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Frequently Asked Questions About Ocu-GLO™ Canine Vision Supplement

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FAQ FACT SHEET FOR PET OWNERS: Frequently Asked Questions About Ocu-GLO™ Canine Vision Supplement

Why does my dog need the antioxidants and vitamins present in Ocu-GLO™ for their eye health?


  • The eye exists in a risky state; flooded with light from the sun, it is bombarded by light that creates enormous oxidative stress, which in turn generates a toxic soup of Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS). These are unstable oxygen and nitrogen molecules that attack all of the cells in the body!
  • Vitamins and antioxidants are well-proven to provide protection against oxidative stress.
  • The formation of free radicals from oxidative stress can set off a chain reaction that damages DNA or cell membranes, often causing cell death.
  • There is no way to avoid oxidative stress because it is a normal process occurring during routine living and aging, from exposure to UV (ultraviolet) light, and from normal cellular metabolism.
  • Disease processes also cause oxidative stress--- e.g. retinal degenerations in dogs such as PRA (Progressive Retinal Atrophy), cataracts, uveitis (intraocular inflammation), glaucoma, keratoconjunctivitis sicca (KCS or dry eye) and diabetes mellitus and cancer.
  • Healthy normal cells have their own innate ways to fight oxidative stress and free radicals; that is, through naturally occurring antioxidants inside the cells.
  • These include ascorbic acid (Vitamin C), glutathione, and many others.
  • When cells are overwhelmed by too much oxidative stress (for example, chronic disease states such as cancer, diabetes, and cataracts), then the normal stores of these antioxidants become depleted and the cells become less efficient and can die.
  • Another huge factor is normal aging. In humans, middle age (40 years) brings on the depletion of normal antioxidants in the body. The equivalent of middle age in humans is approximately 5 years in the average sized dog (30 to 40 lbs); younger in large and giant breeds and slightly older in toy and small breeds.
  • While genetic factors can predominate in destruction of vision, the additive damage caused by sun-induced damage is significant.


Dogs do not absorb nutrients as efficiently as humans do! This means that we either must radically improve our dogs’ diets (and possibly our own diets!), or carefully implement supplementation with antioxidants and vitamins specifically targeted to support ocular health.

Dogs do not consume large amounts of fruits and vegetables in their natural diets. However, the small herbivores that ancestral dogs would hunt and eat definitely consumed diets rich in antioxidants. Therefore, dogs would indirectly ingest their required nutrients in fruits and vegetables. Numerous studies in humans and in animals have shown that certain antioxidants can slow or possibly prevent the progression of certain eye diseases. The most commonly evaluated diseases include cataracts and also retinal degeneration, especially Progressive Retinal Atrophy (PRA). However, other diseases impacted by oxidative stress that could benefit from specific antioxidant support include senile retinal degeneration in geriatric dogs (reduced vision in dim light), glaucoma (increased intraocular pressure), uveitis (intraocular inflammation that can occur as a primary disease, occur secondary to other inflammatory processes such as trauma, and occur following cataract or other intraocular surgery, and dry eye.

Is Ocu-GLO™ safe? Yes! We performed a one-year clinical trial on selected patients. All dogs had some type of ocular disease, ranging from PRA to post-cataract surgery in diabetics, as well as many others. The study was designed to study safety and palatability of the supplement; dogs were examined every 6 months and complete blood-work performed every 6 months. Because supplements are not drugs, the study was not designed to prove efficacy. In fact, nearly all available supplements are not tested to prove efficacy, as the FDA does not require this. However, clinical findings and our clinical impressions strongly supported the continued use of the supplement and the development of the supplement into a patent-pending nutraceutical to help support canine ocular health.

….Thus, Ocu-GLO™ was created!

How is Ocu-GLO™ administered? The Gelcap is natural liver-flavored both inside and outside. If the Gelcap is chewed, the contents could stain carpet (and also the face of white dogs), but the staining easily washes out with water. Do not mistake this staining for blood! If the daily dose is more than one Gelcap, it can be given all at once or divided throughout the day.

Just like ketchup and other tomato-based products, the Gelcap contents might stain carpet and/or clothes. Because the lutein in the Gelcap is oil-based, it does not readily wash out of carpet or clothes and the stain might need to be professionally cleaned. So--- give Ocu-GLO to your pet where the floor can be easily cleaned, and don’t wear your best white clothes, in case they are accidentally stained!

