Bilateral renal dysplasia with nephron hypoplasia in a foal

Bilateral renal dysplasia and nephron hypoplasia was diagnosed in a Quarter Horse foal with clinical signs of lethargy, convulsions, and diarrhea. Laboratory evaluation revealed anemia, hypoproteinemia, leukopenia, hyponatremia, hypochloremia, and hyposmolality. The foal also had high concentrations of serum creatinine, BUN, and phosphorus. Evaluation of urinary indices revealed a high ratio of urinary gamma-glutamyl-transferase activity to concentration of creatinine, as well as a high fractional clearance ratio of sodium and potassium. Intravenous treatment with saline solution (0.9% NaCl) and antimicrobials provided only temporary resolution of some of the abnormalities. Diagnosis was partly established by histologic evaluation of renal tissue obtained via an ultrasonographically guided biopsy and was confirmed at necropsy. Pathologic changes in the kidney were unique in that the size of the kidneys, along with the appearance and number of glomeruli, were essentially normal despite marked hypoplasia of nephron tubules in the medulla.     

Incomplete nasomaxillary dysplasia in a foal.

Atresia of the nasal punctum is the most common congenital anomaly for the equine nasolacrimal system. Nasomaxillary dysplasia has not been previously documented in foals, is of unknown etiology, and appears to be a rare condition. Conjunctivomaxillary sinostomy was successful in resolving the epiphora.     

Bilateral hypoplasia of the soft palate in a foal

Bilateral hypoplasia of the soft palate and aspiration pneumonia occurred in a Standardbred foal. The filly was presented with a history of illthrift, dyspnoea, coughing and bilateral nasal discharge. Abnormal sounds (crackels and wheezes) were auscultated over all lung fields and the cervical trachea. Endoscopy revealed a shortened soft palate with a uvula-like mass protruding from the free border into the nasopharynx. Mucopurulent material was present in the trachea. Samples obtained by tracheal wash were submitted for cytology, culture and sensitivity testing. Results indicated a septic inflammatory process. On lateral radiographs of the thorax there were patchy areas of consolidation and air bronchograms. The foal was euthanased. Necropsy confirmed the presence of a palatal defect and aspiration pneumonia of moderate severity. No other congenital abnormalities were present.     

Suspected ivermectin toxicosis in a miniature mule foal causing blindness

A 9-week-old miniature mule foal presented to the Veterinary Medical Teaching Hospital for acute blindness, ataxia, and depression following an overdose of an over-the-counter ivermectin-based de-worming medication. Ophthalmic examination and electrodiagnostic evaluation eliminated outer retinal abnormalities as the primary cause of the bilateral blindness, implicating instead a central neurologic effect of the drug. With symptomatic and supportive care, the foal recovered fully and regained its vision.     

Surgical treatment of tarsometatarsal joint luxation in a miniature horse foal

A 2-week-old Miniature Horse foal was referred for evaluation and treatment of a luxated right tarsometatarsal joint. Treatment consisted of closed reduction and internal fixation using two partially threaded Steinmann pins placed in normograde fashion through the tuber calcis into the proximal third metatarsus. Traumatic luxation has been reported to occur in the tarsocrural, proximal intertarsal and tarsometatarsal joints within the equine tarsus. Treatment for luxation of the distal intertarsal joint has not been documented. The treatment method most commonly suggested for tarsal luxation is closed reduction and cast immobilisation. Internal fixation using lag screws and plating has also been described. A combination of internal fixation and external coaptation is thought to achieve maximal stability and allow faster convalescence in cases of tarsal luxation. This case report describes for the first time a technique using two Steinmann pins to achieve successful internal fixation of a traumatic tarsometatarsal joint luxation in a 2-week-old Miniature Horse foal.     

