Anaesthesia in the dyspneic canine or feline patient

Summary

The different aspects of the anaesthetic approach of dyspneic patients are outlined, and the various possibilities for sedation, anaesthetic induction and maintenance, and facilitating recovery are discussed. More specific anaesthetic approaches are presented for each of the different types of stridoric dyspnea i.e. dyspnea associated with nasal, pharyngeal, laryngeal, or tracheal stridor.     

Basics in canine and feline rhinoscopy

Patients suffering from upper respiratory disease such as chronic nasal congestion, sneezing, nasal discharge, and epistaxis invite complete evaluation of their paired nasal cavities. Thorough assessment of these cavities employs sundry diagnostic procedures that enable the investigating clinician to characterize the internal structures of the nasal cavities. After the conscious patient undergoes a complete physical examination, a gross assessment of its external nasal structures is established and areas of physical asymmetry are noted. A working anatomic knowledge of these asymmetric foci helps to guide the next diagnostic steps. The patient is then placed under general anesthesia, during which, in list order, imaging studies, rhinoscopy, and nasal biopsy or foreign body retrieval, are performed.     

Microbiology of the canine and feline eye

Knowledge of the microbiology of the canine and feline eye in normal and pathologic states is an important aspect of the clinician's assessment of external ocular disease. Gram-positive bacteria predominate in surveys of microbial flora in normal and diseased eyes. These same organisms are routinely isolated from skin and the upper respiratory tract. Injury to the eye may result in proliferation and potential pathogenicity of normal ocular flora. A variety of bacterial, fungal, viral, and other microbial isolates affect the diagnosis and treatment of external ocular disease.     

Perspectives on canine and feline hepatozoonosis

Two species of Hepatozoon are currently known to infect dogs and cause distinct diseases. Hepatozoon canis prevalent in Africa, Asia, southern Europe, South America and recently shown to be present also in the USA causes infection mainly of hemolymphoid organs, whereas Hepatozoon americanum prevalent in the southeastern USA causes myositis and severe lameness. H. americanum is transmitted by ingestion of the Gulf Coast tick Amblyomma maculatum and also by predation on infected prey. H. canis is transmitted by Rhipicephalus sanguineus, in South America also by Amblyomma ovale, and has also been shown to be transmitted transplacentally. Hepatozoonosis of domestic cats has been described mostly from the same areas where canine infection is present and the exact identity of the species which infect cats, their pathogenicity and vectors have not been elucidated. The diagnosis of hepatozoonosis is made by observation of gamonts in blood smears, histopathology, PCR or serology. The main treatment for H. canis is with imidocarb dipropionate whereas H. americanum infection is treated with an initial combination of trimethoprim-sulfadiazine, pyrimethamine and clindamycin followed by maintenance with decoquinate. Treatment for both diseases has not been reported to facilitate complete parasite elimination and new effective drugs are needed for the management of these infections. Prevention of hepatozoonosis should be based on avoidance of oral ingestion of infected tick vectors and infected prey.     

Immune-mediated canine and feline keratitis.

Although the normal cornea is devoid of vasculature and lymphatics, there are still several immune-mediated corneal conditions that can occur in dogs and cats. An overview of corneal immunology is presented. Diseases of dogs, including chronic superficial keratitis, superficial punctate keratitis, and canine adenovirus endotheliitis, as well as feline diseases, including eosinophilic keratitis and herpesvirus-related conditions, are discussed.     

Pathology of the canine and feline uterine tube

Lesions of the uterine tube were described in 37 dogs and nine cats. Of the 52 lesions noted, 18 were developmental abnormalities; four paramesonephric remnants, and 14 mesonephric remnants. Uterine tube cysts were seen in 16 animals, and seven animals had salpingitis. One dog had hyperplastic changes of the infundibular mucosa, and one cat and one dog demonstrated adenomyosis. There were three primary benign uterine tube neoplasms, one adenocarcinoma, two metastatic neoplasms in the uterine tube, and two bursal lipomas, all in dogs. With the exception of neoplasia of the uterine tube, most lesions were unlikely to affect the reproductive performance of these animals and/or were incidental or secondary to disorders elsewhere in the reproductive tract.     

