Term
| . What are the reasons to perform necropsies? |
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Definition
- establish causes of death
- verify a pre-mortem dx
- establish the efficacy or lack of efficacy of tx prior to the animal’s demise
- determine whether other animals may be at risk for infxn or injury or environmental hazards |
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Term
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Definition
- a buffered solution
most widely used fixative for preserving tissues |
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Term
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Definition
- a mixture of buffered formalin and formaldehyde
- best for larger tissues, or those that are thicker |
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Term
| Cornified epithelial cells definition |
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Definition
| – large and flattened with small or absent nuclei, caused by rising levels of estrogen |
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Term
| Parabasal cells definition |
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Definition
– the smallest epithelial cells seen on a typical vaginal smear.
- Round or nearly round and have a high nuclear to cytoplasmic ratio.
- Prevalent on smears taken during diestrus and anestrus and not uncommon during early proestrus. Conspicuously absent during estrus. |
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Term
| Intermediate cells definition |
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Definition
- vary in size and shape but typically have a diameter two to three times that of parabasal cells.
- Subclassified into
small intermediates – nearly round or oval shape with large, prominent nuclei
large intermediates – polygonal shape with a small nuclear/cytoplasmic ratio
- prevalent during all stages of the cycle except estrus |
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Term
| Intermediate cells definition |
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Definition
- vary in size and shape but typically have a diameter two to three times that of parabasal cells.
- Subclassified into
small intermediates – nearly round or oval shape with large, prominent nuclei.
large intermediates – polygonal shape with a small nuclear/cytoplasmic ratio.
- prevalent during all stages of the cycle except estrus |
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Term
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Definition
– the largest cells seen on a vaginal smear
– polygonal in shape and distinctly flat, sometimes have the appearance of being rolled up.
– Nuclei are either absent or pyknotic (very small and dark).
– Superficial cells w/o nuclei are often referred to as being “fully cornified”.
– Often seen in large sheets or strings |
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Term
| Other cells seen on vaginal smears |
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Definition
Aside from the epithelial cells described above, a number of other cells are seen on vaginal smears.
•Erythrocytes are usually observed in large numbers during proestrus. In some bitches, they are seen through estrus and even into early diestrus.
•Neutrophils are often abundant in smears taken during early diestrus, and are not uncommon at other stages, though rare during estrus. Moderate numbers of neutrophils are a common, though not consistent feature of normal canine vaginal smears and not by themselves indicative of vaginitis.
•"Foam cells" is a term given to non-descript epithelial cells containing numerous vacuoles that are typically seen on smears prepared during anestrus |
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Term
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Definition
| very small and dark nucleus |
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Term
| What do the cytological changes reflect and what do they predict? |
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Definition
Cytologic changes through the canine estrous cycle reflect changes in blood concentrations of estrogen
Since cytologic changes reflect the underlying endocrine events of the cycle, they are almost always a better predictor of the "fertile time" and gestation length than are behavioral or physical signs. The period of receptivity to a male varies considerably among bitches; some bitches are receptive well before and after the period of potential fertility. Similarly, signs such as "proestrus bleeding" are often unreliable indicators; some bitches bleed very little and other show bleeding through estrus and into diestrus. |
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Term
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Definition
| Basal cells are the youngest cells of the vaginal epithelium and serve as precursors of the other epithelial cell types. They are located along the basement membrane and rarely are seen in exfoliative cytology. These cells have a high nuclear to cytoplasmic (N/C) ratio, a round nucleus, and a small amount of basophilic cytoplasm. |
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Term
| Parabasal cells definition 2 |
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Definition
| These cells are the smallest cells vaginal epithelial cells seen in cytologic preparations. Parabasal cells also have a high N/C ratio, round nucleus, and basophilic cytoplasm. They are uniform in size and shape. Parabasal cells also may contain cytoplasmic vacuoles and are known as foam cells. The function of the vacuoles in these cells is unknown. Large numbers of foam cells may be found in prepubertal samples and should not be confused with neoplastic cells. |
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Term
| Intermediate cells definition 2 |
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Definition
| These cells vary in size but are usually two times the size of parabasal cells. Their N/C ratio is decreased and they have large amounts of blue-green, keratinized cytoplasm. Their borders are round to irregular and folded. Intermediate cells also may be subclassified as superficial intermediate or transitional intermediate cells according to their stage in the reproductive cycle. |
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Term
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Definition
| Superficial cells are the oldest vaginal epithelial cells. They either have small, round, pyknotic nuclei or lack a nucleus if they are cornified. Their cytoplasm is abundant, blue-green, and keratinized. Cell margins are angular with folded edges. |
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Term
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Definition
| inflammation of the uterus |
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Term
| . In addition to vaginal epithelial cells, what cells can you see on a vaginal smear? When are these normally seen? |
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Definition
• Erythrocytes are usually observed in large numbers during proestrus. In some bitches, they are seen through estrus and even into early diestrus.
