Congenital occipitoatlantoaxial malformation in a Warmblood mare

A 3-year-old Warmblood mare was presented with spinal ataxia of 3 months’ duration. Clinically, reduced mobility of the neck and a prominent atlas were identified. Neurological evaluation revealed hypermetria, circumduction and reduced proprioception, predominantly in the hindlimbs. Occipitoatlantoaxial malformation (OAAM) was diagnosed based on radiography and computed tomography, and confirmed on post-mortem magnetic resonance imaging and pathological examination. Both the atlas and axis were hypoplastic and dysplastic, and a fusion of the atlanto-occipital joint was found. A dynamic compression of the spinal cord was present at the first and second cervical vertebrae. Histologically, the spinal cord was degenerated due to compression. Furthermore, there were muscular malformations including a fibrotic obliquus capitis cranialis muscle, aplasia of parts of the rectus capitis muscles and presence of additional abnormal muscle. Such muscular abnormalities associated with OAAM have not been reported yet and this is the first report of a case of OAAM in a Warmblood horse.     

Congenital branchial apparatus malformation in a Haflinger colt

Objective— To report the diagnosis and treatment of a branchial apparatus anomaly (BAA) associated with a mandibular malformation in a foal.
Design— Clinical report.
Animal— Haflinger foal.
Methods— A 6-day-old foal had a fluctuating cystic mass in the pharyngeal (throatlatch) region, which changed in appearance after ingestion of milk. Upper airway endoscopy and diagnostic imaging (ultrasonography, radiography, computed tomography) permitted identification of the anatomic location of a communicating tract between the lumen of the cystic mass and the pharynx. The mass was surgically removed and communication with the pharynx ligated. Histologic appearance of this mass was consistent with a branchial cyst or sinus. The mandibular malformation was managed conservatively.
Results— Surgical resection of a third branchial sinus resulted in an excellent functional and cosmetic outcome. There was no evidence of any mandibular deformity 2 years later.
Conclusion— BAA may induce secondary mandibular deformation in utero and may cause respiratory compromise postpartum. Careful surgical dissection and removal of BAA resulted in an excellent outcome.
Clinical Relevance— BAAs should be included in the differential diagnosis of a throatlatch region mass in equine neonates. Complete surgical excision is recommended and full recovery of any associated mandibular deformity may be anticipated without additional treatment in very young patients.     

Post-traumatic peripheral arteriovenous fistula manifesting as digital haemorrhages in a cat: diagnosis with contrast-enhanced 3D CT imaging

Arteriovenous fistulae (AVF) are defined as congenital or acquired abnormal direct communications between an artery and a vein leading to abnormal blood circulation. This report describes an unusual manifestation of acquired peripheral AVF in a cat for which the diagnosis was confirmed by computed tomographic (CT) imaging and three-dimensional (3D) reconstruction. A 10-year-old female spayed domestic shorthaired cat was presented with a 2-month history of nonhealing, crusting, erosive and ulcerative skin lesions on the dorsal right forepaw. Severe chewing and biting, but not lameness, had been reported. Systemic abnormalities were not noted. Histopathology revealed increased numbers of thin-walled and slightly grouped vascular profiles in the superficial and mid-dermis, which were often markedly dilated and partially obscured by prominent hyaline deposits. There were a few pyknotic nuclear fragments and haemorrhages in vascular walls as well as multifocal luminal thrombosis with or without recanalization. Differential diagnoses included progressive angiomatosis with trauma or AVF with secondary regional venous hypertension. Computed tomographic images were acquired using a 16-slice Siemens Somotom Sensation CT scanner, and 3D images were created using the Voxar 3D software. Image reconstruction revealed tortuous aberrant vasculature on the medial aspect of the radius and around the carpus compared to normal vascularization on the contralateral limb. These changes were suggestive of the diagnosis of acquired peripheral AVF. The differential diagnosis for localized, nonhealing, haemorrhagic, crusted, erosive or ulcerative distal extremity skin lesions in cats should include acquired AVF, and diagnosis may be confirmed with contrast-enhanced CT imaging.     

2002: Hiatal hernia in a puppy

A sliding hiatal hernia (where the terminal oesophagus, oesophagogastric junction and part of the stomach move cranially through a diaphragmatic defect) was diagnosed in a 4-month-old, Shar-Pei puppy presented for evaluation of regurgitation. The diagnosis was confirmed using radiography. Herniorraphy consisted of repositioning the stomach within the abdomen, plicating the diaphragmatic hiatus and performing a tube gastropexy to the left abdominal wall. Veterinary practitioners should have a high index of suspicion of hiatal hernia in young puppies, particularly Shar-Peis and British Bull Dogs, that present with persistent vomiting or regurgitation.     

