Objective—To characterize the antigen-specific
immune response to dietary proteins in cats and evaluate
whether there was a qualitative or quantitative
difference between the responses to dietary proteins
when those proteins were fed unprocessed or as part
of a canned diet.
Animals—14 healthy domestic shorthair cats.
Procedure—Cats were fed 2 dietary proteins (soy
and casein) either as unprocessed aqueous suspensions
or as part of canned diets for 21 days. Serum
IgG and IgA and salivary IgA were assayed by indirect
ELISA, and antigen-specific proliferation of mesenteric
lymph node-derived lymphocytes was determined.
Results—Robust serum IgG and IgA responses to
dietary proteins were elicited, irrespective of the form
in which they were fed. Salivary IgA responses to
unprocessed proteins were not detected. However, a
significant salivary IgA response to the protein isolated
from the canned casein diet was observed in cats
fed canned casein but not in those fed unprocessed
casein. Lymphocyte proliferation to the antigens was
slight, and there were no significant differences
Conclusions and Clinical Relevance—Results indicated
that cats develop robust serum IgG and IgA
responses to dietary proteins when fed as either
aqueous suspensions or as part of canned diets. For
certain proteins, there may be an increase and a qualitative
difference in the immunogenicity of canned
diets, compared with unprocessed proteins. Canned
diets may not be ideal for management of cats with
enteritis. (Am J Vet Res 2004;65:1427–1433)
OBJECTIVE To assess feasibility of flexible endoscopic evaluation of swallowing (FEES) in awake dogs, determine whether specific variables associated with the oropharyngeal phase of swallowing can be recognized, and evaluate the safety and tolerability of FEES.
ANIMALS 6 healthy client-owned large- and giant-breed adult dogs.
PROCEDURES A topical anesthetic was applied to the nasal passage of each dog, and a fiberoptic endoscope was passed transnasally until the tip of the scope was positioned in the oropharynx. All dogs voluntarily drank colored water followed by consumption of a commercial canned diet and then a kibble diet mixed with food color. During each swallow, laryngeal and pharyngeal anatomic structures were evaluated and depth of bolus flow prior to the pharyngeal phase of swallowing was assessed. Evidence of bolus retention in the vallecula or pyriform sinuses and laryngeal penetration of the bolus were recorded.
RESULTS FEES was completed without major adverse events and was tolerated well by all 6 dogs. Mild, self-limiting epistaxis was noted for 2 dogs. The nasopharynx, oropharynx, and hypopharynx were observed in all dogs; movement of food boluses through the esophagus was observed in 2 dogs, and food boluses in the stomach were visible in 1 dog. Pharyngeal and laryngeal function was considered physiologically normal in all dogs.
CONCLUSIONS AND CLINICAL RELEVANCE FEES appeared to be a feasible diagnostic tool for use in large- and giant-breed dogs. Studies are warranted in dogs with oropharyngeal dysphagia to determine whether FEES can be tolerated and whether it can augment videofluoroscopy findings.
Objective—To determine associations among infectious
pathogens and diarrheal disease in dogs in an
animal shelter and demonstrate the use of geographic
information systems (GISs) for tracking spatial distributions
of diarrheal disease within shelters.
Sample Population—Feces from 120 dogs.
Procedure—Fresh fecal specimens were screened
for bacteria and bacterial toxins via bacteriologic culture
and ELISA, parvovirus via ELISA, canine coronavirus
via nested polymerase chain reaction assay,
protozoal cysts and oocysts via a direct fluorescent
antibody technique, and parasite ova and larvae via
microscopic examination of direct wet mounts and
zinc sulfate centrifugation flotation.
Results—Salmonella enterica and Brachyspira spp
were not common, whereas other pathogens such as
canine coronavirus and Helicobacter spp were common
among the dogs that were surveyed. Only
intestinal parasites and Campylobacter jejuni infection
were significant risk factors for diarrhea by univariate
odds ratio analysis. Giardia lamblia was significantly
underestimated by fecal flotation, compared with a
direct fluorescent antibody technique. Spatial analysis
of case specimens by use of GIS indicated that diarrhea
was widespread throughout the entire shelter,
and spatial statistical analysis revealed no evidence of
spatial clustering of case specimens.
