Cat Development

Introduction

Cat with 6 toes

Cat Ovary

Cats (Felis catus) are seasonally polyestrous animals that have multiple estrous cycles only during certain periods of the year.

Links: Estrous Cycle | Toxoplasmosis | Category:Cat

---

Some Recent Findings

Follicular growth monitoring in the female cat during estrus "This study was designed to describe follicular dynamics by transabdominal ultrasonography. Secondly, the stage of follicular growth was associated to behavioral and vaginal changes. Ovarian ultrasonography was performed during nine anovulatory and 12 ovulatory cycles. Forty-eight follicles were followed during anovulatory cycles: on the first day of estrus behavior, 4.8 ± 0.2 follicles (2 to 7 per female) of 2.3 ± 0.01 mm mean diameter were present. Follicular growth continued at a rate of 0.2 ± 0.04 mm per day. At least one follicle in the cohort reached a diameter greater than 3.0 mm." Development of external genitalia in fetal and neonatal domestic cats "The female urogenital folds budded from each side of the genital tubercle and, gradually extended to the tip of the genital tubercle by the 6.8 cm stage in crown-rump length. Then, the well-developed urogenital folds ensheathed completely the genital tubercle to form the prepuce of clitoris and the labia, flanking the external opening of vagina as the folds of skin which were equivalent to the labia minora in humans. The genital swellings known to become the labia majora in humans were clearly recognized in the caudolateral region of the genital tubercle during the fetal stage. These swellings became flat and obscure after birth. Thus, in cats the genital swellings did not join to the formation of the labia in the same way as in humans. The sex difference in the external genitalia was first observed at the 3.2-3.3 cm stages. In the male, the anogenital raphe appeared and the caudal portion of the genital swellings moved and fused each other at the caudal region of the genital tubercle. In the female, both features were not easy to observe."

Developmental Timeline

Cat oocyte calcium concentration

Twenty-two stages have been described for the prenatal development of the domestic cat.

The following data on early development is based upon the time after copulation

oviduct embryo development

• 64 hours - 1 to 4 cells (17 of 20; 85.0%)

• 76 hours - 5 to 8 cells (18 of 28; 64.3% )

• 100 hours - 9 to 16 cells (14 of 24; 58.3%)

• 124 hours - morulae (15 of 21; 71.4% )

uterine embryo development

• 148 hours - compact morulae or early blastocysts

Oocyte and Spermatozoa

The following scanning electron micrographs are from a recent paper on fresh and frozen cat oocytes. Scale bar is 10 microns.

Genetics

Lineage: Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Coelomata; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Laurasiatheria; Carnivora; Feliformia; Felidae; Felinae; Felis; Felis catus

• There is not much genomic sequencing information available for the cat.
• The entire mitochondrial genome 17,009 bp has been sequenced.

Links: Mitochondrial Genome

Placenta

Links: Comparative Placentation - Cat

Historic Images

• 
• 
• 

References

Articles

<pubmed>19151510</pubmed> <pubmed>19262023</pubmed> <pubmed>18405438</pubmed> <pubmed>12606460</pubmed> <pubmed>11841356</pubmed>

Search Pubmed: cat development | feline development

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

---

Cite this page: Hill, M.A. (2026, April 17) Embryology Cat Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Cat_Development

What Links Here?

© Dr Mark Hill 2026, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G