Use of continuous-flow peritoneal dialysis for the treatment of acute renal failure in an adult horse

A 15-year-old Paso Fino gelding was evaluated because of acute renal failure following an episode of exertional rhabdomyolysis. The horse was azotemic and treated conservatively at another referral practice with no improvement in the azotemia. With conservative treatment and intermittent peritoneal dialysis, the horse had minimal improvement. Continuous-flow peritoneal dialysis (CFPD) was instituted on day 7 and continued for 3 consecutive days. Dramatic changes in the horse's attitude and serum creatinine concentration were detected within the first 24 hours of CFPD treatment. The horse remained hospitalized for 23 days; within 3 months of discharge, serum BUN and creatinine concentrations had returned to within the reference ranges and the horse had resumed normal activity. In adult horses, it appears that CFPD can be used to successfully treat acute renal failure that is refractory to conventional treatments.     

Intermittent peritoneal dialysis for the treatment of acute renal failure in two horses

Acute renal failure (ARF) in the horse is most commonly due to decreased renal perfusion or a nephrotoxic insult. Conventional therapy includes the administration of i.v. fluids, frusemide, mannitol and/or dopamine, as well as general supportive care. However, not all horses with ARF will respond to these treatments. In these cases, peritoneal dialysis is a viable therapeutic option. This case report describes 2 horses with ARF that was refractory to conventional therapy. Intermittent peritoneal dialysis was used effectively in both cases for treatment of the ARF. Dialysis was easy to perform and associated only with minor complications. To the authors' knowledge, this is the first report describing the successful use of intermittent peritoneal dialysis in the treatment of ARF in the horse.     

ULTRASONOGRAPHY AS AN AID IN THE DIAGNOSIS OF RENAL CELL CARCINOMA IN A HORSE

Clinical diagnosis of renal tumors in the horse has been difficult because the traditional diagnostic techniques are inadequate. Because of this shortcoming, early publications rarely reported antemortem diagnosis of primary renal tumors. Conventional radiographic techniques cannot effectively outline kidneys in the adult horse. With the advent of ultrasonography, a new dimension to the evaluation of the large-animal kidney has been introduced. Percutaneous diagnostic ultrasonography provides a noninvasive method of examining both kidneys. This report describes a 15 year-old Tennessee Walking Horse mare presented for evaluation of a mass in the sublumbar region, polyuria and polydipsia. Clinical examination and laboratory test results suggested intra-abdominal neoplasia. Two-dimensional ultrasonographic images of the mass were consistent with renal neoplasia. Histologic diagnosis of ultrasound-guided renal biopsy was renal tubular cell carcinoma.     

The Use of Pneumatic Impact Lithotripsy in a Laparoscopic Retrieval Pouch for Removal of Large Cystoliths in Two Female Horses

Two mares, aged 15 and 21 years, were examined because of urinary incontinence, intermittent hematuria, and urine scalding. On admission of both horses, physical parameters were within normal limits and urine scalding of the skin at the ventral perineum was noted. Transrectal palpation and cystoscopy revealed a large type I cystolith (>10 cm) with associated hyperemia and focal ulceration of the bladder mucosa. In horse 1, hemogram, serum biochemical analysis, and renal ultrasound were not performed because of owner finances. In horse 2, results from hematological and serum biochemical analysis were unremarkable and renal ultrasonography did not reveal any abnormalities. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch was performed under cystoscopic guidance after caudal epidural anesthesia, with the horses standing and under sedation. A laparoscopic retrieval device was passed alongside a flexible endoscope into the urinary bladder and the cystolith was manipulated into the pouch. A customized single stainless-steel rod scaler attached to an air compressor was used for fragmentation of the cystolith contained within the retrieval pouch. Lithotripsy time was 42 minutes for horse 1 and 31 minutes for horse 2. Both horses were released from hospital the day of surgery. Both horses were continent and voided normal streams of urine for the duration of the follow-up periods of 27 and 19 months for horse 1 and horse 2, respectively. Pneumatic impact lithotripsy in a laparoscopic retrieval pouch provided a time-efficient and minimally invasive surgical treatment option for removal of large cystoliths in mares.     

Urethrolithiasis and nephrolithiasis in a horse.

A 9-year-old, quarter horse gelding with obstructive urethrolithiasis was treated with a perineal urethrostomy. The horse's condition deteriorated and abdominocentesis confirmed septic uroperitonitis. The horse was euthanized and postmortem examination revealed peritonitis, a tear in the lateral wall of the bladder, and a nephrolith within the left renal pelvis.     

