Development of two surgical approaches to the pituitary gland in the Horse

Background: Current treatment of equine pituitary pars intermedia dysfunction (PPID) requires daily oral medication. Minimally invasive surgical palliation of this condition is appealing as a single treatment to alleviate the clinical signs of disease, dramatically improving the welfare of the horse.

Objective: To develop a surgical approach to the equine pituitary gland, for subsequent treatment of PPID.

Study design: A cadaver study to develop methodology and a terminal procedure under anaesthesia in the most promising techniques.

Animals and methods: Four surgical approaches to the pituitary gland were investigated in cadaver animals. A ventral trans-basispheniodal osteotomy and a minimally invasive intravenous approach via the ventral cavernous sinus progressed to live horse trials.

Results: Technical complications prevented the myeloscopic and trans-sphenopalatine sinus techniques from being successful. The ventral basisphenoidal osteotomy was repeatable and has potential if an intra-operative imaging guidance system could be employed. The minimally invasive approach was repeatable, atraumatic and relatively inexpensive.

Conclusions: A minimally invasive surgical approach to the equine pituitary gland is possible and allows for needle placement within the target tissue. More work is necessary to determine what that treatment might be, but repeatable access to the gland has been obtained, which is a promising step.     

Book reviews

Recent Advances in Turkey Science. Edited by C. Nixey and T. C. Grey, Poultry Science Symposium Number 21. London, Butterworths, ISBN 0 408 00971 3

Egg and Eggshell Quality. Sally E. Solomon, 1991, 149 pp., illustrated. London, Wolfe Publishing Ltd., £35.00, ISBN 0 7234 1647 8.

Aleen Cust, Veterinary Surgeon, Britain's First Woman Vet. Connie M. Ford, 1990, 109 pp., £5.99, Bristol, Biopress Ltd., The Orchard, Clanage Road, ISBN 0 948737 11 5.

Avian Incubation. Edited by S. G. Tullett, 1991, xiv + 335 pp., illustrated. London, Butterworth‐Heinemann. £00.00, $00.00. ISBN 0–7506–1002–6.

A Colour Atlas of Diseases & Disorders of the Domestic Fowl & Turkey. Edited by C. J. Randall, second edition, 1991, 175 pages, 432 illustrations in colour. London, Wolfe Publishing Ltd, £35, ISBN 0723416281.     

Investigation of cell-free DNA in canine plasma and its relation to disease

Background: DNA is released from dying cells during apoptosis and necrosis. This cell-free DNA (cfDNA) diffuses into the plasma where it can be measured. In humans, an increase in cfDNA correlates with disease severity and prognosis.

Objective: It was hypothesized that when DNA in canine plasma was measured by emission fluorometry without prior DNA extraction, the concentration of cfDNA would increase with disease severity.

Animals: The diseased population consisted of 97 client-owned dogs. The clinically normal population consisted of nine client-owned dogs presenting for ‘wellness screens’, and 15 colony-owned Harrier Hounds.

Methods: Plasma cfDNA was measured by fluorometry without prior DNA extraction. The effects of ex vivo storage conditions were evaluated in plasma from two clinically normal dogs. In all other dogs, plasma was separated within two hours of collection. The association between the cfDNA concentration in hospitalized dogs and a variety of clinical, clinicopathological and outcome variables was tested.

Results: The concentration of cfDNA was reliably measured when plasma was separated within two hours of blood collection. The diseased dogs had significantly higher cfDNA than clinically normal dogs (P < 0.001), and the more severe the disease, the higher the cfDNA when severity was categorized according to the American Society of Anesthesiologists (ASA) status (P < 0.001). Dogs that did not survive to discharge had significantly higher cfDNA concentrations than survivors (P = 0.02).

Conclusions/Clinical Importance: The concentration of cfDNA in the plasma of diseased dogs is associated with disease severity and prognosis. Measurement of canine cfDNA could be a useful non-specific disease indicator and prognostic tool.     

