Due to a travel commitment, this week's issue of Questions On Dogs and Cats will be a bit shortened and lacking some of the up-to-date news items. The conclusion of What Your Pets Are Eating will follow below.
WHAT YOUR PETS ARE EATING....a discussion of dog and cat nutrition, Part 3
Most commercial dog and cat foods are fortified with vitamins to levels that exceed minimal requirements. There is no Association of American Feed Control Officials (AAFCO) dietary requirement for vitamins C or K for dogs and cats have no documented dietary requirement for vitamin C.
The water-soluble vitamins include all of the B series and Vitamin C. Water-soluble vitamins are readily excreted in the urine if excess amounts are ingested and rarely cause disease even in very high doses. Thiamine, also known as Vitamin B1, usually is not a problem arising from properly prepared commercial cat food; however, a deficiency can occur if a cat is fed uncooked freshwater fish, which contains high levels of thiaminase, an enzyme which destroys thiamine in the rest of the diet. Thiamine-deficient cats develop loss of appetite, scruffy-looking hair coat, a hunched position, and neurologic signs including balance problems and convulsions.
Fat-soluble vitamins include those in the A, D, E, and K series and some of these can be associated with serious diseases if ingested in too high quantities. Excessive consumption of liver can lead to high levels of Vitamin A, resulting in skeletal deformities in dogs. Cats, on the other hand, can suffer from too little Vitamin A being available in their diet and the list of disorders associated with this deficiency is too long to include here. Suffice it to say that most commercial cat foods do have the necessary supplement of Vitamin A.
Vitamin D deficiency results in rickets in young animals and osteomalacia (softening of the bones) in adult animals. The classic signs of rickets are most often seen in puppies and kittens when homemade diets are fed without supplements being added. Too much Vitamin D can result in high blood calcium and phosphorus which then lead to chronic kidney failure and death in both dogs and cats.
A balanced amount of the necessary dietary minerals in relation to the energy density of the diet is important. Indiscriminate mineral supplementation should be avoided due to the likelihood of causing a mineral imbalance. Mineral deficiencies are rare when pets are fed a well-balanced diet.
In both dogs and cats, the requirements for dietary calcium and phosphorus are increased over normal maintenance levels during growth, pregnancy, and lactation. Calcium and phosphorus deficiency is uncommon in well-balanced growth diets. The most common problem is an all meat diet which has an imbalance of the calcium/phosphorus ratio and can lead to demineralization of bone, resulting in bone weakness and pathologic fractures. Excessive supplementation of calcium and phosphorus not only leads to bone formation problems in the larger breeds of dogs but also contributes to a decreased absorption of magnesium, which can cause lethargy and muscle weakness in puppies. Excessive supplementation of magnesium can contribute to the formation of urinary crystals in male cats, which then can lead to the "plugged cat" syndrome.
Nutrition is an important part of disease management, even though few disorders can be cured solely with diet. The interaction between illness, health, and nutritional status is multifactorial and complex. The nutritional requirements of sick dogs and cats are qualitatively the same as those of healthy ones. However, they differ in the amounts required...certain nutrients may be needed in greater amounts or may need to be restricted.
Manufacturers of all commercial dog and cat foods are legally required to provide certain information on the label, including the name of the product, guaranteed analysis, ingredient guarantee, net weight, and name and address of the manufacturer or distributor. The most important nutritional information on the label is the guaranteed analysis, ingredient list, and the statement of nutritional adequacy. In the USA, all pet foods sold must be registered with state feed control officials and must contain approved ingredients generally regarded as safe, unless they are for specialized purposes such as the improvement or prevention of disease. Such foods are considered to be drugs and must be approved by the FDA.
Commercial dog and cat foods are available in 3 principal forms: canned, dry, and semi-moist. These classifications depend more on the processing method and water content than on the ingredient content or nutrient profile. Complete and balanced commercial pet diets are formulated to provide adequate quantities of each required nutrient without an intolerable excess of any nutrient. Any supplementation of particular nutrients to commercially produced complete and balanced pet foods should be done carefully and only with appropriate justification, along with some consultation with your veterinarian. Remember that dog foods are not going to be satisfactory for cats because most dog foods are lower in protein than what cats need and usually are not supplemented with taurine.
Dry food is the most popular category of pet foods in the USA. It usually contains 90% dry matter and 10% water. The advantages of dry food would include lower cost than canned or semi-moist, and refrigeration is not necessary for unused portions. Additionally, it provides some beneficial massaging of the gums and teeth to help reduce periodontal disease.
Canned pet foods will usually contain 70-75% water and 25-30% dry matter. The advantages of canned food are mainly a fairly long shelf in a very durable container and its high degree of palatability. The main downside is the cost...it's more expensive than dry foods.
Semi-moist pet foods will contain 60-75% dry matter and 25-40% water. They usually do not require any refrigeration, have been preserved by substances that do not allow bacteria and molds to grow. This also gives them a good shelf life. Other advantages of semi-moist pet foods include convenience of packaging, high energy digestibility, and higher palatability. Similar to canned foods, they are more expensive than dry foods.
Dogs can be successfully maintained on properly formulated home-cooked diets, but this is much more difficult for cats. The advantages are obviously the use of fresh, high-quality ingredients that are chosen by the dog owner. The disadvantages include preparation time, unreliable quality control and diet consistency, higher costs, and the difficulty in formulating and preparing a nutritionally complete and balanced diet. Some of the most common problems with home-cooked diets is that they result in high protein and caloric density, inappropriate calcium/phosphorus ratios, and inadequate levels of calcium, copper, iodine, fat-soluble vitamins, and several of the B vitamins.
The bottom line here is that you should discuss your pet's individual dietary needs and considerations with your veterinarian. The type of food you choose may be different for each of your dogs or cats. Remember, your pets really can't go to the refrigerator, pull open the door, and fix their own meals. They are relying on you to make the right decision for them!
If any of our readers have a story you'd like to share about your choice of pet food or about any problems or concerns you've had with your pets' food, either send an e-mail to: firstname.lastname@example.org or post a comment at the end of this issue.
1) Most of our readers will remember the old TV show, MacGyver. Well, there's a cat owner who thinks their cat is Kitty MacGyver: http://www.funnieststuff.net/viewmovie.php?id=1489
Looks to me like all the right moves....
2) Helpful Buckeye is starting to wonder if dogs and cats are beginning to read our news updates. That would be the only logical explanation for all the "copy cat" antics we're hearing about: http://www.pawnation.com/2009/12/15/all-aboard-kenmore-the-subway-cat-rides-on-to-new-home/
Maybe he was looking for MacGyver?
3) Sadie, a Scottish Terrier, won the best in show award at the recent AKC/Eukanuba National Dog Show: http://www.pawnation.com/2009/12/15/scottie-named-sadie-wins-best-in-show-at-akc-eukanuba-national/
She has won shows at all levels and now has her sights set on the upcoming Westminster Dog Show in February.
4) The following video was sent to Helpful Buckeye by 4 different readers, but Dianne from Chico, CA was the first. If any of you had these dogs, you wouldn't have to spend so much time trimming the Christmas tree! Enjoy: http://www.youtube.com/watch?v=AUtPKbMwnRo
For your holiday pleasure
~~The goal of this blog is to provide general information and advice to help you be a better pet owner and to have a more rewarding relationship with your pet. This blog does not intend to replace the professional one-on-one care your pet receives from a practicing veterinarian. When in doubt about your pet's health, always visit a veterinarian.~~