Cysts In Dogs Research Articles

Periapical cysts in dogs: 10 cases (2000-2020).

To characterize the clinical, diagnostic imaging, and histologic features with description of treatment outcome of periapical cysts in dogs. Ten client-owned dogs diagnosed with periapical cysts biopsied between July 1, 2000 and June 30, 2020. Medical records of the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania were retrospectively searched to identify dogs that had surgical biopsy specimens of cavitary lesions diagnosed as odontogenic cysts and that met additional inclusion criteria. Complete medical records were reviewed. Range age and body weight of affected dogs were 2.5-12.1 years and 4.3-38.4 kg (9.5-84.7 lb), respectively. All periapical cysts were affecting the incisive bone and/or the maxilla. Nine dogs presented with a fluctuant swelling of the oral mucosa and gingiva; one dog without clinical swelling presented with a history of difficulty breathing. All cysts originated from a non-vital tooth with a structural defect (wear or fracture without pulp exposure) and/or intrinsic staining. Extraction of the associated non-vital teeth, enucleation of the cysts, and curettage of the surgical sites resulted in resolution of the clinical signs. The findings indicate that periapical cysts are associated with a non-vital tooth without pulp exposure. Complete evaluation of the clinical, diagnostic imaging, and histologic features of the lesion in affected dogs is necessary to differentiate periapical cysts from other odontogenic cysts and tumors.

Marsupialisation of 12 odontogenic cysts in Boxer dogs: Retrospective case series.

Marsupialisation of odontogenic cysts is a minimally invasive treatment method used in human dentistry. Marsupialisation decompresses the cyst and promotes remodeling of alveolar bone and shrinkage of the cyst. In this retrospective study we look at the effectiveness of marsupialisation at reducing the size of odontogenic cysts in dogs. The case series consists of six Boxer dogs with 12 odontogenic cysts. Each case underwent a high resolution CT scan prior to treatment and at follow-up. Each CT scan was reviewed, the volume of each cyst calculated using manual segmentation and the reduction in cyst volume calculated. There was a marked reduction in cystic volume of 66.6% over a mean of 138 days. This shows that the use of marsupialisation effective method of reducing cyst volume.

Surgical treatment and outcome of sterile prostatic cysts in dogs.

ObjectiveTo describe the surgical treatment and outcome of a large cohort of dogs with sterile prostatic cysts (PCs).Study DesignRetrospective study.AnimalsForty‐four client‐owned dogs.MethodsDogs with sterile PCs with at least 6 months of follow‐up were included. Clinical variables, type of surgery, complications, recurrences, and outcomes (telephonic interviews or rechecks) were recorded.ResultsExtra‐ and intraparenchymal cysts were diagnosed in 29 and 11 dogs, respectively. Four dogs had both types. Extraparenchymal cysts were treated by partial resection and omentalization (n = 22) and complete resection (n = 7). Drainage and intracapsular omentalization were performed in all dogs with intraparenchymal cysts. The four dogs with both types of cyst were treated by omentalization. Resolution was documented in 39/44 dogs (88.6%). Intraoperative complications occurred in one dog (urethral tear). Major complications resulting in death occurred in three dogs (oliguric kidney injury, cardiac arrhythmia, and persisting urinary tract obstruction). Minor complications (n = 10) consisted of temporary urinary incontinence (n = 2), permanent urinary incontinence (n = 5), urinary retention (n = 2), and dysuria (n = 1). Recurrence occurred in two dogs with extraparenchymal cysts. Median long‐term follow‐up was 528 days (range, 250–730 days). Thirty‐nine dogs had no signs associated with prostatic disease at long‐term follow‐up.ConclusionPartial or complete resection and/or omentalization of sterile PCs led to resolution of clinical signs in most dogs, although postoperative urinary incontinence was frequent.ImpactThis study is the largest case series relative to canine sterile PCs treated surgically and provides evidence on the prognosis and rate of complications.

Histologic features of hair follicle neoplasms and cysts in dogs and cats: a diagnostic guide.

Hair follicle neoplasms occur in many different species, including humans. In domestic animals, they are most common in dogs. Most hair follicle tumors are benign, but malignant neoplasms can also occur. To diagnose hair follicle neoplasms, a thorough knowledge of follicular anatomy is important, given that follicular tumors are classified according to the differentiation pattern seen in the corresponding part of the normal hair follicle. This review focuses on the key diagnostic features of hair follicle tumors and follicular cysts in dogs and cats.