Detection of pseudocowpox virus in water buffalo (Bubalus bubalis) with vesicular disease in the state of São Paulo,Brazil, in 2016

Background: Parapoxviruses are zoonotic viruses that infect cattle, goats and sheep; there have also been reports of infections in camels, domestic cats and seals.

Objective: The objective of this report was to describe a case of vesicular disease caused by pseudocowpox virus (PCPV) in water buffalo (Bubalus bubalis) in Brazil.

Animals: Sixty buffalo less than 6 months old exhibited ulcers and widespread peeling of the tongue epithelium. There were no cases of vesicular disease in pigs or horses on the same property.

Methods: Samples were analysed by PCR and sequencing. Phylogenetic analysis in MEGA 7.01 was reconstructed using major envelope protein (B2L) by the Tamura three-parameter nucleotide substitution model and the maximum likelihood and neighbor joining models, both with 1000 bootstrap replicates. The genetic distance between the groups was analysed in MEGA using the maximum composite likelihood model. The rate variation among sites was modeled using gamma distribution.

Results: The presence of PCPV in the buffalo herd could be demonstrated in epithelium and serum. The minimum genetic distance between the isolated PCPV strain (262-2016) and orf virus and bovine papular stomatitis virus was 6.7% and 18.4%, respectively. The maximum genetic distance calculated was 4.6% when compared with a PCPV detected in a camel.

Conclusions/Clinical Importance: The peculiar position of the isolated strain in the phylogenetic trees does not necessarily indicate a different kind of PCPV that infects buffalo. More samples from cattle and buffalo in Brazil must be sequenced and compared to verify if PCPV from buffalo are genetically different from samples derived from cattle.     

Intracardiac electrophysiological conduction parameters in adult dogs

Background: Invasive electrophysiology study (EPS) is one of the most important adjunct tests for the evaluation of arrhythmias in human medicine. However, EPS is neither well known nor widely used in veterinary medicine.

Objective: To define the values for intracardiac conduction parameters determined during invasive EPS in dogs.

Animals and methods: The study included 16 admitted dogs of various breeds, sex and ages and 6 control Beagles. In the Beagles, EPS was performed twice at 6-month intervals in order to verify the reproducibility of the results.

Results: No significant differences were found between the results of the baseline and repeated EPS performed in the Beagles. We found retrograde conduction in 13 (59%) out of 22 dogs and including 4 (31%) animals with concomitant ‘jumps’ in the atrioventricular node conduction curve, pointing to the presence of dual conduction in this node. The mean values of the AV and retrograde VA Wenckebach points equaled to 220 and 360 ms, respectively, suggesting that the capability of the descending route is higher than that of the ascending route.

Conclusion: The values determined in this study may be helpful in early detection of abnormalities in the electrical conduction system of the heart.     

Molecular characteristics of new clonal complexes of Staphylococcus pseudintermedius from clinically normal dogs

Background: High prevalence of methicillin resistance among clinical isolates of Staphylococcus pseudintermedius obtained from dogs was reported in Seoul metropolitan area, South Korea. However, no information on genetic lineage and clonal spread is currently available.

Objective: The aim is to identify the genetic diversity of methicillin-resistant or -susceptible S. pseudintermedius (MRSP and MSSP, respectively) from healthy dogs.

Animals and methods: From 119 healthy dogs, 29 isolates consisting of 20 MRSP and 9 MSSP were collected from June 2013 to February 2014. Phenotypic features, antibiogram, multilocus sequence type (MLST), Staphylococcal cassette chromosome mec (SCCmec) type and spa gene type were analyzed.

Results: MLST showed 24 sequence types (STs), including 20 new STs that were genetically distinct from the previous STs in other geographic areas. SCCmec typing revealed that all isolates had SCCmec type V, a predominant type in North America. spa gene typing was successful in only 13 isolates (10 MRSP and 3 MSSP) and revealed two known types (t02 and t06), as well as one novel type (t73).

Conclusion: Our cumulative data indicate the presence of various populations of S. pseudintermedius in clinically normal dogs in Seoul metropolitan area.     

