Companion Animals Symposium: Obesity in dogs and cats: What is wrong with being fat?

Few diseases in modern pets are diet induced. One possible exception to this is obesity, which is ultimately caused by consuming more calories than needed by the dog or cat. Although fat is the most concentrated and efficiently stored source of calories, and protein least so, an excess of calories from any source will contribute to adiposity. Obesity is an excess of body fat sufficient to result in impairment of health or body function. In people, this is generally recognized as 20 to 25% above ideal BW. This degree of excess is important in dogs as well. A lifelong study in dogs showed that even moderately overweight dogs were at greater risk for earlier morbidity; these dogs required medication for chronic health problems sooner than their lean-fed siblings. The average difference in BW between groups was approximately 25%. Obese cats also face increased health risks, including an increased risk of arthritis, diabetes mellitus, hepatic lipidosis, and early mortality. The risk for development of diabetes increases about 2-fold in overweight cats and about 4-fold [corrected] in obese cats. Altered adipokine secretion appears to be an important mechanism for the link between excess BW and many diseases. Once considered to be physiologically inert, adipose tissue is an active producer of hormones, such as leptin and resistin, and cytokines, including many inflammatory cytokines such as tumor necrosis factor-α, IL-1β and IL-6, and C-reactive protein. The persistent, low-grade inflammation secondary to obesity is thought to play a causal role in chronic diseases such as osteoarthritis, cardiovascular disease, diabetes mellitus, and others. For example, tumor necrosis factor-α alters insulin sensitivity by blocking activation of insulin receptors. In addition, obesity is associated with increased oxidative stress, which also may contribute to obesity-related diseases. Management of obesity involves nutritional modification as well as behavioral modification. Increased protein intake combined with reduced calorie intake facilitates loss of body fat while minimizing loss of lean body mass. Limiting treats to 10% of calorie intake and increasing exercise both aid in successful BW management.     

Prevalence and anatomopathological characterization of cutaneous squamous cell carcinomas with regional and distant metastases in dogs and cats: 20 cases (1985–2020)

The aim of this study was to assess the prevalence of regional and distant metastases from cutaneous squamous cell carcinomas (SCCs) in dogs (n = 11) and cats (n = 9) in a retrospective case series over 36 years (1985–2020), as well as to characterize its macroscopic aspects (location and size), degree of differentiation (well, moderately and poorly differentiated [WD, MD and PD, respectively]) and the rate of cell proliferation, by counting the AgNORs. Immunohistochemistry (IHC) was used to identify patterns of tumour migration and invasion (islands, ribbons, cords, small aggregates, individual cells [fusiform and amoeboid]) and to evaluate the intensity of desmoplasia and the amount of myofibroblasts. The prevalence of metastatic SCCs was 4.39% (21/478), being 3.8% in dog (12/309) and 5.3% in cat (9/169). Metastases affected lymph nodes in all dogs and 66% (6/9) of cats, and less frequently distant organs. Primary tumours predominantly affected the abdominal skin in dogs and the nasal planum in cats. Among the 20 cases, 52% were MDs, 34% were WDs, and 14% were PDs. Histological lesions suggestive of exposure to chronic solar radiation were present in 57% (8/14). The main patterns of tumour migration and invasion were islands for WD SCCs and individual cells for PD SCCs. MD SCCs had a mix of patterns. In cats, individual spindle cells were restricted to PDs. A marked desmoplastic reaction was more associated with PD SCCs and often with MDs. This study highlights that the prevalence of SCC metastases in dogs and cats is predominantly regional. The IHC was essential in the identification of individual fusiform keratinocytes, whose presence in surgical margins may represent a greater risk of recurrence. Although the presence of myofibroblasts was observed in all infiltrative and metastatic tumours, further studies evaluating these cells may be important to better understand their role in the tumour microenvironment of cutaneous SCCs with metastasis in dogs and cats.     

