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December 16, 2016

貓白血病的營養需求


Nutrition is Vital for FeLV Cats
貓白血病的營養需求

Last Updated on Saturday, January 23, 2016 07:59 PM
Published on Saturday, January 31, 2015 06:10 PM
Written by Guillermo Díaz, MV
 
最近更新:2016年1月23日
原始刊出日:2015年1月31日
作者:獸醫基勒摩.迪亞茲(Guillermo Diaz, MV
 
原文出處連結:http://feline-nutrition.org/health/nutrition-is-vital-for-felv-cats
 
The feline leukemia virus, generally referred to as FeLV, is classified by virologists as a retrovirus. A retrovirus uses an enzyme called reverse transcriptase to insert copies of its own genetic material into the cells it has infected in order to produce a new copy of a whole virus. Infected cats can be found everywhere, but the prevalence varies depending on many factors: age, health, reproductive status, concurrent disease , environment, lifestyle, etc. The worldwide prevalence is about 5% of free-roaming cats. In the United States, approximately 2 to 3% of all cats are infected with FeLV. Rates rise significantly, above 10%, in sick cats, youngsters, or cats otherwise at high risk of infection.¹
 
貓白血病病毒簡稱 FeLV,被病毒學家歸類為反轉錄病毒。反轉錄病毒使用一種名為反轉錄酶(逆轉錄酶)的酵素,複製病毒自身的遺傳物質,注入已被病毒感染的細胞中,複製出一個全新的完整病毒。任何地方都可能存在著被此病毒感染的貓,但是普及率視許多不同的狀況而定,例如年紀、健康、繁殖狀態、同時有其他疾病、環境以及生活型態等。行動自由的貓,感染此病毒全球普及率大約百分之五。在美國,大約有百分之二到三的貓有此病毒。病貓、幼貓或是處於高感染風險環境中的貓,病毒普及率為百分之十以上,明顯高出許多(註1)。
 
Cats with persistent FeLV infection serve as sources for the spread of the disease. Virus is shed in large amounts through bodily fluids: saliva and nasal secretions, urine, feces and milk. Cat-to-cat transfer of the virus may occur from a bite wound, during mutual grooming and less often by sharing litter boxes and feeding dishes. In utero transmission can also take place from infected queens or while they are nursing. FeLV cannot survive long outside a cat's body because the virus needs the living cells to replicate.² Cats most susceptible to infection are the ones in contact with infected cats or with cats of unknown infection status, either via prolonged close contact or through bite wounds. Young kittens, cats less than one year of age and kittens born to a mother who is FeLV positive are most at risk of infection.
 
長期感染的貓是此病毒的散播源。病毒透過體液(口水和鼻腔分泌物)、尿液、糞便以及母乳傳遞。貓與貓之間的感染可能發生於咬傷或相互舔毛時,共用貓砂盆和食器的感染則比較少見。幼貓有可能在母貓子宮內被感染,母乳也是感染源。白血病病毒在貓的體外無法長時間生存,因為病毒需要活細胞以進行複製(註2)。最容易被感染的途徑是接觸帶有白血病病毒的貓,或是感染狀態不明確的貓,可能因為長期相處而感染,也有可能是咬傷感染。年紀一歲以下的貓,以及帶有此病毒的母貓所生的小貓,感染風險最高。
 
Feline leukemia virus causes systemic immunosuppression which hinders the cat's ability to protect itself against other infections. During the early stage of infection some cats are able to develop an effective immune response.³ Infected cats can be expected to have secondary skin problems, such as recurrent pyoderma. FeLV is the most common cause of cancer in cats and it may cause various blood disorders. The same flora and fauna, such as bacteria, viruses, protozoa, and fungi that may be found in the everyday environment – where they usually do not affect healthy animals – can cause fatal disease in those with weakened immune systems. These secondary infections are responsible for many of the diseases associated with FeLV.⁴
 