Utility of two modified-live virus canine distemper vaccines in wild-caught fishers (Martes pennanti)

Background: Canine distemper virus (CDV) infects families in the order Carnivora. As a preventive measure, vaccinations against CDV are frequently given to mustelids in captive environments.

Objectives: Our objectives were to compare the utility between two modified-live virus canine distemper vaccines (MLV CDV's), Fervac-D® (no longer manufactured) and Galaxy-D® (now manufactured by MSD Animal Health as part of a multivalent vaccine), in developing an immune response in wild-caught fishers.

Animals and methods: The Pennsylvania Fisher Reintroduction Project (PFRP) used 14 wild-caught fishers during one year of the project to evaluate the utility of vaccinations against CDV as part of any reintroduction project. Fishers were injected subcutaneously in the nape of the neck with their designated vaccine.

Results: Fervac-D® did not effectively stimulate development of a serologic antibody response, whereas Galaxy-D® had adequate seroconversion or rise of titer levels to suggest that the general use of MLV CDV may be suitable in fishers pending further studies.

Conclusion: We recommend that future studies be conducted, evaluating the use of currently produced vaccines in fishers. Future research should also focus on the length of days required between administration of primary and booster vaccines to achieve sufficient immune response.

Clinical importance: If only primary doses are required, then hard-release reintroduction projects for fishers could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended that include captive management periods, allowing for appropriate vaccination intervals needed to maximize the probability of protection against CDV.     

Identification through MALDI-TOF mass spectrometry and antimicrobial susceptibility profiling of bacterial pathogens isolated from sow urinary tract infection

Background: Urinary tract infection (UTI) is a common disease in sows due to intensification of pig production. Despite direct economic losses, UTI prevalence and respective microbial identification are still poorly studied.

Objective: The aims of this study were to identify the causative agents of UTI in sows through MALDI-TOF MS and to characterize their antimicrobial resistance profiles.

Materials and Methods: Urine samples from 300 sows of three herds from São Paulo State (Brazil) were screened for UTI; suggestive samples were submitted to bacterial isolation. Species identification was performed by MALDI-TOF MS and susceptibility profiles were determined using disc diffusion method.

Results: 128 samples suggestive of UTI were analyzed; 48% of the animals presented UTI caused by a single pathogen, while the remaining 52% presented mixed infection. Escherichia coli stood out with the highest frequency among both single and mixed infections. The Gram-positive were exclusively associated with 27% of single infections. The mixed infections were further classified into 49 profiles. The high frequency of multiresistant profiles stood out for most of the studied isolates.

Conclusions: MALDI-TOF MS enabled the identification of rare pathogens related to UTI which may represent higher risk for porcine health, especially considering high frequency of multiresistant profiles.     

Book reviews

Animal Reproduction Science, edited by T. J. Robinson. Published quarterly, 1st issue, May 1978. Elsevier Scientific Publishing Company, Amsterdam. $61.75 a year.

Krankheiten des Geflügels, by P. Hilbrich. 1978. 3rd edition, 374 pages. Hermann Kuhn GmbH, Villingen‐Schwenningen. DM 148.

The Ethology and Ethics of Farm Animal Production, edited by D. W. Folsch. 1978. Birkhauser Verlag, Basle and Stuttgart. SFr/DM 29. ISBN 3 7643 1004 9.

Practical Poultry Feeding, by R. Feltwell and S. Fox. 1978. 302 pages. Faber & Faber, London. £5.50. ISBN 0 571 11231 5.     

Immortalized sheep microglial cells are permissive to a diverse range of ruminant viruses

Background: Ruminants, including sheep and goats (small ruminants), are key agricultural animals in many parts of the world. Infectious diseases, including many viral diseases, are significant problems to efficient production of ruminants. Unfortunately, reagents tailored to viruses of ruminants, and especially small ruminants, are lacking compared to other animals more typically used for biomedical research.

