Orthopedic examination in the cat: clinical tips for ruling in/out common musculoskeletal disease

PATIENT GROUP: The majority of cats will develop radiographic evidence of degenerative joint disease by the time they are 12 years of age, and many will suffer from a decline in quality of life associated with undiagnosed and untreated orthopedic disease. PRACTICAL RELEVANCE: A focused, efficient orthopedic examination, including gait observation and palpation (awake and under sedation), supplemented with appropriate history, is key in ruling in, or out, clinically important musculoskeletal disease. Identifying problems assists in both developing a diagnostic plan and monitoring response to treatment. CLINICAL CHALLENGES: Many clinicians feel uncomfortable in their ability to reliably perform an orthopedic examination in the cat, and diagnosis and evaluation of response to treatment in cats with orthopedic disease can be challenging. Hands-on training in feline orthopedic examination is limited in many veterinary curricula. Additional constraints may include failure to obtain important information in the history that indicates feline orthopedic disease, lack of appropriate facilities in which to conduct a complete orthopedic examination, and inability to obtain the most important information during the time available to conduct the examination. These problems can create gaps in the practitioner's ability to provide excellent care for a large proportion of the feline population. GOALS: The above challenges can mostly be overcome with advanced planning and with consideration of the unique behavioral aspects related to feline handling. As discussed in this review, the aim of the initial orthopedic examination is to localize the problem to a specific limb, ideally to a region or joint of the limb, which can further direct diagnostics such as radiography or arthrocentesis. This should provide a basis for follow-up and assessment of whether treatment strategies are effective.     

Small exotic mammal orthopedics.

The basic principles of orthopedic repair are the same for small exotic mammals as for the canine or feline patient. This article assists the clinician in determining the most appropriate method of fixation and maximizes the probability of a favorable outcome.     

牛磺酸在猫营养中的应用

主要综述近年猫的牛磺酸营养,从研究方法来看衡量牛磺酸利用的方法与指标已较完善,对牛磺酸的代谢有了深入的了解,并进一步关注猫肠道菌群影响牛磺酸代谢的机理的研究;初步揭示大豆蛋白和脂肪等营养物质降低牛磺酸利用率的原因;在猫粮加工方面指出不良热处理导致的猫粮中牛磺酸利用率降低的机制,并分析了一些不适合配制猫粮的原料如米糠、大豆蛋白对牛磺酸代谢的影响;以及在猫粮中直接添加晶体牛磺酸的重要性。从文中可以看到,作为必需氨基酸的牛磺酸对于猫的生长繁殖来说十分重要。     

Musculoskeletal imaging in the cat: what's normal? What's abnormal?

PRACTICAL RELEVANCE: Despite the increasing availability of ultrasonography, computed tomography and magnetic resonance imaging (MRI), radiography remains the primary imaging modality for the assessment of feline musculoskeletal disease in practice. In many respects, having a more feline-focused approach to radiography will reward the clinician with better quality images and, hence, a greater likelihood of a correct diagnosis. CLINICAL CHALLENGES: Correct interpretation of radiographic films requires familiarity with some of the unique aspects of normal feline skeletal anatomy. For optimal patient management, the clinician also needs an appreciation of the distinct advantages of advanced imaging modalities in certain circumstances, in particular for head trauma patients. EQUIPMENT: When considering what equipment is most suitable for musculoskeletal imaging, the small size of our feline patients means that image resolution is of primary importance. Choosing an x-ray system (film-screen or digital) that offers more detail, and selecting ultrasound probes of a higher frequency than would be used on larger canine patients, will go some way to improving the diagnostic yield of any feline imaging study. If there is the option of referral for MRI, and a choice between high-field and low-field MRI systems for the feline patient, a high-field system will always provide more detail. AUDIENCE: This review, drawing on the author's experience and established imaging and anatomical principles, aims to assist general veterinary practitioners in their approach to feline musculoskeletal imaging. It provides an overview of the imaging choices and techniques for different regions of the body, and gives examples of normal anatomy that is peculiar to the cat.     

Feline infectious peritonitis.

The article discusses feline infectious peritonitis (FIP), an important disease frequently seen in veterinary practice. FIP causes many problems to the veterinarian as it can be difficult to definitively diagnose the disease, as there is no effective treatment, and as prophylactic interventions are not very successful. Although intense research has created a lot of new knowledge about this disease in the last years, there are still many unanswered questions. The objective of this article is to review recent knowledge and to increase understanding of the complex pathogenesis of FIP.     

Update: Management of calcium oxalate uroliths in dogs and cats.