白血病病毒會造成系統性的免疫力受到抑制,造成貓保護自己以對抗其他感染的能力受阻。感染初期有些貓無法發展出有效率的免疫反應(註3)。受到此病毒感染的貓可能會出現續發性的皮膚問題,例如復發的膿皮症。白血病病毒是最常見造成貓腫瘤的原因,而且可能導致許多不同的血液疾病。在相同的植物群和動物群之中,存在日常環境中的細菌、病毒、原蟲(原生動物)以及真菌,通常不會影響動物的健康,但是卻可能會讓免疫系統較弱者染上致命的疾病。這些續發型的感染,是白血病病毒引起許多疾病的原因(註4)。
 
Pyoderma: A bacterial infection of the skin. Lesions and pustules, which are inflamed pus-filled swellings on the skin, and in some cases partial hair loss, often characterize the infection.

本文對膿皮症的解釋:一種皮膚的細菌感染。病變和膿胞,即皮膚長出有膿的顆粒,有些病例會出現部分落髮,皆是受到感染的特徵。
 
If the cat's immune response failed to initially fight the virus, a later stage characterized by persistent infection of the bone marrow and other tissue is developed. If the infection progresses to this stage it has reached the point of no return: these cats will remain infected for life. These cats are referred to as having a persistent infection and they actively shed the virus in saliva and other bodily fluids. They are very likely to develop FeLV related diseases.
 
如果在感染初期,貓的免疫系統沒有打敗病毒,以後可能會出現持續的骨髓以及其他組織感染。當感染進行到此階段時,已經沒有後路可退,貓會終生處於感染狀態。這些貓被視為持續型感染(persistent infection),口水和其他體液皆會散播病毒,以後可能會出現白血病病毒相關疾病。
 
When cats first get infected with the virus they generally do not show any signs of disease, but they can transmit the virus to other cats. However, over time – weeks, months, years – the cat's health may progressively deteriorate or be characterized by recurrent illness alternating with periods of relative health. Fortunately, most cats that are exposed to the virus do not become viremic but recover and develop immunity.⁵ These cats are referred to as having a regressive infection with the virus. They rarely shed the virus and usually do not succumb to FeLV related illnesses.
 
初期感染到此病毒時,貓通常不會出現任何症狀,但是可能會把病毒傳染給其他的貓。然而隨著時間的過去,可能是幾週、幾個月或幾年,貓的健康可能持續惡化,或是出現復發的疾病,身體健康時好時壞。幸運的是,大部分感染到此病毒的貓,並沒有變成病毒血症(病毒存在血液中),身體會復元而且具有免疫力(註5)。這種貓被視為退行性感染(regressive infection)。這類的貓很少會散播病毒,而且不會染上白血病病毒相關疾病。
 
The most common clinical signs are:
最常見的臨床症狀如下:
 
  • Loss of appetite 沒有食慾
  • Weight loss 體重減輕
  • Enlarged lymph nodes 淋巴結腫大
  • Poor coat condition 毛髮狀態不佳
  • Abscesses 膿腫
  • Fever 發燒
  • Pale mucus membranes 粘膜泛白
  • Gingivitis and stomatitis 牙齦炎和口腔炎
  • Jaundice黃疸
  • Infections of the skin, urinary bladder, and upper respiratory tract 皮膚、膀胱和上呼吸道感染
  • Persistent diarrhea 持續型腹瀉
  • Behavior changes and other neurological disorders 行為改變和其他神經疾病
  • Abortion of kittens 流產
 
The clinical signs listed above are only "signs" or manifestations of a concurrent disease caused by the virus. These diseases can by classified into two categories: malignant and non-malignant. Malignant diseases include lymphoma and leukemia. Non-malignant diseases include anemia, immunodeficiency, enteritis, marrow aplasia and reproductive failure.⁶
 
