Disease of the Reproductive Tract of the Male Cat

Table of Contents

General Considerations

Surgical pathology is a field that combines the traditional discipline of pathology with a keen sense of the clinical picture and prognosis. It is generally focused on the individual animal and thus concentrates on companion animals - mostly dogs and cats. This 'chapter' focuses on materials that would be sent by a clinician to laboratory specializing in surgical biopsies. An accurate diagnosis is fundamental to prognosis, so this section concentrates on reaching an accurate diagnosis so that the prognosis will become obvious.

Diagnoses are best made with a clear understanding of normal functional anatomy, so a section on normal anatomy is included. The link is above.

There are many conditions and diseases that are of a congenital nature, and while many of these are of little consequence, some are important. There is a page dedicated to ambiguous development and this can be accessed from the link on the left.

The vast majority of male cats are castrated before they reach puberty. As a result, very few lesions are to be found in what remains of the male reproductive tract. The literature on reproductive disease is not voluminous but will be cited here where appropriate.

The vast majority of the cases illustrated here are those seen through the surgical biopsy service of Yager-Best Veterinary Surgical Pathology, Guelph, Ontario, (aka YagerBest Histovet) and I am indebted to Drs Julie Yager and Susan Best for the use of this material. The designation YB and number is the case number of the particular sample.

Surgical pathologists are asked to examine materials from the reproductive tract or where the components of the reproductive tract once were. The sample is usually provided as a surgical specimen and is small enough to warrant no further processing than placing in a small jar of formalin ensuring the volume of fluid to sample is at least 10 to 1. Even when the whole testes and epididymides are provided, they are sufficiently small in the cat to be placed in the jar whole. There is no need to cut or section the specimen unless it is thicker than 1 cm.  It is common practice for technicians to trim tissues for histopathology so a whole specimen, less the trimmed tissue, remains available for the pathologist to examine if necessary. In those cases were the clinical history do not match the histological findings, examining the fixed tissue is an essential component of arriving at the correct diagnosis.

Castration is such a common procedure and the scrotal contents so efficiently packaged that it complications are rare and surgical specimens are rarely taken. It is worthwhile though listing some of the complications so that there is a list of differential diagnoses (diagnostic hypotheses) to consider should such a specimen be received. This is a short list of complications of which I am aware.

• anaesthesia
• haemorrhage
• infection
• foreign body reaction to entrapped hair.
• adhesions
• Extratesticular testicular tumours
• Priapism
• Testicular remnants

Most of this list is self explanatory.

Extratesticular testicular tumours will be dealt with below. Briefly, previously castrated cats have developed interstitial cell tumours, in many cases, many years after being castrated. This is very rare.

Testicular remnants will be discussed below in the section on ‘Disease within the abdomen’

Disease of the scrotal skin

 It has been often said that scrotal skin reacts just like the skin elsewhere, so it is not ‘special’. This is true, or at least is considered so. Listed below are some examples of conditions in the YagerBest database.

Masses (including neoplasms)

One may expect any neoplasm of skin to affect this region. Likewise, non neoplastic lesions would surely occur. Here are some examples of lesions that can occur

Sebaceous hamartoma

There is one case described as a sebaceous hamartoma, a proliferation of otherwise normal sebaceous glands in a location where they would be expected to occur (YB157921).

Sebaceous hyperplasia

There is one case of focal sebaceous hyperplasia in the YB database. The cat had hyperplasia of the sebaceous glands of the flank also (YB86116)

Figure 1 : Scrotal sebaceous hyperplasia and distended sebaceous ducts.

Trichoblastoma (basal cell tumour)

There is one case of a trichoblastoma occurring in the scrotum (YB61156)

Scrotal dermatitis (non neoplastic)

Dermatitis of the scrotum can be either a local or systemic primary cutaneous disease, or secondary to lesions within the scrotal cavity. In general, it is best to consider intrascrotal disease in any inflammatory lesion of the scrotum. This does not mean that scrotal dermatitis is always secondary, as it is clearly not, but one neglects an internal cause to ones peril.

Physicochemical disease of the scrotum

Lesions of the scrotum with a reaction pattern of a physiochemical injury occur periodically. The caudal end of a cat is ‘exposed’ to injury and abscess formation secondary to fight (or flight!) wounds, as a pursuing cat bites and scratches a fleeing feline. Lesions of a pyotraumatic nature are occasionally seen also. One such example was one (YB8277) where the scrotum was covered in a crust covering granulation tissue. Trauma was suspected. In another case (YB2957), there was superficial necrosis of the penis and scrotal skin suggesting a local burn or scald.