Objective: The purpose of this study was to determine the permissibility of a stably immortalized, sheep microglial cell line to viruses that are reported to infect ruminants: bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHV-1), small ruminant lentiviruses (SRLV), and bovine respiratory syncytial virus (BRSV).

Methods: Sublines A and H of previously isolated, immortalized, and characterized (CD14-positive) ovine microglial cells were used. Bovine turbinate cells and goat synovial membrane cells were used for comparison. Cytopathic changes were used to confirm infection of individual wells, which were then counted and used to calculate the 50% tissue culture infectious dose. Uninoculated cells served as negative controls and confirmed that the cells were not previously infected with these viruses using polymerase chain reaction (PCR).

Results: Inoculation of the two microglial cell sublines with laboratory and field isolates of BVDV, BoHV-1, and BRSV resulted in viral infection in a manner similar to bovine turbinate cells. Immortalized microglia cells are also permissive to SRLV, similar to goat synovial membrane cells.

Conclusion and clinical relevance: These immortalized sheep microglial cells provide a new tool for the study of ruminant viruses in ruminant microglial cell line.     

Atrioventricular valvular anomalies and their role in the etiopathogenesis of cardiorespiratory syndrome in farmed common foxes (Vulpes vulpes)

Background: Cardiorespiratory syndrome of common foxes is associated with a mortality rate ranging from 2.1% to 20%.

Objective: The aim of this study was to analyze the prevalence of cardiac abnormalities in common foxes (Vulpes vulpes) from Polish farms with a history of cardiorespiratory syndrome.

Animals and methods: The prevalence of cardiac abnormalities in common foxes from a Polish farm with a history of cardiorespiratory syndrome was assessed as well as morphological examination of 60 heart specimens from clinically healthy animals. In addition, 38 foxes were examined echocardiographically and subjected to postmortem examination.

Results: Atrioventricular valvular abnormalities were found in 57 out of the 98 (58%) analyzed hearts. The abnormalities of the mitral valve documented in more than 20% of the foxes in involved tendinous chords (completely lacking or shortened), papillary muscles and mitral cusps associated with both insufficiency and stenosis of the left atrioventricular orifice. Abnormalities of the tricuspid valve included significant shortening of the tendinous chords and thickening of the valve cusps with the impairment of their mobility. The results of the echocardiographic and postmortem examination were consistent in 79% of the cases. The specimens collected from animals with and without atrioventricular valvular anomalies did not differ significantly in terms of cardiomyocyte width, number of inflammatory cells, adipose tissue content and presence of polychromatic cardiomyocytes.

Conclusion: Congenital atrioventricular valvular defects may be involved in the etiology of cardiorespiratory syndrome in common foxes, and echocardiography can be used as a measure of stock's health and a criterion for selection for mating.     

Influence of graded levels of meals from three lupin species on growth performance and nutrient digestibility in broiler chickens

1. This study investigated the effect of different levels of seeds of lupin species (Lupinus angustifolius, Lupinus luteus and Lupinus albus) on broiler growth performance, nutrient digestibility and apparent metabolisable energy of poultry diets.

2. A control diet containing corn–soybean meal and test diets containing 50, 100, 150, 200 and 250 g/kg of three lupin species were fed to broiler chickens during a 35-day study period. There were 10 replicate cages of 8 broiler chickens per treatment.

3. Growth performance of the birds fed with yellow and white lupin diets was found to be similar to that of the birds in the control group. The use of narrow-leaved lupin seeds in the diet quadratically decreased the body weight gain of birds and increased feed conversion ratio during all the experimental periods (0–14, 15–35 and overall 0–35 days of age).

4. A significant interaction between lupin species and their inclusion levels for apparent metabolisable energy and apparent ileal digestibility of starch was observed, showing a negative effect of increasing levels of narrow-leaved lupin. Pearson correlation coefficients demonstrated that the presence of raffinose and non-starch polysaccharides is a key factor affecting the nutritive value of lupin,

5. Yellow and white lupins could be utilised as an alternative ingredient for soybean meal in the diet of broiler chickens without any adverse effects on growth performance. The narrow-leaved counterpart diet reduced broiler performance, and hence did not provide a satisfactory outcome.     