以上所列的臨床症狀,只是此種病毒引起的疾病的症狀。此病毒引起的疾病分為兩類:惡性和非惡性。惡性疾病包括淋巴癌和白血病。非惡性疾病包括貧血、免疫力不全、腸炎、骨髓發育不全和不孕(註6)。
 
There are two types of blood tests available for veterinary use. Both can detect a certain type of protein component of the virus:
 
獸醫有兩種驗血方式可以使用,兩者都可以偵測到病毒中某種特定的蛋白質成分。
 
  • ELISA (enzyme-linked immunosorbent assay) and similar tests can be performed in your veterinarian's office. ELISA-type tests detect both primary and secondary stages of viremia.
 
酵素連結免疫吸附分析法(簡稱ELISA)和類似的檢驗,可以在動物醫院中進行。ELISA式的檢驗可以偵測到病毒血症的第一和第二階段。
 
  • IFA (indirect immunofluorescent antibody assay) tests must be sent out to a diagnostic laboratory. IFA tests detect secondary viremia only, so the majority of positive-testing cats remain infected for life.⁷
 
間接免疫螢光法(簡稱IFA)必須在診斷實驗室進行檢驗。IFA檢驗只能偵測到病毒血症的第二階段,所以絕大多數檢驗呈現陽性的貓,終生處於感染狀態。
 
譯註:
病毒血症的第一階段:
Primary viremia refers to the initial spread of virus in the blood from the first site of infection.
病毒從感染部位開始在血液中擴散。
 
第二階段:Secondary viremia occurs when primary viremia has resulted in infection of additional tissues via bloodstream, in which the virus has replicated and once more entered the circulation.
第一階段發生後,病毒透過血液造成更多的組織受到感染,此時病毒已經開始複製,並且再一次的進入體內循環。
 
Prevention is the best way to protect cats from FeLV exposure. These recommendations can help:
 
最好的預防方式是讓貓沒有接觸到此病毒的機會。以下的建議也許有幫助:
 
  • Keep cats away from potentially infected cats that might fight and bite them. It's safer to keep our cats indoors.
 
不要讓貓有機會接觸到感染到此病毒的貓,因為可能會透過打架和咬傷而感染。把貓養在室內比較安全。
 
  • Consider vaccination of healthy cats if they will be in close contact with an infected cat. Keep in mind that the vaccine is only 70-80% effective. FeLV vaccination of infected cats is not beneficial. Discuss the advantages and disadvantages of vaccination with your veterinarian.
 
如果健康貓和已受感染的貓有近距離接觸的機會,考慮施打白血病預防針。不過預防針只有百分之七十到八十的機率可以有效預防。已感染白血病病毒的貓沒有必要打此預防針,因為沒有幫助。和你的獸醫討論預防針的優缺點。
 
譯註:關於白血病疫苗接種與否,另一個獸醫麗莎.皮爾森(Lisa Pierson)的建議如下:
不要讓小貓注射白血病疫苗,除非你的貓會去室外(不管是小貓或大貓,室外都不是一個很安全的地方)或要去跟一隻白血病呈陽性反應的貓住在一起。
 
成貓也不要注射白血病疫苗,即使他們可以去室外,因為當貓一歲時,他們本身已具有這個疾病的強壯免疫力。如果一隻成貓要去跟白血病呈陽性反應的貓住在一起,才應該考慮是不是要注射疫苗。
 
如果一隻可以去室外的貓,你覺得要打疫苗才比較放心,也不要每年都打。我認為放心的作法是打一次PureVax白血病疫苗(唯一沒有佐劑的選擇)。
 
切記務必選擇沒有佐劑的疫苗!
 
Having said all of the above I'd like to stress a subject that is not talked about in veterinary medical books or on the internet and this is about how to improve the quality of life and perhaps how to accelerate the recovery of sick cats. And that topic is nutrition. Medical textbooks are loaded with the names of drugs and with different approaches to deal with infected cats, but nutrition is often dismissed or underestimated.
 
