Feline ocular toxoplasmosis

Ocular infection with Toxoplasma gondii is a well-recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive for T. gondii , are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed.     

Retrospective Study: Incidence of ionized hypocalcemia in septic dogs and its association with morbidity and mortality: 58 cases (2006–2007)

Objective – To determine the incidence rate and prognostic significance of ionized hypocalcemia (iHCa) among septic dogs. Design – Retrospective study Setting – Veterinary teaching hospital Animals – Fifty‐eight septic dogs that were presented to Cornell University Hospital for Animals between January 2006 and December 2007. Procedure – Cases were diagnosed with sepsis if they exhibited 2 or more criteria of the systemic inflammatory response syndrome with a concurrent documented infectious focus. Cases were excluded if diagnosed with a concurrent illness reportedly associated with calcium derangements. Lowest, mean, and highest blood ionized calcium concentrations were recorded and statistically analyzed for an association with morbidity, as measured by duration of hospitalization and number of blood product transfusions, and outcome. In addition, the incidence rate of iHCa was recorded. Results – Of the 58 cases included in this study, iHCa was documented in 4 of 6 (67%) patients that died, 5 of 19 (26%) euthanized patients and 5 of 33 (15%) patients that survived to discharge, with an overall incidence of 24%. Dogs that died during hospitalization had more severe iHCa than patients that were discharged or euthanized as well as significantly lower mean ionized calcium concentrations than patients who were discharged. Severity of iHCa was also associated with a longer duration of hospitalization. The highest ionized calcium concentration was not associated with outcome. Conclusion and Clinical Relevance – This study is the first to document the incidence of iHCa among septic dogs. Because both low mean ionized calcium and the lowest documented ionized calcium concentration are associated with poor outcome, it is likely that both the severity and duration of hypocalcemia are important in these patients. Further prospective studies investigating the prognostic significance, etiology and treatment of iHCa among septic veterinary patients are needed to better understand its role in sepsis.     

Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse

Reasons for performing study: There is little scientific information available about the ability of ocular disease to cause a systemic inflammatory response. Horses are frequently affected with ocular disease and ensuring their systemic health prior to performing vision saving surgery under anaesthesia is essential for the successful treatment of ophthalmic disease. Hypothesis: Ocular disease will cause elevations in the concentration of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Methods: Whole blood and serum samples were obtained from 38 mature horses with ulcerative keratitis or uveitis and no evidence of systemic disease, 9 mature horses with no evidence of ocular or systemic disease (negative controls) and 10 mature horses with systemic inflammatory disease and no evidence of ocular disease (positive controls). Blood samples were assayed for concentrations of the acute phase proteins fibrinogen and serum amyloid A. Results: Fibrinogen and serum amyloid A were significantly different in the positive control group compared to the negative control, corneal disease and uveitis groups (P<0.126). There was no significant difference between the negative control, corneal disease and uveitis groups (P<0.001). Conclusions: Ulcerative keratitis and anterior uveitis are not associated with elevated concentrations of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Potential relevance: When the clinician is presented with a patient with ocular disease and elevated plasma fibrinogen or serum amyloid A concentrations, a nonocular inflammatory focus should be suspected.     

Three cases of feline ocular coccidioidomycosis: presentation,clinical features,diagnosis, and treatment