Surgical management of atresia ani and perineal hypospadias in a miniature donkey foal

A 3‐week‐old miniature donkey was evaluated for tenesmus and constipation resulting from atresia ani. The foal was also diagnosed with hypospadias extending from its perineum to the glans penis and caudoventral penile deviation. A common opening on the perineum allowed faeces and urine to be excreted together, preventing complete intestinal obstruction. Surgical correction of the atresia ani was performed, along with resection of the incomplete urethra, nonfunctional penis and testes. The anal and perineal reconstruction procedures resolved the miniature donkey's difficulty in defaecation. The anourethral portion of the repair healed, but the anoperineal portion dehisced and healed by second intention. The client was satisfied with the outcome.     

Renal dysplasia in a pig

A diagnosis of renal dysplasia was made in a six-month-old, male, mixed-breed pig. Both kidneys were small, firm, slightly pitted, and contained an indistinct corticomedullary junction. Histologically, primitive tubules were present surrounded by an abundant loose, mesenchymatous stroma. Occasionally, tubules were markedly dilated and lined by a pseudostratified columnar epithelium forming epithelial mats that obscured the lumina. Immature glomeruli were present. Multifocal glomerular sclerosis was evident. Other mature glomeruli were enlarged and characterized by mesangial cell hyperplasia forming an arborizing pattern.     

Phalangeal and navicular bone hypoplasia and hoof malformation in the hind limbs of a foal

Anatomical anomalies in the hind feet of a seven month old Appaloosa foal were identified and investigated through the use of gross anatomical dissection, radiography and angiography. Abnormalities were restricted to the distal aspect of both hind legs, the right hind leg being more severely affected. Anatomically the right foot resembled that of an equine fetus of approximately 120 days gestational age. Disruption of vascular perfusion to hoof structures was evident in both hind legs and was related to areas of abnormal bone conformation as well as to areas of abnormal ossification and calcification. Phalangeal and navicular bone hypoplasia were apparent as were soft tissue and joint anomalies. Although the etiology of the defects identified remains obscure, several theories are suggested, namely heritability, acquired defects and the possible teratogenic effects of clenbuterol.     

Congenital kyphosis secondary to lumbar vertebral hypoplasia causing paraparesis in a Friesian foal

A 5‐day‐old Friesian colt was presented with a history of severe bilateral pelvic limb weakness since birth. Clinical examination revealed a painful dorsal deviation of the spinous processes of the lumbar vertebrae, pelvic limb paraparesis and grade 4/5 ataxia. Radiographic examination revealed kyphosis due to hypoplasia and malformation of the 5 lumbar vertebrae present. At myelography performed immediately after euthanasia, dorsal deviation of the myelographic contrast column was demonstrated at the level of T18–L4 with suspected spinal cord compression noticeable at L1. There was no lateral deviation of the spinal cord or scoliosis of the vertebrae visible.     

Severe hyperkalaemia associated with renal dysplasia in a 2-day-old foal

A 2-day-old filly foal presented with signs of depression, recumbency and inappetence. Blood analyses revealed hypoalbuminaemia, hyperfibrinogenaemia, hyperglycaemia and hyperkalaemia. The foal deteriorated despite intensive treatment and was subjected to euthanasia. At post mortem examination, the urinary bladder, ureters and kidneys appeared normal grossly. Histologically both kidneys showed disorganised development with the presence of structures inappropriate for a foal of this age, including primitive glomeruli, immature renal tubules and persistent metanephric ducts. Based on these findings a diagnosis of bilateral renal dysplasia was made.     

Renal dysplasia in boxers and Finnish harriers

Puppies from two litters of dogs were found to have severe polyuria and polydipsia. Four of the dogs were investigated by means of clinical examination, haematological and biochemical analysis, and urinalysis. A modified water deprivation response test was also performed in two of the dogs. Renal changes on postmortem examination in three of the dogs were found to be consistent with renal dysplasia. A possible explanation for the finding of hyposthenuria and the extreme polyuria and polydipsia in association with renal dysplasia may be lack of response to antidiuretic hormone owing to anomalous maturation of the renal tubules. Six other puppies from the two litters of dogs did not show any clinical signs of polyuria and polydipsia, although postmortem examination in one of them also revealed renal dysplasia. The clinical features of renal dysplasia may therefore vary greatly between individuals.