What Deficiency Causes Itching in Dogs?

"A balanced diet is key to healthy skin — providing the right nutrients can work wonders in reducing itching and keeping your dog comfortable." — Hannah Shepherd, Registered Veterinary Nurse

When a dog starts scratching incessantly, it's natural for owners to become concerned. While there are many potential causes of itching in dogs, including allergies (which you can test for), parasites, and skin infections, nutritional deficiencies can also play a significant role. Here, we explore the various nutritional deficiencies that can cause itching in dogs, how these deficiencies occur, and what can be done to address them.

Understanding Canine Skin Health and Nutrition

Before looking at specific deficiencies, it's good to understand the relationship between nutrition and skin health in dogs. A dog's skin is its largest organ and often reflects their overall health status. The skin acts as a barrier against environmental threats, helps regulate body temperature, and plays a role in vitamin D synthesis.

Proper nutrition is essential for maintaining healthy skin and coat. The skin is in a constant state of renewal, with new cells being produced and old ones shed, and this process requires a steady supply of nutrients. When there's a deficiency in certain nutrients, it can disrupt this renewal process, leading to various skin issues, including itching.

Nutritional Deficiencies That Can Cause Itching in Dogs

Several nutritional deficiencies can potentially lead to itching in dogs. Let's explore each in detail:

1. Essential fatty acid deficiency. One of the most common nutritional deficiencies associated with itching is a lack of essential fatty acids, particularly omega-3 and omega-6 fatty acids.

Role in skin health: essential fatty acids maintain the skin barrier, reduce inflammation, and promote a healthy, shiny coat. They're components of cell membranes and help keep skin hydrated and supple.

Symptoms of deficiency: dry, flaky skin; a dull, brittle coat; increased shedding; itching and scratching; slow wound healing; and increased susceptibility to skin infections.

Causes of deficiency: a poor-quality diet lacking these nutrients, increased need during pregnancy, lactation, or growth, or certain health conditions that affect fat absorption.

Sources: fish oil, flaxseed oil, and fish like salmon and sardines. Many high-quality commercial dog foods are also supplemented with these fatty acids.

2. Zinc deficiency. Zinc is an important mineral for skin health and overall immune function.

Role in skin health: zinc is involved in numerous enzymatic reactions, including skin cell production and turnover, and has anti-inflammatory properties.

Symptoms of deficiency: red, inflamed skin, especially around the eyes, mouth, and ears; hair loss; crusty, scaly skin lesions; itching and scratching; slow wound healing; and increased susceptibility to skin infections.

Causes of deficiency: insufficient dietary intake, poor absorption due to certain gastrointestinal conditions, increased need during growth, pregnancy, or lactation, or genetic factors in certain breeds (such as Siberian Huskies and Alaskan Malamutes) that affect zinc absorption.

Sources: meat, liver, eggs, and seafood — many commercial dog foods are also fortified with zinc.

3. Vitamin A deficiency. Vitamin A is essential for maintaining healthy skin and mucous membranes.

Role in skin health: crucial for skin cell differentiation and growth, and helps regulate sebum production, which keeps skin and coat hydrated.

Symptoms of deficiency: dry, scaly skin; itching and scratching; poor coat quality; increased susceptibility to skin infections; and, in severe cases, night blindness.

Causes of deficiency: rare in dogs fed commercial diets, but can occur with long-term poor-quality or imbalanced homemade diets, certain liver diseases affecting vitamin A storage, or malabsorption disorders.

Sources: liver, fish liver oils, egg yolk, and dairy — many commercial dog foods are fortified with vitamin A.

4. Vitamin E deficiency. Vitamin E is a powerful antioxidant that protects skin cells from oxidative damage.

Role in skin health: protects cell membranes from oxidative stress, supports immune function, and works alongside selenium to maintain skin health.

Symptoms of deficiency: dry, flaky skin; itching and scratching; a dull coat; increased susceptibility to skin infections; and, in severe cases, muscle weakness and reproductive issues.

Causes of deficiency: diets low in vitamin E, diets high in polyunsaturated fats without adequate vitamin E, or certain fat malabsorption disorders.

Sources: vegetable oils, nuts, seeds, and green leafy vegetables — many commercial dog foods are fortified with vitamin E.

5. B-complex vitamin deficiencies. The B-complex vitamins, including biotin (vitamin B7), play important roles in skin health.