Scrotal dermatitis occurs secondary to extension from intrascrotal disease. There is 1 case where this was suspected. There was a severe peri and testicular rupture and necrosis (YB93766).

Subepidermal vesicular dermatosis.

There is one case of this rare disease, thought to be a type of erythema multiforme or drug eruption, in the YB database (YB123722)

Figure 2 : Subepidermal vesicular dermatosis, likely a drug eruption.

Figure 3 : Subepidermal vesicular dermatosis, same case as Fig 2.

Dermatitis secondary to intrascrotal disease

Involvement of the scrotal skin can be secondary to intrascrotal disease, especially of the tunics (see below) and periorchitis.

Disease of the Scrotal Contents

 Tunics (vaginal tunic and testicular capsule)

Fluid accumulation

Hematocele

An accumulation of blood within the cavity of the tunica vaginalis is haematocele. Local trauma is the most likely cause.

Hydrocele

An accumulation of fluid within the cavity of the tunica vaginalis is hydrocele. This fluid is typically a transudate and identical to ascitic fluid. It will form for all the same reasons that ascites formes.

Inflammation (periorchitis)

Feline infectious peritonitis

Feline infectious peritonitis, caused by the coronavirus, feline infectious peritonitis virus, is one of the more common lesions of the serosal surfaces of the tunics. The tunic vaginalis is an extension of the peritoneal cavity, so it only makes sense that FIP will affect this area as well.

Figure 4 : Feline infectious peritonitis of the tunica vaginalis.

Penetrating wounds

Any penetrating wound of the scrotum can result in periorchitis, and it tends to be fibrinosuppurative. Differentiation from feline infectious peritonitis can be a challenge, but the hallmark large numbers of plasma cells are usually absent in the underlying connective tissues of the serosa. Inflammation of the tunics as a complication castration when there is infection or a reaction to hair can have an identical appearance. As will most surgical biopsies, a good history will lead you to the correct diagnosis.

Figure 5 : Histology of fibrinosuppurative periorchitis

Secondary to disease of the testis and epididymis

Epididymitis is one of the most common associated lesions with periorchitis. Epididymitis in the cat is extremely rare, however, so this is not an expected cause of periorchitis. There is on case of epididymitis in the YB database (YB15491). There was a severe periorchitis as well.

Periorchitis, testicular rupture and testicular necrosis (YB93766) was also seen in one case, but no specific cause was identified. Trauma, with rupture of the testis, inflammation and necrosis was suspected. 

Disease of the testis

Testicular atrophy/necrosis

The retained testis is hypoplastic, virtually by definition, as the raised temperature compared to scrotal testes prevents spermatogenesis. Further details are listed below under cryptorchidism. Testes retained in the abdomen, despite their hypoplastic nature, also undergo a process of degeneration and they will atrophy. The process is a degenerative one, the histological appearance is that of degeneration, but the macroscopic change is atrophy – this is the convention used to define these particular terms as they apply to the testis. For further information about testicular degeneration, see the section below.

The process of degeneration of a retained testis is thought to mirror the degenerative changes of a scrotal testis, although the lack of spermatogenesis or spermatic arrest already exists. Tubules shrink in size, the basement membranes become wavy, and with time, the Sertoli cells disappear so that all that remains is an outline of the previous tubule. The epididymis remains as a hypoplastic tube, but over time, it too may ‘fade’ and only a vestige remains. This usually occurs after the testis becomes completely degenerate. On occasion, the testis suffers a severe process where it dies, and the necrosis is assumed to be a vascular event. Torsion of the retained testis can occur and both testis and epididymis will be affected.

 

Figure 7 : Retained testis that is completely necrotic, presumably from torsion.

 

  

Figure 8 : Higher magnification of Fig 7.

 

Cystic interstitial cell tumour

One of the differential diagnoses of cystic rete testis is a rete cyst. Cystic interstitial cell tumour can, on rare occasions, be cystic and confused with a true cyst.

 Testicular atrophy – degeneration.

The convention in reproductive pathology is to call a reduction in size of the testis, atrophy. This is a term used to describe a macroscopically small testis that once was larger. Typically, an atrophic testis has a normally sized epididymis so the proportions change. The capsule of the testis is white and the testicular vessels in the tunica albuginea are less obvious or missing. On cut section, an atrophic testis may be a red brown colour, or could contain bands of or diffuse white areas of fibrosis. Mineralization can also occur, often beginning at the mediastinum and extending outward.

