Ultrasonographic findings in horses with right dorsal colitis: five cases (2000-2001)

OBJECTIVE: To determine whether ultrasonography would be useful in the diagnosis of right dorsal colitis in horses. DESIGN: Retrospective study. ANIMALS: 5 horses with right dorsal colitis and 15 healthy adult horses. PROCEDURE: Mural thickness and appearance of the right dorsal colon were determined from ultrasonographic images obtained at right intercostal spaces 10, 11, 12, 13, and 14. RESULTS: The right dorsal colon could be imaged most consistently at the right 11th, 12th, and 13th intercostal spaces, below the margin of the lung and axial to the liver. Mural thickness measured from ultrasonographic images was significantly greater in horses with right dorsal colitis than in healthy horses. The right dorsal colon in affected horses had a prominent hypoechoic layer associated with submucosal edema and inflammatory infiltrates. Successful treatment of 1 horse with right dorsal colitis was associated with a decrease in mural thickness coincident with an increase in serum albumin and total protein concentrations and weight gain. A decrease in mural thickness was also observed in a second horse treated for right dorsal colitis that was not associated with healing of the right dorsal colon or an increase in serum albumin concentration but rather thinning of a segment of the right dorsal colon that eventually ruptured. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ultrasonographic measurement of mural thickness and evaluation of the appearance of the right dorsal colon may be useful in the diagnosis of right dorsal colitis in horses.     

Peritoneal dialysis in cats with acute kidney injury: 22 cases (2001-2006)

Background: Peritoneal dialysis (PD) has been described for use in animals with acute kidney injury refractory to fluid therapy. However, no study has examined the use of PD in a large group of cats. Hypothesis: PD is an important adjunctive therapy to treat acute kidney injury in cats. Animals: The medical records of 22 cats with acute kidney injury that had received PD were examined. Animals were excluded if acute uremia was a result of postrenal causes such as uroabdomen or urethral obstruction. Methods: Medical records were reviewed for the following: indication for PD, outcome, number of cycles performed, survival time, and predialysis and postdialysis results for blood urea nitrogen (BUN), creatinine, potassium, chloride, sodium, phosphorus, total protein, and albumin concentrations, and urine output.

Results:

Indications for PD include acute‐on‐chronic kidney injury, acute kidney injury caused by toxins, bilateral ureteroliths, bilateral ureteral ligation as a complication of ovariohysterectomy, and unknown causes. The median survival time for all cats on PD was 4 days, although the median survival time for the cats that were discharged was 774 days. The most common complications were dialysate retention and sequestration of dialysate SC. There was a significant (P< .05) decrease between predialysis and postdialysis results for BUN, creatinine, potassium, phosphorus, total protein, and albumin concentrations. There was a significant (P< .05) difference in survival times between sexes. Conclusions and Clinical Importance: PD is an effective option for treatment of cats with acute kidney injury refractory to fluid therapy.     

Radiographic evidence of degenerative joint disease in geriatric cats: 100 cases (1994-1997)

OBJECTIVE: To determine prevalence of radiographic evidence of degenerative joint disease (DJD) in geriatric cats. DESIGN: Retrospective study. POPULATION: 100 cats > 12 years of age. PROCEDURE: One investigator reviewed radiographs and for each articulation (or group of articulations) that was visible assigned a grade of severity (0, 1, 2, 3) for DJD. Another investigator reviewed medical records and recorded signalment, environment, previous disease, diseases evident at time of radiography, FeLV vaccination and infection status, feline immunodeficiency virus serologic status, serum creatinine concentration, serum globulin concentration, and any other important findings. Associations between DJD of grade 2 or 3 and variables recorded from the medical record were determined. RESULTS: Radiographic evidence of DJD was evident in 90% of cats. Neurologic disease was associated with lesions in the lumbosacral portion of the vertebral column. Severe lesions were found in 17% of the elbow joints, but an underlying cause was not determined. CONCLUSIONS AND CLINICAL RELEVANCE: Degenerative joint disease was detected radiographically in most geriatric cats and may be an overlooked cause of clinical disease. Clinicians should be alert to the possibility that DJD is associated with neurologic signs.     

