans who have the dormant HSVI have it by age 5 years. For all we know, infection rates in iguanids and other reptiles may be comparable, and perhaps higher in imported species or wild domestic iguanid species. If this is the case, the only risk factor would be to either keep an IgHV-1 positive iguana away from other iguanas during a reactivation that results in skin lesions, or keep any such lesions coated with topical acyclovir while the lizard is being treated systemically (either by pill or injection).

Over-the-Counter Complementary Treatment
L-Lysine, an amino acid, is a useful adjunct therapy for reactivations, as it appears to inhibit the herpes virus that resides in the trigeminal nerve ganglion. Lysine is now available in pill, capsule, topical ointment, and liquid oral supplement form. The recommended dose for HSV1 in the dormant state is 500-1000 mg/day; 3-4 times that amount when the virus is reactivated. What the dose would be for an iguana I have no idea...that's something for you to talk with your vet about. Ginkgo biloba supplement might also be useful during a reactivation as it boosts circulation which would get the Lysine and acyclovir to the affected nerves more quickly. Something else I recently found useful for HSV1 is Mycel Vitamin A (also called mycellized A). This is a special form of vitamin A that increases its bioavailability. Just dab a drop on the tingle, repeating several times throughout the day. Prescriptions for Nutritional Healing, by James Balch MD & Phyllis Balch CNC, has more information on recommended vitamins and nutrients for dealing with this herpesvirus.

For those of you who don't already know or haven't figured it out yet, the word herpes and herps (the collective noun for reptiles and amphibians) both come from the same root word, the Greek herpeton, meaning things that creep and crawl. In the case of herpes, the virus crawls along nerves; in the case of herps, well, whoever named herps herps has obviously never seen an iguana leap from his basking shelf to the floor rather than scurry down his climber!

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