Objective To describe clinical and diagnostic features of ocular coccidioidomycosis in cats and the response to fluconazole and anti‐inflammatory therapy. Animals studied Three cats with naturally acquired coccidioidomycosis. Procedure Cats were treated with topical or systemic corticosteroids and systemic fluconazole, an antifungal of unproven efficacy against feline ocular coccidioidomycosis. Results Two cats presented for periocular swellings, either subpalpebral or periorbital, with systemic signs including weight loss, unkempt hair coat, and lethargy. One cat presented for apparent blindness with no systemic signs. Clinical ophthalmologic abnormalities were bilateral in each cat and included hyperemic, conjunctival masses, fluid‐filled periorbital swellings, granulomatous chorioretinitis, nonrhegmatogenous retinal detachments, and anterior uveitis. Cats were diagnosed with coccidioidomycosis using a combination of clinical findings, serology and, in two cases, visualization of Coccidioides spherules by either aspiration cytology or biopsy. Active anterior uveitis and periocular swelling were resolved in all cats during treatment. Chorioretinal granulomas, although persistent, significantly decreased in size. Conclusions Coccidioidomycosis should be considered as a differential diagnosis for cats with a travel history to the southwestern United States that demonstrate periocular swelling, anterior uveitis, or granulomatous chorioretinitis, with or without evidence of systemic disease. Aspiration cytology or biopsy of suspicious conjunctival or skin lesions, if present, may aid in diagnosis. A combination of corticosteroids and fluconazole may be effective in treating ocular coccidioidomycosis, although chorioretinal granulomas may persist and long‐term fluconazole therapy may be necessary.     

Toxoplasmosis.

Toxoplasmosis in dogs and cats can cause chorioretinitis, anterior uveitis, or both. Ocular lesions are a common manifestation of generalized toxoplasmosis. The prevalence of toxoplasmosis as a cause of idiopathic anterior uveitis in cats is not clear, although there is a significant association between exposure to T. gondii and feline anterior uveitis. The pathogenesis of ocular toxoplasmosis may be different in humans and cats, and the anterior uveitis may represent a type of immune-mediated inflammation. A diagnosis is made by observing compatible clinical findings and obtaining supportive findings on serologic tests. Despite improved diagnostic techniques, including determination of IgM class antibodies and PCR testing, definitive diagnosis of ocular toxoplasmosis remains a challenge. Topical anti-inflammatory therapy should be used in cats with anterior uveitis, a positive serum titer, and no concurrent systemic signs. Systemic clindamycin should be given to cats with ocular and systemic signs and to cats with suggestive serology and idiopathic anterior uveitis that fails to respond to topical therapy alone.     

Retrospective Study: Surgical intervention in the management of severe acute pancreatitis in cats: 8 cases (2003–2007)

Objective – To evaluate clinical characteristics and outcomes of cats undergoing surgical intervention in the course of treatment for severe acute pancreatitis. Design – Retrospective observational study from 2003 to 2007 with a median follow‐up period of 2.2 years (range 11 d–5.4 y) postoperatively. Setting – Private referral veterinary center. Animals – Eight cats. Interventions – None. Measurements and Main Results – Quantitative data included preoperative physical and clinicopathologic values. Qualitative parameters included preoperative ultrasonographic interpretation, perioperative and intraoperative feeding tube placement, presence of free abdominal fluid, intraoperative closed suction abdominal drain placement, postoperative complications, microbiological culture, and histopathology. Common presenting clinical signs included lethargy, anorexia, and vomiting. Leukocytosis and hyponatremia were present in 5 of 8 cats. Hypokalemia, increased total bilirubin, and hyperglycemia were present in 6 of 8 cats. Elevated alanine aminotransferase and aspartate transferase were present in all cats. Surgery for extrahepatic biliary obstruction was performed in 6 cats, pancreatic abscess in 3 cats, and pancreatic necrosis in 1 cat. Six of the 8 cats survived. Five of the 6 cats that underwent surgery for extrahepatic biliary obstruction and 1 cat that underwent pancreatic necrosectomy survived. All 5 of the cats with extrahepatic biliary obstruction secondary to pancreatitis survived. The 2 nonsurvivors included a cat with a pancreatic abscess and a cat with severe pancreatitis and extrahepatic biliary obstruction secondary to a mass at the gastroduodenal junction. Postoperative complications included progression of diabetes mellitus, septic peritonitis, local gastrostomy tube stoma inflammation, local gastrostomy tube stoma infection, and mild dermal suture reaction. Conclusion – Cats with severe acute pancreatitis and concomitant extrahepatic biliary obstruction, pancreatic necrosis, or pancreatic abscesses may benefit from surgical intervention. Cats with extrahepatic biliary obstruction secondary to severe acute pancreatitis may have a good prognosis.     

