關於貓咪飲食的討論 - 貓

此篇文章是對於「貓咪飲食」這個主題，
透過閱讀、節錄或整理以下四篇文獻中，我認為與貓咪飲食較相關的重點或內容，
以此為基礎的非學術性貓奴交流討論。
由於並非嚴謹的學術討論，亦非科普或衛教，
因此以下引用文獻內容時將不以學術引用文獻格式(如APA)表示，
僅以寫作順暢的引用方式為主，以不影響行文脈絡，
而文獻中與本文討論主題較無直接相關的表格、圖片與圖表，便不隨文附上。
同時對貓咪飲食相關主題的討論亦以寫作流暢為主，沒有一定順序。

由於要討論的內容相當多，因此如果寫作到一個段落已花費太多時間，
此篇文章本文可能將會重覆編輯數次以進行站上存檔，
或可能將會拆成兩篇或三篇文章來討論。
(打到一半發現要寫的東西多到爆炸，應該會分個幾次寫完)

本文要引用的四篇文獻是：

1．《Small Animal Clinical Nutrition, 5th Edition》(2008)
https://goo.gl/7YhKk6
以下會以《SACN 5th》作為引用縮寫使用
關於此本文獻中所有章節的reference可以在以下連結中查詢：
http://www.markmorrisinstitute.org/sacn5_references.html

2．《小動物腸胃科學》(2012)
https://www.taaze.tw/goods/11100851684.html
此本文獻中沒有詳列出reference，僅有延伸閱讀文獻。

3．《Nutritional management of feline gastrointestinal diseases》(2008)
https://www.ncbi.nlm.nih.gov/pubmed/19081554
此篇文獻中有列出reference，有引用到的段落部分若作者有註記，
會再依作者當時使用的格式列於文末。

4．《Food sensitivity in cats with chronic idiopathic gastrointestinal
problems》(2001)
https://www.ncbi.nlm.nih.gov/pubmed/11215916
此篇文獻中有列出reference，有引用到的段落部分若作者有註記，
會再依作者當時使用的格式列於文末。

首先是《SCAN 5th》，
我們將會引用Chapter1、Chapter19、Chapter20、Chapter21中，
對貓咪飲食的基本說明、飲食改變的說明、範圍以及幅度建議等內容，
此文獻後本章節有對罹患各腸胃疾病貓咪的營養需求建議與飲食建議，
有興趣的版友可以參閱此本文獻後本內容，在此便不詳列，
關於腸胃疾病、食物過敏、食物不耐受相關的貓咪飲食主題，
我們將透過上述其他文獻的內容進行討論。

Chapter19《Introduction to feeding normal cats》中，
對貓咪飲食生理學和基本模式的說明。(SACN5TH CHAPTER 19 P.362~367)
內容如下，僅引用於本文討論相關的部分，
並僅於有必要處進行說明，說明不一定正確，僅是個人解讀：
--------------------------------------------------------------------------

CATS AS CARNIVORES

Taxonomically, cats and dogs are members of the order Carnivora and are
therefore classified as carnivores (Table 12-4). From a dietary perspective,
however, dogs are omnivores (Chapter 12) and domestic cats and other members
of the superfamily Feloidea are strict or true carnivores, along with
raptors, mosquitoes and some coldwater fish. This basic difference is
supported by specific behavioral, anatomic, physiologic and metabolic
adaptations of cats to a strictly carnivorous diet.

