Have a question?

 

 

Regarding life stages, the bag of food says for all life stages on the puppy and adult formulas. Can you please explain all life stages food? Thank you

AAFCO defines nutrient level requirements for two categories; Adult Maintenance, and Growth and Reproduction.  The majority of essential nutrients listed by AAFCO have a minimum requirement, but no defined maximum, and for those with defined maximums, the acceptable range is typically quite large.  Growth and Reproduction are life phases with increased nutrient requirements.  A formula with nutrient levels above the minimum requirements for growth and reproduction will automatically also be above the minimum nutrient requirements for adult maintenance, so legally, a pet food company is permitted to claim “all life stages” in the AAFCO statement if it chooses.    While it may seem more convenient to offer the same formula regardless of age and activity level,, if you would like your pet to thrive throughout their whole life I believe that you need to tailor their nutrition to the specific needs of each life stage. 

Puppies have different nutrient requirements while they are growing than their adult counterparts.  Senior pets require additional support as they age in order to maintain healthy organs.  Even the life style of a dog will change through its different life stages.  A once very active puppy will not have the same activity level as a senior dog. Not only will the energy requirements differ at different life stages but levels of vitamins and minerals can be tailored to specifically support the different needs of each life stage.

It is important when choosing a formula that you consider the needs of your dog and the nutrients provided in the formula to meet those needs. 

From: Laura Western, MSc

I’ve just recently purchased a European Great Dane from Poland and I live in Canada. I’m wondering if you can suggest to me the BEST food on the market that should be fed to her as a growing puppy. I’m very confused with labels and the opinions of other breeders.

Here at petfoodnutrition.com we want to focus on nutrition.  We are not here to promote one brand over another or discuss the merits of one product compared to another.  Our goals are to help owners understand various ingredients, their benefits to your pet’s health, and aid in making the right decision for your pet. 

The most important factors of any formula include the nutrient profile it provides, whether those nutrients are relevant to your pet’s needs, and if they are digestible and available for the body to use.  This information is not available on the bag of food you buy.  Some companies will spend extensive time, money, and resources researching the nutrients required by individual dogs and cats, and source ingredients that provide these nutrients in the most digestible form.  Other companies prefer to focus on ingredient names and build their nutrient profile based on the ingredients they want to use. 

Depending on the adult size of each puppy, growth curves will differ significantly. Small breeds and medium breeds reach their final body conformation between 8-10 months.  These puppies have a short and intense growth period, requiring high levels of energy. Transition to adult food must be done earlier than in other breeds to avoid obesity. Larger dogs experience something completely different: adult size will only be reached around 12-15 months in large breed puppies. Giant breed puppies (like your Great Dane puppy) are even more specific since they go through a 2 step growth curve (first bone development, then muscular development), ending around 24 months. To avoid orthopedic diseases like elbow or hip dysplasia, lean growth is the rule, requiring solutions with lower energy. In these breeds, calcium supplementation should also be avoided since it has known effects on bone and joint deformity. Feeding a diet respecting these specific growth curves is recommended.  No matter what your food choice it should be formulated for large or giant breed dogs.

In order to be diligent about your food choices, call or e-mail a few companies and learn more about them.  I think you will be surprised at the answers you receive in response to the questions AAHA recommends asking (http://www.petfoodnutrition.com/nutrition/choosing-the-right-food/).  Learning more about the company will help you make the most appropriate choice for your Great Dane puppy.

I hope I have helped you understand how much more there is to a pet food than what is put on the bag and by getting to know the company you can make a decision about the food you feed that you can feel good about.

From: Laura Western, MSc

My cat is overweight. He is a pretty big cat, but he has now reached a point where I am worried about his health. I have recently switched from “brand A” to “brand B” and I feed him 1/4 cup in the morning and again at night and have been doing this for about 6 months now but he still doesn’t seem to be losing weight. I don’t know a lot about types of cat food and have no idea where to start looking for a new diet food and was hoping you had some suggestions?

Obesity in cats and dogs is a growing concern, as it is with the human population.  It would be a good idea to consult your veterinarian about the current body condition score of your cat. 

