News from research - 3. januar 2012

#3 - January 2012

Intro Knowledge means nothing if it is not shared!

The 1st issue of “News From Research_ Royal Canin” started with the words: “Spread Knowledge”. It is one of Royal Canin commitments to help you receive all the recent information linked with veterinary research. Of course, this newsletter was created to reach that objective.

But this is not the only thing that we do to help vet practitioners in their post-graduate training. For example, Royal Canin has been the partner of several colleges of specialists for several years. The ECVIM - CA (European College of Veterinary Internal Medicine - Companion Animals) is one of these. The last congress took place in Sevilla, Spain,

Urinary

in September 2011. It was an opportunity for us to share the latest results of the studies conducted by Royal Canin and its partners within the veterinary scientific world. All the content in this issue of “News From Research” comes from the lectures and posters presented at the ECVIM congress. We hope you will enjoy reading it as much as we enjoyed writing it. Hopefully you will be able to join us for the 2012 ECVIM congress in Maastricht – Netherlands (September 6th – 8th 2012) to hear the latest developments in veterinary scientific research.

Marie-Anne Hours (Scientific Support Manager - R&D) & Gregory Casseleux (Scientific Communication Manager - Europe)

More information on: http://www.ecvimcongress.org/

Soluble fibres do not decrease diuresis in cats Food amounts were adjusted to maintain the cats’ weights. Water was offered as libitum. Water content of the feces was determined by weight difference after desiccation in a drying oven. Water content of the urine was derived from the total urine weight.

Voluntary water intake was 17% greater in average for diet A than for diet B (p<0.05). Urinary and faecal water excretion with diet A were also significantly greater than with diet B. Urine specific gravity was lower with diet A. Overall, including moisture from the diet, water intake and excretion were greater for diet A than diet B (p<0.05).

A study investigated the effect of soluble fibres on urine and faecal water excretion. The results did not support the hypothesis that diets promoting faecal moisture divert part of the ingested water into feces, decreasing urinary volumes.

Seven healthy adult cats were sequentially fed two identical dry diets, except for the source of dietary fibres. The levels of total dietary fibre (TDF) were similar between the 2 diets (7.3% on a dry matter basis), but the main sources of fibres differed: • Diet A contained soluble fibres ( fructo-oligosaccharides, chicory pulp) and cellulose; • Diet B contained mainly insoluble fibres: cellulose.

Each diet was fed for a period of 14 days: 9 days of adaptation followed by 5 days of collection, during which cats were individually housed with daily recording of food and water intakes and collection of all feces and urine.

This study shows that in cats, the addition of soluble fibers to a dry expanded diet results in higher water content in the feces, but also in the urine. Cats appear to be able to adjust their water intake to compensate for increased faecal water losses.

Voluntary water intake* (g/kg/day) Urinary water excretion* (g/kg/day) Faecal water excretion* (g/kg/day) Urine specific gravity* (g/kg/day)

Diet A Soluble fibres

Diet B Insoluble fibres

36.9 [18.4-41.0] 15.3 [12.0-23.6] 4.4 [2.3-4.9] 1.054 [1.040-1.059]

29.0 [16.7-36.5] 11.6 [9.4-18.9] 2.0 [1.6-3.8] 1.060 [1.045-1.067]

* significant difference between diet A and diet B for the studied parameter Results presented as median [range]

Queau Y, Van Hoek I, Le Verger L, Soulard Y, Biourge V. Effect of the addition of soluble fibers to dry expanded diets on faecal and urine water content in healthy cats. Proc. 21th ECVIM Congress. Sevilla 2011: 219-220.

Intestinal

Faecal Calprotectin: a new marker for inflammatory chronic diarrhoea?

A prospective study in 28 dogs with chronic diarrhoea was conducted to determine the accuracy of faecal calprotectin as a non invasive method to mark bowel inflammation.

Measurement of faecal calprotectin concentrations is widely used in human medicine for differentiating organic from nonorganic intestinal disease, monitoring treatment response and predicting clinical relapse in patients with Inflammatory Bowel Disease (IBD).

To assess the accuracy of this marker of bowel inflammation in dogs, a prospective study was conducted in 28 adult dogs with chronic diarrhoea.

For each dog, the severity of clinical signs was evaluated using a clinical disease activity index (CCECAI1). To assess intestinal inflammation, gastroscopy and duodenoscopy were systematically performed, with histopathological evaluation of mucosal biopsies.