Feline infectious peritonitis.

Feline infectious peritonitis is a noncurable viral disease affecting cats worldwide. Recent evidence suggests that the FIPV has evolved as a deletion mutation of FECV. Immune complex deposition and vasculitis with pyogranulomatous lesions are the hallmark of FIP. The only definitive antemortem diagnostic test for FIP is histopathologic examination of tissue. Ocular manifestations occur commonly with noneffusive FIP. The most common clinical sign is a bilateral granulomatous anterior uveitis often accompanied by chorioretinitis. Treatment of ocular FIP is symptomatic, and the mainstay of palliative therapy is topical or systemic corticosteroids or both.     

Veterinary ocular microbiome: Lessons learned beyond the culture

Ocular pathogens cause many painful and vision‐threatening diseases such as infectious keratitis, uveitis, and endophthalmitis. While virulent pathogens and pathobionts play important roles in disease pathogenesis, the scientific community has long assumed disruption of the ocular surface occurs prior to microbial colonization and subsequent infection. While nonpathogenic bacteria are often detected in corneal and conjunctival cultures from healthy eyes, cultures also frequently fail to yield growth of common ocular pathogens or nonpathogenic bacteria. This prompts the following question: Is the ocular surface populated by a stable microbial population that cannot be detected using standard culture techniques? The study of the microbiome has recently become a widespread focus in physician and veterinary medicine. Research suggests a pivotal symbiotic relationship with these microbes to maintain healthy host tissues, and when altered is associated with various disease states (“dysbiosis”). The microbiota that lives within and on mammalian bodies have long been known to influence health and susceptibility to infection. However, limitations of traditional culture methods have resulted in an incomplete understanding of what many now call the “forgotten organ,” that is, the microbiome. With the introduction of high‐throughput sequencing, physician ophthalmology has recognized an ocular surface with much more diverse microbial communities than suspected based on traditional culture. This article reviews the salient features of the ocular surface microbiome and highlights important future applications following the advent of molecular techniques for microbial identification, including characterizing ocular surface microbiomes in our veterinary species and their potential role in management of infectious and inflammatory ocular diseases.     

Septic lens implantation syndrome in a cat

A 13-year-old female spayed domestic shorthair cat was presented initially for a change in the appearance of the left eye. On initial examination, a small penetrating wound was suspected as the cause for a corneal scar, an anterior cortical incipient cataract and mild iritis. The cat was not re-presented until 1 year later at which time ocular pain was marked. Severe anterior uveitis and glaucoma were diagnosed and the eye enucleated. Histopathology documented intralenticular coccoid bacteria and septic lens implantation syndrome.     

Gastrointestinal tract perforations caused by ingestion of multiple magnets in a dog

Objective – To describe a case of gastrointestinal tract perforation, septic peritonitis and coagulopathy caused by ingestion of multiple magnets in a dog. Case Summary – An 8‐month‐old castrated male Rottweiler, weighing 30.5 kg was presented for evaluation of vomiting and weakness. Abdominal radiography and abdominal ultrasonographic examination identified a metallic foreign object within the gastric lumen, presence of free peritoneal gas, and peritoneal effusion. Septic peritonitis was diagnosed by abdominal fluid analysis. Exploratory celiotomy revealed the presence of an omental abscess, and gastric and colonic perforations. Four magnetic foreign objects were found within the lumen of the perforated stomach. Surgical management including removal of the magnets, abscess debridement and excision, perforation repair, and abdominal drainage combined with intensive medical therapy resulted in complete recovery of this dog. New or Unique Information Provided – This report describes in detail the case management of a dog that developed both gastric and colonic perforations and severe morbidity secondary to ingesting multiple magnets.     

