Tuesday, November 6, 2012

My theory about the Jerky Treat Threat


Is protein the root of the problem with the Jerky Dog Treats? or Possible mulfactorial causes.

 By Marion Smart DVM, PhD Professor of Nutrition Western College of Veterinary Medicine


Introduction
The effect of dietary protein intake on renal function has been studied and reviewed extensively.[i] [ii]Although we have a better appreciation of the problem there is still much controversy surrounding the topic. This debate is related to:
·         external factors such as:

o    dietary protein quality, the source, the amino acid profile,

o    impact of heat processing, high pressure sterilization and irradiation on the protein structure, and digestibility

·         . Internal factors such as:

o   to the digestion and bioavailability of dietary protein

o    the gastrointestinal microbial utilization, metabolism and by-product production of the endogenous and exogenous protein that reaches the colon

 This paper explores the possible explanation of the illness in dogs associated with the Irradiated dehydrated Jerky treats originating from China and Thailand. The assumption being the cause is multifactorial.

The hypothesis
These jerky treats when fed to dogs on a commercial processed  diet of 30% Crude Protein  (CP)or more results  in an excess of dietary protein which the body may or may not be able to handle metabolically especially if there is some subclinical impairment of kidney and/or liver function, and an associated abnormal  gastro intestinal micro flora. This could be further complicated if the protein in the treats was heat damaged or denatured or if crude glycerine from the Biofuels industry was added as a preservative 

Asumptions:     

·         That the minimum Protein % indicated on the package label/website represents the actual protein analysis for both the treats and the dog’s daily diet.

                This assumption may be false as the true protein % is likely higher in these products than is represented on the label’s guaranteed analysis.

·         The energy requirement of a 5kg dog (model dog) was based on NRC’s 2007[iii] requirement and only applies to an inactive healthy normal adult dog with a normal body condition.

                These requirements may not represent all 5 kg adult dogs.

·         The energy density of the treats was calculated based on the protein% and fat% listed on the label or website and the calculated carbohydrate %. Atwater modified coefficients for protein of 3.5 Kcal/g of protein, 3.5 Kcal/g of carbohydrates, and 8.5 Kcals/g of fat were used in the calculations

·         Treats are not fed at more than 15% of a dog’s daily energy requirements. This is based on the information found on the Milo’s Kitchen Website. Most owners would not understand what this restriction means or how to calculate it. If they even read it. Most owners will likely over feed these treats especially if the dogs like them. They may also be feeding other high protein treats as the popular press implies that fat and     carbohydrates can lead to obesity

·         That a total dietary dry matter protein percentage of 30 % may be potentially  be metabolically inappropriate for dogs with subclinical hepatic or renal disease

·         An abnormal intestinal microbial flora (dysbiosis) may be present in these dogs

Calculations:

Table1: The calculated daily energy requirements and protein intake g/d for a normal inactive adult 5 kg dog

.  5kg Dog's  requires Kcal/d
400
% Protein in Diet 10% Moisture
25%
35%
g/d of a 400Kcal/100g Diet
100
g/protein/d
25g
35

 Table 2: The percent total protein in the diet of a 5 kg dog if the treats are limited to 5, 10, and 15% of the dog’s daily  caloric requirements, and if the protein percentages in the actual diets are  25 and35 respectively

5% Daily Calories
10% of Daily Calories
15% of Daily Calories
Treats
% CP in diet
Treats
% CP in Diet
Treats
% CP in Diet
Kcal/100g
Kcal/d
g/d
g CP/d
25%
35%
Kcal/d
g/d
g CP/d
25%
35%
Kcal/d
g/d
g CP/d
25%
35%
% Total CP
% Total CP
% Total CP
%Total CP 
%Total CP
% Total CP
Vital Life Chicken Tenders
275
20
7.3
4.7
28
37
40
14.5
9.3
30.0
43.3
60
21.8
14.0
32.0
46.6
Canyon Creek Duck tenders
275
7.3
5.1
28
37
14.5
10.2
30.7
43.3
21.8
15.3
33.1
46.6
Chew Master Chicken Strips
298
6.7
4.7
28
37
13.4
9.4
30.3
42.7
20.1
14.1
32.5
45.9
Milo's Kitchen
289
6.9
4.2
27
37
13.8
8.3
29.3
42.9
20.8
12.5
31.0
46.2

Table 2 supports the fact that Jerky treats fed to dogs on diets with 35% Crude protein or greater can result in a total dietary protein intake of greater than 40% even when the treats represent   10% of the dog’s daily caloric intake.