Ultrasonographic findings in dogs with hyperammonemia: 90 cases (2000-2002)

OBJECTIVE: To determine ultrasonographic abnormalities in dogs with hyperammonemia. DESIGN: Retrospective study. ANIMALS: 90 client-owned dogs with hyperammonemia. PROCEDURE: Ultrasonography of the abdominal vessels and organs was performed in a systematic way. Dogs in which the ultrasonographic diagnosis was a congenital portosystemic shunt were included only if they underwent laparotomy or necropsy. Dogs in which the abdominal vasculature appeared normal and dogs in which the ultrasonographic diagnosis was acquired portosystemic shunts and portal hypertension were included only if liver biopsy specimens were submitted for histologic examination. RESULTS: Ultrasonography excluded portosystemic shunting in 11 dogs. Acquired portosystemic shunts were found in 17 dogs, of which 3 had arterioportal fistulae and 14 had other hepatic abnormalities. Congenital portosystemic shunts were found in 61 dogs, of which 19 had intrahepatic shunts and 42 had extrahepatic shunts. Intrahepatic shunts originated from the left portal branch in 14 dogs and the right portal branch in 5. Extrahepatic shunts originated from the splenic vein, the right gastric vein, or both and entered the caudal vena cava or the thorax. Ultrasonography revealed splenic-caval shunts in 24 dogs, right gastric-caval shunts in 9 dogs, splenic-azygos shunts in 8 dogs, and a right gastric-azygos shunt in 1 dog. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ultrasonography is a reliable diagnostic method to noninvasively characterize the underlying disease in dogs with hyperammonemia. A dilated left testicular or ovarian vein was a reliable indicator of acquired portosystemic shunts.     

Ultrasonographic findings in horses with cholelithiasis: eight cases (1985-1987)

Cholelithiasis and/or obstructive biliary tract disease was diagnosed ultrasonographically in 8 horses, 5 to 15 years old. Ultrasonographic findings revealed greater than normal amount of hepatic parenchyma in the right side of the abdomen in 8 horses and in the left side in 3 horses. The echogenicity of the liver was greater than normal, and thick distended bile ducts were seen in all horses. Choleliths were imaged ultrasonographically in 6 horses. Subsequently, postmortem findings in 6 horses revealed periportal and intralobular fibrosis, moderate bile duct dilatation, proliferation, and cholestasis. One or more choleliths were found in all horses. Ultrasonographic findings accurately depicted the histologic changes in the hepatic parenchyma in horses with cholelithiasis.     

Ultrasonographic findings in dogs and cats with oxalate nephrosis attributed to ethylene glycol intoxication: 15 cases (1984-1988)

Renal ultrasonographic findings in 12 dogs and 3 cats determined to have oxalate nephrosis presumed to be secondary to ethylene glycol intoxication were examined. Ultrasonographic changes varied from mild to marked increases in renal cortical echogenicity. A pattern of greater than normal cortical and medullary echogenicity with persistence of areas of lesser echo intensity at the corticomedullary junction and central medullary regions was observed. This pattern, termed the halo sign, was recognized in 7 dogs and 1 cat concurrent with the development of clinical anuria. Ultrasonographic patterns in these clinical cases were similar to those observed in a previous study of dogs with experimentally induced ethylene glycol nephrosis. Ultrasonographic findings were not considered pathognomonic of ethylene glycol nephrosis. Due to the high death rate reported in the cases surveyed, detection of ultrasonographic changes was considered to warrant a guarded to poor prognosis. Because of the association of the halo sign with anuria, its detection was considered to warrant a grave prognosis.     

Cerebral astrocytoma in four cats: clinical and pathologic findings

Cerebral astrocytoma was diagnosed in 4 cats. A long-standing history of seizures followed by an increase in frequency of uncontrolled seizures were prominent features in these cats. Anticonvulsants provided effective seizure control in 3 cats for a period of 1 to 3 years. On initial and subsequent neurologic examinations, all cats were postictal and had focal neurologic deficits. In 2 cats, there were focal EEG patterns consistent with the neuroanatomic diagnosis of the tumor. White blood cell pleomorphism of the CSF was determined in the cats that underwent CSF analysis. Pathologic findings in all cats included tumor necrosis and edema, compression of the opposite hemisphere, and invasion of the third and lateral ventricles.     