If you would like to see what different body condition scores look like, the following link provides graphics and information about body scoring:

https://www.aahanet.org/Library/NutritionalAsmt.aspx 
 

If your cat is overweight, there are some weight care formulas available without a prescription to help trim down your cat.  If your cat is obese, weight loss should be carefully monitored by a veterinarian using a prescription weight loss formula.  Whichever formula you decide is right for your cat, the key to weight loss is adjusting food intake and exercise so that the number of calories burned in a day is more than the number of calories the cat eats. In order to determine how many calories your cat needs, you first need to determine how many calories your cat is currently eating.

It is important to note that, weight control and light diets are designed for weight maintenance, not for significant weight loss.  They are marketed towards obese prone animals, aiming to decrease the number of calories consumed in order to help prevent weight gain.  There are a number of ways these formulas help to decrease caloric intake, including; lower density kibble, tailored kibble shape, increased fibre content, as well as specialized nutrients such as L-carnitine.  L-carnitine is an amino acid that increases fat burning by transporting fatty acids into the mitochondria (the powerhouse) of the cell to be broken down.

When you do start a weight loss program, weight loss should be gradual and closely monitored.  Obesity is a disease associated with many health conditions.  It is important to be aware of any concurrent illnesses an animal may be dealing with before starting a weight loss program, as some health conditions have specific nutritional requirements not achieved with a weight loss diet.  In addition to this, if an animal loses weight too quickly it can develop life-threatening side-effects.  This is especially true in cats.  Because of this, it is always recommended that a veterinarian prescribes and monitors all weight loss programs in overweight animals.

No weight loss program is complete without the addition of an exercise program.  Again, your veterinarian can help determine the correct amount and intensity of exercise that is appropriate for your cat.  There are many toys available to stimulate a cat’s senses and encourage activity.  Spending a few minutes multiple times a day engaging in play with your cat can help support their weight loss while supporting their cardiovascular health, digestion, and muscle tone. 

My suggestion is to speak to your veterinarian who has a complete medical history of your cat and can provide tailored advice about weight loss and light formulas or prescription weight loss diets.

From: Laura Western, MSc

I have a 2.5 year old French Bulldog with very severe skin allergies that are believed to be environmental. While we are sure that environmental allergens play a big part in her condition, I do think she has some food allergies/sensitivities as well. She gets salmon oil and probiotic supplementation every day, but what are some things I should look for and some things I should stay away from in a food for her?

Allergies can be very complicated and difficult to diagnose and treat. 

I would recommend staying away from food that contains many different protein sources.  If there is an existing food allergy her susceptibility to becoming allergic to other food items will be increased.  The most common food allergies are the most commonly eaten foods, because the body must be exposed before it can become allergic to something.  Since allergies are most commonly a reaction to protein molecules I would suggest choosing a food that provides only one or two sources of protein.  Some pet food manufacturers provide a reduced allergen formula; these are specifically formulated to support dogs prone to skin irritation and itching.  Depending on how this food is formulated you may not require further supplementation, speak to a company representative for more information.

I would strongly recommend working with your veterinarian if you do suspect a food allergy.  The only way to positively diagnose a food allergy is through a strict elimination diet trial, followed by an allergen challenge to confirm an allergic reaction to the ingredient suspected.  Until the allergen is identified, there is no way to know which formula will work best for your Frenchie.  Veterinarians will have prescription diets available to them that contain hydrolyzed proteins or novel protein sources presenting an extremely reduced allergen potential. These formulas are specifically formulated for diagnosing and managing allergic reactions to food. 

There are many nutrients that help to support skin and coat health, including:

  • Omega 3 fatty acids (specifically EPA and DHA)
  • Omega 6 fatty acids (including GLA)
  • A combination of pantothenic acid, inositol, nicotinamide, choline, and histidine
  • Sulfur amino acids (cysteine and methionine)
  • Vitamin A
  • Biotin
  • Zinc
  • And many others…

Some additional guidance can be obtained from our webpages:

http://www.petfoodnutrition.com/allergies/
http://www.petfoodnutrition.com/environmental-allergies/
http://www.petfoodnutrition.com/food-allergies/
 

And there is also a lot of great research and information available here:

http://www.waltham.com/document/nutrition/dog/dog-skin-and-coat/266/
 

From: Laura Western, MSc

I have fed my dogs “diet A” in the past but have switched to “diet B” due to its higher meat and protein content. “Diet B” is also freshly made and contains no wheat, corn, or grains. Is this the better food for my dog or is a food like “diet A” that is chicken meal, corn gluten meal, and grain a better choice. I am not skeptical but I find it hard to believe that a food with grains and corn gluten meal can be better than a food with many meat sources and no grains. Would love to know you thoughts!