做了以上的解釋之後,我想要強調一個在所有獸醫課本或是網路都沒有被討論過的主題,關於如何改善生活品質,以及或許如何加快病貓的復元,這個主題是營養。醫學教科書充滿了藥名以及不同的治療方法,但營養往往被忽略或是低估。
 
Sick cats need the best quality of food available because of their catabolic state. Their requirements for protein, fat and energy exceed those of healthy cats so high-quality nutrition is of the utmost importance. Cats that don't get enough high-quality protein will start to metabolize their own tissues to compensate, leading to wasting and a reduced ability to fight off disease. Balanced raw meat diets are ideal for their superior nutrition. Cats with regressive infection can be fed the usual raw diets as their immune system is not compromised. More care should be taken in cats that have persistent infection with the virus as the immune system may not be able to handle even normal amounts of pathogens. With these cats, dry food especially should be avoided. Besides the inferior quality of nutrition from kibble-type foods, they are more likely to harbor molds and bacteria than other foods.
 
因為身體的分解代謝狀態,病貓需要品質最好的食物。病貓對蛋白質、脂肪和熱量的需要高於健康貓,所以品質好的養分是最重要的重點。沒有獲得品質好的蛋白質,貓會開始新陳代謝自身組織以補足,造成身體組織耗損,抗病能力降低。均衡的生肉餐是優質養分的理想來源。退行性感染的貓應該餵一般的生肉餐,因為他們的免疫系統還沒有受損。持續型感染的貓更需要細心照顧,因為免疫系統可能連正常數量的病原體都無法處理,尤其要避開乾飼料。和其他食物比起來,乾飼料除了營養品質差以外,也比較可能產生霉菌和細菌。
 
You should work with your veterinarian if you are feeding a persistently infected cat a raw meat diet. A few extra steps should be added when making the food. This method can also be used for any cat that may have a compromised immune system, such as a cat that is on steroids. When making the ground raw diet, the meat can be briefly baked before grinding to kill surface bacteria. In whole raw meats, pathogens that may have been introduced onto the meat are on the outside only. Place the meat – the recipe given at Feline Nutrition uses chicken thighs with bone, chicken liver and chicken hearts – in a baking dish and bake for about 10 to 15 minutes at 350 degrees Fahrenheit. Then remove the meat from the pan and immediately immerse it in cold water for a minute or two to stop the cooking process. This method will drastically reduce or eliminate any bacteria present. It will cook just the outside of the meat, but that's okay. Do not discard any liquid in the cooking pan; add it into the ground mix. Follow the rest of the recipe as you normally would.
 
如果你餵持續型感染的貓吃生肉,應該找一個願恴配合的獸醫。當你在製作貓食時,可以採取一些額外的安全措施。如果貓有免疫系統受損的問題,例如有在服用類固醇,也可以採取這些相同的安全措施。也就是在做生肉餐時,可以在絞肉之前先把肉稍微烤一下以殺死肉的表面細菌。在生肉中,可能會和肉有接觸的病原體只會存在肉的外面。把「貓科營養」的生肉食譜所會用到的雞肉、雞心和雞肝放進烤箱,用攝氏一百七十七度烤五到十分鐘。把肉拿出來後,立刻放入冷水中一到兩分鐘,以停止加熱。這個方式可以大大減少或消滅任何細菌。肉的表面會是熟的,但沒有關係。不要把烤肉時流出來的肉汁倒掉,要加入絞好的肉泥中。其他的製作步驟維持不變。
 
An alternative is to feed a commercially prepared raw diet that has been HPP, high pressure pasteurization, treated. This method uses pressure to kill bacteria without cooking the food. This method is highly effective at eliminating bacteria in foods and is also used for many foods intended for human consumption. In the US there are a number of national brands that use this method, so they are readily available.
 