Serology and protein electrophoresis for evidence of exposure to 12 mink pathogens in free-ranging American mink (Neovison vison) in Argentina

Background: Basic pathologic characteristics for farmed minks were previously reported worldwide. However, its status in the wild has not been studied in detail.

Objective: Serology and electrophoresis were carried out for evidence of exposure to 12 mink pathogens on two different locations.

Animals and methods: Serology was done in 87 wild minks by reference techniques against Toxoplasma gondii, Encephalitozoon cuniculi, Neospora caninum, Brucella abortus, Mycobacterium bovis, Leptospira interrogans, canine distemper virus (CDV), canine adenovirus (CAV), canine parvovirus (CPV), rabies virus (RV), Influenza A virus (FLUAV) and Aleutian disease virus (ADV). Hypergammaglobulinemia, the ADV main clinical feature, was determined by conventional electrophoresis.

Results: Seventy-one percent of the 87 sera had antibodies against one or more pathogens. ADV accounted for the highest seroprevalence (29%), followed by T. gondii (26%), L. interrogans (14%), M. bovis (12%), B. abortus (9%), N. caninum (3%), CPV (3%) and CDV (2%). Seroprevalence was influenced by location but not sex or age. Additionally, 16% of the seropositive samples for ADV had gammaglobulin levels >40.0 g/L. Antibody titers for CDV and CPV were low and difficult to interpret as almost all these cases had borderline concentrations.

Conclusion: A cautious interpretation of the results is urged as the epidemiological role of the wild mink is largely unexplored for most of these agents. Nevertheless, the information may be clinically relevant..     

Molecular and antimicrobial susceptibility characterization of Globicatella sulfidifaciens isolated from sow's urinary tract infection

Background: The Globicatella genus comprises Gram-positive, facultative anaerobic, α-hemolytic and catalase negative cocci morphologically and phenotypically very similar to Streptococcus and Aerococcus genus which can lead to misidentification and underestimation of this pathogen. Globicatella species have already been isolated from human and animals with heart and brain disorders. Their clinical relevance in animals, and its zoonotic potential, remains unknown due to the difficulty in their identification.

Objective: To present the isolation, phenotypic and molecular characterization of G. sulfidifaciens from urinary tract infection in sows.

Materials and Methods: Urine samples from 140 sows of two swine herds located in São Paulo State (Brazil) yielded the isolation of three presumptive G. sulfidifaciens strains. Identification and species confirmation were done by MALDI-TOF MS and 16S rRNA sequencing. Strains were further characterized by single enzyme amplified fragments length polymorphism (SE-AFLP) and broth microdilution techniques.

Results: All three isolates were confirmed as G. sulfidifaciens. The SE-AFLP genotyping resulted in distinct fingerprint patterns for each strain. All isolates presented high MIC values to tetracycline, sulphonamides, aminoglycosides and tylosin tartrate, which present high usage in human and animal medicine.

Conclusions: Globicatella sulfidifaciens could be related to sporadic urinary tract infections in swine and appear to present alarming antimicrobial susceptibility profile. It is necessary to differentiate Streptococcus-like microorganisms in routine laboratory diagnostics for the correct identification of underestimated species potentially pathogenic to animals.     

Potent immune responses induced by a Salmonella ghost delivery system that expresses the recombinant Stx2eB,FedF, and FedA proteins of the Escherichia coli-producing F18 and Shiga toxin in a murine model and evaluation of its protective effect as a porcine vaccine candidate

Background: In the pathogenicity of porcine edema disease (ED), which is caused by the Escherichia coli-producing F18 and Shiga toxin, F18⁺ fimbrial adhesins and Shiga toxin 2e (Stx2e) play pivotal roles in the colonization and enterotoxicity of this pathogen.

Objective: To develop a vaccine candidate against ED by combining three selected antigens of F18⁺ E. coli.

