MAXI/GUARD® Zn4.5 Otic®

MAXI/GUARD® Zn4.5 Otic® provides veterinary medicine with its first complexed zinc ear care topical for otitis externa. The formula delivers the essential micronutrient zinc, complexed with select amino acids and the proven Malassezia agent, Boric Acid. Active ingredients are delivered in a well tolerated propylene glycol vehicle at a pH of 4.5.

Resolves difficult ear cases associated with Otitis Externa while aiding in the healing of the ear canal.

  • Clears chronic yeast otitis
  • Very low incidence of stinging
  • Safe for use with a ruptured tympanum
  • No antibiotics/steroids
  • Safe/effective for long term maintenance
  • No interference with allergy testing
  • Resolves itching
  • Scent free
  • Calms, clears, and restores problems ears
  • Not oily/greasy

MAXI/GUARD Zn4.5 Otic Detail Sheet

How Does it Work?

MAXI/GUARD Zn4.5 Otic is the first water soluble ear maintenance topical offering veterinary medicine the essential micronutrient zinc, complexed with two select amino acids, Taurine and L-lysine, in combination with boric acid, a proven anti-Malassezia agent. The amino acid complex stabilizes the zinc ion for better topical utility.

Zinc is an essential trace element and is a component of about 300 metalloenzymes systems. Many of these enzymes play key roles in extra-cellular matrix remodeling; wound healing, connective tissue repair, inflammation, and cell proliferation.


MAXI/GUARD Zn4.5 Otic is not an ear cleanser. Boric acid combined with amino acid complexed zinc, is very effective for Malassezia otitis typically associated with allergic ear disease. It can be used on acute or chronic ears. Zn4.5 Otic offers these positive benefits:

  • calming pruritic and painful ears for 2-3 days prior to cleansing
  • clinical and home use post-cleaning in dogs affected with otitis externa
  • long term maintenance to prevent future outbreaks
  • will not interfere with allergy testing

Zn4.5 Otic is ‘First-Line’ for fostering healing or returning the micro-environment of the ear to normality. Chronic Pseudomonas ears require powerful antibiotics and steroids, but Zn4.5 Otic can be used as an adjunct in these situations for restoration in a shorter period of time.

Zn4.5 Otic is very effective and safe for long term maintenance. Once the initial problem is resolved, the product can be used 2-3 times per week to prevent future outbreaks. Due to the large number of clients using Zn4.5 Otic for maintenance or prevention, we have a more economical 4 ounce size available.



MAXI/GUARD Zn4.5 Otic is a very safe product. Zinc gluconate and the amino acids Taurine and L-lysine have wide margins of safety. Zn4.5 Otic is even safe in cases where the tympanic membrane is ruptured and will not cause ototoxicity or other side effects. This product is safe and effective for various problems found in the ears of dogs, cats, rabbits, ferrets, and other animals.


Due to the zinc and amino acid utility, this product works well without the extremely low pH or higher concentration of boric acid in other ear car products. Zn4.5 Otic is well tolerated in most ear care situations.

Does Your Pet…


  • Scratch its ears often?
  • Have an unpleasant odor coming from its ears?
  • Have a discharge coming from its ears?
  • Have red, swollen ear canals?
  • Shake its head often?
  • Show signs of sensitive/painful ears?



If you answered yes to one or more of the above conditions, please schedule an appointment with your veterinarian soon. Your pet may have Otitis Externa or another condition which requires immediate veterinary care.

How do I apply Zn4.5 Otic?

Otic ApplicationThe ear should be cleansed with a suitable cleanser before a regimen of treatment is started. Instill 5-8 drops once to twice daily into the vertical ear canal, gently massage and then wipe away any excess with a tissue. The attending veterinarian may desire to initially immerse (flood) the ear canal fully in the clinic before sending the product home with the owner.


Interesting Fact:

Top 10 Reasons Pets Visit Vets: Ear infections top the list.





“I have had a problem with my dogs ear for 2 to 3 years. Something like a yeast infection. The vet just kept giving me Tresaderm and Otimax for her ears it never helped. Even a deep ear cleaning by the vet did nothing. I saw your product and gave it a try. Five days later her ear is clean, smells wonderful, no moisture in them, nice pink color is back and she is so happy now. Thanks for producing this wonderful product MAXI/GUARD Zn4.5 Otic!!!”
GY, Pet Owner

“We have been using the Zn4.5 Otic product for the last year and have found it to be a big help in treating and preventing otitis cases in dogs and cats. During the 17 years of practice I have used a variety of ear cleansers and washes, Zn4.5 Otic is now my first choice to treat or maintain pets with chronic ear problems. We hope the team at Addison can continue to develop such useful products. Thanks again!”

“When the Zn4.5 Otic was first introduced, I was skeptical due to many false claims made by “miracle” ear cures over the years. My clients and I were both pleasantly surprised at the results. Zn4.5 Otic has made a tremendous difference for many of my patients with chronic ear infections. I feel extremely confident recommending this product for life-long management in some cases without side effects or antibiotic resistance issues.”