The canine furcation cyst, a newly defined odontogenic cyst in dogs: 20 cases (2013-2017).

To characterize clinical, radiographic, and histologic features of canine furcation cysts (CFCs) in dogs and to propose possible mechanisms of CFC development. 20 client-owned dogs with CFCs biopsied between January 1, 2013, and December 31, 2017. Medical records of the Center for Comparative Oral and Maxillofacial Pathology at the University of Wisconsin-Madison were retrospectively searched to identify records of dogs that had surgical biopsy specimens of mandibular or maxillary cavitary lesions diagnosed as odontogenic cysts and that met additional inclusion criteria. Biopsy sample submission records, medical records, clinical and radiographic images, and histologic samples were reviewed. Clinical, radiographic, and histologic features were evaluated. Mean body weight and age of affected dogs were 23.5 kg (51.7 lb) and 8.2 years, respectively. All 20 dogs had a unilateral cyst, with the right (n = 13) or left (7) maxillary fourth premolar tooth affected and viable in all dogs. A predominant clinical sign was a fluctuant swelling of the buccal gingiva and mucosa overlying the CFC, and enucleation of the cyst lining, with or without extraction of the affected tooth, resolved the lesion in most dogs. Our findings indicated that CFC is an odontogenic cyst of uncertain etiopathogenesis and that complete evaluation of the clinical, radiographic, and histologic features of the lesion in affected patients is necessary to distinguish a CFC from other odontogenic cysts and tumors in dogs. Defining CFCs in terms of characteristic features permits accurate diagnosis and appropriate treatment of these previously unclassifiable odontogenic cysts in dogs.

Cytologic features of cutaneous follicular tumors and cysts in dogs

Follicular tumors and cysts are common skin lesions in dogs. Both are distinguished based on their cellular origin (matrical, isthmus, or infundibular cells) and the type of keratin they produce. Typically, differentiation requires histopathology, as all these lesions often have similar cytologic features. The goal of this retrospective study was to identify unique cytologic features that may assist differentiation of canine benign follicular tumors and cysts at cytology, using histopathology as gold standard. Electronic medical records of the University of California-Davis Veterinary Medical Teaching Hospital were searched for diagnoses of follicular tumors and cysts in dogs that had both histopathologic and cytologic diagnoses between January 2000 and December 2013. Cytologic specimens were reassessed in a blinded manner for the presence and type of background, cells, noncellular elements, and inflammation. Forty-six samples were included in the study. Follicular cysts (n = 25) and infundibular keratinizing acanthomas (n = 5) contained sheets of keratinized anucleate to nucleated squamous cells. Trichoepitheliomas (n = 8) had 2 primary cytologic presentations: those with primarily basaloid cells that appeared to be undergoing keratinization (3/8; 38%) and those with keratinizing anucleate to nucleated squamous cells (5/8; 63%). Trichoblastomas (n = 8) had pink matrix with spindle cells and contained cohesive clusters of basaloid cells. Trichoblastomas, and to a lesser extent, trichoepitheliomas, have unique cytologic features with the potential to distinguish them from other benign follicular tumors and cysts. These results are an important first step toward improving the diagnostic specificity of cytologic examination of cutaneous follicular lesions.

Advancement flap associated to bürrow's triangle after removal of infundibular cyst in dog: case report

Cutaneous cysts in dogs and cats are characterized by an epithelial wall and a content that generally is keratin. Most cysts have follicular origin and good prognostic. Surgical removal is recommended and as a result it has a large surgical defect that typically requires technical knowledge of reconstructive plastic surgery for occlusion. This report describes the case of a female boxer dog that had a nodule on the head. After clinical and laboratory examination was recommended removal of the lump and the execution of an histopathologic exam. The surgical procedure demanded to perform an unilateral advancement flap associated with Bürrow’s triangle, to approach the wound edges that were under high tissue tension. In postoperative was made a bandage to avoid formation. The histopathologic exam revealed it to be an infundibular cyst, that is usual in dogs.

Introduced and Native Haplotypes of Echinococcus multilocularis in Wildlife in Saskatchewan, Canada.