Methods: Genetically engineered Salmonella Typhimurium (ST) ghosts that express Stx2eB, FedF, and FedA were individually inserted in a ghost plasmid cassette, and the resultant plasmids were transformed into an attenuated ST (JOL912). The individual expression of Stx2eB, FedF, and FedA in JOL912 was validated by using an immunoblotting assay.

Results: Immunization of the ghosts in BALB/c mice led to a significant increase in antigen-specific secretory IgA and serum IgG. Significantly marked elevation of the CD3⁺CD4⁺ T cell subpopulation and lymphocyte proliferating activity in the primed splenocytes were also observed. Furthermore, mRNA of IL-4 and IFN-γ were highly upregulated in in vitro stimulated splenic T cells. Subsequently, the immunized mice showed significant protection efficacy against a lethal dose 50 of a virulent strain, resulting in approximately 85% and 92% survival rates in mice with a single- and double-dose immunization, respectively, compared to only 40% of the non-immunized controls.

Conclusion: A mixture of the ghosts expressing these three antigens is a potential vaccine candidate for protection against the porcine edema disease.     

Isolation and genotyping of Campylobacter species from kiwi (Apteryx spp.) in captivity: implications for transmission to and from humans

Aims: To investigate the presence of Campylobacter spp. in captive kiwi (Apteryx spp.) and compare their genotypic profiles with those of human and animal origin, in order to assess their potential for zoonotic or zooanthroponotic transmission.

Methods: Conventional selective enrichment and filter-based isolation methods were applied to isolate Campylobacter spp. from fresh faecal samples from 12 North Island brown kiwi (Apteryx mantelli) and one great spotted kiwi (A. haastii), housed in one of five different areas in a kiwi sanctuary in Christchurch, New Zealand. Isolates were identified using multiplex PCR and 16S rRNA gene sequencing. High-resolution rapid genotyping using multiplex ligation-dependant probe amplification-based binary typing (MBiT) was applied and profiles compared with similar results from 2,165 Campylobacter spp. isolates contained in a database derived from human clinical, veterinary and environmental samples.

Results: One isolate of C. jejuni, and one belonging to the C. lari phylogenetic group were recovered from faeces from two kiwi. High-resolution rapid genotyping by MBiT demonstrated these to be indistinguishable from isolates obtained previously from human cases of diarrhoea, and others from chicken, cattle, sheep and water.

Conclusions: These data provide evidence for potential zoonotic or zooanthroponotic transmission of Campylobacter spp. in kiwi with implications for management of birds kept in captivity. We believe this is the first formal report of C. jejuni and a C. lari-like organism in kiwi.

Abbreviations: MBiT: Multiplex ligation-dependant probe amplification-based binary typing     

Evaluation of the effects of performance dentistry on equine rideability: a randomized,blinded, controlled trial

Objective: This study attempted to determine: (1) if degree of dental malocclusion assigned prior to dental treatment was associated with equine rideability, assessed using a standardized score and (2) if performance dentistry improved this score.

Animals: Thirty-eight Franches-Montagnes stallions.

Methods: All horses were examined and assigned a dental malocclusion score by a veterinary dentist and randomized into two groups: sham treatment (Group S) and performance dentistry including occlusal equilibration (Group D). The horses were ridden twice before and three times after treatment by a professional dressage rider (unaware of treatment allocation). The horses were assigned a rideability score using a 27-point scale. The malocclusion score was compared to the average of the first two rideability scores using Spearman's coefficient of rank. Change in rideability scores over time was assessed by repeated measures ANOVA. Statistical significance was set at P < 0.05.

Results: There was no correlation between dental score and rideability score prior to treatment (r_s = 0.06, P = 0.73). In addition, there were no differences in the rideability score between treatment groups or as an interaction of treatment group and time (P = 0.93, P = 0.83, respectively).

Conclusions: In conclusion, we were unable to show that performance dentistry improved equine rideability assessed by rider scoring. The addition of more objective measurement tools and a longer assessment period may help to scientifically prove what is anecdotally believed.     