這段主要說明，從飲食觀點上來看，
貓與猛禽等動物一樣是嚴格或真正的食肉動物，
狗則是雜食動物。

Adaptations in Feline Feeding Behavior

Domestic cats share several feeding behaviors with their wild counterparts.
Unlike most mammals, cats do not display a regular daily rhythmicity in
sleep-wake cycles, activity, feeding and drinking. Cats typically eat 10 to
20 small meals throughout the day and night (Kane et al, 1981; MacDonald et
al, 1984). This eating pattern probably reflects the evolutionary
relationship of cats and their prey. With the exception of African lions,
cats are solitary hunters. Small rodents (e.g., voles and mice) make up
40% or more of feral domestic-type cats’food source; however, young rabbits
and hares may compose a large portion of their natural diet (Fitzgerald,
1988). A variety of other prey (e.g., birds, reptiles, frogs and insects) is
also eaten, but in smaller amounts. The average mouse provides approximately
30 kcal (125 kJ) of metabolizable energy (ME) (Mugford, 1977). This amount is
about 12 to 13% of a feral cat’s daily energy requirement. Repeated cycles
of hunting throughout the day and night are required to provide sufficient
food for an average cat. Thus, meal feeding cats once per day is in conflict
with their natural feeding behavior.

這段主要說明了貓咪基本飲食模式的來源與型態。
由於貓典型的飲食模式是少量多餐型態(10~20small meals/day)，
因而一天餵食一次的做法不符合貓咪的自然進食模式。

The predatory drive is so strong in cats that they will stop eating to make a
kill (Adamec, 1976). This behavior may frustrate owners who confuse predatory
behavior with hunger (Box 19-1). Many owners reason that a fed cat will not
hunt and are disappointed when their housecat kills songbirds. Supplemental
feeding may reduce hunting time, but otherwise does not alter hunting behavior
(Turner and Meister, 1988).

Cats are very sensitive to the physical form, odor and taste of foods. Oral
tactile sensation is important to normal feeding behavior and should be
considered when feeding novel foods. Unless accustomed to foods with
different textures such as dry foods, cats generally prefer solid,
moist foods and reluctantly accept food with powdery, sticky and very greasy
textures (NRC, 2006, 1986; Kane et al, 1981a).

這段主要說明了貓咪對食物的物理形態、氣味與味道非常敏感，
「口感」對於正常的貓咪進食行為來說很重要，
在給予新食物時也需要考慮口感。
除非貓咪已經習慣了乾食，
不然貓咪通常更喜歡固體的、潮濕的食物，
勉強接受粉末狀的、黏黏的和非常油膩的食物。

The flavor and texture preferences of individual cats are often influenced
by early experience that can affect preferences throughout life. Cats
accustomed to a specific texture or type of food (i.e., moist, dry, semi-moist)
may refuse foods with different textures. This becomes an important
consideration when feeding cats novel foods.

這段主要說明，
貓咪對味道和質地的喜好通常來自於他們的早期經驗的影響，
並可影響他們終生。
貓咪習慣於特定一種質地或型態的食物可能會拒絕其他質地的食物。

Cats find certain flavors very attractive, which seems to reflect the
nutritional characteristics of their natural foods. Cats prefer the tastes of
animal fat, protein hydrolysates (digests), meat extracts and certain free
amino acids abundant in muscle tissue (i.e., alanine, proline, lysine,
histidine and leucine). Cats search out wild prey more often when meat is not
in their diet (Robertson, 1998). Even the feeding behaviors of cats in the
wild reflect their preference for animal tissues. When ingesting prey,
wild cats avoid consuming plant materials contained in the entrails.
African lions have been observed to first empty the digesta from the entrails
by expressing the contents with their tongues (Leyhausen, 1979).

這裡有個很有趣的地方，
此段後半說到，當野貓攝取獵物時，野貓會避免吃下獵物內臟中的植物。
非洲獅子們曾經被觀察到攝取獵物時首先用舌頭排空獵物內臟中的消化物。

This behavior contrasts with that of a pack of wild dogs or wolves eating
similar game. Wolves often first consume the viscera of prey (Mech, 1970).

狼則經常先吃掉獵物的內臟。

Herbivores are common prey; therefore, the gastrointestinal contents are
generally of plant origin and have a high carbohydrate content. Unlike dogs
and other omnivores, cats are not attracted to the taste of sugars and are
averse to flavors derived from plant products (e.g., glutamic acid and
medium-chain triglycerides) (MacDonald et al, 1984).