Calcium oxalate has become the most common mineral occurring in canine and feline uroliths. Although calcium oxalate urolith formation may be a consequence of metabolic disease, the underlying cause is not identified in many dogs and cats. Currently, there is no successful medical dissolution protocol, and calcium oxalate uroliths must be removed physically if causing problems. Effective preventative protocols are available for dogs and cats, although they are not uniformly successful.     

Oral pathology

Oral disease is exceedingly common in small animal patients. In addition, there is a very wide variety of pathologies that are encountered within the oral cavity. These conditions often cause significant pain and/or localized and systemic infection; however, the majority of these conditions have little to no obvious clinical signs. Therefore, diagnosis is not typically made until late in the disease course. Knowledge of these diseases will better equip the practitioner to effectively treat them. This article covers the more common forms of oral pathology in the dog and cat, excluding periodontal disease, which is covered in its own chapter. The various pathologies are presented in graphic form, and the etiology, clinical signs, recommended diagnostic tests, and treatment options are discussed. Pathologies that are covered include: persistent deciduous teeth, fractured teeth, intrinsically stained teeth, feline tooth resorption, caries, oral neoplasia, eosinophilic granuloma complex, lymphoplasmacytic gingivostomatitis, enamel hypoplasia, and "missing" teeth.     

Instrumentation for external fixation.

External skeletal fixation is a very useful technique for managing many orthopedic problems in veterinary practice. The Kirschner apparatus has been the most widely used fixator for many years in veterinary orthopedics because of its versatility, simplicity, and economy in use. The medium-sized device has the widest indications and is easiest to begin with. The small size can be acquired later for use on cats and small dogs. The new "raised thread" fixation pin designs improve bone-pin integrity and can be used in combination with nonthreaded pins to decrease the incidence of postoperative complications and for economy. Acrylic-pin external fixators are particularly useful for treatment of mandibular fractures and transarticular application since they allow nonlinear placement of fixation pins in highly contoured bones. A commercial system, currently being developed, will have all the equipment and materials necessary for their application in a convenient kit. Circular fixators (Ilizarov design) use thin K wires placed under tension to replace rigid fixation pins. Their unique adjustability characteristics make them useful in the treatment of limb deformity and shortening. Many other human fixators can be used for veterinary application if the basic principles of fixators are followed. Instrumentation required for external fixator application include a pin driver, pin cutter, and wrenches. Although surgical versions of these materials are available, less expensive alternatives are available using gas sterilization instead of autoclaving. The use of selected orthopedic instrumentation such as a periosteal elevator, bone clamps, and curets will facilitate fracture management.     

Management of equine orthopedic pain.

Pain management is an extremely vital part of equine orthopedic surgery. Providing optimum analgesia for the patient will decrease recovery time, decrease physiologic stress on the animal, and provide maximum comfort during the post-operative period. The major analgesic drug categories and routes covered are nonsteroidal anti-inflammatory drugs, local anesthetics, intra-articular drugs, and epidurals.     

Prevalence of feline leukemia virus and antibodies to feline immunodeficiency virus in cats in Norway.

Serum samples from 224 Norwegian cats were analyzed for the presence of feline leukemia virus (FeLV) p27 common core antigen, and for antibodies to feline immunodeficiency virus (FIV). Ninety specimens originated from the serum bank at the central referral clinic at the Norwegian College of Veterinary Medicine, which had been collected during the years 1983-1989; 67 sera were submitted from veterinarian practitioners; while 67 sera originated from cats presented for euthanasia. The cats were classified into one "healthy" and one "sick" group. Only 2.2% of sick cats and 1.2% of healthy cats showed FeLV antigenemia, a finding which is lower than which has been reported from many other countries. The prevalence of FIV antibodies was 10.1% in sick cats and 5.9% in healthy cats. Antibodies to FIV was most prevalent in male cats (14.7%) than in female cats (2.1%), and more prevalent among domestic cats (12.0%) compared to pedigree cats (2.4%). Antibodies to FIV in the cats demonstrated increasing prevalence with increasing age. It may be concluded that FeLV causes minor problems in Norwegian cats, while FIV is present in a similar prevalence to what is reported from other countries.     