Degeneration is a microscopic change, and a process. The earliest stages of degeneration are seen as spermatogenic arrest, and increased single cell death of the germinal cells. Spermatid desquamation, multinucleated spermatid giant cells and vacuolation of Sertoli cells are early changes. Spermatocytes are often also involved and eventually, no spermatogenesis may be visible, so that the tubules are lined by Sertoli cells only. In the early phases, the tubules reduce in diameter and the basement membranes become undulating or wavy. With progressively severe degeneration, Sertoli cells die, and when this occurs, all that remains is an outline of the basement membranes. Interstitial endocrine cells often remain, but as there is constant cross talk between interstitial endocrine cells, Sertoli cells and spermatocytes, loss of one group will eventually result in loss of all. Interstitial endocrine cells may appear to be more numerous in some instances, but this is not an absolute increase in cells, but rather a relative increase as the area that is tubules is reduced. Interstitial endocrine cells can contain lipochrome pigment and this may become more obvious.

Figure 13 : Subgross photograph of testicular degeneration, note prominent fibrous tissue septae within the testis.

Figure 14 : Testicular degeneration; note the thick capsule, interstitial fibrous tissue, and tubules with a prominent lumen.

 

Figure 15 : Testicular degeneration; note relative prominence of interstitial endocrine cells, and tubules with a distended lumen. Spermatogenesis is arrested at the primary spermatocyte stage.

 

Figure 16 .: Testicular degeneration; seminiferous tubules are mostly 'Sertoli cells only'

 

The causes of testicular atrophy – degeneration are legion. A more complete list is available in the texts, Pathologic basis of Veterinary Disease, and Pathology of Domestic Animals. The short list includes heat from fever, drugs, poor health and debility, and advancing age. Elcock and Schoning (1984) identified degenerative change in feline testes with age. Hypervitaminosis A was identified as a nutritional cause (Seawright et al 1970)

Elcock LH, Schoning P. (1984) Age-related changes in the cat testis and epididymis. Am J Vet Res. 45(11):2380-4.

Seawright AA, English PB, Gartner (1970) Hypervitaminosis A of the cat. Adv Vet Sci Comp Med 14: 1-27.

Orchitis

From a pathology point of view, orchitis is inflammation of the testis. Clinically though, orchitis is used to indicate any disease of the scrotal contents, including periorchitis, epididymitis and orchitis itself. Orchitis is, in general, a rare finding.

While feline infectious peritonitis is primarily a disease of serosal surfaces (at least in the so called wet form), there are rare instances where FIP manifests as a primary orchitis. Foster et al (1996) and Sigurdardottir et al (2001) reported one case each. Lawler and Evans (1993) reports on a cat with an hepatic cavernous lymphangioma that also had an enlarged testis. It had a unilateral necrotic orchitis. Lewis and O'Brien (2010) report a single case identified on ultrasound and subsequently confirmed on histology.

Figure 17 : Severe interstitial orchitis due to Feline infectous peritonitis virus.

Published reports

Foster RA, Caswell JL and Rinckardt N. (1996). Necrotic and fibrinous interstitial orchitis in a cat with feline infectious peritonitis. Canadian Veterinary Journal 37: 681-682.

Lewis KM, O'Brien RT: (2010) Abdominal ultrasonographic findings associated with feline infectious peritonitis: a retrospective review of 16 cases. J Am Anim Hosp Assoc 2010 46: 152-160.

Sigurdardottir OG, Kolbjornsen O, Lutz H.J (2001) Orchitis in a cat associated with coronavirus infection. Comp Pathol. 124(2-3):219-22
Lawler DF, Evans RH. (1993) Multiple hepatic cavernous lymphangioma in an aged male cat. J Comp Pathol. 109(1):83-7.

Necrosis

Testicular necrosis is where there is death of whole regions of the testis. It usually affects the whole testis, but in some species can be a segmental disease. The blood flow to the testis is via a tortuous testicular artery that is part of the pampiniform plexus. By the time the blood reaches the testis, it is barely pulsile and has a lower pressure than normal arterial pressure. A slight change in flow will result in ischemia. This fortunately does not occur very often. Necrosis of the testis is particularly seen in retained (or cryptorchid) testes, and is assumed to occur because of an avascular event, particularly torsion. Torsion of a fully descended testis is virtually unheard of in all species expect for the horse.