這裡說到草食動物是常見的獵物，
因此胃腸內容物通常來源自植物，且有高碳水化合物含量。
和狗與其他雜食動物不同，貓咪不會被糖的味道吸引，且不喜歡來自植物的氣味。
(例如麩胺酸和中鏈三酸甘油脂)

Cats are also sensitive to bitter tastes when compared to tastes of other
species (Carpenter, 1956). A great deal of variation in preference is
apparent in the cat population; owners often report that cats have an
appetite for cantaloupe, pumpkin, bananas or celery.

這裡主要說到貓對苦味很敏感。且貓咪有各式各樣對食物不同的喜好。

Food temperature also influences food acceptance by cats (Figure 19-1).
https://i.imgur.com/qekxz4g.png
(Figure 19-1，截自SACN 5th P.362)

Cats prefer that moist foods be offered at, or near, body temperature (38.5ºC
[101.5ºF]). This preference is logical considering that in the wild, a cat’
s food typically consists of freshly killed prey.

貓咪主要喜歡溫度接近獵物體溫的濕食，
圖19-1可以明確看到貓咪對濕食食物溫度的偏好程度。

Oral Cavity

Cats and dogs have the same number of incisor, canine and carnassial teeth
(i.e., the enlarged upper premolar and lower molar teeth specialized for
shearing flesh); however, cats have fewer premolar and molar teeth, and they
do not possess fissured crowns, which are a hallmark of omnivorous animals
(Figure19-2).

這段在說明貓咪的牙齒構造。

The jaws of cats have limited lateromedial and craniocaudal movement,
thereby limiting grinding ability. The scissors- like action of the
carnassial teeth is ideal for delivering the cervical bite used to transect
the spinal cord and immobilize or kill prey. Cats lack salivary amylase used
to initiate digestion of dietary starches. This adaptation reflects the
nutritional composition of the typical prey (i.e., low starch content).

這段前半解釋了貓咪牙齒結構限制了貓咪磨碎食物的能力。
後半說明了貓咪的唾液中缺乏澱粉酶，反映了典型獵物的營養成份(如低澱粉含量)。

Stomach

Because cats evolved to eat small frequent meals, the stomach is less
important as a storage reservoir compared with the stomach of dogs. Thus, the
stomach of domestic cats is simpler than that of dogs (i.e., relatively
smaller with a smaller glandular fundus).

這段說明了貓咪因為少量多餐，因此胃的儲存庫相較於狗沒有這麼重要。

Small and Large Intestine

Intestinal length, as determined by the ratio of intestine to body length, is
markedly shorter in cats than in omnivores and herbivores (Table 19-3). A
greater villus height in cats increases the absorptive surface area. Overall,
however, the absorptive capacity is estimated to be 10% less than that of
dogs (Kendall et al,1982; Morris and Rogers, 1989). Therefore, dogs can more
efficiently use a variety of foods, some of which may require more digestion
than animal tissues.

這裡說明了貓咪的腸道長度與身體長度的比例上較雜物動物與草食動物來得短，
雖然貓透過增加了腸道絨毛高度增加了吸收的表面積，
但總體來說腸道的吸收能力還是比狗低了大約10%，
因此狗相較於貓可以更有效地利用各種食物，如有些可能需要更多的消化的動物組織。

Unlike in omnivores, the sugar transport systems of the small intestine of
cats are not adaptive to varying levels of dietary carbohydrate (Buddington
and Diamond, 1992). Cats do not waste energy or protein by turning over
carriers or enzyme systems of little value because free sugars and complex
carbohydrates normally make up a negligible percentage of their food (Table
19-4). This lack of adaptability has been noted in other strict carnivores,
such as raptors and coldwater fish.