Clinical trials in spontaneous disease in dogs: a new paradigm for investigations of sepsis

Objective: To provide evidence that naturally occurring sepsis in dogs provides a unique opportunity to test new therapies in clinically relevant settings. Data sources: Human and veterinary literature. Human data synthesis: Sepsis is a devastating condition responsible for most intensive care unit deaths. Most clinical trials targeting inflammatory mediators of sepsis have failed to improve outcome in clinical patients despite promising results in laboratory animal models. Animal models of sepsis fail to reproduce the clinical syndrome and therefore lead to conclusions that may not be relevant to clinical care. Veterinary data synthesis: Sepsis is recognized but not well‐characterized in companion animal species. Despite some species variability, the cardiopulmonary response to sepsis in dogs is similar to humans. Additionally, inflammatory and coagulation changes that accompany canine sepsis are consistent with those documented in humans. Sepsis secondary to canine parvoviral infection offers the advantages of relative population homogeneity, predictable course, and easy early diagnosis. The disadvantages of canine parvovirus are that it affects a predominantly young and healthy population and results in low mortality with aggressive supportive care. Septic peritonitis and pneumonia have high mortality but can be challenging to diagnose, have a variable course, and affect a heterogeneous population, which can be an advantage or a disadvantage. Conclusions: Similar to trials currently being performed in canine cancer patients, veterinary clinical trials of new sepsis therapeutics may provide a unique opportunity to advance the treatment of sepsis in dogs, humans, and other species. Spontaneous sepsis from canine parvovirus, peritonitis, and pneumonia are common clinical conditions in which therapeutics can be tested.     

Morphea-like lesion following topical endectocide application in a cat

Background – Scleroderma is a rare chronic disease of connective tissues that may affect the skin in humans. Although still unclear, its aetiology may be related to drug reactions. To date, scleroderma has been reported in only a few dogs and one cat. Case report – Localized (morphea‐like) scleroderma was diagnosed in a 3‐year‐old intact male Persian cat that developed a nonpruritic, well‐demarcated alopecic plaque a few days after topical application of a ‘spot‐on’ solution containing praziquantel and emodepside. The lesion occurred at the site of application at the dorsal cervical region, and was characterized histologically by fibrosing dermatitis. There was no response to systemic treatment with pentoxifylline. Following topical therapy with minoxidil 5% for 30 days, hair regrowth occurred, and the lesion had completely disappeared after 60 days. Conclusions and clinical importance – The relationship between the alopecic plaque and the topical application of the spot‐on solution cannot be proved; however, according to the Naranjo scale, which estimates the probability of adverse drug reactions, this case could be classified as a ‘possible’ reaction to one of the components of the product. Sclerodermoid reactions have not been described as a cutaneous drug eruption in veterinary medicine, so this case may possibly represent the first such idiosyncratic reaction to one of the applied substances. Furthermore, to the best of the authors’ knowledge, this is the second report of a morphea‐like lesion in a cat.     

Review of hypocalcemia in septic patients

Objective: To review the occurrence and etiologies of hypocalcemia in septic human and veterinary patients. Data sources: A thorough search was conducted using CAB abstracts and MEDLINE and the keywords hypocalcemia, ionized calcium, sepsis, and procalcitonin (proCT). Human data synthesis: Ionized hypocalcemia (iHCa) is a common finding in septic human patients. The cause is unknown but is likely multifactorial. Low ionized calcium (iCa²⁺) concentrations coincide with increased severity of illness and increased mortality. Recent studies show that iHCa has a strong correlation with elevated calcitonin precursor concentrations. Veterinary data synthesis: There is a paucity of publications in the veterinary literature pertaining to iHCa in septic animals. Experimental models of sepsis indicate that iHCa exists in animals. iHCa has also been investigated in horses with enterocolitis and endotoxemia. Prospective studies are needed to determine the prevalence of iHCa among septic small animals, and to determine whether iHCa correlates with increased mortality and severity of disease. Indications for the treatment of iHCa in septic small animals also need to be investigated. Conclusions: iHCa is well documented in septic human patients, but little is known about iHCa in septic veterinary patients. Future veterinary studies should focus on documenting the presence of iHCa in septic patients and steps should be taken to determine the cause. proCT concentrations may show promise for predicting sepsis and mortality in critically ill veterinary patients.     