Recent detection of a European-type haplotype of the cestode Echinococcus multilocularis in a newly enzootic region in British Columbia prompted efforts to determine if this haplotype was present elsewhere in wildlife in western Canada. In coyote (Canis latrans) definitive hosts in an urban region in central Saskatchewan (SK), we found a single haplotype of E. multilocularis that was most similar to a haplotype currently established in the core of this parasite's distribution in Europe and to the European-type haplotype found in coyotes and a dog (Canis lupus familiaris) in British Columbia. We found six haplotypes of E. multilocularis from deer mouse (Peromyscus maniculatus) intermediate hosts in southwestern SK that were closely related to, and one haplotype indistinguishable from, a haplotype previously reported in the adjacent north-central US. This is a higher level of diversity than has previously been recognized for this parasite, which suggests that the population native to central North America is well established, rather than a recent introduction from the Arctic. These findings, in combination with recent cases of alveolar hydatid cysts in dogs in Canada, raise concerns that European haplotypes of E. multilocularis may be increasing in distribution within wildlife in Canada. European haplotypes may pose greater risks to veterinary and human health than native haplotypes long established in central North America.

Prevalence of Giardia Cysts in Household Dog Faeces within Zaria Metropolis, Kaduna State, Nigeria and its Public Health Significance

Giardiasis is a major cause of diarrhoea in both humans and animals. In developing countries such as Nigeria, the disease has important Veterinary and public health consequences. This study determined the prevalence of Giardia cysts in dog faeces in Zaria, Kaduna State, Nigeria and its Public Health Significance. Four hundred and two (402) dog faecal samples were collected and examined for Giardia cysts using zinc sulphate flotation technique. Of the 402 dog faecal samples examined, 70 (17.4%) were positive for Giardia cysts. Giardia cysts were higher in male dogs (18.9%) than in females (15.6%). Higher prevalence of Giardia cysts were observed in puppies ( 6months) (16.7%). Also higher prevalence of Giardia cysts was observed in cross/exotic breeds (20.9%) as compared to local breeds (16.4%). There was no statistical association between the prevalence of Giardia cysts and dogs with diarrhoea, sex, age and breed (P>0.05). There was a higher prevalence (15.7%) of Giardia cysts in strayed dogs than in confined dogs (14.6%). There was statistical significant association (P=0.01) between Giardia cysts and straying of dogs. Purpose of keeping dogs as Pet (OR: 0.36; 95% C I on OR 0.05) This research provides useful information on the prevalence of Giardia cysts in household dogs, which may help regulatory bodies and Government agencies in making policies in controlling Giardiasis in the study area.

Erratum

Thank you to Sharon Hoffman, DVM, for drawing the authors' attention to the following oversight in Menzies RA, Reiter AM, Lewis JR. Assessment of apical periodontitis in dogs and humans: a review. J Vet Dent 2014; 31: 8–21. On page 8, paragraph 2 it is incorrectly stated that radicular cysts are not recognized to occur in dogs. The reference provided was published prior to the publication of two confirmed cases of radicular cysts.1,2 Two suspected cases of radicular cysts have also been published.3,4 Radicular cysts and periapical cysts are synonyms; periapical cysts in dogs were briefly elaborated on in the last paragraph of page 9. Robert A. Menzies, BVSc 1 Verstraete FJ, Zin BP, Kass PH, et al. Clinical signs and histologic findings in dogs with odontogenic cysts: 41 cases (1995–2010). J Am Vet Med Assoc 2011; 239:1470–1476. 2 French SL, Anthony JM. Surgical removal of a radicular odontogenic cyst in a four year-old Dalmatian dog. J Vet Dent 1996; 13:149–151. 3 Beckman BW. Radicular cyst of the premaxilla in a dog. J Vet Dent 2003; 20:213–217. 4 Lommer MJ. Diagnostic imaging in veterinary dental practice. Periapical cyst. J Am Vet Med Assoc 2007; 230:997–999.

Extramedullary spinal cysts in dogs.

To (1) synthesize the terminology used to classify extramedullary spinal cysts in dogs to clarify some of the commonly reported misconceptions, and (2) propose a classification scheme to limit confusion with terminology. Literature review. An online bibliographic search was performed in January 2013 for articles relating to extramedullary spinal cysts in dogs using PubMed (http://www.pubmed.gov/) and Google Scholar (http://scholar.google.com/) databases. Only peer-reviewed clinical literature describing cystic lesions pertaining to the spinal cord and associated structures was included. From 1962 to 2013, 42 articles were identified; 25 (95 dogs) reported meningeal cysts, 10 (24 dogs) described 60 extradural cysts, 3 reports (18 dogs) described discal cysts or acute compressive hydrated nucleus pulposus extrusions (HNPE). Spinal cysts were categorized by location based on cross-sectional imaging as meningeal or extradural non-meningeal. Sub-classification was then performed based on surgical findings and pathology. Meningeal cysts included arachnoid diverticulae and Tarlov (perineural) cysts. Extradural non-meningeal cysts included intraspinal cysts of the vertebral joints, ligaments and discs. Discal cysts also fit this category and have been reported extensively in humans but appear rare in dogs. Extramedullary spinal cysts should be first classified according to location with a sub-classification according to pathologic and surgical findings. Previous canine cases of discal cysts appear to represent a different disease entity and the term acute compressive HNPE is therefore preferred.