Here at petfoodnutrition.com we want to focus on nutrition.  We are not here to promote one brand over another or discuss the merits of one product compared to another.  Our goals are to help owners understand various ingredients, their benefits to your pet’s health, and aid in making the right decision for your pet. 

The most important factors of any formula include the nutrient profile it provides, whether those nutrients are relevant to your pet’s needs, and if they are digestible and available for the body to use.  This information is not available on the bag of food you buy.  Some companies will spend extensive time, money, and resources researching the nutrients required by individual dogs and cats, and source ingredients that provide these nutrients in the most digestible form.  Other companies prefer to focus on ingredient names and build their nutrient profile based on the ingredients they want to use. 

Protein from any source provides amino acids.  Amino acids are the building blocks used by the body to perform its many critical roles involving the musculoskeletal system, enzymes, the immune system, bones, blood, and functions within cells of the body.  Same amino acids from different sources are the same (for example, a methionine amino acid from chicken is identical to a methionine amino acid from corn); the body cannot tell if the amino acid originated from an animal or plant source.  Therefore, the ingredients providing the amino acids (or any nutrient for that matter) are not the most important aspect of a food.  It is the amino acid profile the combined ingredients provide and the total digestibility that will determine the benefits to your pet.

Fresh meat contains approximately 80% water, kibble contains a moisture content no greater than 10%.  The ingredient list is based on ingredient weight prior to processing.  Fresh meat will always weigh the most prior to having the water content removed and will be listed as the first ingredient.  However, once it has been dehydrated it is not likely to be the ingredient in the greatest quantity within the kibble.  I feel this is very misleading to consumers and creates an even bigger mystery of what the actual food composition is. 

In addition, if we consider what an ingredient name means the picture becomes even more confusing.  Some companies in Canada choose to adhere to the ingredient naming guidelines set out by the Association of American Feed Control Officials (AAFCO 2013), as equivalent guidelines do not exist in Canada.  I’d like to provide you with the AAFCO (2013) definitions of meat and meat meal.

“Meat – is the clean flesh derived from the slaughtered mammals and is limited to that part of the striate muscle which is skeletal or that which is found in the tongue, in the diaphragm, in the heart, or in the esophagus; with or without the accompanying and overlying fat and the portions of the skin, sinew, nerve, and blood vessels which normally accompany the flesh.  It shall be suitable for use in animal food.  If it bears a name descriptive of its kind (ie: chicken, beef, lamb, etc.), it must correspond thereto.”

“Meat Meal – is the rendered (dried) product from mammal tissues, exclusive of any added blood, hair, hoof, horn, hide trimmings, manure, stomach and rumen contents, except in such amounts as may occur unavoidably in good processing practices.  It shall not contain added extraneous materials not provided for by this definition.  The calcium level shall not exceed the actual level of phosphorus by more than 2.2 times.  It shall not contain more than 12% pepsin indigestible residue and not more than 9% of the crude protein in the product shall be pepsin indigestible.  The label shall include guarantees for minimum crude protein, minimum crude fat, maximum crude fibre, minimum phosphorus, and minimum and maximum calcium.  If it bears a name descriptive of its kind (ie: chicken meal, beef meal, lamb meal, etc.), composition or origin, it must correspond thereto.”

As you can see even with these definitions it would be difficult to decipher exactly what is contained in your pet food based on the ingredient deck.  In addition, companies can choose to include or exclude any tissues from the definition in their raw materials, which can affect the nutrient profile and digestibility, but will not change the ingredient name.  Finally, Canada currently does not require pet food companies to adhere to AAFCO labeling guidelines, companies have much more liberty with their naming practices.  Yes a high quality meat source will assist in completing a balanced amino acid profile, however, reading the ingredient list alone will not tell you if the listed ingredient is of a high quality.  When choosing a pet food company, ask them if they adhere to AAFCOs naming principles for their ingredient lists, and find out what measures they have in place to ensure they are receiving quality and consistency from their ingredient suppliers.