Association of magnetic resonance imaging findings and histologic diagnosis in dogs with nasal disease: 78 cases (2001-2004)

OBJECTIVE-To determine whether magnetic resonance imaging (MRI) features correlated with histologic diagnosis in dogs with nasal disease. DESIGN-Retrospective case series. ANIMALS-78 Dogs undergoing MRI for evaluation of nasal disease. PROCEDURES-Medical records and MRI reports of dogs were reviewed to identify MRI features associated with histologic diagnosis. Features evaluated were presence of a mass effect, frontal sinus involvement, sphenoid sinus involvement, maxillary recess involvement, nasopharyngeal infiltration by soft tissue, nasal turbinate destruction, vomer bone lysis, paranasal bone destruction, cribriform plate erosion, and lesion extent (ie, unilateral vs bilateral). RESULTS-33 Dogs had neoplastic disease, 38 had inflammatory rhinitis, and 7 had fungal rhinitis. Lesion extent was not significantly associated with histologic diagnosis. Absence of a mass effect was significantly associated with inflammatory disease. However, presence of a mass was not specific for neoplasia. In dogs with evidence of a mass on magnetic resonance (MR) images, nasal turbinate destruction, frontal sinus invasion, and maxillary recess invasion were not useful in distinguishing neoplastic from nonneoplastic disease, but cribriform plate erosion, vomer bone lysis, paranasal bone destruction, sphenoid sinus invasion, and nasopharyngeal invasion were. CONCLUSIONS AND CLINICAL RELEVANCE-Results suggested that in dogs with nasal disease, the lack of a mass effect on MR images was significantly associated with inflammatory disease. In dogs with a mass effect on MR images, vomer bone lysis, cribriform plate erosion, paranasal bone destruction, sphenoid sinus invasion by a mass, and nasopharyngeal invasion by a mass were significantly associated with a diagnosis of neoplasia.     

Evaluation of complications and prognostic factors associated with administration of total parenteral nutrition in cats: 75 cases (1994-2001)

OBJECTIVE: To determine frequency and types of complications, prognostic factors, and primary diseases affecting clinical outcome associated with administration of total parenteral nutrition (TPN) in cats. DESIGN: Retrospective study. ANIMALS: 75 cats that received TPN for > or = 12 hours. PROCEDURE: Medical records were reviewed, and information was obtained on signalment, history, problems at initial evaluation, physical examination findings, weight and changes in weight while receiving TPN, duration in the hospital before initiation of TPN, the type of TPN catheter used, duration of TPN administration, and final diagnosis. Laboratory results obtained immediately prior to TPN and at 24 and 96 hours following initiation of TPN administration were compared. RESULTS: Reports of weight loss at initial evaluation, hyperglycemia at 24 hours, or diagnosis of chronic renal failure were significantly associated with increased mortality rate. Greater serum albumin concentrations prior to and at 96 hours following TPN administration were significantly associated with decreased mortality rate. Mechanical and septic complications were infrequent and not associated with increased mortality rate. Most cats had multiple diseases. The overall mortality rate was 52%; among 75 cats, 36 recovered, 23 were euthanatized, and 16 died as a result of their primary illness or complications associated with their illness. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated high mortality rate in cats maintained onTPN that had multiple concurrent diseases associated with a poor prognosis. Indicators of poor prognosis included a history of weight loss, hyperglycemia at 24 hours following TPN administration, hypoalbuminemia, and chronic renal failure.     

Feline idiopathic cardiomyopathy: a retrospective study of 106 cats (1994-2001)

The case records of 106 cats with idiopathic cardiomyopathy that presented to the Feline Centre of the University of Bristol between September 1994 and September 2001 were reviewed retrospectively. Hypertrophic cardiomyopathy (HCM) was the most common form seen (57.5%), followed by restrictive cardiomyopathy (RCM) (20.7%), dilated cardiomyopathy (DCM) (10.4%) and unclassified cardiomyopathy (UCM) (10.4%). One cat showed echocardiographic changes compatible with a moderator band cardiomyopathy (MBCM). Most affected cats were domestic short hairs (DSH) (57.5%). The mean (+/-SD, range) age of cats with cardiomyopathy at presentation was 6.8 (4.3, 0.5-16) years, with an equal distribution of males and females. Clinical findings, electrocardiographic changes and radiographic abnormalities were also reviewed. The median survival time for 73 cats for which follow-up data was available was 300 days. A greater survival time was observed for cats with UCM (925 days) when compared with those with HCM (492 days), RCM (132 days) or DCM (11 days).     