另一個替代作法是餵貓吃有HPP高壓殺菌處理過的商業生肉。這個方法是用壓力去殺死細菌,不是用烹煮的方式。HPP在消滅食物細菌時極為有效,許多人吃的食物也會用此方式殺菌。美國有許多商業生肉品牌有用HPP殺菌方式。
 
Feeding your FeLV infected cat the best possible diet can greatly affect her overall health and ability to fight off the onset of FeLV associated disease. You don't have to give up feeding raw diets because of this diagnosis. Fresh raw food contains all the nutrients, enzymes, vitamins and amino acids your cat needs in an easily digested form. Good food contributes to a fast recovery and will provide a better quality of life for your sick cat.
 
餵白血病帶原貓吃最好的食物,可以給整體健康以及對抗白血病相關疾病的能力,帶來極為正面的影響。不需要因為貓身上有此病毒就放棄餵生肉。新鮮的生肉含有貓需要的所有養分、酵素、維他命和氨基酸,而且是以容易消化的型式存在。好食物不但對身體恢復健康有幫助,還可提高病貓的生活品質。
 
譯註:

我們家的生肉餐雖然擺盤不是很美,但也是有精心準備的。我會在生肉淋上一些罐頭魚湯,每天開不同的罐頭,算是給貓變化口味。而且我家的生肉餐也是有醬汁的,雖然是可怕的血水。當我把精心準備的食物親手端到貓面前請貓吃時,如果他們聞一聞後掉頭就走,我會立刻臉色大變&立刻把生肉收起來,留到下一餐吃。這麼好的食物,我還親手端到你面前請你吃,掉頭就走當然就不要吃啊,皮在癢!所以我家大多時候會乖乖吃肉肉(敲木頭),除非是肚子有毛吐不出來之類的時候會不吃。
 
已經不止一次聽到中獸醫說病貓不要吃生肉,因為是生冷的食物。我不明白為什麼生肉是生冷的食物,全宇宙的貓科動物不全都是吃生肉嗎?因為是生肉,所以生冷嗎?就因為那個「生」字嗎?那如果我們有把生肉加熱回溫到獵物本身的體溫,生肉依然是生冷的食物嗎?有溫度並不表示肉就是熟的啊,像我的體溫有三十七度,但我很肯定我身上的肉是生的XD。而且如本文所寫,生肉中的養分是以容易消化的型式存在,健康貓需要如此的養分,病貓當然更加需要。容易消化的型式存在的養分,表示身體可以做最有效的吸收,不是嗎?XD
 
祝大家週末愉快
 
Researcher Dr. Guillermo Díaz studied veterinary medicine at the Universidad Mayor de San Marcos in Lima, Perú. He currently practices in Lima and also provides veterinary services to a large number of local rescue organizations.
 
本文作者獸醫基勒摩.迪亞茲(Dr. Guillermo Diza) 就讀位於秘魯利馬的 Universidad Mayor de San Marcos 獸醫系。他目前在利馬執業,同時提供許多當地的動物救援組織獸醫服務。
 
  1. GD Norsworthy, SF Grace, MA Crystal and LP Tilley (editors), The Feline Patient, 4th ed, Wiley-Blackwell, October 2010, 184-186.
  2. EA Chandler, RM Gaskell and CJ Gaskell, Feline Medicine and Therapeutics, 3rd ed, Wiley-Blackwell, February 2004, 597-598.
  3. MR Lappin, Feline Internal Medicine Secrets, Hanley & Belfus, Inc., March 2001, 327.
  4. JR August, Consultas en Medicina Interna Felina, Inter-médica, 1993, 222-224.
  5. EA Chandler, RM Gaskell and CJ Gaskell, Feline Medicine and Therapeutics, 3rd ed, Wiley-Blackwell, February 2004, 597-598.
  6. GD Norsworthy, SF Grace, MA Crystal and LP Tilley (editors), The Feline Patient, 4th ed, Wiley-Blackwell, October 2010, 184-186.
  7. Norsworthy et. al., The Feline Patient.

 


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