The extraosseal intrathoracic radiopaque bone cyst in West Highland White Terrier – a case report

The aim of this report was to present a clinical case and diagnostics of intrathoracic bone cyst as well as successful outcome of the surgical treatment in a male, 3-year-old West Highland White Terrier dog, weighing 6.9 kg. The dog was admitted in a very poor condition with clinical signs of severe dyspnoea that developed during about one month period of time before admission to our clinic. The dog underwent physical examination and further examinations including radiological examination which revealed a radiopaque mass formation in the cranial mediastinum. Ultrasonographic examination showed the presence of fluid; following thoracentesis revealed pseudochylous fluid. The bone cyst was surgically removed and more than 10 months after surgery the dog’s health was very good without any difficulties. Bone cysts in dogs are infrequent; this was the first case at our clinic and presented a successful treatment.

Glaucoma associated with uveal cysts and goniodysgenesis in American Bulldogs: a case series

We present a series of three American Bulldogs with clinical signs of glaucoma and intraocular inflammation accompanied by bilateral uveal cysts and abnormal gonioscopic findings. All dogs proved refractory to medical management and were enucleated. Histopathologic findings were similar in all three and included significant preiridal fibrovascular membranes and mononuclear inflammatory infiltrates in the anterior uvea. On microscopic evaluation, cysts appeared to arise primarily from the ciliary body and iridociliary sulcus, with smaller cysts also budding from the posterior iris. Pigment dispersion was variable but consistent, involving deposition of a small number of pigment-laden cells in the dependent trabecular meshwork. Cataract formation was not noted. Glaucoma associated with uveal cysts has been described previously in Golden Retrievers and Great Danes, although clinical and histopathologic findings in those breeds are not identical to those described here. American Bulldogs with uveal cysts should have gonioscopy performed and should be monitored carefully for signs of increased intraocular pressure and intraocular inflammation. Furthermore, documentation of cyst-associated glaucoma in a third breed suggests clinicians should exercise caution in dismissing uveal cysts in dogs as incidental findings.

Congenital orbital cysts of neural tissue in two dogs

A 3-month-old English Cocker Spaniel and a 6-month-old miniature poodle presented with clinical signs related to an abnormal right eye since birth. In both dogs, the right globe could not be identified and was replaced by a fluctuant intraorbital mass covered by a vascularized mucous membrane. Ultrasonography demonstrated that both masses were cystic structures markedly larger in size than the normal contralateral globes. In both cases, surgical excision revealed a multilobular cyst filling the whole orbital cavity. Histopathologic examination and immunostaining for glial fibrillary acid protein and S100 protein supported a diagnosis of neural cysts associated with ocular dysplasia. The definitive diagnosis was congenital cystic eye and microphthalmos with cyst for the Cocker Spaniel and miniature poodle, respectively. Karyotype was normal in both dogs. Congenital cystic eye and microphthalmos with cyst result from defects in early embryonic life that arise following formation of the optic vesicle and prior to closure of the optic fissure. To the authors' knowledge neither has been reported in the canine species. They should be considered in the differential diagnosis of orbital cysts in dogs.

Ventral Intraspinal Cysts Associated with the Intervertebral Disc: Magnetic Resonance Imaging Observations in Seven Dogs

To report clinical and diagnostic imaging features, and outcome after surgical treatment of ventral intraspinal cysts in dogs. Retrospective study. Dogs (n=7) with ventral intraspinal cysts. Clinical signs, magnetic resonance imaging (MRI) findings and surgical findings of 7 dogs and histologic findings (1 dog) with intraspinal cysts associated with the intervertebral disc were reviewed. Ventral intraspinal cyst is characterized by: (1) clinical signs indistinguishable from those of typical disc herniation; (2) an extradural, round to oval, mass lesion with low T1 and high T2 signal intensity on MRI, compatible with a liquid-containing cyst; (3) cyst is in close proximity to the intervertebral disc; and (4) MRI signs of disc degeneration. Although the exact cause is unknown, underlying minor disc injury may predispose to cyst formation. Intraspinal cysts have clinical signs identical to those of disc herniation. Given the close proximity of the cyst to the corresponding disc and the similarity of MRI findings to discal cysts in humans, we propose the term "canine discal cyst" to describe this observation. Discal cysts should be considered in the differential choices for cystic extradural compressing lesions.