這段主要說明了貓咪和雜食動物不同，
小腸中的糖運輸系統並不適應不同程度的膳食碳水化合物。
這種適應性上的缺乏在其他食肉動物如猛禽和冷水魚身上也有被注意到。

Also, cats have low activities of intestinal disaccharidases (i.e., sucrase,
maltase and isomaltase) (Kienzle, 1993). This reflects adaptation to foods
limited in simple sugars and other carbohydrates. In cats, pancreatic amylase
production is about 5% of that in dogs (Kienzle, 1987, 1993a). Pancreatic
amylase production is relatively nonadaptive in cats, as would be expected
in a species unaccustomed to significant changes in dietary carbohydrate
levels.

這段主要說明了貓咪的腸道二糖酶活性低，
這反映了貓咪對單醣和其他碳水化合物適應性上的限制。
貓胰澱粉酶的產量約為狗的5%，
和其他不適應飲食中碳水化合物水平顯著變化的物種一樣，
對貓而言，胰澱粉酶的製造是非適應性的。

Cats have higher concentrations of bacteria in their small intestine than dogs
and other omnivores studied ( Johnston et al, 1993, 2001; Gruffydd-Jones et
al, 1998). Interestingly, the numbers typical for cats would be diagnostic for
small intestinal bacterial overgrowth in dogs (NRC, 2006). Although the reason
for this finding is unclear, their relatively short small intestine and
carnivorous physiology have been suggested as possibilities. Increased numbers
of small intestinal bacteria might enhance protein and fat digestion (Zoran,
2002).

這段主要是在說貓咪小腸中的細菌濃度相較於狗和研究中的其他雜食動物來得高，
雖然這個原因不明，
但以貓咪相對較短的小腸和食肉生理學來說，
小腸中增加的細菌量對幫助蛋白質和脂肪的吸收是有可能的。

Certain amino acid transporters in the small intestines of cats are highly
adaptable, particularly the transporter responsible for arginine uptake. This
finding underscores the importance of the amount of protein and specific
amino acids in foods for cats. Unlike omnivores, cats are unable to
synthesize significant quantities of ornithine or citrulline within the
intestine. Both are precursors to arginine synthesis. This inability results
in the absolute requirement for arginine in cat foods, which is discussed
below.

這裡主要是說，貓咪小腸中的某些胺基酸轉運蛋白具有高度的適應性，
特別是負責精氨酸攝取的轉運蛋白，
這個發現強調了貓咪飲食中特定胺基酸與蛋白質含量的重要性。
和雜食動物不同，貓咪沒有辦法在腸內大量合成鳥氨酸和瓜氨酸，
而鳥氨酸和瓜氨酸是合成精氨酸的前體，
這種能力上的缺乏導致貓咪飲食裡對精氨酸有絕對要求。

Cats have a vestigial cecum and a relatively short colon (0.4m). These
anatomic features would appear to limit cats’ capability to use poorly
digestible starches and fiber by microbial fermentation in the large bowel
(Morris and Rogers, 1989).
The primary end products of bacterial fermentation (i.e., shortchain fatty
acids: acetate, propionate and butyrate), however, are present in relatively
high concentrations in the large bowel of cats (Brosey et al, 2000). Large
intestinal fermentation may be more important to cats than previously thought.

這裡主要是說，貓咪有一個退化的盲腸和一個相對較短的結腸，
這種解剖學上的特徵，
限制了貓咪在大腸中透過微生物發酵難消化的澱粉與纖維的能力。
然而在貓的大腸中，細菌發酵的主要終端產物以相對高的濃度存在，
大腸發酵的重要性可能比先前認為得來得重要。

《SACN 5th》在Chapter1中提到了Feeding Plan大方向，
以及Food Replacement的原則說明與建議，如下(Chapter1 P.7~P.12)：
----------------------------------------------------------------------

If food assessment indicates that an animal’s key nutritional factor
requirements are not being met, the most practical way to balance a food is
to simply select a different food (i.e., one that does a better job of
meeting the patient’s requirements).