Traumatic diaphragmatic hernia in cats: 34 cases (1991-2001)

OBJECTIVE: To determine whether signalment, duration of hernia, clinical signs, contents of hernia, CBC and serum biochemical abnormalities, concurrent injuries, perioperative treatment and administration of analgesics, results of intraoperative anesthetic monitoring data, or level of training of the veterinarian performing the herniorrhaphy was associated with mortality rate after surgical repair of traumatic diaphragmatic hernia in cats. DESIGN: Retrospective study. ANIMALS: 34 cats. PROCEDURE: Review of medical records and a telephone follow-up with owners and referring veterinarians were performed. RESULTS: Mean age of affected cats was 3.6 years; cats that survived to the time of discharge were significantly younger than cats that died or were euthanatized. Tachypnee was the most common clinical sign at hospital admission; cats that survived to the time of discharge had significantly higher respiratory rates than cats that died or were euthanatized after surgery. Postoperative complications developed in 50% of cats; tachypnea and dyspnea were most common. Mortality rate was not associated with duration of hernia or results of preoperative CBC and serum biochemical analyses, but was significantly associated with concurrent injuries. Mortality rate was not associated with hernia contents, intraoperative use of positive inotropes or corticosteroids, episodes of hypotension or severe hypoxia during anesthesia, or level of training of the veterinarian performing the surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Cats that are older or have low to mildly increased respiratory rates and concurrent injuries are more likely to die after surgical repair of traumatic diaphragmatic hernia.     

Arterial thromboembolism in cats: acute crisis in 127 cases (1992-2001) and long-term management with low-dose aspirin in 24 cases

Records of 127 cats with arterial thromboembolism (ATE) were reviewed. Abyssinian, Birman, Ragdoll, and male cats were overrepresented. Tachypnea (91%), hypothermia (66%), and absent limb motor function (66%) were common. Of 90 cats with diagnostics performed, underlying diseases were hyperthyroidism (12), cardiomyopathy (dilated [8], unclassified [33], hypertrophic obstructive [5], hypertrophic [19]), neoplasia (6), other (4), and none (3). Common abnormalities were left atrial enlargement (93%), congestive heart failure (CHF, 44%), and arrhythmias (44%). Of cats without CHF, 89% were tachypneic. Common biochemical abnormalities were hyperglycemia, azotemia, and abnormally high serum concentrations of muscle enzymes. Of 87 cats treated for acute limb ATE, 39 (45%) survived to be discharged. Significant differences were found between survivors and nonsurvivors for temperature (P < .00001), heart rate (P = .038), serum phosphorus concentration (P = .024), motor function (P = .008), and number of limbs affected (P = .001). No significant difference was found between survivors and nonsurvivors when compared by age, respiratory rate, other biochemical analytes, or concurrent CHE A logistic regression model based on rectal temperature predicted a 50% probability of survival at 98.9 degrees F (37.2 degrees C). Median survival time (MST) for discharged cats was 117 days. Eleven cats had ATE recurrences, and 5 cats developed limb problems. Cats with CHF (MST: 77 days) had significantly shorter survival than cats without CHF (MST: 223 days; P = .016). No significant difference was found in survival or recurrence rate between cats receiving high-dose aspirin (> or = 40 mg/cat q72h) and cats receiving low-dose aspirin (5 mg/cat q72h). Adverse effects were less frequent and milder for the lower dosage.     

Clinical and pathologic findings in dogs with atherosclerosis: 21 cases (1970-1983)

Atherosclerosis was diagnosed on necropsy in 21 dogs in a 14-year period. Nine dogs died and 12 were euthanatized because of complications associated with the disease. The mean age was 8.5 +/- 0.5 years; 18 dogs were male. Three breeds (Miniature Schnauzer, Doberman Pinscher, and Labrador Retriever) had a higher prevalence of the disease than other breeds in the canine necropsy population of The Animal Medical Center. Most common clinical signs were lethargy, anorexia, weakness, dyspnea, collapse, and vomiting. Hypercholesterolemia, lipidemia, and hypothyroidism were common in affected dogs tested, and protein electrophoresis revealed high values for alpha 2 and beta fractions in all dogs tested. Electrocardiography indicated conduction abnormalities and myocardial infarction in 3 of 7 dogs. Necropsy revealed that affected arteries (including coronary, myocardial, renal, carotid, thyroidal, intestinal, pancreatic, splenic, gastric, prostatic, cerebral, and mesenteric) were yellow-white, thick and nodular, and had narrow lumens. Myocardial fibrosis and infarction also were observed in the myocardium. Histologically, affected arterial walls contained foamy cells or vacuoles, cystic spaces, mineralized material, debris with or without eroded intima, and degenerated muscle cells.     