Clinical and Magnetic Resonance Imaging Characteristics of Quadrigeminal Cysts in Dogs

Background: Quadrigeminal cysts (QC) are the most common intracranial intra‐arachnoid cysts in dogs, primarily affecting small breeds. Clinical significance is controversial. Hypothesis: Male, brachycephalic, small breed dogs are predisposed to QC, and objective measurement of parenchymal compression can distinguish clinically relevant QC from incidental findings. Animals: A total of 4,100 client‐owned dogs. Methods: A retrospective study that recorded signalment, history, clinical signs, and magnetic resonance imaging features. The degree of brain compression was evaluated in the presence of relevant clinical signs. The percentage compression of cerebellum and forebrain was calculated by comparing the expected to the actual diameter and longitudinal dimension, respectively. Results: QC were diagnosed in 28 dogs, of which 21 (75%) were small breed dogs. Fifteen dogs (54%) were brachycephalic. Eighteen dogs were male, and 10 were female. Cerebellar, occipital lobe, or compression in both areas occurred in 86% (24/28 dogs). Clinical signs included focal and generalized seizures in 5 dogs and cerebellar signs in 6 dogs. Mean occipital lobe compression was 17% (SD = 4) in clinically affected and 10% (SD = 3) in normal dogs (P = .006). Occipital lobe compression >14% was always associated with clinical signs. The mean cerebellar compression was 18%, but there was no association between compression and clinical signs. The animals were more likely to develop clinical signs if both areas were compressed (P = .04). Conclusions and Clinical Importance: Parenchymal compression by QC can be incidental, and other central nervous system diseases must be excluded when assessing the clinical significance of QC. However, occipital lobe compression over 14% is likely to cause clinical signs.

Craniotomy with Cystoperitoneal Shunting for Treatment of Intracranial Arachnoid Cysts in Dogs

To describe a technique of decompressive craniotomy with cystoperitoneal shunt (CPS) placement for treatment of canine intracranial arachnoid cyst (IAC), and to evaluate outcome in 4 dogs. Retrospective study. Dogs (n=4) with IAC. Medical records of dogs diagnosed with IAC by magnetic resonance imaging (MRI; 3 dogs) or computed tomography (CT; 1 dog) were evaluated. All dogs had varying degrees of neurologic dysfunction before surgery. A combined lateral (rostrotentorial)/suboccipital craniotomy was performed sacrificing the transverse sinus on the operated side. The rostral (ventricular) end of a low-pressure valve shunt (3.0 mm outer diameter, 7.0 cm length) was placed transversely into the cyst cavity; the distal end was placed in the peritoneal cavity. All dogs were rechecked at various intervals by >or=1 of the authors either directly, by telephone consultation with owners, or both. Three dogs were imaged postoperatively (CT-1 dog; MRI-1; ultrasonography-1). Intraoperative complications were limited to excessive transverse sinus hemorrhage requiring blood transfusion in 1 dog. There were no postoperative complications. Clinical signs of neurologic dysfunction resolved in 3 dogs and improved substantially in 1 dog. The latter dog required long-term, low-dose corticosteroid therapy. No dogs required repeat surgery. Mean follow-up time was 23.8 months (range, 12-43 months). Collapse of the intracranial cyst was verified in 3 dogs with repeat imaging. In 2 dogs, there was no evidence of the cyst on CT or MRI; in the third dog, a small amount of fluid was demonstrated rostral to the cerebellum on ultrasonography, but there was no identifiable cyst. In 1 dog, the rostral aspect of the shunt had shifted; however, this was not associated with any clinical deterioration. Craniotomy with CPS placement was well tolerated and resulted in sustained improvement or resolution of dysfunction. Cyst decompression was verified in 3 dogs that were re-imaged. None of the patients required re-operation. Excessive transverse sinus hemorrhage is a potential danger that may necessitate blood transfusion. Other IAC patients treated with this method will need to be evaluated to fully evaluate its effectiveness. Craniotomy with CPS placement may be an effective treatment method for dogs clinically affected with IAC.