Table 3:The total  daily  Protein intake in g/d and  % Protein  in the diet plus treats  of a 5, 10 and 20 kg dog
 The caloric density of the diet is 4000Kcal/1000g. Protein requirements are between 33*(AAFCO maintenance) to 90 g/day*(ancestral diet) or 20% to 54%CP in DM. Each treat has weights approximately 12 g and provides 8.28 g of protein
The optimum number of treats per day  at 15%  of daily caloric  requirements
g/day of diet  for a 5 kg  dog
100
% CP in diet
20% CP
25% CP
30% CP
35% CP
40%CP
g/d of protein
20
25
30
35
40
# Treats/day
Total CP g/d  from treats
% CP in Total Diet
Total g CP /day
% CP in Total Diet
Total g CP/day
% CP in Total Diet
Total g CP/day
% CP in Total Diet
Total g CP/day
% CP in Total Diet
1
8.28
25%
33.28
30%
38.28
34%
43.28
39%
48.28
43%
2
16.56
29%
41.56
34%
46.56
38%
51.56
42%
56.56
46%
3
24.84
33%
49.84
37%
54.84
40%
59.84
44%
64.84
48%
4
33.12
36%
58.12
39%
63.12
43%
68.12
46%
73.12
49%
5
41.4
38%
66.4
42%
71.4
45%
76.4
48%
81.4
51%
10
82.8
47%
107.8
49%
112.8
51%
117.8
54%
122.8
56%
g/day of diet for a 10 kg dog
165
%CP in Diet
20% CP
25% CP
30% CP
35%CP
40%CP
g/d of protein from diet
33
41.25
49.5
57.75
66
# Treats/day
CP g from treats
% CP in Total Diet
Total g CP in Diet
% CP in Total Diet
Total g CP in diet
% CP in Total Diet
Total g CP in diet
% CP in Total Diet
Total g CP in diet
% CP in Total Diet
1
8.28
23%
49.53
28%
57.78
33%
66.03
37%
74.28
42%
2
16.56
26%
57.81
31%
66.06
35%
74.31
39%
82.56
44%
3
24.84
29%
66.09
33%
74.34
37%
82.59
41%
90.84
45%
4
33.12
31%
74.37
35%
82.62
39%
90.87
43%
99.12
47%
5
41.4
33%
82.65
37%
90.9
40%
99.15
44%
107.4
48%
10
82.8
41%
124.05
44%
132.3
46%
140.55
49%
148.8
52%
g/day of diet for a 20kg dog
300
%CP in Diet
20% CP
25% CP
30% CP
35%CP
40%CP
g/d of protein
60
75
90
105
120
#treats/day
Total g CP/d in treats
% CP in Total Diet
Total g CP/d
% CP in Total Diet
Total g CP/d
% CP in Total Diet
Total g CP/d
% CP in Total Diet
Total g CP/d
% CP in Total Diet
1
8.28
22%
83.28
27%
98.28
32%
113.28
36%
128.28
41%
2
16.56
24%
91.56
28%
106.56
33%
121.56
38%
136.56
42%
3
24.84
25%
99.84
30%
114.84
34%
129.84
39%
144.84
43%
4
33.12
27%
108.12
31%
123.12
35%
138.12
40%
153.12
44%
5
41.4
28%
116.4
32%
131.4
37%
146.4
41%
161.4
    45%
10
82.8
34%
157.8
38%
172.8
41%
187.8
45%
202.8
48%

The results in table 3 are based on the number of treats eaten per day with one treat weighing 12g and providing on average8.28 g of protein to the diet. The row in yellow represents treats fed at 15% of the total caloric requirements for that dog. .

The feeding directions on all of the treats implicated recommend so many pieces  per weight group of dog nowhere is mentioned the optimal number of grams per day that should be fed . To determine this, the pet owner would have to count the pieces in the package and then divide that number into the total weight of treats in the package...

Interpretation:

Simplistically (trying to explain a very complex system in a simple fashion), protein digestion begins in the stomach and through a coordinated series of enzymatic, hormonal and environmental (pH, electrolytes and fluids) interactions the protein is broken down into amino acids which are actively transported by a complex series of chemical reactions through the enterocytes and wall of the small intestine into the portal circulation to the liver.