 

Torsion of the testis can produce venous infarction, with both testis and epididymis becoming hemorrhagic. Death of the testis is an expected sequel. When only the testis is affected, some vascular event apart from torsion should be invoked.  Oedema, inflammation, or anything reducing testicular arterial pressure, or increasing venous pressure could induce necrosis.

 

There is one case in the YB files (YB93766) of testicular necrosis, and a catastrophic local event was suspected, as there was also rupture of the testis.

 

Testicular rupture

Pressure sufficient to overcome the ability of the tunica albuginea to contain the testicular parenchyma will result in rupture. Local blunt force trauma could do this, but it is a rare event. The outcome of testicular rupture is twofold. There will be severe trauma and the formation of a hematocele, and inflammation will occur. Rupture and exposure of the germinal cells, that are outside the blood testis barrier will induce a foreign body type reaction (granulomatous) and immune mechanisms will be mediated to induce a further reaction. This is particularly the case in postpubertal animals. There is one case in the YB files (YB93766) 

Testicular neoplasia

In general, testicular neoplasia in cats is very rare. The literature contains only individual case reports or reports of low numbers.

All species have a similar range of primary testicular neoplasms, including germ cell tumors (seminoma, teratoma), sex cord/stroma tumors (interstitial cell tumors, Sertoli cell tumors), and epithelial tumors (rete adenoma and carcinoma). The number of cases reported is so low that no accurate prognosis is possible, although the lack of reports of metastatic tumors suggests this is an even rarer event.

Germ cell tumors

Teratoma

Teratomas are the most differentiated of the germ cell tumors. By definition, they should contain elements from all germ cell layers of the embryo, including endoderm, mesoderm, ectoderm and neuroectoderm. In the veterinary world, two or even three representatives of these layers are all that is required.

Miyoshi et al (2001) and Silva (2002) each report a teratoma in a cat. The testis was retained in each case. One had an omental metastasis.

Nagumo et al (2024) reported a teratoma in a scrotal testis. There was extension of the mass in the abdomen/retroperitoneum to the diaphragm.

Seminoma

Seminomas are amongst the least differentiated of primary testicular neoplasms, and they are round cell tumors that are very anaplastic and have a high mitotic rate. Cotchin (1984) reports a possible seminoma. Carpenter et al (1987) reported a malignant seminoma in a 2 year old cat with bilaterally retained testes.

Sex cord - stromal tumours

Neoplasms with a phenotype  resembling the cells that originate from stroma or sex cords of the primitive gonad include the interstitial cell tumour and Sertoli cell tumour.

Interstitial cell tumour

Interstitial endocrine cells occur within the testis and secrete androgens such as testosterone. They are also occasionally seen in the epididymis (Wrobel and Hees, 1987).

Neoplasms with a phenotype resembling the interstitial endocrine (Leydig) cells in cats have the typical appearance of interstitial cell tumours of other species. There are said to be 3 different patterns, the solid-diffuse, cystic-vascular and pseudoadenomatous. The solid-diffuse type is the one illustrated below.

If you include the extratesticular testicular tumours (see below), this is the most common. McEntee reports seeing one as an incidental finding in a 13 year old cat. Cotchin (1984) reports seeing 2. Miller et al (2007) reports on a cat with both interstitial cell tumor and Sertoli cell tumor in the same cat. I have only seen one in the testis of a cat (YB93734). Tucker and Smith (2008) report a cat with interstitial cell tumour that also developed prostatic squamous metaplasia.

Figure 18 : Interstitial cell tumour, solid-diffuse type.

Figure 19 : Interstitial cell tumor, high magnification of cell type.

Sustentacular (Sertoli) cell tumour

Feline sustentacular cell tumours have the same characteristic appearance as those of other species. As with all feline testicular tumours, these are very rare. Meier (1956) reports 2 cases. Benazzi et al (2004) reports 1 case - in a cryptorchid cat. Benazzi et al (2004) also quotes Silva (2004) who reports a malignant sustentacular cell tumour in the ectopic testis of a cat. Miller et al (2007) reports on a cat with both interstitial cell tumor and Sertoli cell tumor in the testis.

I have seen two cases (YB30990 and YB135279). One affected testis was inguinally retained.

