Roth J A
Vet Clin North Am Small Anim Pract. 1987 May;17(3):603-16. doi: 10.1016/s0195-5616(87)50056-0.
"Wasting" or "fading" syndromes are common causes of puppy and kitten mortality. Numerous infectious and toxic, metabolic, or nutritional factors could potentially be responsible for wasting and death in young animals. Evidence has been presented that infectious canine hepatitis virus infection, beta-hemolytic streptococcus infection, and feline infectious peritonitis virus infection are responsible for a significant number of deaths due to wasting syndrome. However, many cases of wasting syndrome cannot be attributed to infectious agents or other specific etiologies. The thymus gland warrants special attention when one is evaluating an animal with a wasting syndrome because it is known that, in some species, neonatal thymectomy results in wasting and death. Unfortunately, most reports describing fading syndromes in puppies and kittens do not mention the gross or histologic appearance of the thymus gland at postmortem examination. When examining the thymus gland, one must keep in mind that the thymus may be hypoplastic owing to a congenital or genetic defect in its structure and function or it may be atrophic secondary to whatever is causing the fading syndrome. If a thorough history, clinical examination, and/or postmortem examination do not reveal a cause for the fading syndrome, then defective thymus function should be considered as a possible causative or contributing factor to the fading syndrome. In these cases, therapy designed to replace or improve the defective thymus function should be considered. At least one form of wasting syndrome in puppies (immunodeficient dwarfism) has been found to respond to short-term therapy with a thymus hormone (thymosin fraction 5) or with bovine growth hormone (which is thymotropic) in limited clinical trials. It is possible that other forms of wasting or fading syndromes would also respond to therapy with thymus hormone or growth hormone. Certain thymus hormones (thymopoietin pentapeptide, thymosin alpha 1, facteur thymique serique, and rabbit thymus acetone powder) and bovine growth hormone are commercially available. Before initiating therapy, one should consider that if the cause of the wasting syndrome is genetic, then successful treatment may perpetuate a genetic defect. More research (both basic and clinical) is needed to determine the role of thymus gland dysfunction in fading syndromes of puppies and kittens and if therapy with one or several of the thymus hormones or with growth hormone could reverse the symptoms of wasting.
“消瘦”或“衰弱”综合征是幼犬和幼猫死亡的常见原因。许多感染性、中毒性、代谢性或营养性因素都可能导致幼小动物消瘦和死亡。已有证据表明，犬传染性肝炎病毒感染、β溶血性链球菌感染和猫传染性腹膜炎病毒感染是导致大量因消瘦综合征死亡的原因。然而，许多消瘦综合征病例无法归因于感染因子或其他特定病因。在评估患有消瘦综合征的动物时，胸腺值得特别关注，因为已知在某些物种中，新生期胸腺切除会导致消瘦和死亡。不幸的是，大多数描述幼犬和幼猫衰弱综合征的报告在尸检时都未提及胸腺的大体或组织学外观。检查胸腺时，必须记住胸腺可能由于其结构和功能的先天性或遗传性缺陷而发育不全，或者可能继发于导致衰弱综合征的任何因素而萎缩。如果详细的病史、临床检查和/或尸检未揭示衰弱综合征的病因，那么应考虑胸腺功能缺陷是衰弱综合征的可能病因或促成因素。在这些情况下，应考虑设计旨在替代或改善缺陷胸腺功能的治疗方法。在有限的临床试验中，已发现至少一种幼犬消瘦综合征（免疫缺陷侏儒症）对胸腺激素（胸腺素5组分）或牛生长激素（具有促胸腺作用）的短期治疗有反应。其他形式的消瘦或衰弱综合征也可能对胸腺激素或生长激素治疗有反应。某些胸腺激素（胸腺生成素五肽、胸腺素α1、胸腺血清因子和兔胸腺丙酮粉）和牛生长激素有商业供应。在开始治疗之前，应考虑到如果消瘦综合征的病因是遗传性的，那么成功的治疗可能会使遗传缺陷持续存在。需要更多的研究（基础研究和临床研究）来确定胸腺功能障碍在幼犬和幼猫衰弱综合征中的作用，以及使用一种或几种胸腺激素或生长激素治疗是否可以逆转消瘦症状。