Tick paralysis in dogs and cats in Australia: treatment and prevention deliverables from 100 years of research

This review of tick paralysis caused by Ixodes holocyclus in Australia addresses the question: What are the key discoveries that have enabled effective treatment and prevention of tick paralysis in dogs and cats? Critical examination of 100 years of literature reveals that arguably only three achievements have advanced treatment and prevention of tick paralysis in animals. First, the most significant treatment advance was the commercial availability of tick antiserum in the 1930s. Hyperimmune serum currently remains the only specific anti-paralysis tick therapy available to veterinarians in Australia. Second, advances in veterinary critical care have increased survival rates of the most severely affected dogs and cats. Critical care advancements have been enabled through specialised veterinary hospitals that can provide appropriate care 24 h a day, and advanced training of veterinarians, veterinary nurses and technicians. Third, perhaps that biggest advance of all in the last 100 years of research has been the commercial availability of the isooxazoline class of acaricidal preventatives in Australia specifically for I. holocyclus. This highly effective class of preventatives offers long duration of action, low cost, spot-on or oral formulations and a low rate of adverse reactions. Animal owners and veterinarians now have the most useful tool of all – a reliable preventative. This review reveals the key events in research over the last 100 years and the tortuous pathway to delivering better treatment and preventative options for this enigmatic Australian parasite.     

Methicillin‐resistant Staphylococcus aureus in dogs and cats: an emerging problem?

There is concern over transmission of methicillin-resistant Staphylococcus aureus (MRSA) between animals and humans. The spread of hospital-acquired and community-acquired MRSA is a major challenge in human medicine. MRSA is rarely isolated from animals but methicillin resistance occurs in staphylococci that are more prevalent in animals. MRSA infections in animals are uncommon and most are associated with exposure to medical hospitals, extensive wounds, prolonged hospitalisation and immunosuppression. The risk to human health appears to be small but a survey of methicillin-resistant staphylococci in animals is required. Thorough investigation of possible zoonotic infections to establish linkage is encouraged. Medical and veterinary staff should appreciate that animals can carry MRSA, cooperate in eliminating infections and monitor animals in medical environments. Veterinary clinics should implement guidelines for dealing with MRSA. Responsible antibiotic use should minimise the spread of antibiotic resistance but a UK monitoring scheme is desirable.     

Ehrlichia canis in dogs of Mexico: Prevalence,incidence, co–infection and factors associated

Rickettsial infections in dogs of Mexico were investigated. A total of 246 dogs were blood sampled and initially screened to detect Ehrlichia canis, E. chaffeensis, E. ewingii, Anaplasma phagocytophilum and Rickettsia rickettsii by a quantitative real–time PCR (qPCR) assay. Sixty–five dogs were monitored and sampled twice 7–8 months apart. Using the qPCR, 72 positive dogs to E. canis were detected (prevalence of 29.26%). These dogs were also tested by nested PCR to detect the same pathogens. None of the studied dogs were positive to E. chaffeensis, E. ewingii, R. rickettsii nor A. phagocytophilum by both PCR assays. The cumulative incidence of E. canis infection was 38.46%. Sequencing analysis of the nested PCR products revealed 100% and 98.1% identity of E. canis and R. parkeri, respectively. We found a dog co–infected with E. canis and R. parkeri.     

Hypoventilation following oxygen administration associated with alfaxalone–dexmedetomidine–midazolam anesthesia in New Zealand White rabbits