Conclusions and Clinical Relevance—This study
provided an epidemiologic overview of diarrhea and
interacting diarrhea-associated pathogens in a densely
housed, highly predisposed shelter population of
dogs. Several of the approaches used in this study,
such as use of a spatial representation of case specimens
and considering multiple etiologies simultaneously,
were novel and illustrate an integrated
approach to epidemiologic investigations in shelter
populations. (Am J Vet Res 2005;66:1018–1024)
OBJECTIVE To validate the use of high-resolution manometry (HRM) in awake, healthy dogs and compare the effects of bolus type (liquid vs solid) and drug treatment (saline [0.9% NaCl] solution [SS] vs cisapride) on esophageal pressure profiles.
ANIMALS 8 healthy dogs.
PROCEDURES In a crossover study, each dog received SS (10 mL) IV, and HRM was performed during oral administration of 10 boluses (5 mL each) of water or 10 boluses (5 g each) of canned food. Cisapride (1 mg/kg in 60 mL of SS) was subsequently administered IV to 7 dogs; HRM and bolus administration procedures were repeated. Two to 4 weeks later, HRM was repeated following administration of SS and water and food boluses in 4 dogs. Pressure profile data were obtained for all swallows, and 11 outcome variables were statistically analyzed.
RESULTS After SS administration, predicted means for the esophageal contractile integral were 850.4 cm/mm Hg/s for food boluses and 660.3 cm/mm Hg/s for water boluses. Predicted means for esophageal contraction front velocity were 6.2 cm/s for water boluses and 5.6 cm/s for food boluses after SS administration. Predicted means for residual LES pressure were significantly higher following cisapride administration.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that HRM was feasible and repeatable in awake healthy dogs of various breeds and sizes. Stronger esophageal contractions and faster esophageal contraction velocity occurred during solid bolus and liquid bolus swallows, respectively. Lower esophageal sphincter pressure increased significantly following cisapride administration. Esophageal contractions and bolus transit latency should be further evaluated by HRM in clinically dysphagic dogs.
Objective—To characterize a genetic component to
cricopharyngeal dysfunction (CD) in Golden Retrievers.
Procedure—The CD phenotype was determined by
videofluoroscopy, and dogs were classified as affected
if the upper esophageal sphincter (UES) did not open,
if there were morphologic abnormalities of the UES, or
if opening of the UES was delayed for ≥ 6 videofluoroscopic
frames (0.2 seconds) after closure of the
epiglottis. All survey radiographic and videofluoroscopic
studies were reviewed by the same radiologist.
Results—Of the 117 dogs (47 males and 70 females)
with a CD phenotype determined via videofluoroscopy,
21 dogs (18.0%) had abnormalities of the
UES (affected). Of these 21 dogs, 9 were males
(19.1% of all males) and 12 were females (17.1% of all
females). The heritability of CD in a threshold model
was estimated as 0.61, which established that CD
could be passed from parent to offspring. Results of
complex segregation analysis suggested that a single
recessive allele of large effect contributed to the
expression of this disease in Golden Retrievers.
Conclusions and Clinical Relevance—The determination
that CD is inherited in Golden Retrievers is an
important step in providing information for veterinarians
attending dogs with this disorder. Breeders also
require this information to make informed breeding
decisions. ( Am J Vet Res 2004;65:344–349)
Objective—To characterize the effect of maintenance
hemodialysis on plasma amino acid concentrations
and to quantitate free amino acid losses into the
dialysate during hemodialysis in healthy dogs.
Animals—8 healthy adult dogs.
Procedure—Five dogs received hemodialysis treatments
3 times per week for 4 weeks. Plasma amino
acid concentrations were evaluated once per week
for 4 weeks in each of the 5 dogs prior to hemodialysis
(time 0), 90 minutes during hemodialysis, and
immediately after hemodialysis (180 minutes). Total
free amino acid concentrations and plasma amino
acid concentrations (time 0, 90 minutes, and 180 minutes)
in the dialysate were evaluated in 3 dogs that
received 1 hemodialysis treatment.