Extratesticular testicular tumours

There are several reports of interstitial cell tumours developing in previously neutered cats. Rosen and Carpenter (1993) reported one case. The largest series is that of Doxsee et al (2006). Five cats in the YB database had interstitial cell tumours in the scrotum or spermatic cord. These cats were castrated at a young age. All cats began to show masculinisation between 5 and 13 years after castration. The tumours developed in the spermatic cord, scrotal skin, incision site or inguinal canal. No reoccurrence was reported.

Epithelial (rete) tumours

There is one report of a rete testis tumor in a cat (Peyron and Cocu 1938) .

References

Benazzi C, Sarli G, Brunetti B (2004) Sertoli cell tumour in a cat. J Vet Med A Physiol Pathol Clin Med. 51(3):124-6.

Carpenter JL, Andrews LK, Holzworth J (1987) Tumors and tumor-like lesions. In Diseases of the Cat: medicine and surgery (J Holzworth ed) pp 517-518. Saunders Philadelphia. as quoted by McEntee (1990)

Cotchin E (1984). Neoplasia. In Diseases of the cat and their management GT Wilkinson ed Blackwell, Oxford.

Doxsee AL, Yager JA, Best SJ, Foster RA. (2006) Extratesticular interstitial and Sertoli cell tumors in previously neutered dogs and cats: A report of 17 cases. Canadian Vet J. 47: 763-766.

McEntee K (1990). Reproductive Pathology of Domestic Mammals. Academic press

Meir H. (1956) Sertoli cell tumour in the cat: Report of two cases. North Am Vet J 1956; 37: 979-981.

Miller MA, Hartnett SE, Ramos-Vara JA (2007) Interstitial cell tumor and Sertoli cell tumor in the testis of a cat. Vet Pathol 44: 394-397.

Miyoshi N, Yasuda N, Kamimura Y, Shinozaki M, Shimizu T. (2001) Teratoma in a feline unilateral cryptorchid testis. Vet Pathol. 38(6):729-30.

Nagumo T, Yoshii R, Uzuka Y, et al. Computed tomographic characteristics of testicular teratoma in a cat. Vet Radiol Ultrasound. doi:10.1111/vru.13380

Peyron A, Cocu J: Sur une petite tumeur wolffienne du testicule d'un chat de neuf mois. Bull Acad Vét France 91:507-510, 1938

Rosen DK, Carpenter JL (1993). Functional ectopic interstitial cell tumour in a castrated male cat. J Am Vet Med Assoc 1993; 202: 1865.

Silva JF (2002) Malignant Sertoli cell tumor in an ectopic testis of a cat (Felis catus). Rev. Port. Cienec. Vet. 97: 87-92 as quoted by Silva (2001)

Silva FJ. (2002) Tertoma in a feline unilateral cryptochid testis.Vet Pathol 39(4):516.

Tucker AR, Smith JR (2008) Prostatic Squamous Metaplasia in a Cat with Interstitial Cell Neoplasia in a Retained Testis Vet Pathol 45: 905-909.

Wrobel KH, Hees H.(1987) [Heterotopic Leydig cells in the cat] Anat Histol Embryol. 16(4):289-92.

 

Testicular spermatocele

Two spermatoceles of the testis of a 9 year old cat was reported by Elcock and Schoning (1984). These spermatoceles was reported to involve tubules without Sertoli cells, and the spermatozoa were tightly packed. This same cat had an 'epididymal' spermatocele.

 

Elcock LH, Schoning P. (1984) Age-related changes in the cat testis and epididymis. Am J Vet Res 45: 2380-2384

Testicular torsion

Testicular torsion is extremely rare in the cat. Giuliano (2013)reported on a single case of a five-month-old cat with venous infarction of the testis with torsion high in the spermatic cord. It was non-painful and discovered at routine castration.

Giuliano A (2013) testicular torsion in a normally descended testicle in a cat. J Small Anim Pract 2013, 54: 164,

Disease of the epididymis

The major diseases of the epididymis of all species, particularly in prevalence, involve inflammatory diseases. Infectious epididymitis is studied in those species where it occurs commonly and where it has a major economic impact. Where epididymitis is not a significant disease, and that is certainly the case in the domestic cat, then non-infectious conditions become of relative importance. One very important and often missed disease is spermatic granuloma of the epididymal head. This is an inflammatory (granulomatous inflammation to spermatozoa) disease with an anomalous and potentially genetic basis. I have chosen to place this in the noninflammatory/non-infectious category.