• Neutrophils are often abundant in smears taken during early diestrus, and are not uncommon at other stages, though rare during estrus. Moderate numbers of neutrophils are a common, though not consistent feature of normal canine vaginal smears and not by themselves indicative of vaginitis.
• "Foam cells" is a term given to non-descript epithelial cells containing numerous vacuoles that are typically seen on smears prepared during anestrus |
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Term
| . What type of cell is a parabasal, intermediate, superficial, cornified cell? |
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Definition
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Anestrus |
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Definition
Anestrus
Intermediate and parabasal cells predominate in smears taken during anestrus. Superficial cells are absent or found in very small numbers. Neutrophils may also be present or absent. |
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Term
| . List the characteristics of semen samples that should be determined in the clinic laboratory. |
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Definition
A large number of assays have been developed and advocated for assessing semen quality. Inevitably, at least three core parameters are evaluated:
• Sperm concentration and total sperm in the ejaculate. Total sperm is determined by multiplying concentration (sperm per ml) by ejaculate volume (ml).
• Sperm motility is usually assumed to be the percentage of sperm that are progressively motile. A progressively motile sperm swims briskly forward in a relatively straight line, as opposed to moving in circles. In some cases (e.g. with human sperm), total motility, or the percentage of sperm that are wiggling at all, is also recorded.
• Sperm morphology. The best samples of semen inevitably contain some sperm that have abnormal structure, such as bent tails or misshapen heads. To obtain a standard measure of sperm morphology, the percentage of sperm with normal shape and size is determined. It can also be useful to classify the abnormal sperm as to type of defect. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Proestrus |
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Definition
Proestrus
Serum concentrations of estrogen rise during proestrus, leading to capillary breakage and leakage of red blood cells through uterine epithelium, as well as proliferation of the vaginal epithelium.
Examination of vaginal smears from early to late proestrus will reveal a gradual shift from intermediate and parabasal cells to superficial cells. Typically, red blood cells are present in large numbers and neutrophils are commonly observed. Large numbers of bacteria are also often present.
In some bitches, proestrus can persist for two to three weeks. In such cases, prolonged lack of receptivity may suggest the need to artificially inseminate or force-breed the animal. Examining vaginal smears in such cases will alleviate such concerns - certainly, if more than a very small percentage of cells are parabasals and small intermediates, breeding is a waste of time. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Estrus |
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Definition
Estrus
The defining characteristic of cytologic estrus is the predominance of superficial cells. Most, but not all, bitches will undergo full cornification, and the smear will reveal a monotonous pattern composed almost exclusively of anucleate superficial cells.
If the bitch has been bred within a day of preparing a vaginal smear, it is quite likely that sperm will be observed among the epithelial cells. Indeed, careful examination for sperm in a smear taken within a few hours of an alleged breeding is a fairly reliable means of confirming or denying such an incident. In the image below, an intact sperm (left panel) and a sperm head (right panel) are present next to superficial cells. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Diestrus |
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Definition
Diestrus
The onset of diestrus is marked by a precipitous decline in the number of superficial cells and reappearance of intermediate and parabasal cells. Most commonly, the cellular profile changes within a single day from essentially 100% superficial cells to less than 20% superficial cells. However, it is best to confirm the onset of diestrus by examining a smear prepared on diestrus day 2.