Results—Significant time versus week interactions
with any plasma amino acid were not detected; however,
significant decreases in all plasma amino acid
concentrations measured were detected at the midpoint
of dialysis (46 ± 2%) and at the end of each dialysis
session (38 ± 2%). Mean (± SEM) total free
amino acid loss into the dialysate was 2.7 ± 0.2 g or
0.12 g/kg of body weight.
Conclusions and Clinical Relevance—Hemodialysis
is associated with significant alterations in plasma
amino acid concentrations and loss of free amino
acids into the dialysate. Loss of amino acids into the
dialysate, coupled with protein calorie malnutrition in
uremic patients, may contribute to depletion of amino
acid stores.(Am J Vet Res 2000;61:869–873)
OBJECTIVE To evaluate the effect of intra-abdominal pressure (IAP) on morphology and compliance of the lower esophageal sphincter (LES) by use of impedance planimetry in healthy dogs and to quantify the effect of changes in IAP.
ANIMALS 7 healthy, purpose-bred sexually intact male hound-cross dogs.
PROCEDURES Dogs were anesthetized, and cross-sectional area (CSA), minimal diameter (MD), LES length, LES volume, and distensibility index (DI) of the LES were evaluated by use of an endoscopic functional luminal imaging probe. For each dog, measurements were obtained before (baseline) and after creation of a pneumoperitoneum at an IAP of 4, 8, and 15 mm Hg. Order of the IAPs was determined by use of a randomization software program.
RESULTS CSA and MD at 4 and 8 mm Hg were not significantly different from baseline measurements; however, CSA and MD at 15 mm Hg were both significantly greater than baseline measurements. The LES length and LES volume did not differ significantly from baseline measurements at any IAP. The DI differed inconsistently from the baseline measurement but was not substantially affected by IAP.
CONCLUSIONS AND CLINICAL RELEVANCE Pneumoperitoneum created with an IAP of 4 or 8 mm Hg did not significantly alter LES morphology in healthy dogs. Pneumoperitoneum at an IAP of 15 mm Hg caused a significant increase in CSA and MD of the LES. Compliance of the LES as measured by the DI was not greatly altered by pneumoperitoneum at an IAP of up to 15 mm Hg.
In Latvia in 2014, acquired idiopathic megaesophagus (AIME) was observed in increased numbers of dogs that consumed varieties of 1 brand of dog food. Within 2 years, 253 dogs were affected. In Australia in November 2017, 6 working dogs that consumed 1 diet of another brand of dog food developed AIME. In total, 145 Australian dogs were affected.
AIME was diagnosed predominantly in large-breed male dogs (> 25 kg [55 lb]). Regurgitation, weight loss, and occasionally signs consistent with aspiration pneumonia (coughing, dyspnea, or fever) were noted. Most Latvian dogs had mild to severe peripheral polyneuropathies as evidenced by laryngeal paralysis, dysphonia, weakness, and histopathologic findings consistent with distal axonopathy. In Australian dogs, peripheral polyneuropathies were not identified, and histopathologic findings suggested that the innervation of the esophagus and pharynx was disrupted locally, although limited samples were available.
TREATMENT AND OUTCOME
Investigations in both countries included clinical, epidemiological, neuropathologic, and case-control studies. Strong associations between the dog foods and the presence of AIME were confirmed; however, toxicological analyses did not identify a root cause. In Latvia, the implicated dietary ingredients and formulations were unknown, whereas in Australia, extensive investigations were conducted into the food, its ingredients, the supply chain, and the manufacturing facilities, but a cause was not identified.
A panel of international multidisciplinary experts concluded that the cause of AIME in both outbreaks was likely multifactorial, with the possibility of individualized sensitivities. Without a sentinel group, the outbreak in Australia may not have been recognized for months to years, as happened in Latvia. A better surveillance system for early identification of pet illnesses, including those associated with pet foods, is needed. (J Am Vet Med Assoc 2021;259:172–183)