What if my dog does not want to eat the Gelcap? Well, many dogs will eat the Gelcap when added in their food, especially if there is a little soft food to hide it in. Some dogs prefer chewy or crunchy treats, and since the Gelcap might “pop” when chewed, some dogs might not like this popping sensation in their mouths and it would be best to get them to swallow it whole. Chewing and popping it could also create an orange/red mess on your floor (cleanable but still annoying!) so be careful. Another suggestion is having more than one dog around, as this invites competition and they won’t tend to leave any food behind.

However, probably the BEST way for most dogs to readily take Ocu-GLO™ is to get them to swallow it whole--- such as coating the Gelcap with Cheese-Whiz ™ (the kind in the spray can), low or non-fat cream cheese, peanut butter, braunschweiger (liver paste), Cool Whip™, or other soft foods with strong tastes. Some dogs will take Ocu-GLO™ hidden in a piece of turkey hot dog (hollow out the center and push the Gelcap into it; don’t use the end-piece of hot dog due to it being a choking hazard), or hidden in a Pill Pocket ™. Alternatively, you can also place the Gelcap in the back of your pet’s throat as you would a regular medicine capsule. The active ingredients are inside the Gelcap, so cutting a small hole in the end and squirting it on their food may also work nicely. What is the shelf life of Ocu-GLO™? The shelf life is long!-- three years from date of manufacture, due to the special way in which Ocu-GLO™ is made. Can any dog take the supplement, even if they don’t have eye problems? Of course! Ocu- GLO™ is safe for dogs of all ages and may help prevent chronic diseases as our dogs age. However, It should not be given to pregnant or lactating animals because some of the ingredients have not been tested in these dogs.

What kind of eye diseases could Ocu-GLO™ help? Retinal degenerations such as PRA (Progressive Retinal Atrophy), SARDS (Sudden Acquired Retinal Degeneration) in which sight is not completely gone, IMR (immune mediated retinopathy); also toxic cataracts secondary to PRA or uveitis, diabetes-related cataracts and other diabetes-related neuropathies; non-lens related uveitis or other inflammatory diseases; immune-mediated diseases; and any disease that results in oxidative stress (e.g. from inflammation, sun exposure, and bad diet). We (Drs. Terri McCalla and Carmen Colitz) are also dispensing Ocu-GLO™ for patients predisposed to primary glaucoma (having lost their first eye to glaucoma) and that already have glaucoma; for Golden Retrievers with pigmentary uveitis (also called “Golden Retriever Uveitis”); for diabetic dogs in which cataracts are incipient, immature or have not yet formed; for dogs with senile retinal degeneration; for dogs prior to and after cataract surgery and for any dogs for which owners want to provide the best nutritional support for their pet’s eyes. Additionally, if our patients have cataracts but cataract surgery is not an option, Ocu- GLO™ is prescribed as a lifetime supplement to help reduce lens-induced uveitis (LIU)—by helping to lessen LIU the eye has a reduced risk of developing severe complications of LIU such as glaucoma and/or retinal detachment.

One very exciting use of Ocu-GLO™ is for dogs DNA tested (by Optigen™) and found to be affected with PRA. If they are supplemented with Ocu-GLO™ prior to developing complete vision loss, this may help delay or possibly prevent complete loss of vision. What are the contraindications of taking Ocu-GLO™? None, other than it is safest to stop giving Ocu-GLO™ 5 to 7 days before any surgery, especially a surgery in which excessive bleeding could occur (such as a spay or neuter). Cataract surgery is usually a bloodless surgery, and for most of our cataract patients we do not discontinue supplementation with Ocu-GLO™ at the time of surgery. Supplementation with Ocu-GLO™ can resume immediately following surgery. Can pregnant or lactating dogs take the supplement? No, some of the ingredients have not been tested in pregnant or lactating animals.

My dog is on a bunch of other supplements. Can I still use Ocu-GLO™? Yes, as long as the other supplements don’t cause toxicity due to overlapping some of the ingredients in Ocu-GLO™ (e.g. zinc or alpha lipoic acid). Yes to arthritis types of supplements like glucosamine and chondroitin sulfate. Excessive omega-3 fatty acid intake can also cause diarrhea but the dose is high and concurrent use with products such as Welactin ™ (an omega-3 fatty acid supplement) has not caused problems.

What are the ingredients and how do they support the eye? The 12 anti-oxidants in Ocu-GLO™ were specifically chosen to synergistically support canine eye health. Of these 12 ingredients, Grapeseed extract, Lutein/zeaxanthanin, and Omega-3 fatty acids (GLO), are combined as a proprietary blend in the optimal doses for canine eye health.