這裡主要說明，
如果食物評估表明了動物的關鍵營養需求要素沒有被滿足，
平衡一項食物最實際的方式，單純就是選擇另一項食物。
(也就是能更好地符合患者需求的另一項食物)

The most likely application of this method occurs when one commercial food is
substituted for another. If homemade foods are being used, they can be
replaced by appropriate commercial foods or another homemade food if other
recipes are available (Chapter 10).

這裡主要說明，
當一種商業食品得以替代另一個時最有可能應用上述這種方式。
如果配方合適的話，自家製食品可以被合適的商業食品或其他自家製食品替換。

The process is straight forward and simple. The nutrient content of other
foods is evaluated to see which food most closely meets the animal’s
requirements. Assuming comparable palatability, the most acceptable food
replaces the previous food. Case 1-3 demonstrates food replacement.

這裡是說上述這種替換的過程是非常簡單明了的，
也就是比較其他食物的營養成分，評估看看哪個食物最貼近動物的需求，
假設適口性相當，動物最能接受的食物取代之前的食物。
(個案1-3有飲食更換的案例說明，在此便不引了)

This process is greatly facilitated by the food tables in the feeding healthy
dog and cat chapters (Chapters 12 through 17 for dogs and 19 through 24 for
cats) and the feeding clinically ill patient chapters (Chapters 25 through 68).

Chapter19~24章此文獻有列出針對各年紀與狀態的貓咪營養需求分析表格，
非常詳細但引用上非常困難(在ptt上不知道怎麼引，單貼圖應該會看到眼花)，
因此在此便不引了，有興趣的版友可以查閱以下連結中的table updates：
http://www.markmorrisinstitute.org/sacn5_tables.html

These tables list the key nutritional factor targets and the key nutritional
factor contents of commercial foods commonly marketed for patients at various
lifestages and those having specific diseases.

Changing foods for most healthy dogs and cats is of minor consequence. Some
owners switch their pets from one food to another daily. Most dogs and cats
tolerate these changes. However, vomiting, diarrhea, belching, flatulence or
a combination of signs may occur with sudden, rapid switching of foods,
probably because of ingredient differences. It is prudent, therefore,
to recommend that owners change their pet’s food over the course of at least
three days. A seven-day period is even better, as owners increase the
proportion of new food and decrease the proportion of old food (Table 1-1).

這裡是說對健康的犬貓來說，更換食物的後果很輕微，
有些飼主每天為他們的寵物從一項食物換另一項。
大多數的犬貓容許這些改變。
然而，突然、快速的食物轉換可能會發生嘔吐、腹瀉、噯氣、胃腸脹氣或一些綜合徵狀，
這可能是由於成分的差異。
(我個人註：這裡後續會用本篇文章開頭提到的文獻4，也就是「食物敏感」進一步討論)

因此，建議飼主至少用三天的時間為他們的寵物更換食物，是謹慎的。
當飼主增加了新食物的比例並降低了舊食物的比例時，七天的期間甚至更好。
詳細的食物更換時間表可以看表1-1

https://i.imgur.com/oRnGkIx.png
(表1-1，SACN 5th P.12)

表1-1中提到對飲食改變出現低容忍狀況的貓，建議用到4週時間更換食物。

Nearly all pets readily tolerate a seven-day transition period. A much longer
transitional period is recommended in cases in which the food change is known
to be significant, the pet has demonstrated a poor tolerance to such changes
in the past or food refusal is expected (Table 1-1). For example, a long
transition schedule is likely to be needed for an old cat recently diagnosed
with kidney disease when the food must be switched from a highly palatable
grocery “gourmet” food to an appropriate veterinary therapeutic food.

此段同上述，這裡主要是說明幾乎所有的寵物都容易接受七天的轉換期，
而有些貓咪的狀態則建議需要更長的轉換期。

《SCAN 5th》在Chapter20、Chapter21兩章中，
提到了餵養年輕貓至中年貓，以及中年貓至老年貓的方式與建議，
引用相關內容如下(Chapter20, P.384~P.386 ; Chapter21, P.398)：
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Assess and Determine the Feeding Method

Veterinarians should evaluate the feeding method, including how the food is
fed, the feeding frequency and the amount of food offered. It is also useful
to know how the food is prepared (e.g., heated, water added, etc.) and by
whom and where the cat is fed. This information may help explain any apparent
discrepancies between the dietary history and the physical findings and help
identify risk factors associated with various feeding methods.
For example, a thorough evaluation of an obese cat includes verification that
an appropriate feeding method is being used (Chapters 1 and 27).