Any partially digested protein, amino acids and the protein left associated with the digestive process (endogenous nitrogen loss),then  passes into the colon. The amount of dietary protein that reaches the colon is dependent on the quality of the protein (limiting amino acids, denatured protein are poorly digested), and the amount of protein ingested.  Other factors such as body weight, dietary fibre, anti-nutritive factors (inhibitors, denatured) and the composition of the colonic micro flora will influence the amount of protein and the by-products formed iv. The gut micro flora break down these nitrogenous compounds into ammonia, indoles, phenols, volatile sulphur containing compounds, potential neurotoxins, and many unknown and potentially toxic  compounds[iv].  Some of these compounds are absorbed into the body. Some like ammonia are metabolized in the liver and eventually excreted through the kidney as urea.  We are just beginning to appreciate the significant role these colonic microorganisms play in the body’s normal and abnormal metabolic processes[v]. Exactly how these microorganisms respond to different dietary loads, and quality of proteins is still unknown.

I believe that this may-be a plausible explanation for many of the cases, especially in the older dogs with liver and kidney pathology .In support of this theory  is that older dogs require at least 25% ii of their calories from protein, I was unable to find any studies were higher protein percentages were fed to normal or compromised dogs. The jerky treats may be contributing to an unbalanced or inappropriate amino acid profile in the dog’s diet. The acute cases and those seen in puppies under a year of age are more difficult to explain unless in some cases the protein is denatured or heat damaged. Some unprocessed raw diets definitely exceed 35% protein and yet they do not appear to be associated with the problem. But these diets may be providing a healthier functioning colonic microbial flora, a more balanced amino acid profile and more efficiently digested and metabolized protein.

Conclusions:

A detailed history of problems and treatments prior to and at the time of the current illness and clinical evaluation must be obtained for each dog. The clinical course of the disease and treatments need to be chronologically tabulated.  Complete laboratory findings should be charted and the hi-lite of a complete necropsy report recorded, if available, on all the dogs that died. A detailed dietary history (chronologically tabulated) is essential including the regular diet, dietary changes and all the treats fed (Name, amount, and time of Day).

References:


[i] Finco D.R. 1999. Effects of Dietary protein Intake on renal functions. Supplement to The Compendium on Continuing  Education for the Practicing Veterinarian 21.#11:5-10
[ii] Laflame D.P.2008.  Pet Food Safety: Dietary Protein Topical Review23#3:154-157-
[iii] NRC 2007 Nutrient requirements of Dogs and cats
[iv] Savage D.C. 1986 Gastrointestinal micro flora in Mammalian Nutrition Ann. Rev Nutri 6:155-178
[v]  Oozeer R. et al 2010. Gut Health: Predictive biomarkers for preventive medicine and development of functional foods British Journal of Nutrition 103:1539-1544

8 comments:

  1. I have to say that from where I stand, with exception of already ill dogs, I can't see protein alone causing such a problem, unless adulterated in some way.

    ReplyDelete
  2. My point exactly. But protein digestion and metabolism can be influenced by a number of factor as a resullt excess protein reaches the colon were it is broken down by the microbial population for their own rowth and metabolism producing many metabolites some potentially toxic if absorbed and metabolized in the liver and excreted through the Kidney. If he micrbial flora is compromised then this may influence their meetabolic by products.

    I beleive that there should be a clear caution on the package not to exceed X grams of these treats per day in language that the consumer can understand.

    ReplyDelete
  3. Excellent information about protein helpful site - thanks

    Royal Canin Pet Food

    ReplyDelete
  4. I have a 12 week old very small puppy, less then 2 lbs. he loved the dried chicken treats and they were helping with training but three days after giving them to him he is not active, not eating and has loose stools. Our only change were the dried chicken treats but we were giving them every time he went outside probably 6-7 pieces a day, your article makes the most sense Thanks

    ReplyDelete
  5. Are they screening now for melamine and other contaminants from the treats out of China? Are you not buying that that was the explanation for the large outbreak of sick dogs a few years ago?

    ReplyDelete
  6. The problem a few years ago was associated with melamine being added to the protein source in order to increase the protein level in the ingredient to make it cheaper and more attractive to the pet food manufacturer. No real reason for the problem with Jerky treats has been identified

    ReplyDelete
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  8. Thank you for your positive comments. I really appreciate them and I hope you other posts

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