All Ocu-GLO™ ingredients are not only natural—they are also GMP-certified (Good Manufacturing Practices) and are pharmaceutical grade, which is the highest quality possible. The FDA does not regulate supplements—there is no premarket approval process and the quality and purity of supplements, therefore, varies widely. Most human supplements are food grade and most animal supplements are food grade or feed grade. Pharmaceutical grade means that the product is of the highest quality and purity. It must be in excess of 99% purity and made using the same quality control standards as those used for prescription drugs. Food grade means that the product meets standards set for human consumption. Feed grade means that the product meets standards set for animal consumption.[1]

We are very proud of the quality and purity of Ocu-GLO™, and of its proven safety and palatability!

1. Grapeseed Extract (GSE) is a Proanthocyanidin

  • Proanthocyanidins are naturally occurring compounds found at high concentrations in fruits, vegetables, wine, tea, nuts, seeds, flowers, bark and cacao.
  • Proanthocyanidins have a wide range of biological activities such as antioxidant and free radical scavenging capabilities, anti-inflammatory and antimicrobial properties, inhibition of cancer cell growth, prevention of low-density lipoproteins oxidation, cardioprotection, and inhibition of viral replication.[2-5]
  • GSE has been shown to prevent cataract formation in a hereditary cataractous rat model and in a diabetic rat model.[6, 7] GSE may have use as a dietary supplement to prevent and/or delay cataract formation, depending on the cataract’s etiology.[8]
  • GSE lowers blood glucose levels in diabetics and improves endothelial cell function.[9]
  • Oxidative stress has been shown to be an important part of glaucoma especially in the trabecular meshwork cells.[10, 11] Therefore, antioxidant supplementation, including polyphenols (grapeseed extract), ubiquinol and EGCG (green tea extract) may help slow the progression of the damage occurring in glaucoma.[12]
  • GSE may significantly reduce posterior capsule opacification (PCO, after-cataract, secondary cataract) by inhibiting pAkt (this is a protein that helps cells survive; Colitz C., unpublished data).


2 and 3. Lutein/zeathanthin (Cartenoids)

  • Lutein (LUT) and zeathanthin (ZEA) are oxycarotenoids important in ocular health found in dark leafy vegetables, colored fruits, and egg yolks.
  • They selectively accumulate in the lens and the retina and there are trace levels of lutein and zeaxanthin in the cornea and sclera[13], with higher levels in lens and uvea.
  • These compounds may be particularly effective in preventing or slowing the progression of cataracts and retinal degeneration in animals. Animals fed diets lacking LUT and ZEA are significantly more susceptible to developing cataracts.
  • LUT and ZEA benefit humans with Age-Related Macular Degeneration [ARMD] and cataract formation, and this observation has resulted in a plethora of lutein supplements of uncertain quality in the human health marketplace.
  • Unfortunately, almost all dietary supplements for human vision health contain only enough LUT/ ZEA for a mouse. These are the same products often used in dogs with PRA or other eye diseases. The amounts are too low!
  • Dogs do not consume large amounts of fruits and vegetables in their natural diets. However, the small herbivores that ancestral dogs would hunt and eat definitely consumed diets rich in antioxidants. Therefore, dogs would indirectly ingest their required nutrients in fruits and vegetables.
  • Dogs are able to easily absorb lutein/zeaxanthin. Plasma lutein/zeaxanthin increased rapidly and immune function was enhanced in response to dietary supplementation with LUT.[14] Diets supplemented with lutein significantly enhance cell-mediated and humoral immunity in dogs.[14, 15]
  • The possibility that LUT supplementation results in the accumulation of xanthophylls in ocular tissues was not examined, but is probable based on human studies.
  • Lutein has been prescribed for many years by both MD and DVM ophthalmologists.
  • Recovery of electroretinographic function in dogs with PRA has been demonstrated following nutritional supplementation; these findings suggest that the progression of canine PRA is inhibited by antioxidant supplementation, including lutein and zeathanthin. Umeda Y, Maehara S, Wakaiki S, Tsuzuki K, Yamashita K, Izumisawa Y, Itoh N. Electroretinographic evaluation of supplementation including lutein for canine progressive retinal atrophy. 2004 Procedings Notes, ACVO 35th Annual Conference. 2004;84.
  • Ocu-GLO™ contains a patented pharmaceutical-grade lutein, LipoLut®, which is a natural bioavailable form of carotenoids.