The presence of spermatozoa, a highly antigenic structure that also induces a foreign body type disease, within the lumen of the epididymis complicates the responses of this organ to injury. Spermatozoa induce a foreign body and immune mediated response and the character is typically granulomatous. Spermatozoa are continuously produced and move through the tubules. Any obstruction of the tube results in increased pressure and the likelihood of rupture. A rupture or perforation of the tube will eventually lead to the formation of a cavity containing impacted spermatozoa. In severe cases, the spermatozoa will be released into the cavity surrounded by the vaginal tunics. Inflammation ensues with fibrosis and further obstruction of the epididymal duct.

Infectious epididymitis

Infection of the epididymis usually occurs via two main mechanism, ascending infection from the urethra via the ductus deferens and accessory genital glands, or hematogenous spread. Descending infection from the testis, and direct penetrating injury are both theoretically possible.

In general, infection is recognized when there is bacterial infection. Little is known of bacterial epididymitis in cats. There are two case in the YB files (YB15491 and YB30655). One was in a cat that was a hermaphrodite! Both cases had suppurative inflammation suggesting an ascending bacterial cause. Both cats were 7 months old.

Viral infection of the epididymis would be expected to occur in feline infectous peritonitis, but there is little information about other causes.

It is apparently 'not uncommon' to see lymphocytic foci in the epididymides of cats of all ages (Bloom 1954). Elcock and Schoning (1984) saw them in 8 cats of all ages.

Bloom F (1954) Pathology of the dog and cat - The genitourinary system, with clinical considerations. American Veterinary Publications, Inc, Evanston Illinois. p214.

Spermatic granuloma of the epididymal head

Spermatic granuloma of the epididymal head undoubtably occurs but is seldom recognized. It is the end result of efferent ductules failing to join to the epididymal duct at the head of the epididymis. At puberty, spermatozoa are forced into the blind ended tubule, form a spermatocele and eventually a spermatic granuloma. Elcock and Schoning (1984) reported a spermatocele in the head of the epididymis of a 9 year old cat. The affected duct was distended with tightly packed spermatozoa. I suspect that was actually a spermatocele of an efferent ductule, as the epididymal duct is one continuous tube and its obstruction would surely lead to rupture. This cat also had 2 testicular spermatoceles.

Noninflammatory disease

Large scale surveys of the reproductive tract have not been undertaken, so many of the rarer conditions have not been described in domesticated cats. They no doubt exist.

Segmental aplasia

Congenital absence of a part of or the whole epididymis is a very rare anomaly. Its longer name is segmental aplasia of the mesonephric duct. It is believed, at least in the bull and dog, to be an inherited anomaly. While I have not seen any published reports of this anomaly, I have seen a case (YB). This case was in a cat with a cystic rete testis - a careful examination of the photograph reveals the lack of an epididymis!

Intraepithelial lumina/cysts

Elcock and Schoning (1984) reported intraepithelial cysts in the epididymides of cats of 2 age groups - 0.5-1 year and >5 years.

 References

Elcock LH, Schoning P. (1984) Age-related changes in the cat testis and epididymis. Am J Vet Res 45: 2380-2384

The spermatic cord is a structure composed of the testicular artery and veins that form the pampiniform plexus, and the ductus deferens. It is covered by the tunica vaginalis and by the cremaster muscle

Disease of the Penis and Prepuce

Inflammatory disease

Balanoposthitis

Pointer and Murray (2011) report on a dramatic case of prostatitis were the prostate was massively enlarged and filled with multiple pockets of neutrophils with marked fibrosis and squamous metaplasia. This extended along the urethra to the penis. Cystitis, pyelonephritis and balanoposthitis was present also.

Pointer E, Murray L. (2011) Chronic Prostatitis, Cystitis, Pyelonephritis, and Balanoposthitis in a Cat. J Am Anim Hosp Assoc 2011; 47: 258-261

Inflammatory polyp

I have seen a case where the penis of an older cat had an inflammatory polyp (YB153 )

Non inflammatory disease

Os penis

The os penis of the cat is a rarity, only occurring in some old toms. This, while a ‘normal’ finding is also a case of acquired ossification (or mineralization)

Diphalia

Diphalia is a double penis. This is a very rare disease. Axner et al (1996) reports one case of diphalos in a 12 months old Siamese.

Axner E, Strom B, et al (1996) Reproductive disorders in 10 domestic male cats. J Sm Anim Pract. 37: 394-401

Hair ring

Hart and Peterson (1971) report the formation of a ring of hair around the penis at the base of the glans penis.

