Clinical signs, magnetic resonance imaging features, and outcome after surgical and medical treatment of otogenic intracranial infection in 11 cats and 4 dogs

Brainstem dysfunction resulting from central extension of infection is a life-threatening complication of otitis media/interna (OMI) that has been described infrequently in dogs and cats. We review the clinical signs of disease, diagnostic findings, and results of surgical and medical treatments of brainstem disease attributable to otogenic intracranial infection in cats and dogs. Eleven cats and 4 dogs were examined because of acute, subacute, or chronic clinical signs of brain disease including central vestibular signs, altered mentation, abnormal posture/gait, cranial nerve deficits, and seizures. Results of a minimal database (CBC, serum biochemical panel, urinalysis, thoracic radiographs, and abdominal ultrasonographic images or radiographs) were within reference intervals in all animals. Magnetic resonance (MR) images of the head were acquired for all animals, and cisternal cerebrospinal fluid (CSF) from 9 of 11 cats and 3 of 4 dogs was examined. Surgical exploration and ventral bulla osteotomy were done for 12 of 15 animals, followed by 1–3 months of antibiotic therapy; the remaining animals were euthanized before treatment. In all animals, MR imaging was effective in characterizing the location and extent of the pathologic changes intracranially as well as within middle/inner ear structures. Results of CSF analysis were characteristic of bacterial infection in most of the animals with acute or subacute disease. Since long-term outcome in all treated animals was very good to excellent, it was concluded that dogs and cats with intracranial disease secondary to extension of otitis media/interna have a good-to-excellent prognosis when the condition was diagnosed and was treated by surgical exploration and appropriate antibiotic therapy.     

Multidrug-resistant E. coli and enterobacter extraintestinal infection in 37 dogs

BACKGROUND: Extraintestinal infections caused by multidrug-resistant (MDR) Escherichia coli and Enterobacter are becoming more common in veterinary medicine. OBJECTIVE: To generate hypotheses for risk factors for dogs acquiring extraintestinal infection caused by MDR E. coli and Enterobacter, describe antimicrobial resistance profiles and analyze treatment and clinical outcomes. ANIMALS: Thirty-seven dogs diagnosed with extraintestinal infection caused by MDR E. coli and Enterobacter spp. between October 1999 and June 2006. METHODS: Retrospective case series assembled from hospital records data, including clinical history before 1st MDR isolation and treatment outcome. Identity and antimicrobial susceptibility profiles were confirmed by standard microbiological techniques for 57 isolates. RESULTS: Most dogs had an underlying disease condition (97%), received prior antimicrobial treatment (87%), were hospitalized for >or =3 days (82%), and had a surgical intervention (57%). The urinary tract was the most common infection site (62%), and urinary catheterization, bladder stasis, or both were common among dogs (24%). Some dogs were treated with high doses of co-amoxyclavulanate (n = 14) and subsequently recovered even though the isolates showed in vitro resistance to this antimicrobial. Other dogs were successfully treated with chloramphenicol (n = 11) and imipenem (n = 2). CONCLUSION AND CLINICAL IMPORTANCE: Predisposing disease condition, any prior antimicrobial use rather than a specific class of antimicrobial, duration of hospitalization, and type of surgical procedure might be risk factors for acquiring MDR extraintestinal infections. Whereas culture and sensitivity results can indicate use of last-resort antimicrobials such as imipenem for MDR infections, some affected dogs can recover after administration of high doses of co-amoxyclavulanate.     

Structural and ultrastructural changes in the lungs of cats Felis catus (Linnaeus, 1758) experimentally infected with D. immitis (Leidy, 1856)

Clinical signs are seldom observed in feline heartworm disease, and the pathophysiological changes in the lungs of infected animals remain undefined. The goal of this study was to evaluate the structural and ultrastructural changes in the lungs of cats experimentally infected with Dirofilaria immitis. Six healthy cats were each infected with two adult heartworms by intravenous transplantation (Receptor Group, RG). The control group consisted of two uninfected animals kept under the same conditions as the RG. At 42 days after transplantation, all cats were euthanized and necropsied for worm recovery and collection of lung samples for examination by light microscopy (LM) and transmission electron microscopy. By LM, lung sections from the six infected cats exhibited bronchial and bronchiolar lesions. Alterations in all tissues of the pulmonary arteries were observed in the infected animals. In conclusion, cats infected experimentally with D. immitis developed lesions in their lungs as a consequence of arterial disease and intense interstitial pneumonia.     

