Postmortem Examination of the Puppy and Kitten

CHAPTER 31 Postmortem Examination of the Puppy and Kitten

Puppy and Kitten Losses and Common Causes

The pediatric patient poses some unique challenges with respect to postmortem examinations. The quick succession of developmental phases is associated with a rapid change of commonly encountered diseases to which the diagnostic approach has to be tailored. The perinatal puppy or kitten is commonly worked up as an abortion with a simplified gross examination and emphasis on histopathology and microbiological testing. In contrast, animals older than 1 day of age require a thorough and complete necropsy because gross findings determine the menu of additional tests to be performed. Before weaning, health concerns extend to littermates, the dam, and often the breeding program in general. After weaning, the problem is usually viewed as that of an individual animal and rarely of the household.

Very few studies on necropsy findings of the puppy and kitten have been published in the primary literature. In puppies, most deaths occur before rather than after weaning, which amount to more than 20% and less than 5% of all puppy deaths in the first year of life, respectively. More than 50% of the preweaning puppy losses occur during the first week of life. Common causes in this age group are stillbirth (incidence of 2.2% to 4.6%), trauma, failure to thrive, or congenital anomalies resulting in death or euthanasia. In puppies older than 1 week, respiratory and gastrointestinal diseases are the most common primary issues identified on postmortem examination, followed by malnutrition. In kittens, 50% of neonatal mortalities are the result of stillbirth (incidence of 4.3% to 10.1%), and an additional 25% occur in kittens less than 1 week of age. Approximately 15% of all litters have at least one kitten with one or more congenital anomalies (nearly 10% of kittens born alive). Based on histopathological examination, more than half of the kitten deaths up to 4 months of age are caused by infectious diseases, with the majority having a viral etiology. Before weaning, feline herpesvirus 1 and feline calicivirus are the main causes; after weaning, it is feline parvovirus followed by feline infectious peritonitis (corona)virus.

Box 31-1 highlights commonly encountered causes of canine and feline mortality by age group.

BOX 31-1 Common causes of mortality by age group

In a large number of cases, a definitive diagnosis is not established, and the cases are released as idiopathic deaths or abortions. In a retrospective study on kitten losses during the first 4 months of life, this apparent failure to identify a specific cause was significantly associated with submission of tissue samples instead of the entire animal to the diagnostic laboratory for postmortem diagnostics. This underlines the fact that a thorough gross examination and collection of a complete set of samples for histopathology and microbiology are imperative to successful postmortem diagnostics. Gross lesions may be subtle and can be easily missed by an inexperienced examiner. This may result in collection of incomplete sample sets, which in turn will limit the spectrum of available diagnostic tests.

Sep 11, 2016 | Posted by in SMALL ANIMAL | Comments Off on Postmortem Examination of the Puppy and Kitten
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