Streptococcal toxic shock in a horse

A 14-year-old horse was admitted to the veterinary hospital for treatment of tachycardia and lethargy. Initial diagnoses were ventricular tachycardia and renal dysfunction. During hospitalization other findings included fever, renal failure, hepatic failure, hypotension, and intermittent ventricular arrhythmias. Bacteriologic culture of 2 blood samples collected during febrile crises 7 days apart yielded Streptococcus mitis. These culture results along with other clinical and physical examination findings fulfill the criteria for a diagnosis of streptococcal toxic shock syndrome, previously described for humans and dogs. To our knowledge this is the first reported instance of this disease in a horse.     

Diseases of the kidneys

Ultrasound examination offers important diagnostic and prognostic information in renal disease of the horse. Differentiation between acute nephrosis and chronic renal disease can usually be made because of the advanced degree of morphologic change usually prevalent in chronic conditions. Dilatations of the recesses and pelvis (hydronephrosis) as well as the relative thickness of the renal cortex and medulla are readily determined. Mineral densities (calculi) are recognizable by their characteristic acoustic shadowing.     

EQUINE RENAL ULTRASONOGRAPHY: NORMAL AND ABNORMAL

The kidneys of three clinically normal horses were evaluated ultrasonographically, utilizing a standardized approach. The normal renal architecture, including cortex, medulla, pyramids, renal sinus fat, collecting system, and intrarenal vessels, was evaluated.
A horse with hematuria was examined in the same manner and a mass was found in the right renal pelvis.
Ultrasonographic determinations were correlated with gross anatomy, clinical signs, and pathologic findings of a renal pelvic adenoma.     

CASE REPORT AND CLINICAL REVIEW: Acute lameness associated with osseous metastasis of a peri-renal carcinoma in a horse

We present a case of aggressive metastatic carcinoma in a horse that was initially presented for shoulder lameness. Although radiography and scintigraphy were useful for localising a lesion in the proximal humerus, subsequent development of non-specific signs of systemic disease prompted further evaluation. Haematology and blood biochemistry, urinalysis and ultrasonography were all instrumental in identifying renal involvement. A diagnosis of a peri-renal mass causing secondary renal failure prompted euthanasia of the horse because of the poor prognosis. Antemortem findings were supported by necropsy, with secondary lesions also identified in the spleen, liver, 8th left rib and proximal humerus. Histological examination yielded a diagnosis of undifferentiated metastatic carcinoma.     

Tissue distribution and blood levels of gamma-glutamyl transferase in the horse.

In the horse, gamma-glutamyl transferase (GGT) was found to be mainly located in the kidneys, liver and pancreas. As renal lesions are followed by a urinary escape of enzyme, it can be assumed that if there are raised serum enzyme levels then the source will be chiefly from the liver and pancreas. In the blood, GGT can be measured either in plasma or serum. Its mean level in 58 horses was 12 U/L. This level was not affected by moderate dilution or slight haemolysis and its activity was only slightly decreased by storage at--30 degrees C. The relative hepatic specificity of this enzyme and its easy measurement make it a potentially very useful measure of liver dysfunction in the horse.     

Neoplasia of captive yellow sea horses (Hippocampus kuda) and weedy sea dragons (Phyllopteryx taeniolatus)

Syngnathidae is the family of fish that includes sea horses, pipefish, and sea dragons. To date, only a single publication has described neoplasia in syngnathids, a fibrosarcoma of the brood pouch in an aquarium-reared lined sea horse (Hippocampus erectus). From 1998 until 2010, the Toronto Zoo submitted 172 syngnathids for postmortem; species included the spotted or yellow sea horse (Hippocampus kuda), the pot-bellied sea horse (Hippocampus abdominalis) and the weedy sea dragon (Phyllopteryx taeniolatus). Seven neoplasms and two neoplastic-like lesions were identified from these cases. Under light microscopy, the neoplasms had morphological characteristics of a cardiac rhabdomyosarcoma, renal adenocarcinoma, renal adenoma, renal round cell tumors, which were likely lymphomas, exocrine pancreatic carcinoma, and intestinal carcinoma. Of these neoplasms, four had clear evidence of metastasis: the pancreatic and intestinal carcinomas and both round cell tumors. As syngnathids are highly fastidious animals, they can be difficult to maintain in captivity. In order to improve their husbandry, preventative and palliative care, as well as treatment, it is important to investigate and document the types of diseases affecting syngnathids.     

Halicephalobus gingivalis (H. deletrix) infection in two horses in southern California.

Two horses, a 16-year-old male Holsteiner and a 5-year-old male miniature horse, were diagnosed with halicephalobiasis at the California Veterinary Diagnostic Laboratory System, San Bernardino Branch, in April and June of 1998. Over a period of 4 weeks, the Holsteiner horse developed renal dysfunction, blepharospasm, and blindness in the right eye. A 15-cm-diameter mass was detected on ultrasound examination in the right kidney. Terminally, the animal developed seizures and was euthanized. The miniature horse had a 6-week-long illness characterized by testicular enlargement and uveitis. This animal developed ataxia and died. Necropsy examination revealed bilateral enlargement of the kidneys in both horses, petechial hemorrhages of the optic nerve (Holsteiner), and a diffusely firm and enlarged left testicle (miniature horse). Microscopic evaluation of tissues revealed granulomatous nephritis, optic neuritis, retinitis, and encephalitis in both horses and orchitis in only the miniature horse with intralesional rhabditiform nematodes. Halicephalobus gingivalis was found in the urine sediment of both animals and in semen of the Holsteiner horse.     