Hart BL, Peterson DM. (1971) Penile hair rings in male cats may prevent mating. Laboratary Anim Sc 21:422.

Hypospadias

Hypospadia is a ventral opening of the urethra somewhere along its length. It is believed to be a failure of the urethra to close in that location. This is a very rare anomaly in any domestic species and is infrequently reported.

King and Johnson (2000) report one case in a Himilayan cat. This defect was accompanied by a bifid scrotum. They also quoted a paper by Foley and Collins (1999) who reported 2 cases.

Foley RH, Collins KS (1999) Hypospadias in two male cats. Feline Practice 27, 18-19

King GJ, Johnson EH. (2000) Hypospadias in a Himalayan cat. J Small Anim Pract. 2000, 41: 508-510.

 

 

Preputial stenosis / Phimosis

Prepubital animals have fusion of the penis and prepuce, so one usually cannot extrude the penis. When surgeons talk about phimosis, they are referring to stenosis of the oriface of the prepuce that prevents urination, so clinical phimosis is the condition where the oriface of the prepuce is too small for urine to pass freely.

Bright and Mellanby (2004) report congenital phimosis in an 8 week old cat!

May and Hauptman reported on 10 cases of phimosis in cats. The majority of these cats were under 9 months of age. (range 8 to 125 weeks, median 19 weeks). This was a clinical paper and those cats that were treated had preputoplasty.

de Vlaming et al (2019) reported on the surgical outcome for kittens with preputial stenosis - called phimosis.

 

Bright SR, Mellanby RJ (2004) Congenital phimosis in a cat. J Fel Med Surg 6: 367-370

Elkins AD.(1983) Surgical correction of congenital stricture of the preputial orifice in the cat. Feline Pract 13:20-25.

May LR Hauptman JG (2009) Phimosis in Cats: 10 Cases (2000-2008) J Am Anim Hosp Assoc 45: 277-283

de Vlaming A, Wallace ML, Ellison GW. Clinical characteristics, classification, and surgical outcome for kittens with phimosis: 8 cases (2009-2017). J Am Vet Med Assoc. 2019; 255: 1039-1046.

Paraphymosis

Paraphymosis is a clinical sign of urethral obstruction secondary to urolithiasis in castrated and non castrated cats.

Priapism

Priapism is persistent erection of the penis. Swalec and Smeak (1989) report one cat that developed priapism after castration. Gunn-Moore et al (1995) reported on 7 cats with priapism. Four were neutered cats that developed priapism after attempting to mate with estrus females.

Gunn-Moore DA, Brown PJ, Holt PE, Gruffydd-Jones TJ.(1995) Priapism in seven cats. J Small Anim Pract. 36(6):262-266

Rochat MC. (2001) Priapism: a review. Theriogenology. 56(5):713-722

Swalec KM, Smeak DD (1989) Priapism after castration in a cat. JAVMA 195 (7): 963-964

Persistent frenulum

A band from the frenulum of the penis to the prepuce is a persistent frenulum. The frenulum is located on the ventral surface of the penis, so a persistent frenulum should produce a ventral deviation of the extruded penis. Other retained bands, called balanopreputial folds or bands will cause deviation in other directions. Axner et al (1996) report a on a cat with 'persistent frenulum' that caused a dorsal deviation.

Axner E, Strom B, et al (1996) Reproductive disorders in 10 domestic male cats. J Sm An Pract. 37: 394-401

Disease inside the abdomen

Retained testis/cryptorchidism.

Retention of a testis (cryptorchidism) is the most common disease of the male cat. It is mentioned here as this is the location of the retained testis. Cryptorchidism is discussed above under disease of the testis.

Disease of the Prostate.

Most pathologists are unaware that cats have accessory genital glands, except for bulbourethral glands that are an anatomical landmark for perineal urethrostomy. Apart from the bulbourethral gland, cats do have a prostate (see normal). The first disease that would come to mind is prostatic hyperplasia or carcinoma. Prostatic hyperplasia is basically unknown and carcinoma is rare. Other diseases and conditions are even rarer.

Prostatic neoplasia

Carcinoma

Carcinoma of the Prostate in cats is rare. Obstruction of the urinary tract and obstipation is occasionally seen (LeRoy and Lech, 2004). Details are sketchy and the exact prognosis is unknown. Of the 5 reported, 2 had metastases. In the YB database there

Reports include these:-

Barrett and Nobel 1975. 1 case - no metastases.