Corn gluten meal is an excellent source of two sulfur amino acids that play an important role in skin and coat health.  Corn gluten also provides a concentrated source of the antioxidants lutein and zeaxanthin.  These nutrients help to support eye health and prevent cellular damage caused by free radicals.

Grains are a source of carbohydrates and, depending on the quality of the grain, many other beneficial nutrients.  Other sources of carbohydrates include fruits, legumes and vegetables.  Whether a grain, fruit, legume or vegetable is included in the diet, carbohydrates serve many valuable functions (http://www.petfoodnutrition.com/nutrition/carbohydrates/). 

In order to be diligent about your food choices, call or e-mail a few companies and learn more about them.  I think you will be surprised at the answers you receive in response to the questions AAHA recommends asking (http://www.petfoodnutrition.com/nutrition/choosing-the-right-food/).  Learning more about the company will help you make the most appropriate choice for your pet.

I hope I have helped you understand how much more there is to a pet food than what is put on the bag and by getting to know the company you can make a decision about the food you feed that you can feel good about.

 From: Laura Western, MSc

I completely understand that humans and dogs are different species with different nutritional needs. However, I’m having a difficult time feeling good about feeding kibble. Wouldn’t feeding well-planned and nutritionally sound meals of fresh food be healthier?

It takes a lot of knowledge and know-how to create a nutritionally adequate and balanced food for dogs and cats.  Although the idea of creating well-planned and nutritionally sound meals for your dog or cat may appear to be in the best interest of your pet there are many things to consider.  At home you cannot analyze the meals you prepare, so you cannot be 100% sure they will meet the nutrient requirements of your pet.  In fact, Roudebush and Cowell (1992) reported that of the recipes provided to owners for their dogs and cats only 65% and 46%, respectively, were nutritionally adequate.  Almost half of the dogs and more than half of the cats fed home prepared meals did not receive the nutrients they require.  These animals will most certainly suffer from deficiencies and potential illnesses associated with these.  It is important to note as well, that the ingredients you choose will vary in nutrient levels based on time of year, growing location, feed, housing, etc.  Unlike a company that has the ability to perform nutrient analyses on raw materials and final products, at home you have to rely on estimates.  Estimating nutrient levels can lead to excess and deficiencies that you may not be aware of until a health issue presents.  You also must consider potential bacterial and microbial contamination when preparing meals.  If you choose to feed raw foods there will be no measure to kill harmful bacteria and pathogens, which can affect both the health of your pet and family.  In addition, how will you be sure that the meal you have prepared is highly digestible and that the nutrients are bioavailable (i.e. – your pet’s body has access to them)?

Kibble diets have been prepared so that each bowl provides consistent nutrition, is balanced to meet the nutrient requirements of specific pets, is highly digestible and provides bioavailable nutrients.  Many manufacturers have strict safety and quality guidelines, performing multiple safety and quality analyses throughout the manufacturing process.  It is incredible the practices some companies have in place, in fact some manufacturing plants have International Organization of Standardization (ISO) certifications for safety, quality, and environmental protection above those of human food plants.  I encourage you to speak to a few different companies or send out a quick e-mail with the questions proposed by AAHA (http://www.petfoodnutrition.com/nutrition/choosing-the-right-food/).  This is how you can do your due diligence as a pet owner and feel good about the kibble you’re feeding your pet.

 From: Laura Western, MSc

We feed our dog carrots, squash, sweet potatos apple, pears and peas. Can we feed him too many? She eats 1 1/2 cups of dental food as her regular diet.

When offering your pet their favourite treat, even healthy vegetables, we need to remember that these are treats and provide additional nutrients that may contribute to an excess in the daily requirements of certain nutrients.  Carrots, squash, sweet potatoes, apples, pears, and peas are sources of the vitamins and minerals, as well as, sugar, starch, and fibre. 

Yes, you can feed your dog too many carrots, squash, sweet potatoes, apples, pears, and peas.  The occasional treat of these is unlikely to cause any health problems, however, if the amount of fruits and vegetables fed begins to affect the amount of balanced nutrition provided by the dental diet (i.e. – she consumes less of her food and more vegetables and fruit) you may in time begin to see effects in her health caused by eating an unbalanced diet.

Water soluble vitamins (Vitamin C and Vitamin B complex) are excreted in urine when consumed in excess. However, fat soluble vitamins (Vitamin A, D, E, K) are stored in fat and are not excreted when consumed in excess.  It is possible to develop vitamin toxicosis, which can affect different organs of the body.  Minerals consumed in excess can create many health issues as well. 