ObjectiveTo investigate the relationship between oxygen administration and ventilation in rabbits administered intramuscular alfaxalone–dexmedetomidine–midazolam.Study designProspective, randomized, blinded study.AnimalsA total of 25 New Zealand White rabbits, weighing 3.1–5.9 kg and aged 1 year.MethodsRabbits were anesthetized with intramuscular alfaxalone (4 mg kg^–1), dexmedetomidine (0.1 mg kg^–1) and midazolam (0.2 mg kg^–1) and randomized to wait 5 (n = 8) or 10 (n = 8) minutes between drug injection and oxygen (100%) administration (facemask, 1 L minute^–1). A control group (n = 9) was administered medical air 10 minutes after drug injection. Immediately before (PRE_oxy/air5/10) and 2 minutes after oxygen or medical air (POST_oxy/air5/10), respiratory rate (f_R), pH, PaCO₂, PaO₂, bicarbonate and base excess were recorded by an investigator blinded to treatment allocation. Data [median (range)] were analyzed with Wilcoxon, Mann–Whitney U and Kruskal–Wallis tests and p < 0.05 considered significant.ResultsHypoxemia (PaO₂ < 88 mmHg, 11.7 kPa) was observed at all PRE times: PRE_oxy5 [71 (61–81) mmHg, 9.5 (8.1–10.8) kPa], PRE_oxy10 [58 (36–80) mmHg, 7.7 (4.8–10.7) kPa] and PRE_air10 [48 (32–64) mmHg, 6.4 (4.3–8.5) kPa]. Hypoxemia persisted when breathing air: POST_air10 [49 (33–66) mmHg, 6.5 (4.4–8.8) kPa]. Oxygen administration corrected hypoxemia but was associated with decreased f_R (>70%; p = 0.016, both groups) and hypercapnia (p = 0.016, both groups). Two rabbits (one per oxygen treatment group) were apneic (no thoracic movements for 2.0–2.5 minutes) following oxygen administration. f_R was unchanged when breathing air (p = 0.5). PaCO₂ was higher when breathing oxygen than air (p < 0.001).Conclusions and clinical relevanceEarly oxygen administration resolved anesthesia-induced hypoxemia; however, f_R decreased and PaCO₂ increased indicating that hypoxemic respiratory drive is an important contributor to ventilation using the studied drug combination.     

Preanaesthetic blood tests in cats and dogs older than 8 years: anaesthetists’ prediction and peri-anaesthetic changes

ObjectiveTo evaluate the anaesthetist’s ability to predict abnormalities in preanaesthetic blood test results obtained from cats and dogs older than 8 years and to describe the impact of these preanaesthetic blood test results on the American Society Anesthesiologists (ASA) physical status classification, anaesthetic protocol and procedures.Study designObservational, prospective, clinical multi-centre study.AnimalsA total of 333 cats and dogs.MethodsAfter a clinical examination and review of the animal´s clinical history the anaesthetist completed the first part of a set of questions including ASA status and anticipated abnormalities in blood tests. After this, blood results were presented, and the anaesthetist completed the second part of the set of questions, including changes in ASA status or anaesthetic protocol, and procedure delay or cancellation. Preanaesthetic blood tests included: haematocrit, total proteins, electrolytes, glucose, lactate, urea and creatinine. Examiners were classified as senior clinicians, clinicians, anaesthesia residents or nurses, and interns. For statistical analysis, the chi-square test was used. A p value < 0.05 was considered significant.ResultsThe ASA status increased in three dogs and one cat (1.2%); in two of them abnormalities were not expected by the examiner. The anaesthetic protocol changed in seven animals (2.1%); the most common change related to fluid therapy. Anaesthesia was delayed in two dogs (0.6%) to administer intravenous fluid therapy. No cases were cancelled. Abnormalities were more commonly found [37 out of 58 assessments (approximately 64%)] when the anaesthetist predicted them compared to when they were unexpected [49 of 275 assessments (approximately 18%); p < 0.001].Conclusions and clinical relevanceRoutine non-targeted blood tests in cats and dogs older than 8 years led to few changes in the anaesthetic management, and anaesthetists correctly predicted blood test results in most cases.     

Intestinal parasites of dogs and cats in Australia: The veterinarian’s perspective and pet owner awareness

During a recent national study of intestinal parasites in dogs and cats in Australia, questionnaires were submitted to veterinarians and pet owners to evaluate from a veterinary and public health standpoint the veterinarians’ perception, awareness and knowledge of gastrointestinal parasites in their locality. The study included sourcing information with regard to commonly recommended deworming protocols. The awareness of pet owners regarding parasitic zoonoses and the degree of education provided to them by veterinarians was also determined.Very few veterinarians routinely discussed the zoonotic potential of pet parasites with clients but most recommended regular prophylactic administration of anthelmintics throughout a pet’s life. Some pet owners were unaware of the existence of zoonoses. It is possible that an overreliance on anthelmintics may have led to a certain complacency about the need to educate pet owners about the risks of zoonoses. Veterinarians are important educators in the community and it is important to evaluate their performance if improvements are to be made.     