Activity of pulmonary intravascular macrophages in cats and dogs with and without adult Dirofilaria immitis

Pulmonary intravascular macrophages (PIMs), large (20-80 microm diameter) monocytes are present in sheep, pigs, and horses, but not in dogs, rats, rabbits, or primates. The present study evaluated the phagocytic activity of various organs in cats and dogs and determined the influence of Dirofilaria immitis infections on PIM activity. Live or dead adult heartworm (HW) was transplanted via jugular venotomy into cats and dogs. Cats (four per group) were allocated to five groups: surgical controls--no HW, dead HW for 1 week, live HW for 1 week, dead HW for 3 weeks, or live HW for 3 weeks. Radioactive technetium (Tc-99m, 1.2mCi in 0.3ml) sulfa-colloid was injected intravenously. All cats with HW were clinically asymptomatic and developed radiographic pulmonary parenchymal changes. No gross changes were visible at necropsy for cats with HW; inflammatory changes were less severe in cats with live HW. In cats with dead HW for 3 weeks, worms were present but folded, flattened, and located in distal pulmonary arteries. Uninfected control dogs and those with dead HW did not demonstrate any PIM activity. In control cats, lungs were the primary phagocytic organ after systemic IV colloid injection (72.5% of the total recovered radioactive dose). The lung and liver together represented over 95% of the recovered Tc-99m colloid in all cats. In each group of cats with HW, phagocytic activity of the lung was significantly less (p < 0.001) than the PIM activity of controls. Cats with dead HW at 1 week (50.1%) had a significant (p < 0.019) decrease in PIM activity compared with cats with dead HW at 3 weeks (59.5%). The PIM activity in cats with live HW was significantly decreased (p < 0.001) from that in groups with dead HW, but there was no significant difference between the two groups infected with live worms. There were no significant differences in recovery between any groups in pairwise analysis of the spleen, heart, skeletal muscle, kidney, bone marrow, or blood. Significant increases (p < 0.001) in liver activity for each group inversely reflected the decreased lung activity; consistent with increased hepatic uptake of Tc colloid "escaping" a relatively suppressed lung macrophage system. Transmission electron microscopy confirmed PIM glycocalyx changes and vacuolization, moderate Type 1 cell damage and Type II cell hypertrophy in cats with dead HW. There was no evidence of PIM death. The significant decrease in PIM activity in groups with dead HW and a greater decrease in groups with live HW are consistent with a down-regulation of PIM function in cats with live HW.     

Renal biopsy of dogs and cats

Renal diseases are common in dogs and cats. Renal biopsy may be required during the evaluation of the patient to establish a definitive diagnosis, determine the severity of the lesion and formulate an optimal treatment plan. Renal biopsy specimens can be collected via several methods. Percutaneous techniques are performed with ultrasound guidance in both dogs and cats or blindly in cats. If ultrasound guidance is not available, the keyhole technique can be used in dogs. Biopsy can also be performed using laparoscopy or surgery. While complications can arise with any of these techniques, complications are less frequent when an experienced operator uses proper technique. Renal biopsy specimens must be processed and evaluated appropriately if consistent and accurate diagnoses are to be rendered. The article summarizes patient selection and evaluation, renal biopsy techniques, expected complications of renal biopsy, and appropriate processing and evaluation of the renal biopsy specimen.     

Photodynamic therapy for the treatment of intranasal tumors in 3 dogs and 1 cat

Three dogs and 1 cat with intranasal tumors were treated with pyropheophorbide-a-hexyl ether-based photodynamic therapy (PDT). PDT was well tolerated by all the animals, and no adverse effects from photosensitizer injection, such as cutaneous photosensitization, were observed. Facial swelling was observed in all animals after each PDT treatment but resolved spontaneously within 72 hours after treatment. All animals had a decrease in severity of epistaxis, frequency of sneezing, and amount of nasal discharge after PDT. Clinical signs were controlled for variable time, although long-term responses were comparable with radiation therapy in 2 animals. This small case series demonstrates another application for PDT in veterinary medicine. On the basis of these findings. further studies are warranted to define the role of PDT in the management of intranasal tumors in dogs and cats.     