這段主要說明，
獸醫師需要評估的貓咪餵食方式，包含如何餵食食物、餵食頻率、食物的餵食量、
食物的準備方式(例如加熱、加水等)、由誰準備、貓咪被餵食的地點。
這些資訊可能有助於解釋身體檢查結果與飲食史之間的明顯差異，
同時有助於辨認與各種餵食方式相關的風險因素。

No single feeding method is optimal for all cats. The preferred method of
feeding an individual cat is often determined by non-nutritional factors
(i.e., food type, owner preference, owner schedule and feeding environment
including whether there are other pets [cats, dogs] in the household).

這裡主要是說，
沒有單一種餵食方式對所有貓而言都是最佳的，
餵食貓咪方式的偏好通常由非營養因素決定，
即食物型態、飼主偏好、飼主的行程安排、餵食環境(包含家中是否有其他寵物)。

Nutritional considerations for selecting an appropriate feeding regimen
include the cat’s body condition, health status/disease risk factors and the
food’s energy density and palatability.

這裡主要說明，
在選擇合適的貓咪餵養方案的營養考量上，
包含貓咪的身體狀況、健康狀態、疾病風險因素以及食物的能量密度與適口性。

There are basically two ways to feed cats: 1) free choice in which the food
is continuously available and the cat eats as much as it wants whenever it
wants and 2) meal feeding in which a specific amount of food is offered one
or more times per day.

這裡主要說明有兩種基本的貓咪餵食方式：
(1) 任食制
(2) 定量制(一天一次或數次)

Most cats tolerate once daily feeding with no problems; however, meal feeding
at least twice daily is preferred. Cats should be allowed one to two hours to
complete a measured meal; many cats will return for several small feedings
before finishing the entire offering.

這裡是說多數貓咪可以容許一天餵一次，但更偏好一天至少吃兩餐。
貓咪應該被允許花一至兩小時吃完經評估適量的一餐，
許多貓咪會回來小量吃個幾次直到吃完。

Many owners use a combination of free-choice and meal-feeding methods.
Usually, dry food is available throughout the day and supplemented with one
or more meals of moist food. Free-choice or combination feeding accommodates
the normal feeding behavior of cats by allowing them to eat several small
meals spaced irregularly throughout the day and night (Kane et al, 1981a).
Each feeding method has advantages and disadvantages that should be
considered when making recommendations (Table 20-5).

這段主要是說，
許多飼主會合併使用任食制與定量制，
通常，乾食為任食，輔以一餐或數餐的濕食，
任食制或合併任食制與定量制，
符合貓咪少量多餐且餐間間隔不固定的自然進食行為。
每一種餵食方式都有其優缺點，如表20-5。

https://i.imgur.com/RKNXu3B.png
(表20-5 SACN 5th Chapter 20, P.385)

Unless a specific amount of food is fed, the major disadvantage to
combination feeding is the inability to accurately monitor and control food
intake. Most obese-prone cats should be fed a measured quantity of food;
however, some obese-prone cats can be fed low-calorie foods free choice.
Food should be available at all times for underweight cats to encourage
sufficient food intake. The amount fed is important because nutrient
requirements are met, or exceeded, by a combination of nutrient levels
in the food and the amount of food fed. Even if a food has an appropriate
profile of key nutritional factors, significant malnutrition could result
from feeding excessive or insufficient amounts. The amount fed is appropriate
if the cat has an optimal BCS (Body condition score 2.5/5 to 3.5/5) (Chapter 1)
and body weight is stable. The amount fed can be estimated by calculation
(Table 5-2) or by referring to feeding guides on product labels or product
information.