Current research in canine and feline pheromones.

Pheromonotherapy seems to be a new therapeutic approach allowing practitioners to tackle the treatment of behavioral disorders in a natural, specific, and safe way. Although the efficacy of pheromones has been assessed in some specific behavioral problems, it seems that their range of action could cover the wide field of reduction of stress. Therefore, the use of pheromones should not be reduced to treatment of behavioral disorders (potentially associated with psychotropes or a behavioral modification program) but should be included in a strategy of improving the welfare of pets in veterinary structures (during examination and hospitalization) and in breeding networks (separation from the mother and transport). Moreover, further studies may allow the veterinary practitioner to use pheromone analogues in the field of diagnostics to determine the behavioral status of a pet (e.g., anxious or not, dominant or not). Pheromonotherapy is at its beginning, and the use of pheromones in various fields of medicine is heartening.     

Apoptosis in feline panleukopenia and canine parvovirus enteritis

Tissue samples of cats and dogs with panleukopenia and parvovirus enteritis, respectively, were examined for the presence of viral antigen-positive cells and apoptotic cells by immunohistochemistry and by TUNEL assay (Terminal Transferase-Mediated dUTP Nick End Labelling). Compared to control animals, infected cats and dogs generally had more TUNEL-positive cells. Cell types positive for parvovirus antigen, for example digestive tract epithelial and mesenchymal cells, and lymphocytes and macrophages in lymphoid tissues were also positive for TUNEL signals. Occasionally, TUNEL signal and viral antigen were present in the same tissue areas, suggesting a direct viral trigger of apoptosis. More frequently, however, there was no complete overlap of antigen and TUNEL-positive areas. The results of this study indicate that apoptotic cell death contributes significantly to the widespread tissue damage of parvovirus infection in cats and dogs.     

Addressing canine and feline aggression in the veterinary clinic.

Handling aggressive dogs and cats in the veterinary clinic can be frustrating, time consuming, and injurious for both employee and animal. This article discusses the etiology of the aggressive dog and cat patient and how best to approach these cases. A variety of handling techniques, safety products, and drug therapy are reviewed.     

Comparison of chemotherapeutic drug resistance in cells transfected with canine ABCG2 or feline ABCG2

ABCG2 (ATP binding cassette subfamily G, member 2) mediates resistance to a variety of cytotoxic agents. Although human ABCG2 is well characterized, the function of canine ABCG2 has not been studied previously. Feline ABCG2 has an amino acid substitution in the adenosine triphosphate‐binding domain that decreases its transport capacity relative to human ABCG2. Our goal was to compare canine ABCG2‐mediated chemotherapeutic drug resistance to feline ABCG2‐mediated chemotherapeutic drug resistance. HEK‐293 cells stably transfected with plasmid containing canine ABCG2, feline ABCG2 or no ABCG2 were exposed to carboplatin, doxorubicin, mitoxantrone, toceranib or vincristine, and cell survival was subsequently determined. Canine ABCG2 conferred a greater degree of chemotherapy resistance than feline ABCG2 for mitoxantrone. Neither canine nor feline ABCG2 conferred resistance to doxorubicin, vincristine or toceranib. Canine, but not feline, ABCG2 conferred resistance to carboplatin, a drug that is not reported to be a substrate for ABCG2 in other species.     

Diagnostic imaging of the canine and feline ear.