Current prevalence of Dirofilaria immitis in dogs, cats and humans from the island of Gran Canaria, Spain

The island of Gran Canaria is a hyperendemic area for canine dirofilariasis. The aim of the present study was to provide data on Dirofilaria immitis in dogs, cats, and humans on this island in 2010. The data confirms the prevalence in the overall canine population (19%), with a considerably higher prevalence (43%) in the autochthonous breed of Canarian Warren hound. The prevalence in the feline population (33%) is higher than that of the canine population, and the existence of specific D. immitis antibodies in the inhabitants of the island of Gran Canaria (12%) is confirmed. In both cats and humans, the prevalence, according to the different climate areas on the island, is related to the prevalence of D. immitis in dogs in the same area, which shows the key epidemiological role played by the canine host with regard to the transmission to other hosts of D. immitis.     

Pancreatic Pseudocysts in 4 Dogs and 2 Cats: Ultrasonographic and Clinicopathologic Findings

Pancreatic pseudocysts were diagnosed in 4 dogs and 2 cats based on ultrasonographic and clinicopathologic findings. All 6 animals had a clinical diagnosis of pancreatitis. Five of 6 pseudocysts were in the left pancreatic limb, and in 1 cat the pseudocyst was in the pancreatic body region. Cyst size ranged from 2 x 2 cm to 7 x 6 cm. All pseudocysts had anechoic regions that were aspirated using ultrasound guidance for diagnostic and therapeutic purposes. No morbidity was associated with the aspiration procedures. Cytologically the pseudocyst fluid was aseptic in all patients and had low numbers of inflammatory cells in 5 of 6 patients. All animals had high lipase activity in the pseudocyst fluid and in 2 dogs and 1 cat the lipase activity in the fluid was greater than in serum. Three of the 4 dogs were managed medically. In the 1 dog that had long-term follow-up ultrasound examination, the pseudocyst persisted for several days following aspiration and had disappeared 8 months after diagnosis. All 3 of these dogs were clinically normal 1.5-4 years after presentation. The 4th dog underwent surgical exploration and was euthanized shortly thereafter because of bronchopneumonia and chronic pancreatitis. The 2 cats died 10 days and 2 months, respectively, following initial diagnosis of the pseudocyst, but necropsies were not performed in either case. Ultrasound-guided fine-needle aspiration of pancreatic pseudocysts and clinicopathologic evaluation of cystic fluid are useful for diagnosis of pancreatic pseudocysts.     

Clinical evolution and radiographic findings of feline heartworm infection in asymptomatic cats

Clinical manifestations of heartworm disease in cats are variable; most cats seem to tolerate the infection well for extended periods. Heartworm-infected cats may undergo spontaneous self-cure due to the natural death of parasites without any symptomatology, or they may suddenly show dramatic and acute symptoms. Sudden death in apparently healthy cats is not a rare event. Thoracic radiographs are important tool for the diagnosis of cardiopulmonary disease. However, thoracic abnormalities are often absent or transient and highly variable in heartworm-infected cats. Findings, such as enlargement of the peripheral branches of the pulmonary arteries, with a varying degree of pulmonary parenchymal disease and hyperinflation, are the most typical features consistent with infection. A field study was performed for cats referred to the Veterinary Hospital Città di Pavia from January 1998 to December 2001 for routine health examinations and procedures to evaluate the clinical evolution and radiographic findings of feline heartworm infection. Thirty-four asymptomatic cats diagnosed with feline heartworm infection by antibody and antigen tests together with an echocardiogram that allowed worm visualization were included in the follow-up study. Cats were routinely examined every 3 months from the time of heartworm diagnosis until the outcome (self-cure or death). Self-cure was defined as no positive serology for heartworm antigens and no visualization of worms by echocardiography. A final examination for antibodies was carried after 12 months as a final confirmation of self-cure. Twenty-eight cats (82.4%) self-cured; including 21 that showed no clinical signs of infection throughout the study. Six cats died. The most common clinical features observed were acute respiratory symptoms and sudden death. Infection lasted over 3 years in the majority of the cats enrolled in the study. Thoracic radiograph appearance was variable, and the most commonly observed findings were focal and diffuse pulmonary parenchymal abnormalities.     