這裡是在說除非餵食特定量的食物，
不然使用合併式餵法(任食+定量)的缺點就是無法準確監控和控制食物的攝取量。
多數有肥胖傾向的貓咪需要餵食特定量的食物，
然而有些肥胖傾向的貓咪可以以任食制餵食低卡路里的食物，
而體重過輕貓則應該以任食制餵食以鼓勵足夠的食物攝取。
餵食量相當重要，因為即便食物含有關鍵營養素，
過多或不足的餵食量都可能造成嚴重的營養失調。
合適的餵食量可以透過貓咪的身體狀態分數(BCS)和穩定的體重來確認評估。

These guides, however, usually represent population averages and thus may not
be optimal for individual cats. Table 20-6 summarizes the feeding plan for
young adult cats. A reduction in the amount of food fed is usually necessary
in normally active cats that are temporarily confined, such as during boarding,
or if their environment changes permanently. These cats may become overweight
if food intake is not adjusted accordingly. A normal decline in food intake
should not be confused with inappetence due to stress or disease. Domestic cats
display a variety of feeding behaviors that may have nutritional or
non-nutritional bases (Box 19-1). Some of these behaviors are worrisome to
owners and considered abnormal, when in fact they are normal. Other behaviors
may indicate an underlying disease.

(表20-6要從表20-4查建議食物，但表20-4有明確的品牌暗示，因此我就不引了)

這裡主要是說當正常活動力的貓咪有暫時活動受限，例如登機或環境永久變化時，
食物的減量通常是必要的，如果沒有因應狀況調整食物攝取量，貓咪可能會超重。
正常的食物攝取量下降與疾病或壓力造成的食慾不振不應混淆。
表19-1說明了一些貓咪可能基於營養或非營養因素的各種進食行為，
其中一些行為可能在飼主看起來是不正常的因而會擔心，但其實是正常的，
其中一些行為則表示貓咪可能有潛在的疾病。
(表19-1與飲食相關性比較低，因此不引)

Cats do not typically develop digestive problems associated with food
changes; furthermore, food variety stimulates increased food intake (Mugford,
1977). Unfortunately, rapid changes in the food or feeding method can cause
GI upsets or food refusal for some cats. Transitioning to a new food over four
to seven days may be necessary to avoid food intolerances. To change to a new
food, replace 25% of the old food with the new food on Day 1 and continue this
incremental change daily until the change is complete on Day 4. A slower
transition may be required for cats that have been historically sensitive to
dietary changes, those with GI diseases and when the new food differs
markedly from the old (e.g., low fat vs. high fat or raw meat vs. dry food).

這段和上述引用中對飲食改變的說明一樣，
雖然貓咪通常不會因為飲食改變而出現消化系統問題，
但突然或過快的改變貓咪飲食可能導致腸胃系統問題或拒食，
因此給予貓咪4~7天或更長的飲食改變轉換期以避免對食物的不耐受可能是有必要的，
尤其是對已經有對飲食改變敏感記錄、有腸胃疾病的貓而言，
或是新食物與舊食物有顯著的不同時(例如低脂vs高脂，或生食vs乾食)。

Feeding Mature Adult Cats: Middle Aged and Older
(SCAN 5th Chapter 21 P.398)
FEEDING PLAN

Older cats are more prone to weight loss, cardiac disease, renal disease,
cancer and metabolic aberrations and usually have a decreased activity level
than younger cats. The feeding plan should be based on the information
obtained in the assessment and any detected risk factors. Nutritional
surveillance and therefore the number of contacts per year should be
increased for older cats. Although general feeding goals remain the same as
those listed in Chapter 20 for young adult cats (maximize health, longevity
and quality of life), each patient should be evaluated individually. The
feeding plan includes assessing and selecting the best food and feeding
method for the individual patient as described for young adult cats.