Renal hypoplasia and dysplasia in an American miniature foal

Diagnostic imaging, including computed tomography, of a two-month-old foal with renal failure indicated that its right kidney was probably absent and that its left kidney was abnormal in shape. The foal was stabilised and released, but three days later its clinical signs recurred. Postmortem examination revealed renal hypoplasia and dysplasia, the first reported case of this condition in an American miniature horse.     

Morphological Observation of a Horseshoe (fused) Kidney and its Vascular Pattern in a Horse

The present study describes the anatomical and microscopic features of a horseshoe kidney that was found in a 7-year-old male horse. The specimen consisted of two kidneys joined at their caudal poles by an isthmus composed of renal parenchyma and situated caudal to the caudal mesenteric artery. Six main renal arteries arose from the aorta and the external iliac arteries and ramified into 21 branches before entering the kidney. A hypoplastic and ectopic left testis, located in the inguinal canal, was observed as an associated anomaly.     

Azathioprine for treatment of immune-mediated thrombocytopenia in two horses.

Azathioprine, a thiopurine antimetabolite used in the treatment of immune-mediated thrombocytopenia in human beings and dogs, was used in 2 cases of immune-mediated thrombocytopenia in horses that failed to respond to corticosteroid therapy alone. Platelet counts were increased to acceptable values in both horses. One horse returned to a successful racing career, and the other was euthanatized after developing renal disease and mild laminitis.     

Renal carcinoma as a cause of sudden death in an aged horse

This report describes rupture of a primary renal carcinoma as a cause of sudden death of an aged horse that presented with mild clinical signs of colic. The case is considered in the context of the few reported cases in the veterinary literature. The most striking feature of this case was the absence of prodromal signs prior to a catastrophic rupture of the tumour during a diagnostic work‐up.     

RENAL COCCIDIOSIS OF THE HORSE ASSOCIATED WITH KLOSSIELLA EQUI

SUMMARY Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.     

Some characteristics of the antibodies involved in allergic skin reactions of the horse to biting insects

Active skin tests were carried out on a horse with sweet itch using extracts of various biting insects and the resulting reactions compared with those produced when rabbit anti-human IgE was injected intradermally into a normal horse. The horse with sweet itch produced a large reaction to an extract of Culicoides which was similar to those produced by anti-human IgE. Absorption of serum from an allergic horse with anti-human IgE reduced its ability to sensitize skin of a normal horse to challenge with the extract of Culicoides. Passive transfer of allergic horse serum to guinea-pig skin gave significant reactions when challenged after a latent period of 4 h but not after 24 h.     

Cryoglobulinemia in a horse.

Cryoglobulin was isolated from a horse which had glomerulo-nephritis and a history of swelling and skin ulcers of the limbs in the winter. The isolated cryoglobulin showed a single peak on a gel permeation chromatography column with an apparent molecular mass (Mr) of 180,000 which could be divided into two gamma bands by cellulose acetate electrophoresis. Immunoelectrophoretic analysis revealed that the cryoglobulin formed two precipitation lines with anti-horse IgG. Spur formation was observed when the cryoglobulin and the IgG purified from a normal healthy horse were cross-reacted with anti-horse IgG on a double diffusion gel. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis under the reduced conditions showed that the isolated cryoglobulin consisted of two doublets of polypeptides with Mr values of 52,000 and 50,000, and 31,000, and 30,000, corresponding to the heavy chain and the light chain of the horse IgG molecules, respectively. These results suggest that the isolated cryoglobulin might consist of two different IgG molecules, and that the manifestations such as foot swelling with skin ulcers and renal failures were all induced by the cryoglobulin in the serum.     

Persistent Hematuria as a Result of Chronic Renal Hypertension Secondary to Nephritis in a Stallion

A 13-year-old Lusitano stallion was referred to our institution with a history of severe hematuria for 8.5 months. The origin of the hematuria was determined to be the left kidney. The diagnostic workup failed to identify obstructive, infectious, or neoplastic conditions. The history and ultrasonographic examination suggested a chronic condition. The stallion was subjected to left nephrectomy because of the persistent hematuria and anemia. A histopathological examination detected lesions, which were compatible with chronic nephritis and vascular renal hypertension. It is hypothesized that changes in the normal parenchymal architecture produced a vascular aberration that led to renal hypertension, with subsequent blood extravasation and hematuria. The horse recovered completely after nephrectomy.