Effect of pimobendan or benazepril hydrochloride on survival times in dogs with congestive heart failure caused by naturally occurring myxomatous mitral valve disease: the QUEST study

Background: Myxomatous mitral valve disease (MMVD) continues to be an important cause of morbidity and mortality in geriatric dogs despite conventional therapy. Hypothesis: Pimobendan in addition to conventional therapy will extend time to sudden cardiac death, euthanasia for cardiac reasons, or treatment failure when compared with conventional therapy plus benazepril in dogs with congestive heart failure (CHF) attributable to MMVD. Animals: Two hundred and sixty client‐owned dogs in CHF caused by MMVD were recruited from 28 centers in Europe, Canada, and Australia. Methods: A prospective single‐blinded study with dogs randomized to PO receive pimobendan (0.4–0.6 mg/kg/d) or benazepril hydrochloride (0.25–1.0 mg/kg/d). The primary endpoint was a composite of cardiac death, euthanized for heart failure, or treatment failure. Results: Eight dogs were excluded from analysis. One hundred and twenty‐four dogs were randomized to pimobendan and 128 to benazepril. One hundred and ninety dogs reached the primary endpoint; the median time was 188 days (267 days for pimobendan, 140 days for benazepril hazard ratio = 0.688, 95% confidence limits [CL] = 0.516–0.916, P= .0099). The benefit of pimobendan persisted after adjusting for all baseline variables. A longer time to reach the endpoint was also associated with being a Cavalier King Charles Spaniel, requiring a lower furosemide dose, and having a higher creatinine concentration. Increases in several indicators of cardiac enlargement (left atrial to aortic root ratio, vertebral heart scale, and percentage increase in left ventricular internal diameter in systole) were associated with a shorter time to endpoint, as was a worse tolerance for exercise. Conclusions and Clinical Importance: Pimobendan plus conventional therapy prolongs time to sudden death, euthanasia for cardiac reasons, or treatment failure in dogs with CHF caused by MMVD compared with benazepril plus conventional therapy.     

Interferon-gamma in the serum and effusions of cats with feline coronavirus infection

The aim of this study was to quantify and compare interferon-γ (IFN-γ) concentrations in the serum of clinically normal cats infected with feline coronavirus (FCoV) with its concentration in the sera and effusions of cats with feline infectious peritonitis (FIP), a disease associated with infection with a mutated form of FCoV.Clinically normal FCoV-infected cats living in catteries with a high prevalence of FIP had the highest serum IFN-γ concentrations. The serum concentration of IFN-γ was not significantly different in cats with FIP compared with clinically normal FCoV-infected animals living in catteries with a low prevalence of the disease. Moreover, the concentration of IFN-γ was significantly higher in the effusions than in the serum of cats with FIP, probably due to IFN-γ production within lesions. These findings support the hypothesis that there is a strong, ‘systemic’ cell mediated immune response in clinically normal, FCoV-infected cats and that a similar process, albeit at a tissue level, is involved in the pathogenesis of FIP.     

A review of coronavirus infection in the central nervous system of cats and mice

Feline infectious peritonitis (FIP) is a common cause of death in cats. Management of this disease has been hampered by difficulties identifying the infection and determining the immunological status of affected cats and by high variability in the clinical, pathological, and immunological characteristics of affected cats. Neurological FIP, which is much more homogeneous than systemic effusive or noneffusive FIP, appears to be a good model for establishing the basic features of FIP immunopathogenesis. Very little information is available about the immunopathogenesis of neurologic FIP, and it is reasonable to use research from the well-characterized mouse hepatitis virus (MHV) immune-mediated encephalitis system, as a template for FIP investigation, and to contrast findings from the MHV model with those of FIP. It is expected that the immunopathogenic mechanisms will have important similarities. Such comparative research may lead to better understanding of FIP immunopathogenesis and rational prospects for management of this frustrating disease.     

Giardia infection of cats and dogs in New Zealand

Giardia intestinalis is a pathogenic protozoan which infects humans and a wide range of animal hosts, including cats and dogs⁽¹⁾. However, the status of animals in New Zealand with respect to Giardia infection has not received much attention, so we undertook a preliminary study of cats and dogs in Palmerston North and Hamilton to determine the prevalence of infection, as indicated by the presence of cysts in faeces.     

