Cryptorchidism is failure of one or both testes to reach the scrotum. It is the most common congenital disorder of sex development in male dogs, and it matters clinically because a retained testis is far more likely to become neoplastic or to twist on its spermatic cord. Because the defect is heritable, affected dogs should be castrated, not bred.
Key facts
Cryptorchidism at a glance- Species and system: male dogs (also cats and horses); reproductive system.
- Cause: congenital failure of testicular descent with a heritable basis, described as sex-limited autosomal recessive; small breeds are over-represented.
- How common: 6.8% of 3,518 dogs castrated over 54 months at one clinic, and 3.2% of 5,476 dogs at a high-volume spay-neuter clinic.
- Classic presentation: a healthy young male with one empty side of the scrotum, usually the right; or an older cryptorchid dog with symmetrical alopecia and feminization from a Sertoli cell tumour.
- Timing: testes are normally scrotal by about 6 to 8 weeks; the diagnosis is confirmed at about 6 months.
- Treatment: bilateral castration. Hormonal treatment does not work reliably and is not recommended.
- Zoonotic or reportable: no.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prevention and breeding advice
- Prognosis
- Quick review
- Test yourself
- References
The full guide also has 5 tables, 3 figures, 3 self-test questions and 18 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.