Another consideration is the oxalate content of the vegetables you are feeding.  Miniature schnauzers are a breed with an increased likelihood of forming calcium oxalate bladder crystals and stones.  Ohf.org/docs/oxalate2008.pdf lists the oxalate content of a number of foods.  High oxalate foods should be avoided in predisposed individuals.

Sugar and starch are sources of energy; however, when consumed in excess are converted and stored as fat in the body.  When we or our pets consume an excess of energy and we begin to store more fat we become susceptible to diseases and health problems associated with obesity.  Fibre can have many benefits for our gastrointestinal tract, including regulating transit and aiding in stool formation.  When fibre is consumed in excess it can lead to uncomfortable issues including bloating, cramping, and diarrhea.

People often have a very emotional connection to food.  We feel comforted by our favourite foods during times of sadness and include large indulgent fests during times of celebration.  This emotional connection is often projected on our animals.  We expect that they may have the same connection with food; however, animals are much more connected to food for a means of survival.  I don’t mean that they don’t derive pleasure from eating, rather they likely don’t associate food with feelings in the same way that we do.  A good “rule of thumb” when feeding treats is to ensure they make up no more than 10% of your pet’s total daily caloric intake.  In other words; in one day, at least 90% of the calories your pet consumes should be from a complete and balanced food, and up to 10% can be from treats, whether that be fruits and vegetables, commercial treats,  or otherwise. 

When you are choosing treats for your pet remember that some foods that we eat are toxic to dogs, including vegetables like grapes, avocados, onions and garlic.

Commercial pet foods by design are formulated to provide a complete nutritional profile for your pet, including balanced amounts of micro- and macronutrients.  This means that treats are not essential for your pet and should be kept to a minimum.  Formulated diets are required as a minimum to undergo feeding trials to assess the nutritional value, palatability, etc. of a food prior to release on the market.  Some pet food companies perform more extensive research and analysis ensuring a consistent product of high quality that meets the nutritional needs of your pet.  In addition to nutritional assessment of diets, specialized diets provided from your veterinarian undergo further testing to ensure product efficacy.  If you have any questions about your pet food manufacturer don’t hesitate to call them or e-mail them and ask the questions found on our “Choosing the Right Food for your Pet” (http://www.petfoodnutrition.com/?page_id=894) page for assistance.

From: Laura Western, MSc

I am a vegan and have very passionate feelings against the slaughter and consumption of animals for nutritional or other purposes. I want my cat to participate in veganism with me. Are there any vegan diets specifically formulated for cats? Can you recommend a vegan home-cooked diet recipe for Mr. Sprinkles?

While it is always a pleasure to share your life with a four legged friend, before making a lifestyle choice for them we must consider their physiology first. Cats are often called true or obligate carnivores. While this doesn’t mean that they can’t obtain valuable nutrients from plant-based sources it does mean they cannot obtain all of the nutrients they require from plant sources alone. Specifically, there are three essential nutrients that cannot be obtained from plant sources in sufficient amounts for a cat to thrive. They are:
1. Vitamin A – Cats do not have the ability to synthesize vitamin A from carotene as many other mammals (including dogs and humans) can, therefore, they require vitamin A in its pure form in order to meet their daily requirements for this nutrient.
2. Taurine – Taurine is a very important amino acid for the maintenance of a healthy heart and cannot be provided or sythesized in sufficient amounts from plant-based proteins.
3. Arachidonic acid – While this fatty acid can be synthesized in sufficient amounts by other omnivorous animals, cats do not have the same ability and must obtain this nutrient from their diet.
Cats also have a high protein requirement that is harder to obtain from eating strictly plant material. All of this must be considered when choosing the most appropriate diet for Mr. Sprinkles.