Clinical and pathologic findings in donkeys with hypothermia: 10 cases (1988-1998)

OBJECTIVE: To describe clinical signs and clinicopathologic findings in donkeys with hypothermia. DESIGN: Retrospective study. ANIMALS: 10 hypothermic donkeys. PROCEDURE: Information on signalment, history, physical examination findings, results of diagnostic tests, treatments, and necropsy findings was extracted from medical records of all donkeys with hypothermia between 1988 and 1998 and compared with information from medical records of all normothermic donkeys and hypothermic horses admitted to the hospital during the same period. RESULTS: Donkeys were more likely to be hypothermic than horses. The mean age of hypothermic donkeys was 6 years (range, 7 months to 11 years), compared with 4.2 years (range, < 1 month to 15 years) for normothermic donkeys; this difference was not significant. Ten of 12 horses with hypothermia were neonates; there were no hypothermic neonatal donkeys. At admission, 7 of 8 hypothermic donkeys were in good body condition and all hypothermic donkeys were weak. Six hypothermic donkeys were able to maintain sternal recumbency, 1 remained in lateral recumbency, and 3 were able to stand. Of the 10 hypothermic donkeys, 2 survived, 1 died, and 7 were euthanatized. Histologically, the thyroid glands from 4 of 5 hypothermic donkeys appeared abnormal and were similar to those of foals with hypothyroidism. During the months that hypothermic donkeys were admitted, there was not a significant difference in environmental temperatures on days of admission between hypothermic and normothermic donkeys. CONCLUSIONS AND CLINICAL RELEVANCE: Hypothermia is a problem in donkeys during cold winter months, and may not be secondary to other disease or related to diet or management.     

Clinical, radiographic, and pathologic features of bronchiectasis in cats: 12 cases (1987-1999)

OBJECTIVE: To determine clinical, radiographic, and pathologic features of bronchiectasis in cats. DESIGN: Retrospective study. ANIMALS: 12 cats with histologic evidence of bronchiectasis. PROCEDURE: Information on signalment, body weight, clinical signs of respiratory disease, concurrent diseases, method by which lung tissue specimens were obtained (surgical biopsy or necropsy), and histopathologic findings was obtained by reviewing medical records from January 1987 to June 1999 for cats with confirmation of bronchiectasis by histologic examination. Available thoracic radiographs were reviewed by a board-certified radiologist. RESULTS: Bronchiectasis was most commonly identified in older male cats. Clinical signs referable to the lower portion of the respiratory tract were detected in only 5 cats but, when evident, were usually chronic (duration > 1 year). Radiographic pattern of bronchiectasis was cylindrical in 4 cats, and in 1 of these cats, a saccular pattern was also identified. For most cats, bronchiectasis was detected in a single lung lobe. Radiographic evidence of bronchiectasis was not detected in 2 cats. Concurrent respiratory diseases included chronic bronchitis and bronchiolitis, neoplasia, bronchopneumonia, endogenous lipid pneumonia, and emphysema. CONCLUSIONS AND CLINICAL RELEVANCE: Bronchiectasis appears to be an uncommon respiratory tract disorder that predominantly affects older male cats. Thoracic radiography may not be sensitive for the diagnosis of bronchiectasis in cats. Bronchiectasis in cats appears to be a sequela of chronic inflammatory bronchopulmonary diseases, especially chronic bronchitis, neoplasia, and bronchopneumonia.     

