ZRD is becoming a widespread condition among Northern breeds,
especially Siberian Huskies. However, it can affect other breeds as well, Great Danes, for example. This page is primarily for dog owners seeking answers regarding zinc-responsive dermatosis (ZRD) in canines.
The etiology and syndrome were first identified in growing pigs and described in 1955. This is a classic story about learning how to feed America its new cheap source of food energy, corn grain, which is low in calcium and protein, and soybean meal, which is our new cheap source of protein. Corn and soy became the top two ingredients in cheap, maintenance-type dry dog foods. The absorption of iron, copper, and especially zinc in the gut of dogs consuming such foods has been hindered.
In 1972 the first case of ZRD (at first called parakeratotic syndrome) was recognized at the Veterinary Hospital of the University of Pennsylvania. It was a nearly mature German Shepherd that presented erythematous inflammation of the skin between its toes and exudative, encrusted skin lesions around its eyes and lips. The dog had been fed a regional copy of the leading high-protein (soy-based) dog food.
There are two zinc-responsive conditions in dogs. One is acquired; the other inherited.
Conditioned deficiencies of zinc occur in growing puppies and adult dogs alike fed dry dog foods that contain abundant fiber, phytin (phytates), and calcium.
Conditioned deficiencies of zinc occur in growing puppies and adult dogs alike fed dry dog foods that contain abundant fiber, phytin (phytates), and calcium. This is the central component of the so-called “generic dog food disease.” The main ingredient in most dry foods is corn. Corn reduces bioavailability of zinc (as do other grains). This food ingredient not only contains poorly available zinc, but it also reduces the availability of supplemental zinc. Phytates bind to minerals within foods, including zinc, and this process prevents zinc absorption in the dog’s body.
In contrast, the inherited defect in zinc absorption reported in certain breeds persists throughout life and requires the supplementation of a higher dose of zinc. The inherited condition may involve a defect in zinc absorption from the digestive tract (a leaky gut). However, a leaky gut can also be an acquired condition in growing pups fed diets based on corn and soybeans.
Common signs of zinc deficiency in dogs are poor growth, lethargy, anorexia, anemia, delayed sexual maturity, hyperkeratotic footpads, erythema between the toes, and exudative, crusted skin lesions around the mouth and eyes. Marginal zinc deficiency may also contribute to reproductive inefficiency. Optimal performance during gestation and lactation may require up to three times the maintenance requirement for dietary zinc.
In dogs suffering from ZRD, zinc absorption is about one-fourth normal, and zinc supplementation is required throughout life.
Treatment and Diet
High doses of a bioavailable zinc are needed during a breakout. Those include zinc gluconate, zinc picolinate, zinc citrate and zinc methionine. Once the condition is under control, maintenance doses of zinc should be supplemented for life. In severe cases, an infection can set in and a course of antibiotics is needed. Topical zinc-based creams are often beneficial during the healing process.
IMPORTANT! Zinc sulfate and zinc oxide are not bioavailable and are not properly absorbed during the digestive process in dogs. These two zinc forms will not treat ZRD. Zinc contained in zinc sulfate and zinc oxide (both inorganic zinc sources) is rendered unavailable by the dog’s gut. Extra supplementation of these inorganic sources tends to cause digestive upsets such as diarrhea. Also, inorganic chemicals (sulfates and oxides) have a shorter shelf life than organic chemicals, therefore preservatives must be added.
The optimal maintenance dose of zinc is 50 mg based on an average dog weight of 50 lbs (22.5 kg). During a breakout, the dose needs to be doubled, tripled, or even quadrupled depending on the severity of the condition. Here are more precise supplementing directions: For dogs suffering from ZRD, supplement 1 to 4 mg/kg body weight or more (1 to 4 mg/2.20 lbs).
ZINC TOXICITY: Higher doses of bioavailable zinc can be supplemented without the fear of toxicity. Toxicities due to over supplementation are very rare. If animals are fed large amounts of zinc supplements, they may be prone to developing copper and iron deficiencies. However, this condition can usually only be created experimentally.
The dog’s leaky gut must be repaired; therefore, a grain-free diet is a must for dogs suffering from ZRD.
IMPORTANT! Calcium interferes with the absorption of zinc (do not feed bones or dairy to a dog suffering from ZRD).
Leaky gut (increased intestinal permeability) is often a major contributing factor to the initiation of autoimmune disease—in fact, it’s at the root of almost every inflammatory condition. It can also exacerbate the disease once it has begun. For this reason, both prevention and healing of leaky gut are critical.
If a dog is dealing with an autoimmune condition, allergies, food intolerance, or other inflammatory conditions, the animal is dealing with a leaky gut. In a leaky gut, the tight junctions between the cells of the lining of the small intestine—which is an active part of the dog’s immune system—loosen, causing the entire defense system against invading bacteria, viruses, small food particles, and other dangerous pathogens to become compromised. The dog’s leaky gut must be repaired. Zinc helps repair the lining of the gut (in other words, it patches the holes in the gut).
While a dog’s system is fully equipped to handle animal proteins, which don’t carry antinutrients, eating large quantities of digestion-resistant foods—primarily grains—day after day can wreak havoc. Foods with a high grain content can compromise a dog’s immune system; therefore, a grain- free diet is a must for dogs suffering from ZRD.
Nutrazinc was introduced to the market in 2000 by Howling Dog Enterprises. It became the first zinc supplement on the market recommended for the treatment of ZRD in canines. Since then, Nutrazinc has been the most economical source of dietary zinc available on the market. It is also one of the most bioavailable forms of zinc available, as it is pure zinc (zinc gluconate). There are no fillers or additives.
Nutrazinc comes in an easy-to-feed powder form and is one of the highest-grade zinc compounds available for the treatment of ZRD. Simply mix the supplement into your dog’s food. Make sure the food is palatable, as most dogs will turn dry food down. Moisten the food; add a little bit of canned food, canned tuna, ground beef, broth, or anything else your dog likes.
If supplementing the correct dose (and following a strict grain-free diet) an improvement in the condition of the dog should be observed in about two to three weeks.
One teaspoon of Nutrazinc contains 650 mg of zinc.
Besides Nutrazinc being a dietary supplement to prevent zinc deficiency (also called zinc- responsive dermatosis), a common condition in Northern breeds, the supplement is beneficial for the following:
- Nutrazinc is a proven nutritional supplement for working dogs (sled dogs, hunting dogs, and herding dogs). It helps to promote tougher feet and healthier coats. Its use reduces the occurrence of splits and cracks in a dog’s feet, as well as reduces toenail breakage
- Nutrazinc also helps to toughen a dog’s pads and speeds up the healing process when an occasional foot problem does occur.
- Nutrazinc can be used as a supplement for show dogs, as it will keep their coats in top condition.
- Nutrazinc is extremely important for the proper function of a dog’s immune system. It should be used as a treatment for almost any kind of skin disease. Its use speeds up post-surgery hair growth.
Reference: Vitamin and Mineral Supplementation For Dogs & Cats: A Monograph on Micronutrients, by D.S. Kronfeld, 1989.