Ethmoidal encephalocoele associated with seizures in a puppy

A six-month-old puppy was presented for investigation of a seizure disorder. Neurological examination indicated persistent cerebral dysfunction in the absence of any identifiable metabolic disorder and magnetic resonance imaging revealed extension of the rostral lobes of the cerebrum into the nasal cavity. Despite symptomatic treatment, the puppy continued to exhibit seizures and appeared distressed and so was euthanased. Postmortem examination confirmed the abnormal anatomy of the rostral part of the brain and absence of a cribriform plate. There was extensive grey and white matter degeneration plus intraparenchymal haemorrhage in the abnormal brain tissue. The findings are consistent with a diagnosis of ethmoldal encephalocoele--a condition that has not previously been reported in the dog.     

Congenital hepatic arteriovenous fistula with intrahepatic portosystemic shunt and aortic stenosis in a dog

Examination of a 2-month-old male golden retriever presented to the hospital revealed malnutrition, ascites, cardiac murmur and hyperammonemia. Identification of subaortic stenosis and hepatic arteriovenous fistula was made through ultrasonography and angiocardiography. In addition, intrasurgical mesenteric portography showed an intrahepatic portosystemic shunt. The dog did not show portal hypertension and secondary multiple extrahepatic portosystemic shunts. Surgical correction was attempted after medical treatment. The hepatic artery branch which was connected to the hepatic arteriovenous fistula was separated, and completely ligated using silk ligature. However, the separation of the intrahepatic shunt blood vessel was unsuccessful and the dog died 15 hr postoperatively.     

Juvenile cellulitis in a puppy

An 8-week-old, male Labrador retriever presented for acute onset of left hind limb lameness. This rapidly progressed to juvenile cellulitis, characterized by dermatitis of the face, otitis externa, regional lymphadenopathy, lethargy, and depression. The puppy made a full recovery on glucocorticoid therapy.     

Congenital malformation of the large colon causing colic in a horse

An abnormal mesocolic attachment which resulted in a stellate malformation of the left colon adjacent to the pelvic flexure was suspected to be the cause of intermittent episodes of colic in a horse. Resection and side-to-side anastomosis of the large colon at the level of the sternal and diaphragmatic flexures was performed and the horse made an uneventful recovery from surgery. Only minor serum biochemical changes were observed in the initial postoperative period. The abnormal mesocolic attachment was probably a congenital anomaly.     

Horner's syndrome in a puppy

A puppy was presented with unilateral Horner's syndrome thought to have been in existence since the eyes first opened. No other clinical signs were evident and the condition was attributed to trauma during assisted birth. All abnormalities resolved spontaneously by 11 weeks of age.     

Purulent pericarditis in a puppy

An eight-week-old female Cavalier King Charles spaniel was presented with tachypnoea, pyrexia and distended jugular veins following bite injuries to the chest and abdomen. Pericardial effusion was suspected from clinical, electrocardiographic and radiographic findings, and confirmed by echocardiography. Pericardiocentesis was carried out and the purulent fluid aspirated yielded Pasteurella multocida on culture. After drainage, broad spectrum antibiotic therapy was instituted and the puppy went on to make an excellent clinical recovery. Despite this, some hyperechoic areas of myocardium were observed on echocardiography and occasional ventricular premature complexes were seen on electrocardiography. These were probably the result of an associated myocarditis.     

Gastrointestinal cryptosporidiosis in a puppy

An 8-week-old female Yorkshire terrier with a history of weakness, diarrhea and intestinal isosporiasis was euthanized and a post mortem examination performed. Histologically, there was severe gastrointestinal cryptosporidiosis, severe intestinal isosporiasis and thymic lymphoid depletion. PCR revealed visible bands for the actin and 18S rRNA genes but not for the acetyl CoA synthetase gene for Cryptosporidium spp. The PCR product for the actin gene was sequenced and found to have a 97.6-99.8% similarity to that of Cryptosporidium canis. To our knowledge, this is the first report of gastric cryptosporidiosis in a canine.     

Lead toxicosis in a puppy

After showing clinical and radiographic signs of a gastrointestinal foreign body, a 5-month-old puppy began head pressing, which progressed to convulsions. Hematological abnormalities suggested lead poisoning; serum lead was 2.61 mumol/L. The puppy made a complete recovery after intensive treatment for lead toxicosis.