Thursday, February 19, 2009

Factoid: Wheat bran and middlings

Wheat bran and middlings, a byproduct of flour milling, are common ingredients in less expensive pet foods. They are composed of the bran coats of the wheat, which is actually a healthy fraction and what we benefit from when we eat whole wheat products. In comparison to the wheat kernel used for white flour, wheat bran and middlings have nearly double the amount of fatty acids, fiber and mineral.

The following are definitions from Kansas State University’s extension service:
• “Wheat Middlings consist of fine particles of wheat bran, wheat shorts, wheat germ, wheat flour, and some of the offal from the “tail of the mill.” This product must be obtained in the usual process of commercial milling and must contain not more than 9.5% crude fiber. (Proposed 1959, Adopted 1960.) IFN 4-05-205 Wheat flour byproduct less than 9.5% fiber
• Wheat Bran is the coarse outer covering of the wheat kernel as separated from cleaned and scoured wheat in the usual process of commercial milling. (Adopted prior to 1928.) IFN 4-05-190 Wheat bran.”

In general, pet owners with an interest in nutrition are told that it’s bad to see this by product in a pet food, because it is a cheap filler. One problem that would occur with high levels would be an elevated fiber content which reduces digestibility. On the other hand, this fiber contains fructooligosaccharides that benefits gut motility and microbial populations.

But a legitimate concern is that ‘messing with mother nature’ – taking grains apart into fractions then putting them into a food artificially, is chancey and a bad idea compared to just using whole grain. And of course, the processors that mill so much white flour that the bran and middlings are available for mass production of cheap pet foods – well, perhaps we should decline to be part of the demand that creates that supply. My two cents – maybe we should stick with whole grain ingredients.

Reference: Aldrich G. Cheap filler or nutritious fiber? Petfood Industry, January 2009 p. 42-43

We can guess or we can know – body condition scores

I recently saw a nice golden retriever whose owner was utterly surprised when I broke the bad news that he was overweight. She had no idea, because he hadn’t gained weight in recent years, no one had mentioned it before, and because he weighed what the books said he should.

In a perfect world, all golden retrievers would stand 21 ½ - 24 inches at the shoulder and weigh 55-75 lbs. However, I’ve seen taller goldens that are fighting weight at 82 lbs, and I’ve seen obese goldens weigh 70 lbs. If we try to determine the right weight for any dog, we can’t just refer to the breed standard, or even to the dog’s history – we need to know the amount of fat being carried by that dog. Hence the advent of the body condition score that I’ve mentioned previously. Body condition scores tell us the pet’s ‘fat content’.

A study by a nutritionist at the veterinary school at University of Liverpool examined medical records of dogs referred to the school over a period of 9 months (German 2008). The hypothesis being studied was that general veterinary practitioners commonly assess body weight and body conditions of the dogs seen in their practices. In the 148 dogs included, the average duration of medical history to examined was 333 days, and since these were dogs being referred to a university, most had been seen multiple times by their general veterinarians – on average, 10 times.

Surprisingly, 30% of the dogs had never had their body weights entered into the medical record. Of those whose weights were noted, the record had a weight entry only 1 time in every 4 visits. Only 29% of the dogs had a body condition of any kind noted in the record (for example, the practitioner noted that they were underweight/thin or overweight/obese). In these dogs, the body condition score was noted only 1 time in 7 visits, on average. Disappointingly, only 1 dog of the entire group of 148 had a body condition score noted.

The authors concluded that local practitioners rarely weighed or assigned body condition scores to the dogs in their care. It is essential that body weight and condition be assessed and monitored throughout a pet’s life. Obviously we want to intervene if they are becoming overweight. More importantly, if drugs are being prescribed, it is vital to have a recent body weight on record to accurately prescribe a dose.

Of the 148 dogs, only 15% were assessed as overweight or obese, which is significantly less than published estimates of dog obesity prevalence (more like 34-52%). Particularly worrisome is the possibility that general practitioners don’t recognize when some dogs are overweight, or worse, don’t consider obesity a disease worth treating. A previous study showed that veterinarians in general practice scored 34% of dogs overweight but recorded obesity as a diagnosis only 4% of the time. In one practice where I’ve worked, I actually had to enter ‘obesity’ as a diagnostic code to the practice management software – the program included every code you could imagine, from medically treated cruciate ligament disease to seizure disorders – but not obesity.

Keeping your dog lean (i.e. you can see the last rib!) will save you money – chances are better that you won’t need to deal with arthritis, expensive cruciate ligament surgery or recurrent pancreatitis, or in your cat, the trouble of treating a diabetic. Most importantly, obesity reduces life expectancy – by an average of 2 years in large dogs!

Body condition scores are still somewhat subjective when estimating fat content in a dog or cat’s body, but with some practice, most people can obtain a body condition score. From that score, we can actually estimate the ‘fat content’ and predict how much weight should be loss to achieve ideal body condition.

By the way, this study concentrated on dogs, but cat owners should not remain complacent – obesity is every bit as common in the cats I say as in the dogs!

German AJ, Morgan LE. How often do veterinarians assess the bodyweight and body condition of dogs? Vet Rec 2008;163:503-505