Antibiotic susceptibility of bacteria isolated from infections in cats and dogs throughout Europe (2002–2009)

A monitoring program of the pre-treatment susceptibility of clinical isolates of bacteria from diseased dogs and cats was active between the years 2002 and 2009. Susceptibility of each isolated strain to a panel of nine antibiotics (amoxicillin/clavulanic acid, ampicillin, penicillin, clindamycin, doxycycline, enrofloxacin, marbofloxacin, trimethoprim and trimethoprim/sulfamethoxazole) was assessed. The Minimum Inhibitory Concentration (MIC) of marbofloxacin was also determined by a standardized microdilution technique following CLSI recommendations. In total, 1857 bacterial strains were collected throughout Europe from cases of otitis, respiratory, urinary and dermatological infections. Although bacterial susceptibility varied for each of the antibiotics within the panel, patterns of susceptibility were similar to those described in the literature for comparable time periods and geographical areas. With a clinical resistance varying from 0 to 14.48% against the isolated strains, marbofloxacin susceptibility was very high and remains an effective antibiotic for the treatment of otitis, urinary, respiratory and dermatological infections in companion animals.     

Pericardial effusion associated with systemic inflammatory disease in seven dogs (January 2006 – January 2012)

Pericardial effusion (PE) is reported in dogs as a consequence of neoplasia, primary cardiac disease or as an idiopathic condition. We describe seven dogs with systemic inflammatory disease, PE without tamponade and increased cardiac troponin I concentrations. Echocardiographic findings and adjunctive testing did not identify other known causes of PE. Resolution of the PE was documented in five of seven dogs in which follow-up echocardiography was performed, often after anti-inflammatory therapy. Resolution of PE was associated with normalisation of cardiac troponin I levels. Clinical signs had not recurred in six dogs with follow-up for more than 12 months and up to 7 years. These findings suggest an association between systemic inflammation and PE in dogs.     

Lungworm infections (Angiostrongylus vasorum, Crenosoma vulpis, Aelurostrongylus abstrusus) in dogs and cats in Germany and Denmark in 2003–2007

Faecal samples of 4151 dogs from Denmark, 958 dogs from Germany and 231 cats from Germany with clinical signs were examined for lungworm larvae using the Baermann funnel technique between 2003 and 2007. In total, 3.6% of Danish and German dogs shed lungworm larvae. In Denmark, patent infections of dogs with Angiostrongylus vasorum were more prevalent (2.2%) than those with Crenosoma vulpis (1.4%). In Denmark, the majority of A. vasorum- (98%) and C. vulpis-infected (80%) dogs originated from Northern Zealand. The frequency of A. vasorum and C. vulpis infections in Danish dogs obviously decreased from 2003 to 2006. In Germany, canine faecal samples were found more frequently positive for C. vulpis than for A. vasorum larvae (2.4% and 1.2%, respectively). Lungworm-infected dogs originated mainly from southern and western Germany. Larvae of Aelurostrongylus abstrusus were detected in 5.6% of cats from Germany. Overall, a distinct seasonal pattern in the detection of infected dogs was apparent for A. vasorum in Denmark and C. vulpis in Germany. The relatively high number of lungworm-infected dogs and cats indicate that these parasitic diseases should be considered in differential diagnosis of cases of treatment-resistant respiratory/cardiopulmonary distress.     

Molecular epidemiological and phylogenetic analyses of canine parvovirus in domestic dogs and cats in Beijing, 2010–2013

Fifty-five samples (15.62%) collected from dogs and cats were identified as canine parvovirus (CPV) infection in Beijing during 2010–2013. The nucleotide identities and aa similarities were 98.2–100% and 97.7–100%, respectively, when compared with the reference isolates. Also, several synonymous and non-synonymous mutations were also recorded for the first time. New CPV-2a was dominant, accounting for 90.90% of the samples. Two of the 16 samples collected from cats were identified as new CPV-2a (12.5%), showing nucleotide identities of 100% with those from dogs. Twelve samples (15.78%) collected from completely immunized dogs were found to be new CPV-2a, which means CPV-2 vaccines may not provide sufficient protection for the epidemic strains.