Genetic Reproductive Abnormalities in Cats

Felines with reproductive genetic abnormalities have a variety of sexual differentials usually noted after puberty. The genitals of a feline may appear regular but are sterile, or the genitals are ambiguous and have an abnormal appearance.

Reproductive genetic abnormalities in cats are errors in a feline’s DNA that cause irregular sexual development. Reproductive traits are established inside the womb as the mother’s chromosomes gives a fetus male or female genitalia. At a specific stage in embryonic life, the genes carry out three major steps in sexual development: establish the chromosomal sex (give the fetus a XX female genes or XY male genes), development of gonadal sex (ovaries or testes), and development of phenotypic sex (penis or vagina). If there is an error in the chromosomal, gonadal, or phenotypic stage of sexual development, the feline is then born with a reproductive genetic abnormality. 

The symptoms of genetic reproductive abnormalities in cats vary with the nature of the condition, but are typically indicated by atypical development or function of the genitalia and related infertility.

Types

Persistent Mullerian Duct Syndrome

A common condition found in Persian cats, Persistent Mullerian Duct Syndrome is a condition describing a feline that has the male XY chromosomes and testes, but the Mullerian Duct System fails to recognize the presence of anti-mullerian hormone (Amh) secreted by the testis Sertoli cells. The Mullerian duct fails to regress despite the presence of the testis and begins forming female reproductive organs. Therefore, both male and female reproductive organs are found in one feline, creating additional reproductive problems as the cat ages. 

Androgen-Dependent Masculinization Disorder

Androgen-dependent masculinization disorder characterizes a male with XY chromosomes, bilaterally descended testes and the Mullerian Duct regresses, but the androgen-dependent masculinization fails, leaving the male with low testosterone levels. 

Female Pseudohermaphroditism

Female Pseudohermaphroditism is a condition characterized by a feline that has normal female ovaries and karyotype, but develop a masculine genitalia. A feline with this reproductive abnormality will have an enlarged clitoris that nearly resembles the penis of a male. 

Male Pseudohermaphroditism

Male Pseudohermaphroditism is a condition characterized by a feline that has testis and male karyotype, but the genitalia may be undescended, small or abnormal.  

Hypospadias

Hypospadias is the term used to describe an abnormal location of the urinary orifice and urethral wall. In this disorder, the prepuce and urethra fail to fuse, causing unusual placement of the urinary opening. 

Cryptorchidism

Cryptorchidism is the lateral or bilateral inability for a male cat to descend the testicles. 

Phimosis

Phimosis is the male feline’s inability to extrude the penis due to an abnormally small preputial opening. 

Paraphimosis

Paraphimosis is the male feline’s inability to retract the penis. 

The majority of reproductive gene abnormalities in cats happen inside the womb, before the feline is ever born. The genes that are responsible for giving a fetus male or female chromosomes, makes an error and a genetic abnormality forms. In other instances, a pregnant female is administered steroids of either progestogens or androgens, giving masculine traits to any female embryos. 

A reproductive genetic abnormality in a cat is usually noted as the cat matures or attempts to breed. A pet owner may bring the feline in after several breeding attempts have failed. The veterinarian will want to discuss your cat’s medical records, focusing on any hormonal treatments that were administered and discussing any information you have on the parents of that feline. The presence of a reproductive genetic abnormality may be found as the veterinarian completes a physical exam, but an ultrasound may need to be taken to view additional sex organs inside the feline. Further diagnostic testing might involve a hormone test to detect the levels of sex steroid hormone the feline is excreting, or a Karyotyping test to determine which chromosomes the cat is carrying. Both the hormone test and Karyotyping diagnostic exams are performed outside the clinic in a specialty clinic, which, for budget reasons, may not be practical for every cat owner.

The treatment options for reproductive genetic abnormalities in cats depends on the type of complication the cat has and the pet owner’s budget. Hormone therapy is often effective for patients with androgen-dependent masculinization disorders and sometimes undescended testicles. Cosmetic surgery can aid a feline’s appearance in enlarged or abnormal genitalia, but these surgeries are not often recommended for financial reasons. A hysterectomy or gonadectomy are the most commonly recommended surgical procedures, as the removal of these organs often prevents health complications down the road. 

If your cat has been diagnosed with a genetic reproductive abnormality, the veterinarian will likely ask you to consider removing the feline from any previously active breeding program. Other felines with hereditary reproductive genetic abnormalities are often spayed or neutered in order to prevent passing the gene mutation to future generations.