Severe sepsis in cats: 29 cases (1986-1998)

OBJECTIVE: To document the clinical, clinicopathologic, and pathologic findings in cats with severe sepsis, identify abnormalities unique to this species, and identify criteria that could be used antemortem to diagnose the systemic inflammatory response syndrome in cats. DESIGN: Retrospective study. ANIMALS: 29 cats confirmed to have severe sepsis at necropsy. PROCEDURE: Pertinent history, physical examination findings, and results of hematologic and biochemical testing were extracted from medical records. RESULTS: Clinical diagnoses included pyothorax, septic peritonitis, bacteremia secondary to gastrointestinal tract disease, pneumonia, endocarditis, pyelonephritis, osteomyelitis, pyometra, and bite wounds. Physical examination findings included lethargy, pale mucous membranes, poor pulse quality, tachypnea, hypo- or hyperthermia, signs of diffuse pain on abdominal palpation, bradycardia, and icterus. Clinicopathologic abnormalities included anemia, thrombocytopenia, band neutrophilia, hypoalbuminemia, low serum alkaline phosphatase activity, and hyperbilirubinemia. Necropsy findings included multi-organ necrosis or inflammation with intralesional bacteria. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that severe sepsis in cats is characterized by lethargy, pale mucous membranes, signs of diffuse abdominal pain, tachypnea, bradycardia, weak pulses, anemia, hypoalbuminemia, hypothermia, and icterus. Recognition of this combination of clinical findings should facilitate the diagnosis of severe sepsis in cats.     

Uveal Inflammation in Septic Newborn Foals

Background: Septicemia in humans is described as a leading cause of uveitis, which eventually can induce blindness. Hypothesis/Objectives: Uveal inflammatory findings could be related to sepsis severity in newborn foals and might be used as an indirect indicator for survival. Animals: Seventy‐four septic foals, 54 nonseptic foals, and 42 healthy foals. Methods: Prospective observational clinical study. A detailed blinded, ophthalmic examination was performed by boarded ophthalmologists on all admitted newborn foals. Foals were grouped as septic (when blood culture resulted positive or the sepsis score was ≥14), nonseptic, and controls. Based on blood culture results, the septic group was subdivided into bacteremic and nonbacteremic foals. Results: Blood culture was performed in 62/74 septic foals, from which 35 (56%) were bacteremic and 27 (44%) were nonbacteremic. Anterior uveitis was diagnosed in a significantly (P < .005) higher number of septic/bacteremic foals (14/35, 40%) than in septic/nonbacteremic foals (5/27, 19%), nonseptic foals (4/54, 7%), and control foals (0%). Anterior chamber fibrin was only observed in 4/14 (29%) septic/bacteremic foals with anterior uveitis. Anterior uveitis was also associated with posterior uveitis in 6/35 (19%) septic/bacteremic foals. The diagnosis of uveitis was related to nonsurvival (P= .001, odds ratio = 6.2, 95% confidence interval = 2.1–18.2). Conclusions and Clinical Importance: Anterior uveitis is highly prevalent in septic newborn foals, especially in those with a positive blood culture, and it should be considered as a survival prognostic factor.     

Feline systemic fungal infections.

Systemic fungal diseases are important diagnostic considerations in all sick cats, particularly in cats with ocular symptoms. The most common ocular manifestation of these diseases is posterior uveitis (choroiditis); however, anterior uveitis is sometimes present and is usually secondary to the inflammation in the posterior segment. Occasionally, adnexal diseases such as blepharitis, inflammation of the nictitating membrane, and ocular discharge may be present in cats with systemic mycoses. The prognosis for cats with systemic fungal diseases has changed with the advent of the triazole antifungal drugs. In the past, the prognosis was guarded to poor for survival of the cat. Today, with prolonged antifungal therapy, many cats recover completely from their disease. The prognosis for return of vision for eyes affected with systemic fungal disease is still guarded. Often, even if the infection is controlled systemically, the retina is severely damaged and may remain nonfunctional.