4. Omega-3 fatty acids

  • Found in fish oils, flaxseeds, pumpkin seeds, and green leafy vegetables
  • Feeding preformed dietary n-3 long chain PUFAs (polyunsaturated fatty acids), such as fish oils, is a more efficient way to enrich diets with DHA than flaxseed oil.
  • Puppies fed diets high in omega-rich fish oils had improved visual performance as evidenced by increased rod response using electroretinography to measure retinal function.
  • A review of the human literature that evaluated evidence for effectiveness of omega-3 fatty acids in preventing the development or progression of retinitis pigmentosa found positive trends in clinical improvement.
  • Research has also demonstrated the efficacy of omega-3 fatty acids for humans in preventing ARMD from progressing to its advanced form.[16]
  • Omega-3 fatty acids may protect the vascular and neural retina against inflammatory-, light-, ischemia-, oxygen-, and age-related pathology.[17]
  • Omega-3 fatty acids have also been shown to be beneficial for the prevention of cataract in humans.[18]


5. Vitamin C

  • Vitamin C is a hydrophilic molecule that scavenges free radicals and it is found in citrus fruits, tomatoes, potatoes, cabbage, and green peppers.
  • It is the strongest physiological antioxidant acting in the host’s aqueous environment.[19]
  • Vitamin C is found in the lens and in the aqueous humor of most species, including dogs, cats, humans, and cattle.[20]
  • Vitamin C’s function relates to the redox reactions and is coupled to glutathione metabolism.
  • Vitamin C protects against various types of cataracts.[21, 22]
  • In humans, Vitamin C concentrations decrease with age and more so in patients with senile cataract.[23]
  • A study in Cocker Spaniels found that dogs with cataracts had lower aqueous humor Vitamin C levels than those without cataracts,[24] suggesting that there is a decrease in antioxidant capacity in the aqueous humor of dogs with cataracts.


6. Vitamin E

  • Vitamin E is found in leafy vegetables, egg yolks and legumes.
  • Vitamin E is the major antioxidant present in cell membranes; it is highly concentrated in rod outer segments and retinal pigment epithelium.[25]
  • Vitamin E may also protect Vitamin A from oxidative degeneration in the retina.
  • Vitamin E is a lipophilic antioxidant that interferes with lipid peroxidation.[19]
  • Vitamin C works synergistically with Vitamin E; i.e. Vitamin E is oxidized to tocopheroxyl radical that is reduced back to tocopherol by Vitamin C.
  • Numerous studies strongly suggest that Vitamin E protects against various types of cataracts.
  • Higher blood levels of Vitamin E are protective against ARMD in humans.[25]


7. Lycopene

  • Lycopene is a major carotenoid found primarily in tomatoes and watermelon.
  • Of all known carotenoids, lycopene has been shown to have the highest physical quenching rate constant with singlet oxygen species.[26]
  • Lycopene has been shown to protect against cataract formation in vitro and in vivo.


8. Zinc

  • Zinc is an essential trace element necessary for numerous homeostatic functions that is found in eggs, seafood, and liver.
  • Zinc is an antioxidant that offers protection against ROS-mediated injury.
  • It competitively displaces iron from binding sites on negatively charged phospholipids and prevents its redox cycling.
  • When combined with Vitamin E, it has synergistic protection against iron-mediated lipid peroxidation.[27]
  • Zinc is important to the health of the retina and in the function of Vitamin A.[28]
  • Zinc deficiency reduces plasma levels of retinol-binding protein and retinol reductase, with a subsequent decrease in retinal Vitamin A levels.
  • It has been shown to slow the progression of ARMD in humans.
  • Zinc is also important in protecting the lens from cataract development by its antioxidant effects.
  • Zinc deficiency in some species is associated with increased risk of cataract formation.[29]


9. Epigallocatechin gallate (EGCG--- Green Tea Extract)

  • EGCG is present in both green and black teas
  • EGCG inhibits diabetic cataracts by reducing certain biochemical indicators as well as glucose;[30] it might also increase insulin activity.
  • EGCG retards the progression of cataract in selenite-induced cataracts in rats.[31]
  • EGCG fed to albino rats attenuated light-induced photoreceptor damage.[32]
  • EGCG reduced retinal neuronal death in rats wherein one eye had induced increase in IOP.[33] This supports evidence of EGCG’s neuroprotective capabilities, especially in glaucomatous eyes.[34]