Clinical and Magnetic Resonance Imaging Characteristics of Quadrigeminal Cysts in Dogs

Quadrigeminal cysts (QC) are the most common intracranial intra-arachnoid cysts in dogs, primarily affecting small breeds. Clinical significance is controversial. Male, brachycephalic, small breed dogs are predisposed to QC, and objective measurement of parenchymal compression can distinguish clinically relevant QC from incidental findings. A total of 4,100 client-owned dogs. A retrospective study that recorded signalment, history, clinical signs, and magnetic resonance imaging features. The degree of brain compression was evaluated in the presence of relevant clinical signs. The percentage compression of cerebellum and forebrain was calculated by comparing the expected to the actual diameter and longitudinal dimension, respectively. QC were diagnosed in 28 dogs, of which 21 (75%) were small breed dogs. Fifteen dogs (54%) were brachycephalic. Eighteen dogs were male, and 10 were female. Cerebellar, occipital lobe, or compression in both areas occurred in 86% (24/28 dogs). Clinical signs included focal and generalized seizures in 5 dogs and cerebellar signs in 6 dogs. Mean occipital lobe compression was 17% (SD = 4) in clinically affected and 10% (SD = 3) in normal dogs (P = .006). Occipital lobe compression >14% was always associated with clinical signs. The mean cerebellar compression was 18%, but there was no association between compression and clinical signs. The animals were more likely to develop clinical signs if both areas were compressed (P = .04). Parenchymal compression by QC can be incidental, and other central nervous system diseases must be excluded when assessing the clinical significance of QC. However, occipital lobe compression over 14% is likely to cause clinical signs.

Cervical Myelopathy Associated with Extradural Synovial Cysts in 4 Dogs

Three Mastiffs and 1 Great Dane were presented to the University of Wisconsin Veterinary Medical Teaching Hospital for cervical myelopathy based on history and neurologic examination. All dogs were males and had progressive ataxia and tetraparesis. Degenerative arthritis of the articular facet joints was noted on survey spinal radiographs. Myelography disclosed lateral axial compression of the cervical spinal cord medial to the articular facets. Extradural compressive cystic structures adjacent to articular facets were identified on magnetic resonance imaging (1 dog). High protein concentration was the most important finding on cerebrospinal fluid analysis. Dorsal laminectomies were performed in all dogs for spinal cord decompression and cyst removal. Findings on cytologic examination of the cystic fluid were consistent with synovial fluid, and histopathologic results supported the diagnosis of synovial cysts. All dogs are ambulatory and 3 are asymptomatic after surgery with a follow‐up time ranging from 1 to 8 months. This is the 1st report of extradural synovial cysts in dogs, and synovial cysts should be a differential diagnosis for young giant breed dogs with cervical myelopathy.

Use of partial prostatectomy for treatment of prostatic abscesses and cysts in dogs

Objective To determine whether dogs had prostatic disease, urinary incontinence, or urinary tract infection 1 year after partial prostatectomy to treat prostatic abscesses and cysts. Design Prospective study. Animals 20 male dogs with prostatic abscesses or cysts. Fifteen dogs had evidence of urinary tract infection. Only 8 dogs urinated normally; the remainder dribbled, had obstructions, or required medical treatment. Procedure Partial prostatectomy was performed on each dog. Sexually Intact dogs (n = 12) also were castrated. Results None of the dogs had return of prostatic cystic enlargement or clinical signs of prostatic disease during the first year after surgery. Two dogs were euthanatized within 1 year after surgery, with 1 dog having prostatic enlargement and adenocarcinoma and 1 dog having unrelated lymphosarcoma. Fifteen dogs were continent. The remaining 5 dogs urinated normally but had intermittent and minor incontinence. Eleven dogs had no signs of infection 1 year after surgery, 5 had pyuria or positive urine bacteriologic culture results, 2 did not have urinalysis performed, and 2 were euthanatized. Clinical Implications Dogs with severe prostatic abscesses or cysts and infections can be successfully treated by partial prostatectomy with an ultrasonic surgical aspirator and castration, resulting in long-term disease resolution. Although most dogs with severe prostatic disease do not urinate normally before surgery, nearly all dogs resume normal micturition after partial prostatectomy. Postoperative results of partial prostatectomy appear to be better than those of previous drainage techniques for treatment of prostatic cavitary disease. (J Am Vet Med Assoc 1997;211:868–871)