The significance of identifying the onset of diestrus is that it is a considerably more accurate predictor of the time of ovulation, and hence gestation length, than sexual behavior.
Dogs ovulate 5-7 days prior to the onset of diestrus (7-9 days after the preovulatory LH surge), and hence, gestation length is usually 57 + 1 day from the onset of diestrus day 1. The period of behavioral estrus is variable, and often extends up to several days before and/or after cytologic estrus. Gestation lengths calculated from the onset or cessation of receptivity are correspondingly inaccurate. The onset of diestrus also correlates well with loss of fertility, and breedings after the diestrus shift are rarely fertile. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Anestrus |
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Definition
Anestrus
Intermediate and parabasal cells predominate in smears taken during anestrus. Superficial cells are absent or found in very small numbers. Neutrophils may also be present or absent. |
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Term
| . List the characteristics of semen samples that should be determined in the clinic laboratory. |
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Definition
A large number of assays have been developed and advocated for assessing semen quality. Inevitably, at least three core parameters are evaluated:
• Sperm concentration and total sperm in the ejaculate. Total sperm is determined by multiplying concentration (sperm per ml) by ejaculate volume (ml).
• Sperm motility is usually assumed to be the percentage of sperm that are progressively motile. A progressively motile sperm swims briskly forward in a relatively straight line, as opposed to moving in circles. In some cases (e.g. with human sperm), total motility, or the percentage of sperm that are wiggling at all, is also recorded.
• Sperm morphology. The best samples of semen inevitably contain some sperm that have abnormal structure, such as bent tails or misshapen heads. To obtain a standard measure of sperm morphology, the percentage of sperm with normal shape and size is determined. It can also be useful to classify the abnormal sperm as to type of defect. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Proestrus |
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Definition
Proestrus
Serum concentrations of estrogen rise during proestrus, leading to capillary breakage and leakage of red blood cells through uterine epithelium, as well as proliferation of the vaginal epithelium.
Examination of vaginal smears from early to late proestrus will reveal a gradual shift from intermediate and parabasal cells to superficial cells. Typically, red blood cells are present in large numbers and neutrophils are commonly observed. Large numbers of bacteria are also often present.
In some bitches, proestrus can persist for two to three weeks. In such cases, prolonged lack of receptivity may suggest the need to artificially inseminate or force-breed the animal. Examining vaginal smears in such cases will alleviate such concerns - certainly, if more than a very small percentage of cells are parabasals and small intermediates, breeding is a waste of time. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Estrus |
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Definition
Estrus
The defining characteristic of cytologic estrus is the predominance of superficial cells. Most, but not all, bitches will undergo full cornification, and the smear will reveal a monotonous pattern composed almost exclusively of anucleate superficial cells.
If the bitch has been bred within a day of preparing a vaginal smear, it is quite likely that sperm will be observed among the epithelial cells. Indeed, careful examination for sperm in a smear taken within a few hours of an alleged breeding is a fairly reliable means of confirming or denying such an incident. In the image below, an intact sperm (left panel) and a sperm head (right panel) are present next to superficial cells. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Diestrus |
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Definition
Diestrus
The onset of diestrus is marked by a precipitous decline in the number of superficial cells and reappearance of intermediate and parabasal cells. Most commonly, the cellular profile changes within a single day from essentially 100% superficial cells to less than 20% superficial cells. However, it is best to confirm the onset of diestrus by examining a smear prepared on diestrus day 2.
The significance of identifying the onset of diestrus is that it is a considerably more accurate predictor of the time of ovulation, and hence gestation length, than sexual behavior.