10. Alpha Lipoic Acid

  • Alpha lipoic acid is an antioxidant that potentiates Vitamin C and Vitamin E levels.
  • Alpha lipoic acid has anti-inflammatory effects.
  • Alpha lipoic acid has traditionally been used in humans for diabetic neuropathy and in ischemia-reperfusion injury.[35]
  • Alpha lipoic acid’s primary function is to increase the body’s production of glutathione, an important antioxidant mechanism in the crystallin lens.
  • One study found that alpha lipoic acid protects the lens from oxidative stress.[36]
  • Alpha lipoic acid is included in Ocu-GLO™ primarily to benefit diabetic canine patients as it promotes normal insulin sensitivity and glucose metabolism, though actual levels of insulin and glucose may not change.[37, 38] Note: It is not safe in cats at a dose higher than 30 mg/day.
  • The amount of Alpha lipoic acid in Ocu-GLO™ is safe. However, alpha lipoic acid in high doses can be toxic and dogs can become quite ill from overdosage.


11. B Vitamin Blend

  • The B Vitamins function in a variety of essential processes and contribute to overall health of the body.
  • Vitamin B1 (thiamine) is important in neuromuscular development and maintenance as well as carbohydrate and fat utilization for energy production and cellular metabolism.
  • Vitamin B3 (niacin) is likewise involved in energy production but also in fat and steroid synthesis and lowers total levels of serum cholesterol, low density lipoproteins, very low density lipoproteins, and triglycerides.
  • Vitamin B5 (pantothenic acid) is essential for breakdown of fatty acids, steroids, cholesterol and amino acids and functions as an antioxidant. It is incorporated into Coenzyme A, which is important in oxidative phosphorylation.
  • Vitamin B6 (pyridoxine) is essential for hemoglobin formation and important for utilization for stored glucose. It is essential in the metabolism of fats, proteins, and carbohydrates.
  • Vitamin B12 (cyano-cobalamin) is an enzyme cofactor essential for normal cell growth and red blood cell development.
  • Folic acid (aka Vitamin B9) is essential for cell growth and development and for preventing neural tube defects in the fetus. It has anti-carcinogenic abilities in elderly humans and insufficient intake may result in anemia.
  • Biotin (aka Vitamin H) is an enzyme cofactor involved in biosynthesis of fats and carbohydrates and metabolism of amino acids. Biotin has been shown to improve glucose tolerance and decrease insulin resistance.
  • The oral administration of antioxidants in humans, including Vitamins A, B1, B2, B6 and E as well as omega-3-fatty acids, improve the quality and quantity of tears in patients with dry eye.[39]


12. Co-enzyme Q10:

  • Co-enzyme Q10 (aka CoQ10 or ubiquinol) is a lipid-soluble antioxidant that functions to protect against lipid peroxidation and therefore acts as an antioxidant.
  • CoQ10 has been measured in the human retina and it was found to decline with aging, suggesting a decrease in antioxidant capacity of the retina with age that is linked to the progression of ARMD[41] and possibly age related retinal degeneration in dogs.
  • CoQ10 also protects retinal ganglion cells from ischemia/reperfusion injury in a rat model wherein intraocular pressure was elevated to cause ischemia; synaptic glutamate became elevated and delayed the apoptosis of the retinal ganglion cells.
  • Therefore, antioxidant supplementation, including CoQ10/ubiquinol, polyphenols (grapeseed extract), and EGCG may help manage the oxidative damage occurring in glaucoma.[12, 34] What is the product guarantee? Animal Necessity is the exclusive distributor for Ocu-GLO™. All Animal Necessity products are 100% guaranteed. Any unopened products may be returned within 30 days after ordering, for any reason.


How do I order Ocu-GLO™ and what does it cost? Anyone can purchase Ocu-GLO™-- a prescription is not needed. It can be purchased from Animal Eye Care (AEC), and shipment is free within the U.S. to our patients, with sales tax applied for Washington residents. There is a discounted shipping charge for mailing to our Canadian patients, but no sales tax is applied to Canadian orders. If pet owners of Non-established patients of AEC wish to have us mail it to them, regular shipping charges will be applied. Both veterinarians and pet owners can also directly purchase Ocu-GLO™ online at, both by the bottle or by the case (12 bottles/case). Creating a log-in account is necessary. Pet owners receive the MSRP (manufacturer’s suggested retail price).

Veterinarians receive the wholesale price but must first register and provide state or provincial licensure information. If you’d like your family veterinarian to dispense Ocu-GLO™, you might want to ask them if they’d consider doing this—the supplement is fairly new and your veterinarian likely does not yet have it in their pharmacy (or might not have heard of it).