Role in skin health: B vitamins, especially biotin, are crucial for fatty acid metabolism and protein synthesis, both essential for healthy skin and coat.

Symptoms of deficiency: dry, scaly skin; itching and scratching; hair loss; a dull, brittle coat; and, in severe cases, dermatitis around the face and paws.

Causes of deficiency: poor-quality diets, certain intestinal disorders affecting absorption, or overconsumption of raw egg white (which contains a protein that binds biotin).

Sources: meat, liver, cooked eggs, and certain vegetables — many commercial dog foods are fortified with B vitamins.

We offer a comprehensive dog multivitamin covering all of the above.

Diagnosing Nutritional Deficiencies in Dogs

Identifying a specific nutritional deficiency as the cause of a dog's itching can be challenging, since symptoms often overlap with other skin conditions. Here's how vets typically approach diagnosis:

1. Thorough history: your vet will ask about your dog's diet, including any recent changes, supplements, and treats.
2. Physical examination: a comprehensive skin and coat exam can reveal signs pointing to specific deficiencies.
3. Elimination of other causes: your vet will likely rule out parasites, allergies, or infections.
4. Blood tests: can help identify some deficiencies, though results aren't always definitive.
5. Skin scrapings or biopsies: may be needed in some cases to rule out other skin conditions.
6. Diet trial: your vet might recommend a diet change to see if symptoms improve.
7. Response to supplementation: a tentative diagnosis may sometimes be made based on how a dog responds to specific nutrient supplementation.

Preventing and Treating Nutritional Deficiencies

Preventing and treating nutritional deficiencies typically involves a combination of dietary changes and, in some cases, supplementation:

1. Balanced diet: feeding a high-quality, balanced commercial dog food appropriate for your dog's life stage is the best way to prevent most deficiencies.
2. Homemade diets: if you feed a homemade diet, work with a veterinary nutritionist to ensure it's balanced and meets all your dog's needs.
3. Supplementation: your vet might recommend specific supplements to address a deficiency — never supplement without veterinary guidance, as over-supplementation can be harmful.
4. Regular check-ups: can help catch and address nutritional issues before they become significant problems.
5. Special considerations: be aware of any breed-specific nutritional needs or health conditions that might affect your dog's requirements.

The Importance of Professional Guidance

While it's tempting to try to diagnose and treat your dog's itching at home, it's crucial to work with a vet. Nutritional deficiencies can have symptoms similar to many other health conditions, and only a professional can accurately diagnose the issue.

Addressing nutritional deficiencies also requires a careful approach — over-supplementation of certain nutrients can be just as harmful as a deficiency. A vet can help you develop a safe, effective plan for your dog's specific needs.

FAQs

Can a dog on a good-quality commercial diet still develop a nutritional deficiency?

It's uncommon but possible — factors like an underlying health condition affecting absorption, or an imbalanced homemade diet, can lead to a deficiency even alongside a reasonable diet.

Is it safe to give my dog a multivitamin without a confirmed deficiency?

A general multivitamin formulated for dogs is usually safe as a preventative measure, but it's still worth checking with your vet, particularly to avoid over-supplementing fat-soluble vitamins like A and E, which can build up to harmful levels.

How long does it take for skin to improve once a deficiency is corrected?

This varies, but many owners see some improvement within a few weeks of correcting the underlying deficiency, with fuller coat and skin recovery taking longer.

Nutritional deficiencies can indeed cause itching in dogs, with essential fatty acids, zinc, and vitamins A, E, and B-complex being the most common culprits. It's worth remembering, though, that itching can be caused by numerous factors, and a nutritional deficiency is just one possibility.

If your dog is experiencing persistent itching, the best course of action is to consult your vet. They can help determine whether a nutritional deficiency is at play and guide you in addressing it safely and effectively.

Prevention is always better than cure. Feeding your dog a balanced, high-quality diet appropriate for their life stage and health status is the best way to prevent nutritional deficiencies, and regular veterinary check-ups can help catch any potential issues early.

To provide you with technically accurate, evidence-based information, content on the My Pet Sensitivity blog is reviewed by medical professionals with veterinary expertise.

Related reading: Does Kibble Make Dogs Itchy? · Signs & Symptoms of Dog Food Intolerance and Allergies