Radiographic evaluation of the tympanic bulla is limited. Improper obliquity or angulation of the skull for radiographs or malpositioning of the tongue can result in an inadequate study [4]. Additionally, because of the complex anatomy of the canine and feline skull, with superimposition of multiple osseous structures, radiography can result in false-negative examinations or understimation of the disease present [2]. When compared with surgical findings of 19 clinical cases of presumptive middle ear disease, false-negative radiographic findings were found in 25% of the surgically confirmed cases of otitis media [4]. Therefore, radiographs are not considered to be a highly sensitive mode of diagnosing otitis media. Radiographs may be helpful in determining lysis associated with neoplasia; however, the extent of involvement is still underestimated. In a study comparing CT and radiographic evaluation of otitis media, CT was determined to be more sensitive but less specific than radiography [11]. CT is the preferred modality for the evaluation of the tympanic bulla at our institution. This opinion may be biased by the fact that most cases are presented for recurrent or chronic otitis. Although radiography is more accessible, the availability of CT in local referral settings is increasing as opposed to being limited to university settings. After the cost (i.e., anesthesia, radiographs) and amount of time necessary to make optimum radiographic studies are taken into account, a CT study may actually be faster and more informative. Given our preference for the CT examination, the cost of the examination has been adjusted to make it more appealing to the owner and clinician. For example, a bulla CT study is only 1.3 times the cost of a radiographic bulla study. In conclusion, imaging of the ear canal can provide important information about ear disease, including unilateral or bilateral ear disease, the degree of middle or inner ear involvement, peripheral versus central vestibular disease, an infectious or inflammatory versus neoplastic process, the chronicity of the disease process, involvement of adjacent structures, and postsurgical complications.     

Topical treatment of canine and feline pyoderma

Abstract This paper is a review of commonly used topical antibacterial medications: benzoyl peroxide, chlorhexidine, povidone iodine, ethyl lactate, triclosan, mupirocin, neomycin, polymyxin B, bacitracin and fusidic acid. Included is a review of the pharmacokinetics, modes of action, adverse effects and clinical uses in veterinary dermatology. General recommendations for topical antibacterial therapy are presented. Résumé— Cet article est une revue des topiques antibactériens les plus couramment utilisés: peroxyde de benzoyle, chlorhexidine, povidone iodée, lactate d'éthyle, triclosan, mupirocine, néomycine, polymyxine B, bacitracine et acide fucidique. Il inclut notamment une revue des pharmacocinétiques, des modes d'action, des effets secondaires et des indications thérapeutiques de ces produits en dermatologie vétérinaire. Les indications générales du traitement topique antibactérien sont présentées. [Guaguere, E. Topical treatment of canine and feline pyoderma. (Traitement topique des pyodermites canines et félines). Veterinary Dermatology 1996; 7 : 145–151.] Resumen Este articulo es una revisión de los productos tópicos antibacterianos más frecuentemente utilizados: peróxido de benzoilo, clorhexidina, povidona yodada, etillactato, triclosan, mupirocina, neomicina, polimixina B, bacitracina y ácido fusidico. Se incluye una revisión de la farmacocinética, mecanismos de acción, efectos colaterales y sus usos clínicos en dermatologia veterinaria. Se presentan recomendaciones generales para la terapia antibacteriana tópica. [Guaguere, E. Topical treatment of canine and feline pyoderma. (Tratamiento topico de la pioderma canina y felina). Veterinary Dermatology 1996; 7 : 145–151.] Zusammenfassung— Diese Veröffentlichung besteht in einer Übersicht von häufig verwendeten topischen antibakteriellen Arzneimitteln: Benzoylperoxid, Chlorhexidin, Povidon-Jod, Ethyllaktat, Triklosan, Mupirocin, Neomycin, Polymyxin B, Bacitracin und Fusidinsäure. Mit eingeschlossen ist eine Übersicht über Pharmakokinetik, Wirkungsweise, Nebenwirkungen und klinische Anwendung in der Veterinärdermatologie. Allgemeine Empfehlungen für die lokale antibakterielle Therapie werden dargestellt. [Guaguere, E. Topical treatment of canine and feline pyoderma (Lokale Behandlung von kaninen und felinen Pyodermien). Veterinary Dermatology 1996; 7 : 145–151.]