Dermoid sinus removal in a rhodesian ridgeback dog

A three year old Rhodesian Ridgeback dog with a history of a small draining tract in the dorsal cervical area, was found to have a dermoid sinus on surgical exploration. The affected tissue was removed and histopathology done. The sinus is an inherited condition in this breed of dog, with surgical correction and neutering of affected individuals the treatments of choice to reduce the incidence of the dermoid sinus condition in the next generation.     

Inheritance of dermoid sinus in the Rhodesian ridgeback

OBJECTIVES: TO define the mode of inheritance of dermoid sinus. METHODS: A chi-squared analysis was performed on data from 46 litters produced between 1990 and 2001. Data were corrected to avoid bias in the segregation ratio. RESULTS: In data from 57 litters (n=492), 82 dermoid sinus positive offspring were observed. The frequency of affected offspring in the Swedish Rhodesian ridgeback population is estimated to be between 8 and 10 per cent. CLINICAL SIGNIFICANCE: Bias in heredity pattern may be caused by undetected dermoid sinus type V. Improved clinical diagnosis of all dermoid sinus types is therefore crucial.     

Renal dysplasia in a Rhodesian ridgeback dog

A six-month-old Rhodesian ridgeback dog was presented for evaluation of facial swelling. Chronic renal failure was clinically diagnosed based on urinalysis, biochemical changes and ultrasonography. The facial swelling was due to fibrous osteodystrophy, which was evident on survey radiographs of the skull. On post mortem examination, chronic renal failure as a result of renal dysplasia was confirmed. This is the first reported case of renal dysplasia in this breed of dog.     

True dermoid cyst in a Rhodesian ridgeback

A case of a true dermoid cyst in a Rhodesian ridgeback is described. The mass was located in the dorsal cervical midline at the level of the first cervical vertebra, and was resected surgically. In contrast to other types of dermoid sinus described in the literature, the mass did not have a tract connecting it to, nor an opening on to, the surface of the skin. A diagnosis of true dermoid cyst was made.     

Magnetic resonance imaging in the diagnosis of type 1 dermoid sinus in two Rhodesian ridgeback dogs

Two cases of type 1 dermoid sinus in Rhodesian ridgebacks are described, with emphasis on the use of magnetic resonance imaging (MRI) in the diagnosis and delineation of the lesions. Magnetic resonance imaging was useful in identifying fluid-filled structures, fibrous capsules, and sinus tracts, but was not able to identify the termination of the tracts.     

Autosomal dominant mutation causing the dorsal ridge predisposes for dermoid sinus in Rhodesian ridgeback dogs

OBJECTIVES: To define the mode of inheritance of the dorsal ridge and investigate if the ridge predisposes to the congenital abnormality dermoid sinus in the Rhodesian ridgeback. METHODS: Segregation analysis was performed, including 87 litters (n=803) produced in Sweden between 1981 and 2002. Data were corrected to avoid bias in the segregation ratio. Chi-squared analysis was performed including 402 litters (n=3598) for the evaluation of a possible genetic correlation between the ridge and dermoid sinus. RESULTS: The ridge is inherited in an autosomal dominant mode and predisposes for dermoid sinus. The frequency of ridgeless offspring in the Swedish Rhodesian ridgeback population is estimated to be 5.6 per cent. CLINICAL SIGNIFICANCE: Rhodesian ridgeback dogs that carry the ridge trait are predisposed to dermoid sinus.     

Dermoid Sinus in the Rhodesian Ridgeback

Abstract—The Rhodesian Ridgeback is a modern breed having been standardized in 1922. It originated in South Africa by crossing Hottentot dogs with various European breeds. The breed has one defect, a congenital malformation, generally known as dermoid sinus. The authors have investigated the inheritance of the condition and, contrary to the hypotheses of others, suggest that it is a simple recessive character. The implications of this are discussed.
Réslamé—Le chien de Rhodesie, dénommé Ridgeback, est d'un élevage récent, bien établi depuis 1922. II est originaire d'Afrique du Sud, résultant d'un croisement de chiens Hottentots et de divers chiens européens. Cette souche a un défaut, une malformation congénitale généralement désignée kyste dermoide. Les auteurs ont recherchés l'hérédité de cette condition, et contrairement à d'autres hypothèses, ils suggèrent qu'il s'agit d'un caractère héréditaire récessif. Les conséquences en sont discutées.
Zusammenfassung—Der Rhodesische "Ridgeback' ist eine neuzeitliche Zucht, die im Jahre 1922 standardisiert wurde. Ihr Ursprung ist in Sued Afrika, vollzogen durch Kreuzung von Hottentotten Hunden mit verschiedenen europaeischen Rassen. Der "Ridgeback' hat einen Fehler: eine congeni-tale Missbildung, die allgemein als "Dermoid Sinus' bekannt ist.
Die Autoren haben die Vererbung dieses Zustandes untersucht und schlagen vor, entgegen den Hypothesen anderer Autoren, sie als ein einfaches, recessives Merkmal zu bezeichnen.
Die sich daraus ergebenden Beziehungen werden eroertert.     

Dermoid sinus in a golden retriever

A case of dermoid sinus is reported in a golden retriever. The skin lesion was characterised by a fistulous tract in the dorsal cervical region. Surgical dissection revealed a cyst connected by a fibrous cord to the seventh cervical vertebra.     

Dermoid sinus and spina bifida in three dogs and a cat

This case series describes four cases of concomitant dermoid sinus and spina bifida in a Chinese crested dog, two Swedish vallhunds and a Burmese cat. The diagnosis was confirmed by computed tomography, computed tomography fistulography and pathology. Two dogs that showed abnormalities during neurological examination underwent magnetic resonance imaging. One of them had imaging findings interpreted as syringohydromyelia. All the dogs underwent surgery and the outcome was considered good in all the cases. Based on clinical and pathological examination as well as diagnostic imaging findings, two of the dermoid sinuses were classified as type IV, and two of them showed a previously unreported type of dermoid sinus. This new type is suggested here as type VI.     

Dermoid sinus and spinal malformations in a Yorkshire terrier: Diagnosis and follow-up

An unusual case of a Yorkshire terrier with a dermoid sinus associated with multiple spinal/costal malformations is described. The dog presented with ataxia and pain in the dorsal thoracic region. Diagnostic characterisation of the lesions was obtained with radiography, myelography and computed tomography. After surgical removal of the sinus, the dog showed marked clinical improvement over a two-year period.     

Dermoid sinus at the lumbosacral junction in an English springer spaniel

A dermoid sinus was identified in a springer spaniel that presented with hindlimb neurological deficits. The sinus was continuous with the dura mater at the level of the lumbosacral junction. The presence of hair and debris adjacent to neural tissue had elicited a myelitis. A dorsal laminectomy was required to allow complete surgical resection of the sinus. The dog's neurological status improved after treatment and this improvement was maintained over a five-month follow-up period.     

Trachyonychia associated with alopecia areata in a Rhodesian Ridgeback

Trachyonychia associated with alopecia areata was diagnosed in an 8-year-old Rhodesian Ridgeback. Clinical and histological findings are described in this respectively unreported and rare condition in the dog.