Anti-CD71 antibody immunohistochemistry in the diagnosis of acute myeloid leukemia,subtype acute erythroid leukemia with erythroid dominance (AML M6-Er), in a retrovirus-negative cat

CD71 is an immunohistochemical marker used in diagnosing acute myeloid leukemia (AML) M6-Er in humans; however, to our knowledge, it has not been reportedly used for immunohistochemistry in veterinary medicine. We evaluated the pathologic features of AML M6-Er in a retrovirus-negative cat and used CD71 to support the diagnosis. A 4-y-old spayed female Scottish Fold cat was presented with lethargy, anorexia, and fever. Whole-blood PCR assay results for pro feline leukemia virus/pro feline immunodeficiency virus and feline vector-borne diseases were negative. Early erythroid precursors were observed in the peripheral blood smear. Fine-needle aspiration of the enlarged spleen and splenic lymph node showed many early erythroid precursors. Bone marrow aspirate smears revealed erythroid hyperplasia with 68.4% erythroid lineage and 3.6% rubriblasts. Dysplastic cells infiltrated other organs. The patient was diagnosed with myelodysplastic syndrome, progressing to the early phase of AML M6-Er. The patient died on day 121 despite multidrug treatments. Postmortem examination revealed neoplastic erythroblasts infiltrating the bone marrow and other organs. Neoplastic cells were immunopositive for CD71 but immunonegative for CD3, CD20, granzyme B, von Willebrand factor, CD61, myeloperoxidase, and Iba-1. Although further studies are necessary for the application of CD71, our results supported the morphologic diagnosis of AML M6-Er.     

An enteric coronavirus infection of cats and its relationship to feline infectious peritonitis

An enteric coronavirus that is antigenically closely related to feline infectious peritonitis virus (FIPV) is ubiquitous in the cat population. This virus has been designated feline enteric coronavirus to differentiate it from FIPV. The virus is shed in the feces by many seropositive cats; in catteries it is a cause of inapparent to mildly severe enteritis in kittens 6 to 12 weeks of age. The virus may produce a more severe enteritis in young specific-pathogen-free kittens. Feline enteric coronavirus selectively infects the apical columnar epithelium of the intestinal villi, from the caudal part of the duodenum to the cecum. In severe infections, there are sloughing of the tips of the villi and villous atrophy. Many cats recovering from the disease remain carriers of the virus. Recovered cats, observed for 3 to 24 months, remained healthy and did not develop peritonitis, pleuritis, or granulomatous disease. The relationship of feline enteric coronavirus and FIPV was studied. Although the viruses were antigenically similar, they were distinctly different in their pathogenicities. The enteric coronavirus did not cause feline infectious peritonitis in coronavirus antibody-negative cats inoculated orally or intraperitoneally nor in coronavirus antibody-positive cats inoculated intraperitoneally or intratracheally. Serologic tests, using FIPV, canine coronavirus, and transmissible gastroenteritis virus of swine as substrate antigens in fluorescent antibody procedures may not accurately identify FIPV infection. These tests do not appear to distinguish between FIPV and this feline enteric coronavirus.     

Feline fear and anxiety

Anxieties and fears play a large role in some of the more common feline behavior problems. The interaction between emotions and stress is complex but pertinent to the field of veterinary medicine, given the physical and emotional consequences of stress in animals. By thinking of behavior "problems" from the perspective of the animal's emotional state, treatment plans can be implemented to reduce the states of anxiety and fears and safeguard against the physical consequences of a prolonged stress response.     

A review of feline serum protein electrophoresis

A review of the current literature available on feline serum proteins is presented. Early studies concentrated on comparative aspects of species variations in the electrophoretic pattern. The feline electrophoretogram was divided into five basic regions: albumin, alpha-1, alpha-2, beta and gamma. Different subdivisions of these areas were recognized depending on the support medium used. Current papers have compared the relative migration distances of each globulin peak to the migration of albumin. This "Rf" value enables reliable peak identification. To date, no data exists identifying the individual proteins responsible for the peaks in the alpha and beta regions. The only feline globulin to be studied is haptolobin; however its precise location on the electrophoretic strip was not identified.     

Microstructure and glycosaminoglycan ratio of canine cornea after reconstructive transplantation with glycerin-preserved porcine amniotic membranes

Objective  Although amniotic membranes of canine, feline, and equine species have some advantages as corneal transplantation material in many canine ocular diseases, their softness, thinness, and low availability can pose problems. As an alternative, the more abundant porcine amniotic membranes may be used. This paper describes the use of glycerin-preserved porcine amniotic membranes in corneal transplantation in eight normal dogs.
Method  A 0.4-mm deep recipient bed in the axial cornea of the OS of all dogs was created using an 8-mm Barron radial vacuum trephine. The recipient bed was then filled with amnion, and the entire cornea was covered with another piece of the glycerin-preserved membrane. The ocular signs evaluated were corneal opacity and corneal vascularization. The dogs were euthanized on days 5, 10, 20, or 40 after surgery, and samples were collected to evaluate corneal thickness, parenchymal cell number, mean collagen fibril diameter, collagen fibril content and the glycosaminoglycan (GAG) ratio.
Results  Corneal opacity was observed immediately after surgery. Restoration of corneal transparency, regression of corneal vascularization, and visualization of the pupil and iris were noted on day 40.
Conclusions  The clinical observations were supported histologically by regained corneal thickness, parenchymal cell number, mean collagen fibril diameter, collagen fibril content, and GAG ratio, suggesting that this technique may be a novel method for the treatment of ocular surface disorders.     