Caney et al (1998). 2 cats - 1 had metastases to lungs but not local lymph nodes, the other had no metastases.

Hubbard BS, et al (1990). 1 case. 1 cat with reoccurrence locally after prostatectomy and metastases in lungs and pancreas.

LeRoy and Lech (2004) 1 case. Cat died 2 months after prostatectomy with unknown causes - no PM..

Tursi et al (2008). 1 case they presumed to be of the dissemminated part of the prostate, in the urethra and it was metastatic. It was in a neutered male.

 

References.

Barrett RE, Nobel TA (1975) Transitional cell carcinoma of the urethra in a cat. Cornell Vet 66: 14-26.

Caney SMA, Holt PE, Day MJ, Rudolf H, Gruffydd-Jones (1998) Prostatic carcinoma in two cats. J Small Anim Pract 39: 140-143.

Hubbard BS, Vulgamott JC, Liska WD (1990) Prostatic adenocarcinoma in a cat. J Amer Vet Med Assoc 197: 1493-1494.

LeRoy BE and Lech ME (2004) Prostatic carcinoma causing urethral obstruction and obstipation in a cat. J Fel Med Surg 6: 397-400.

Tursi M, Costa T, Valenza F, Aresu L. (2008) Adenocarcinoma of the disseminated prostate in a cat. J Feline Med Surg 2008; 10(6): 600-602.

 

Paraprostatic cyst

Newel et al (1992) reported a single case of paraprostatic cyst in a castrated male cat. It was trilobed and larger than a kidney and considered an incidental finding.. It had a lining of transitional epithelium.

Newell SM, Mahaffey MB, Binhazim A, and Greene CE (1992) Paraprostatic cyst in a cat. J Small Anim Pract 33: 399-401.

Prostatitis

Prostatitis is a rare lesion of the prostate.

Tucker and Smith (2008) report a case of prostatic squamous metaplasia and suppurative prostatitis in a cat that had dysuria and a retained testis that contained an interstitial cell tumour.

Pointer and Murray (2011) report on a dramatic case of prostatitis were the prostate was massively enlarged and filled with multiple pockets of neutrophils with marked fibrosis and squamous metaplasia. This extended along the urethra to the penis. Cystitis, pyelonephritis and balanoposthitis was present also.

Pointer E, Murray L. (2011) Chronic Prostatitis, Cystitis, Pyelonephritis, and Balanoposthitis in a Cat. J Am Anim Hosp Assoc 2011; 47: 258-261

Tucker AR, Smith JR. (2008) Prostatic Squamous Metaplasia in a Cat with Interstitial Cell Neoplasia in a Retained Testis. Vet Pathol 45: 905-909.

Prostatic abscess

Mordecai et al (2008) report a cat with a 2.2 cm mass caudal to the bladder which was surgically treated with omentalization. Escherishia coli was isolated from the inflamed prostate. Histologically the reaction was described as pyogranulomatous in type.

Mordecai A, Liptak JM, Hofstede T, Stalker M, Kruth S. (2008) Prostatic Abscess in a Neutered Cat. J Am Anim Hosp Assoc 44: 90-94.

Prostatic squamous metaplasia

Tucker and Smith (2008) report a case of prostatic squamous metaplasia and suppurative prostatitis in a cat that had dysuria and a retained testis that contained an interstitial cell tumour.

Pointer and Murray (2011) report on a dramatic case of prostatitis were the prostate was massively enlarged and filled with multiple pockets of neutrophils with marked fibrosis and squamous metaplasia. This extended along the urethra to the penis. Cystitis, pyelonephritis and balanoposthitis was present also.

Pointer E, Murray L. (2011) Chronic Prostatitis, Cystitis, Pyelonephritis, and Balanoposthitis in a Cat. J Am Anim Hosp Assoc 2011; 47: 258-261

Tucker AR, Smith JR. (2008) Prostatic Squamous Metaplasia in a Cat with Interstitial Cell Neoplasia in a Retained Testis. Vet Pathol 45: 905-909.

 Disease of the bulbourethral gland

The bulbourethral gland of the cat is seldom examined, and disease is extremely rare. Bloom (1954) reports the presence of lymphocytes in aggregates in the stroma and associates them with cystitis and urethritis.

Cystic change is also reported by Bloom (1954).

Bloom F (1954) Pathology of the dog and cat - The genitourinary system, with clinical considerations. American Veterinary Publications, Inc, Evanston Illinois. p308