Dogs ovulate 5-7 days prior to the onset of diestrus (7-9 days after the preovulatory LH surge), and hence, gestation length is usually 57 + 1 day from the onset of diestrus day 1. The period of behavioral estrus is variable, and often extends up to several days before and/or after cytologic estrus. Gestation lengths calculated from the onset or cessation of receptivity are correspondingly inaccurate. The onset of diestrus also correlates well with loss of fertility, and breedings after the diestrus shift are rarely fertile. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Anestrus |
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Definition
Anestrus
Intermediate and parabasal cells predominate in smears taken during anestrus. Superficial cells are absent or found in very small numbers. Neutrophils may also be present or absent. |
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Term
| . List the characteristics of semen samples that should be determined in the clinic laboratory. |
|
Definition
A large number of assays have been developed and advocated for assessing semen quality. Inevitably, at least three core parameters are evaluated:
• Sperm concentration and total sperm in the ejaculate. Total sperm is determined by multiplying concentration (sperm per ml) by ejaculate volume (ml).
• Sperm motility is usually assumed to be the percentage of sperm that are progressively motile. A progressively motile sperm swims briskly forward in a relatively straight line, as opposed to moving in circles. In some cases (e.g. with human sperm), total motility, or the percentage of sperm that are wiggling at all, is also recorded.
• Sperm morphology. The best samples of semen inevitably contain some sperm that have abnormal structure, such as bent tails or misshapen heads. To obtain a standard measure of sperm morphology, the percentage of sperm with normal shape and size is determined. It can also be useful to classify the abnormal sperm as to type of defect. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Proestrus |
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Definition
Proestrus
Serum concentrations of estrogen rise during proestrus, leading to capillary breakage and leakage of red blood cells through uterine epithelium, as well as proliferation of the vaginal epithelium.
Examination of vaginal smears from early to late proestrus will reveal a gradual shift from intermediate and parabasal cells to superficial cells. Typically, red blood cells are present in large numbers and neutrophils are commonly observed. Large numbers of bacteria are also often present.
In some bitches, proestrus can persist for two to three weeks. In such cases, prolonged lack of receptivity may suggest the need to artificially inseminate or force-breed the animal. Examining vaginal smears in such cases will alleviate such concerns - certainly, if more than a very small percentage of cells are parabasals and small intermediates, breeding is a waste of time. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Estrus |
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Definition
Estrus
The defining characteristic of cytologic estrus is the predominance of superficial cells. Most, but not all, bitches will undergo full cornification, and the smear will reveal a monotonous pattern composed almost exclusively of anucleate superficial cells.
If the bitch has been bred within a day of preparing a vaginal smear, it is quite likely that sperm will be observed among the epithelial cells. Indeed, careful examination for sperm in a smear taken within a few hours of an alleged breeding is a fairly reliable means of confirming or denying such an incident. In the image below, an intact sperm (left panel) and a sperm head (right panel) are present next to superficial cells. |
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Term
| Describe the physical and cytological signs that are seen with each of the following stages of the canine estrus cycle. How long do each of these stages last on average? Diestrus |
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Definition
Diestrus
The onset of diestrus is marked by a precipitous decline in the number of superficial cells and reappearance of intermediate and parabasal cells. Most commonly, the cellular profile changes within a single day from essentially 100% superficial cells to less than 20% superficial cells. However, it is best to confirm the onset of diestrus by examining a smear prepared on diestrus day 2.
The significance of identifying the onset of diestrus is that it is a considerably more accurate predictor of the time of ovulation, and hence gestation length, than sexual behavior.
Dogs ovulate 5-7 days prior to the onset of diestrus (7-9 days after the preovulatory LH surge), and hence, gestation length is usually 57 + 1 day from the onset of diestrus day 1. The period of behavioral estrus is variable, and often extends up to several days before and/or after cytologic estrus. Gestation lengths calculated from the onset or cessation of receptivity are correspondingly inaccurate. The onset of diestrus also correlates well with loss of fertility, and breedings after the diestrus shift are rarely fertile. |
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