Feline ocular emergencies

Feline ocular emergencies include any ophthalmic condition that has rapidly developed or is the result of trauma to the eye or periocular structures. Common feline emergencies include proptosis, lid lacerations, corneal ulcers, and foreign bodies. Complete ophthalmic examination including procurement of the minimal ophthalmic database (Schirmer tear test, fluorescein stain, and intraocular pressure measurement) should be obtained whenever possible to ensure that the complete and correct diagnosis is made. Concern for the patient's vision and ocular comfort should guide the practioner's diagnostic and therapeutic plan. This article reviews some of the more common feline ocular emergencies, including conditions affecting the orbit and globe, adnexa, conjunctiva, and cornea. Feline uveitis, glaucoma, and lenticular diseases are covered more thoroughly elsewhere in this issue.     

Orthopedic problems in geriatric dogs and cats.

Senior dogs and cats with orthopedic injuries and diseases often require a treatment plan that differs from that of younger patients. Injured bone and soft tissues tend to heal more slowly in the geriatric patient. The older animal is likely to have a less competent immune system and may have compromised metabolic and endocrine function. Pre-existing musculoskeletal problems may make ambulation difficult for an animal convalescing from a new orthopedic problem. Special attention is often needed when treating these patients for fractures, joint instability, infection, and neoplasia. In general, issues that should be addressed in the geriatric patient include reducing intraoperative and anesthesia time, enhancing bone and soft tissue healing, return to early function, control of postoperative pain, physical therapy, and proper nutrition.     

Understanding feline behavior and application for appropriate handling and management

Feline handling in the veterinary hospital is important to protect both people and cats. Restraint has been used to enable us to perform our duties as veterinarians. With increased knowledge of feline behavior and how cats react to fear, newer information provides us with safer handling techniques. With safer and more respectful handling based on understanding the nature of cats and their communication, we can improve feline health care in our hospitals, the human-animal-veterinarian bond, and the welfare of both cats and people. This article explains important aspects of feline communication and how our actions affect cats. By understanding the cat, we can improve our handling techniques to prevent fear and pain for our feline patients, and thus make our veterinary practices more feline friendly and safer for our clients, their cats, and veterinary staff.     

Lack of circulating thyroid stimulating immunoglobulins in cats with hyperthyroidism

Although feline hyperthyroidism has become a commonly diagnosed disorder of older cats, the underlying etiology remains unknown. Pathological findings of adenomatous hyperplasia involving both thyroid lobes in most hyperthyroid cats suggests the possibility that feline hyperthyroidism may be similar to human Graves' disease, which results from high circulating levels of thyroid stimulating immunoglobulins (TSIs). To exclude high circulating levels of TSIs as the cause of feline hyperthyroidism, we measured intracellular concentrations of cyclic adenosine monophosphate (cAMP) in functioning rat thyroid cells (FRTL-5) incubated with IgG extracted from hyperthyroid cat serum. Since TSIs stimulate thyroid hormone secretion through activation of cAMP, their presence can be evidenced in vitro by generation of high cAMP concentrations in cultured thyroid cells. No significant difference was found in intracellular cAMP concentrations in FRTL-5 cells incubated with IgG from normal versus hyperthyroid cats. In contrast, IgG from a human patient with Graves' disease caused substantially more cAMP generation than either normal human IgG or IgG from the cats of this study. These results indicate that feline hyperthyroidism does not result from high circulating concentrations of TSI and, in that respect, is not analogous to Graves' disease.     

Feline toxicological emergencies: when to suspect and what to do

PRACTICAL RELEVANCE: Confirmed or suspected intoxications with a wide variety of agents represent a small but important group of feline emergency cases. Generally it is thought that toxicities are less common in cats compared with dogs, with a higher proportion relating to dermal as opposed to oral exposure. CLINICAL CHALLENGES: Once toxicity is suspected or diagnosed, it must be recognised that treatment regimes may need modification compared with those established for dogs. Different drugs or different dosages may be warranted and the choice of available drugs may be reduced. EVIDENCE BASE: This review draws on published studies, case reports and clinical experience to summarise key features of the general management of the intoxicated feline patient before describing some of the more serious and common intoxications in more detail. AUDIENCE: The focus throughout the review is on the peculiarities of feline metabolism and how they may impact on presentation and treatment. The aim is to assist companion animal and feline practitioners, who are in the frontline when it comes to managing these emergency cases.