Survey of Helicobacter infection in domestic and feral cats in Korea

Discovery of Helicobacter (H.) pylori has led to a fundamental change in our understanding of gastric diseases in humans. Previous studies have found various Helicobacter spp. in dogs and cats, and pets have been questioned as a zoonotic carrier. The present study surveyed the Helicobacter infections and investigated the presence of H. felis and H. pylori infections in domestic and feral cats in Korea. Sixty-four domestic cats and 101 feral cats were selected from an animal shelter. Saliva and feces were evaluated by Helicobacter genus-specific polymerase chain reaction (PCR). Genus-specific PCR positive samples were further evaluated for H. felis and H. pylori using specific primer pairs. Thirty-six of 64 (56.3%) samples from domestic cats and 92 of 101 (91.1%) samples from feral cats were PCR positive; the positive rate of feces samples was higher than that of saliva samples in both groups. H. felis and H. pylori species-specific PCR was uniformly negative. The prevalence of Helicobacter spp. in feral cats was approximately two-fold higher than that of domestic cats. The fecal-oral route may be more a common transmission route not only between cats but also in humans.     

Prevalence of and risk factors for increased serum levels of allergen-specific IgE in a population of Norwegian dogs

Background

The importance of different allergens in association with IgE production and canine atopic dermatitis (CAD) has been poorly studied and few studies exist on factors influencing allergen-specific IgE antibodies in serum. The aim of this cross-sectional study was to investigate the prevalence of elevated IgE levels to different environmental allergens in Norwegian dogs with a suspicion of CAD. The secondary aim was to identify risk factors associated with elevated serum levels of allergen-specific IgE.

Results

The study sample consisted of serum from 1313 dogs of 161 different breeds. All samples were submitted for serologic IgE-testing (Fc epsilon R1 alpha-based ELISA) based on suspicion of CAD. Overall, 84.3% of the dogs had elevated IgE levels to one or more of the allergen(s). The predominant allergens amongst the positive results were the indoor allergens (Acarus siro 84.0%, Dermatophagoides farinae 80.2%, Tyrophagus putrescentiae 79.9%). Sheep sorrel was the most commonly encountered outdoor allergen (40.0%). Only 2.6% of the dogs with elevated IgE levels were positive to flea saliva.The test results varied significantly depending on when the serum samples were taken. Samples taken during summer and autumn more often came out positive than samples taken during winter and spring. Geographical variations were also demonstrated. A greater proportion of females than males had positive test results, and more females than males tested positive to outdoor allergens. The mean age was significantly higher in the dogs testing positive than amongst the dogs testing negative. The allergen-specific IgE levels varied with breed. The boxer was the only breed with a significantly higher proportion of positive test results compared to the other breeds. Boxers also had a higher prevalence of elevated IgE levels to outdoor allergens, whereas the Rottweiler had a higher prevalence of elevated IgE levels to indoor allergens compared to the other breeds.

Conclusions

IgE hypersensitivity was most often associated with indoor allergens. Outdoor allergens were of minor importance and IgE reactivity to flea saliva was rare. Breed differences in allergen-specific IgE levels were identified. Season of sampling, and the dogs’ geographical localisation, sex and age also affected the results of the IgE analysis.     

Risk factors for Campylobacter infection in Norwegian cats and dogs

Rectal swabs from healthy cats and dogs, and from dogs and cats with clinical diarrhoea were collected approximately every third month from May 2000 to June 2001 from six small-animal practices throughout Norway. A questionnaire was filled in for each animal. Of the 301 healthy cats sampled, 54 (18%) were positive for Campylobacter, compared to 5 out of 31 (16%) cats with diarrhoea. Campylobacter jejuni was isolated from 11 (3%), C. upsaliensis from 42 (13%) and C. coli from 2 (0.6%) of the cats sampled. Isolates from four cats (1%) could not be specified. Of the 529 healthy dogs, 124 (23%) were positive for Campylobacter, compared to 18 of 66 (27%) dogs with diarrhoea. C. jejuni was isolated from 20 (3%) and C. upsaliensis from 117 (20%) of the dogs sampled. Isolates from five dogs (0.8%) could not be specified. Eighteen out of the 20 investigated C. upsaliensis samples were resistant to streptomycin. The clinically healthy animals were included in the analysis to identify factors associated with Campylobacter prevalence. The cat model had low classification ability. The dog-data model indicated increased odds of infection with Campylobacter for dogs ≤1 year, and in dogs sampled during the spring. No difference was observed between the prevalence of Campylobacter infections in cats and dogs with diarrhoea and healthy animals.