這裡是說，
老年貓相較於年輕貓更易於出現體重減輕、心臟疾病、腎臟疾病、癌症、代謝異常、
活動力降低的情況，
老年貓的餵食計畫應該建立在評估中獲得的資訊以及任何檢測到的風險因素之基礎上，
營養監測以及每年與獸醫師的接觸應該增加，
雖然在餵養目標上與第20章給予年輕貓的一樣(最大化健康、壽命與生活品質)，
但每隻貓應該被獨立評估。

It may not always be necessary to change the food and feeding method when
managing healthy mature adult cats. However, a thorough evaluation includes
verification that an appropriate food and feeding method are being used. Older
cats should be reevaluated at each examination because nutrition and health
needs change with disease status, risk factors and overall health.

這段主要是說，在管理健康成熟的成年貓時，
改變食物和餵食方式並不總是必要的。
然而，需要徹底的評估包含驗證目前已使用合適的食物與餵食方式。
每次對老年貓進行檢查時都應該重新評估老年貓的需求，
因為營養與健康需求會隨著老年貓的疾病狀況、風險因素和整體健康狀態而變化。

An important goal when managing the nutrition of mature adult cats is to
ensure adequate food intake. There is little need to change the form of food
a cat eats well because of age. In fact, some cats will refuse to eat a new
food with a different formor texture. However, cats with inadequate food
intake may benefit from changing food forms if the new food is more palatable
and easier to chew.

這裡是說確保足夠的食物攝取對管理成年貓的營養來說是重要的目標，
因為年紀的關係，成年貓吃的食物形式幾乎不需要改變，
事實上，有些貓會拒絕吃形式質地不同於舊食物的新食物。
然而，對食物攝取不足的貓來說，更換食物的形式可能有益處，
如果新食物更可口、更易咀嚼的話。

Assess and Determine the Feeding Method
The feeding method includes how much to feed and how it is fed. Healthy
mature cats may be fed free choice, meal fed or fed by a combination of
methods. Overweight cats should be offered measured amounts of food. The
measured quantity may be fed in meals or dispensed at one time to allow
continuous access throughout the day. Underweight cats should be allowed to
eat free choice.
Only dry and semi-moist foods may be fed free choice and these foods are
generally less palatable than moist foods. Table 20-5 summarizes advantages
and disadvantages of feeding methods.

這裡是在說明餵食中年貓至老年貓的方式，
基本上和上述Chapter20中的建議是一樣的。

Older cats may have reduced olfaction and taste perception; therefore,
it may be preferable to feed moist and warm foods to encourage food intake.
Providing dry foods free choice and several moist food meals throughout the
day may optimize food intake. Adding broth or canned meat juices to dry foods
may enhance food and water intake in older cats.

這段說明老年貓在嗅覺和味覺上可能會退化，
因此餵食老年貓濕食、溫食、提供任選乾食、一天內提供數餐濕食，
可能可以增加老年貓的食物攝取量，
在乾食中加入肉湯或罐頭肉汁可能可以增加老年貓的食物與水分攝取。

However, when considering broths or meat juices to improve palatability,
evaluate the product for excessive sodium chloride content.
(See Key Nutritional Factor discussion, above.) Table 21-5 summarizes a
feeding plan for mature adult cats.

這裡是說透過肉湯和肉汁改善適口性時要評估氯化鈉的含量。

Although most cats do not experience digestive upsets with typical food
changes, a gradual transition to a new food may benefit mature adult cats.
Progressively exchanging the new food for the usual food over four to seven
days will minimize untoward effects and food refusal
(Chapters 1 and 20 provide exact details).

這裡一樣是在說漸進式的食物轉換可以最小化飲食改變對貓咪的不良影響或拒食的情況。

《SACN 5th》的內容大致引到此，
接下來會討論本文提到的文獻2和文獻4。

沒想到有這麼多內容要寫…

0406註記：最近這幾天實在太忙，
沒有時間完整整理文獻四，
連假結束後會盡量找一段完整的時間把文獻四整理完。

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