Clinical differentiation of acute necrotizing from chronic nonsuppurative pancreatitis in cats: 63 cases (1996-2001)

OBJECTIVE: To characterize clinical, clinicopathologic, radiographic, and ultrasonographic findings in cats with histologically confirmed acute necrotizing pancreatitis (ANP) or chronic nonsuppurative pancreatitis (CP) and identify features that may be useful in the antemortem differentiation of these disorders. DESIGN: Retrospective study. ANIMALS: 63 cats with histologically confirmed ANP (n = 30) or CP (33). PROCEDURE: Medical records were reviewed for signalment, clinical signs, concurrent diseases, clinicopathologic findings, and results of radiography and ultrasonography. RESULTS: Cats in both groups had similar nonspecific clinical signs, physical examination findings, and radiographic and ultrasonographic abnormalities. Abdominal ultrasonographic abnormalities, including hypoechoic pancreas, hyperechoic mesentery, and abdominal effusion, were found in cats in both groups and, therefore, were not specific for ANP. Cats with CP were significantly more likely to have concurrent diseases than were cats with ANP (100 and 83%, respectively). Clinicopathologic abnormalities were similar between groups; however, serum alanine aminotransferase and alkaline phosphatase activities were significantly higher in cats with CP. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that ANP and CP in cats cannot be distinguished from each other solely on the basis of history, physical examination findings, results of clinicopathologic testing, radiographic abnormalities, or ultrasonographic abnormalities.     

Tracheal rupture associated with intubation in cats: 20 cases (1996-1998)

OBJECTIVE: To characterize clinical features of tracheal rupture associated with endotracheal intubation in cats and to evaluate the most appropriate treatment for this condition. DESIGN: Retrospective study. ANIMALS: 20 cats with a history of endotracheal intubation that subsequently developed dyspnea or subcutaneous emphysema. PROCEDURE: Medical records of cats with a presumptive diagnosis of tracheal rupture associated with intubation were reviewed. Clinical and clinicopathologic data were retrieved. RESULTS: Cats were evaluated 5 hours to 12 days after a surgical or medical procedure requiring general anesthesia with intubation had been performed. Fourteen (70%) cats were evaluated after dental prophylaxis. All cats radiographed had pneumomediastinum and subcutaneous emphysema. Eighteen of 19 cats were initially treated medically. Duration of medical treatment for cats that did not have surgery ranged from 12 to 72 hours. Cats that had surgery received medical treatment 3 to 24 hours prior to the surgical procedure. Medical treatment alone was administered to 15 cats that had moderate dyspnea, whereas surgical treatment was chosen for 4 cats that had severe dyspnea (open-mouth breathing despite treatment with oxygen) or worsening subcutaneous emphysema. Eighteen cats had improvement of clinical signs, 1 cat died after surgery, and 1 cat died before medical or surgical intervention. CONCLUSIONS AND CLINICAL RELEVANCE: Most cats with tracheal rupture associated with intubation can be treated medically. Cats with worsening clinical signs (severe dyspnea, suspected pneumothorax, or worsening subcutaneous emphysema) should have surgery performed immediately to correct the defect.     

Clinical findings and coronary artery disease in dogs and cats with acute and subacute myocardial necrosis: 28 cases

Records of final diagnoses based on necropsies performed on dogs and cats over a 4.5-year period at a university teaching hospital were examined for the diagnosis of acute or subacute myocardial necrosis. Clinical findings signaling the occurrence of myocardial necrosis were often not specific, due to simultaneously occurring disease processes. However, of 28 animals identified, dyspnea occurred frequently (17/28; 61%) and in some cases in the presence of minimal pulmonary pathology (2/3; 66%) or otherwise unexplained pulmonary edema (4/4; 100%). Elevations in serum aspartate aminotransferase (10/10; 100%) and creatine kinase (5/9; 55%) were also frequent. Disease processes associated with thrombus formation were present for each case in which a coronary artery thrombus occurred (5/28; 18%).     

Feline retinal degeneration: clinical experience and new findings (1994-1997)

A retrospective case series of 26 cats with diffuse retinal degeneration is presented. The most common presenting complaints included bumping into objects, dilated pupils, and reluctance to jump. Ophthalmic examination findings were consistent with those reported in dogs with progressive retinal atrophy. Breed predilection of the Siamese cat was observed. Cats with primary retinal degeneration presented late in the clinical course of their disease, when vision loss was severe. Early symptoms such as night blindness and secondary ocular complications (i.e., cataract and retinal detachment), reported in dogs with progressive retinal degeneration, were not observed in this study. All cats showed excellent adaptive capabilities to blindness.