If clinical signs of lower gastrointestinal disease were present, duodenoscopy was completed by a colonoscopy.

Fecal calprotectin concentrations in 21 dogs with and without intestinal inflammation among those with histological lesions Fecal calprotectin (µg/g)

120 100 Ninth decile

80

Third quartile Median

60

First quartile

40

First decile

Dogs were allocated to 3 groups according to endoscopic findings and histopathological results (figure 1): • Dogs without intestinal inflammation ; • Dogs with intestinal inflammation ; • D ogs with non-concordant results (controversial results between endoscopy and histology).

Faecal samples were collected from all dogs and faecal calprotectin (cCP) concentration was evaluated using a recently validated radio-immunoassay test2.

Faecal calprotectin was significantly higher in dogs with severe clinical signs (CCECAI>12), hypoalbuminemia, and intestinal inflammation, compared to dogs with respectively moderate clinical signs, an albuminemia > 20 g/L, and no sign of intestinal inflammation.

Faecal calprotectin correlates closely with the best objective markers of bowel inflammation in dogs. The measurement of faecal calprotectin is an accurate, objective method of quantifying the intestinal inflammation. More invasive tests are still required to distinguish intestinal inflammation from intestinal tumors, but faecal calprotectin provides a noninvasive, risk-free means of diagnosing and monitoring inflammation and therapeutic responses.

20 0

Dogs without intestinal inflammation (n=6)

Dogs with intestinal inflammation (n=15)

Grellet A, Heilmann RM, Feugier A, Lecoindre P, Hernandez, Freiche V, Peeters D, Suchodolski JS, Grandjean D, Steiner JM. Faecal calprotectin concentration in adult dogs with and without digestive troubles. Proc. 21th ECVIM Congress. Sevilla 2011: 192.

Figure 1: Study design for calprotectin assessment

1: CCECAI: Canine Chronic Enteropathy Activity Index, from Allespach et al, 2007.

2: Heilmann RM, Suchodolski JS, Steiner JM. Development and analytic validation of a radioimmunoassay for the quantification of canine calprotectin in serum and feces from dogs. Am J Vet Res 2008;69:845-853.

Dogs with chronic diarrhoea (n=28) Endoscopic criteria assessed

Histologic criteria assessed

Classification of dogs

No or mild endoscopic lesion (n=9) No histological lesion (n=6) Dogs without intestinal inflamation (n=6)

Histological lesions (n=3)

Moderate or severe endoscopic lesion (n=19) No histological lesion (n=4)

Dogs with no concordant result (n=7)

Histological lesions (n=15) Dogs with intestinal inflamation (n=15)

Urinary

Larger daily urinary volumes increase micturition frequency in cats

Does a higher daily urinary volume in cats result in a higher number of micturitions, a higher The higher the volume, volume per the micturition, both?

To answer lower theor urine specific gravity this question,Meanaurine study evaluated 3580 urine samples, specific gravity each representing a micturition.

1.065 1.060

1.061

Although in1.055 small breed dogs, micturition volumes and frequencies 1.055 are lower than 1.050in larger breeds1, which might explain in part their higher propensity 1.045 for uroliths, this has not been investigated in cats.

To do so, a database of 3580 cat urine samples, each representing 1.040 a micturition, was analyzed. These samples came1.040 from 30 healthy adult cats 1.035 fed ad libitum with different dry and wet diets for 2 weeks each.

Data were collected over 2 years. The objective was 1.030 to assess the relationships between: 1.025 F (micturition/day) • daily urinary volume (ml/day) 1 2 ≥3 • urinary volume per kg bodyweight (ml/kg/day) The higher daily volume, • micturition frequency (number of the micturitions per day) the smaller the volume per micturition • micturition volume (ml) Mean urine • urine specific gravity (USG) volume (ml/day)

70

Data were grouped according to the micturition frequency (F= 1, 60 F= 2 or F ≥3 micturitions/day), and statistically analyzed.

63 The results showed that F was significantly higher (p<0.001) with 50 both daily larger urinary volume (72.9±40.6* ml/day) and urinary 48 volume per kg40 bodyweight (14.6 ± 7.7 ml/kg/d). Micturition volume 40 (55.5±31.4 mL) 30 and urine specific gravity (1.060 ± 0.02) also decreased significantly with higher micturition frequency.