Baruscapillaria obsignata: a serious cause of enteropathy and high mortality in turkeys (meleagris gallopavo)

Background: Capillariasis, an important parasitic disease of birds is caused at least by seven different genera of trichurid nematodes with clinical outcome ranging from mild enteritis to high mortality.

Objective: This study was aimed to investigate the causative agent involved in high mortality associated with severe enteric illness among turkey flocks in an organized commercial poultry farm at Bareilly, India.

Materials and Methods: Turkey carcasses (n = 119) and fecal samples from the affected deep litter pen constituted as the study materials. The disease was investigated by systematic necropsy, direct microscopy and histopathology. Representative samples were screened for other enteric pathogens.

Results: Microscopic examination of mucosal scraping revealed capillarid worms and their eggs in all the samples. The morphological features of adult worms were typically consistent to Baruscapillaria obsignata. Histopathology exhibited thickened muscular and mucosal layers, mononuclear and heterophilic infiltration in the lamina propria, blunting and clubbing of villi, epithelial denudation and sections of capillarid worms. Administration of levamisole at 80 ppm in drinking water reduced the mortality, clinical illness and worm load after three days of therapy.

Conclusions: The capillarid worms in different avian hosts can cause different clinical manifestations and outcomes. From India, this is the first report describing intestinal pathology caused by B. obsignata in turkeys. We conclude that the B. obsignata infection is capable of causing life threatening enteropathy in turkeys and, hence, routine screening, scheduled deworming and good litter management are crucial to control the infection and its associated loss.     

Effect of age and sex on the chemical composition of edible offal and blood from broilers

1. The effects of age and sex on the proximate composition and inorganic constituents in edible offal and whole blood from a commercial British broiler chicken strain were studied.

2. Although the protein content of all tissues varied with age, the only statistically significant effect was on the level of protein in the gizzard.

3. The moisture content of the gizzard was significantly affected by age and blood by age and sex.

4. The fat content of the gizzard was significantly affected by age, as was the effect of sex on the fat content of blood.

5. The ash contents of heart and gizzard were significantly affected by age.

6. The phosphorus contents of the gizzard, heart and liver were significantly affected by age, as were the chloride content of heart and the calcium content of the liver. Blood potassium was significantly affected by sex. Fluctuations in the contents of other elements are discussed.

7. The variability in organ composition is discussed with respect to the degree of trimming and preparation of the samples.     

Histological and immunohistochemical characteristics of cerebral amyloid angiopathy in elderly dogs

Background: Cerebral amyloid angiopathy (CAA) is a disorder characterized by amyloid deposition in the wall of cerebral blood vessels. The deposits of amyloid occur frequently in the blood vessels of the frontal, parietal and occipital cortex.

Objective: To examine the characteristics of CAA classified according to the Vonsattel scale in elderly dogs histologically and immunohistochemically as well as the semi-quantitative evaluation of the amyloid deposits in the different segments of the brain.

Animals and methods: The brains of 36 dogs of different breeds and sexes, which had been routinely necropsied, were used and divided into two groups: dogs from 1 to 5 and 10 to 18 years old. The tissue sections were stained by hematoxylin–eosin, Congo red and immunohistochemically.

Results: Amyloid was accumulated in the wall of cerebral blood vessels in 70% of dogs over the age of 10 years predominantly in the frontal cortex. CAA was demonstrated in elderly dogs as follows: in the frontal cortex (n = 19 or 63%), the parietal cortex (n = 12 or 40%), the hippocampus (40%) and the cerebellum (n = 5 or 17%). The deposits of amyloid in the wall of blood vessels detected by Congo red staining were also Aβ1-14 and Aβ1-42 immunohistochemically positive. Most commonly, the amyloid deposits affected a moderate number of blood vessels. The accumulation of amyloid was immunohistochemically revealed in the blood vessel walls as well as in the senile plaques and neurons.

Conclusion: The amount of amyloid in the arterial walls increased with age in dogs, whereas the amyloid accumulated in plaques was Congo red negative.