Having said that, some companies have developed specific supplements and vegan diets for cats so that they can enjoy a vegan lifestyle with their owner. There is still debate surrounding the efficacy of these supplements, specifically whether cats are able to absorb the nutrients in these supplements. An insufficient supply of the nutrients mentioned can lead to serious health effects including loss of sight, cardiomyopathy, hearing loss, and other symptoms of nutrient deficiency. I would recommend researching any supplement company and vegan pet food company prior to starting Mr. Sprinkles on a strictly vegan diet. If you do decide to make the switch either to a commercial vegan diet or to a vegan home-cooked recipe, be sure to monitor Mr. Sprinkles for any signs of deficiency and speak to your veterarian immediately if any do occur. If you do choose a commercial diet I would recommend using our Questions to Ask any Pet Food Company (http://www.petfoodnutrition.com/nutrition/choosing-the-right-food/) to obtain all the necessary information you will need to ensure the nutrients Mr. Sprinkles requires are provided in adequate amounts.

From: Laura Western, MSc

I have a 10-year old male cat. Six months ago he had a blockage in his urinary tract which was resolved with medication and a change of diet to wet food from my vet. The vet also found signs of crystals in his urine at that time. My poor cat has had repeated episodes of urinary tract infection since then. His latest blood tests show his kidneys are fine and that he doesn’t have stones or crystals (yay!). He just has huge amounts of bacteria. What should I feed him?

Feline Lower Urinary Tract Disease (FLUTD) is a multifactorial condition including any or all of the following:
-bacterial urinary tract infection (UTI)
-crystalluria (urinary crystals)
-uroliths (bladder stones)
-Feline Idiopathic Cystitis (FIC)
-urethral obstruction (blockage)

Because this is a multifactorial condition, and many of the outcomes may require veterinary attention, these cases are best managed under the supervision of a veterinarian. There is no diet that can prevent infection, but diet, in combination with stress management, environmental enrichment, and if necessary; medications, can help to manage the other components of lower urinary tract disease. My advice is to work with your veterinarian to determine the best management plan for your cat.

From: Dr. Sara Ritzie, D.V.M.

My question is regarding olive oil or extra virgin olive oil. Many people tell me that they add it to their dog’s food, but I was under the impression that olive oil does not contain anything that would benefit the dog’s skin/coat. Is that correct?

Olive oil contains both omega 6 and omega 3 fatty acids, which can benefit the coat when consumed in appropriate amounts, BUT, a quality food will already contain these in appropriate amounts.

There are a couple of very real concerns with adding oil on top of food;
1) Oil is fat. Fat is high in calories. Therefore, adding oil could contribute to unwanted weight gain.
2) Adding oil can potentially unbalance the diet. Remember dog and cat foods are made to have precise levels and ratios of nutrients. Adding oil will change both the levels and the ratios.
3) Too much fat can contribute to the development of pancreatitis in dogs. This is very bad.

Bottom line, you are correct. If a pet has coat quality issues, the best way to manage it (after ensuring there are no parasites, infections, disease, etc…..) is to choose a diet specifically formulated to support skin and coat health. Nutrients that can help support healthy skin include omega 3 and 6 fatty acids, vitamins, sulfur amino acids, biotin, EPA/DHA, and antioxidants.

From: Dr. Sara Ritzie, D.V.M.

I have an 8-year old Bichon frise who came down with a gastral infection. We took her to the vet who gave medications and suggested for a bit to have the dog eat a very bland diet of rice and chicken. I have been doing this for a week and she has now turned away from the rice but will still eat the chicken. I started to introduce the chicken with her regular food and she refuses to eat. I have tried several different types of food, no luck. She does not show any signs of being ill. I know she is hungry and I keep giving in to her and give her the bland diet now of chicken and small potatoes. She gobbles this up without a problem. Has anyone run into this situation? The moment dog food is in the bowl with mixture- she will not eat it.

Thank you for your question, I will do my best to help out. I wonder if you mean gastrointestinal infection. What were her clinical signs? Did she have bloodwork done? What medications was she put on? Is she better now? There are some illnesses that will make a dog go off their food, so I want to be sure that’s not what you’re dealing with here. If she’s healthy now, from your description it sounds like your dog is doing an exceptional job of training you to give her what she wants. Think about a little kid who had strep throat and got to eat ice cream for a while, but now he’s better and doesn’t want to eat his broccoli. When he gets hungry and starts whining his mom gives him more ice cream. He’s being rewarded for not eating what he should. Likewise with your dog, she’s learning that if she doesn’t eat her food you will offer her something “better”. The more variety you offer her right now, the pickier she will become. Make sure that she is not still sick, if she’s not, then you have to stay strong and not give in to her game.

From: Dr. Sara Ritzie, D.V.M.