Thehigher higherthe thevolume, volume, The the theurine number of micturitions the higher lower the specific gravity MeanMean urine urine volume (ml/kggravity BW/day) specific

1.06530 28

1.060 1.055 20 1.050

1.061 1.055 19

1.045 1.04010 1.035

13

1.040

1.030 1.025 0

11

22

≥3≥3

FF

(micturition/day) (micturition/day)

The higher the daily volume, the smaller the volume per micturition Mean urine volume (ml/day)

70 60

63

50 48

40

40

30

20

20

10

10

This study showed that in cats, larger daily urinary volumes 0 F increase micturition frequency, with smaller volumes voided per (micturition/day) 1 2 ≥3 micturition. This is of interest for the management of urolithiases, as crystals are less likely to aggregate with a shorter bladder residence time.

Mean u (m

0 1

2

≥3

F (micturition/day)

The higher the volume, the lower the urine specific gravity

Mean (m

Mean urine specific gravity

1.065 1.060 1.055

1.061 1.055

1.050 1.045 1.040

1.040

1.035 1.030 1.025 1

2

≥3

F (micturition/day)

The higher the daily volume, the smaller the volume per micturition Van Hoek Mean I, Feugier urineA, Le Verger L, Venet C, Biourge V. Larger daily urinary volumes in healthy cats induce more volume frequent(ml/day) micturitions of smaller volumes. Proc. 21th ECVIM Congress. Sevilla 2011: 224.

70 Notes: *: Results presented as mean +/- SD 1: Stevenson60 AE and Markwell PJ. Comparison of urine composition of healthy Labrador Retrivers and 63 Miniature Schnauzers. AJVR vol 62 (11) 2001.

50 40

48 40

After weight loss, energy requirements in cats remain low

Energy requirements of 10 obese cats were assessed during 23 weeks after a successful weight loss programme.The results show that food intake in cats with a history of obesity should be closely monitored to prevent weight regain.

Weight regain after weight loss is a well-known phenomenon in humans and companions animals, but little is known about the post-weight loss maintenance energy requirement in cats.

This study was designed to induce weight loss in obese cats and to estimate their post weight loss maintenance energy requirement to avoid weight rebound.

Ten obese colony cats (BCS = 9 on a 9-point scale) undertook Royal Canin weight loss programme by using a moderate protein, high fibre dry diet designed to promote satiety (Satiety Support Feline, Royal Canin).

Initial energy allocation was calculated as 35 kcal per kg of calculated target body weight*, and was then adjusted to achieve a weight loss rate between 1 and 3% per week.

After reaching target weight, maintenance energy requirements were adjusted to maintain the optimal weight within ± 5 % and followed weekly during 23 weeks after the cats had switched to maintenance diets.

Mean allocation

Weight loss Energy allocation

Post weight loss Energy requirement

35 kcal/kg Target body weight* Range: 29-36

46 kcal/kg Ideal body weight* Range: 37-61

The mean energy allowance to induce 1 to 3% weight loss per week was 32 ± 1 kcal/kg of target body weight (BW). Except for an increase in food consumption speed, no behavior changes were observed during weight loss. The difference between the target BW (calculated*) and the ideal BW (BCS = 5 on a 9-point scale, estimated by visual examination) was 6 ± 2 %.

The post-weight loss maintenance energy requirement was 46 ± 2 kcal/kg of ideal BW. The mean time necessary to determine the maintenance energy requirement after weight loss was 6 ± 1 weeks. The mean variation of BW after 23 weeks of maintenance with different diets was - 1.6 ± 1.0 %.

This study showed that a moderate protein, high fibre diet is suitable to induce weight loss in obese cats.

The maintenance energy requirements following weight loss are low, maybe due to increased metabolic efficiency.

This could explain the commonly observed weight rebound phenomenon in cats.

Source: Serisier S, Vialle S, Martinez E, Michel S, Biourge V. Weight loss and post weight loss maintenance energy requirement of obese colony cats.

Proc. 21th ECVIM Congress. Sevilla 2011: 209-210.

Average maintenance energy requirement2 55 kcal/kg Ideal body weight

*Target body weight was calculated using the Body Condition Score (BCS): a BCS equal to 9 corresponds to 40% overweight. The ideal weight (BCS=5/9) was determined upon observation.

2: Bermigham EN et al. Energy requirements of adult cats_a meta-analysis. British Journal of Nutrition (2009).

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