All about their urinary system diseases

1. DISEASES OF
URINARY SYSTEM
OF ZOO AND WILD
ANIMALS
Dr. Urfeya Mirza
Deptt. of Veterinary
Surgery & Radiology

2. Introduction
 The diagnosis of diseases of the urinary system
often presents a challenge.
The urinary tract consists of:
– 2 ureters
– 1 bladder
– 1 urethra
– 2 kidneys
 The outer region of the urethra harbors the
following microbiota: nonhemolytic
streptococci, staphylococci, corynebacteria, and
some lactobacillus

3. Urinary tract diseases
 Diseases of Kidney
 Deposition Disorders
 Infectious Diseases
 Diseases of Urinary Bladder

4. Diseases of Kidney
 1. Abnormalities of Development :
Congenital abnormalities of the kidneys have been
described in a number of wild animal cases.
Although rare, agenesis of parts or a whole kidney
has been reported in snakes and an extra kidney has
been described in anacondas (Eunectus murinus).

5.  2. Renal Cysts:
Renal cysts are characterized by variable cystic
formations within the renal parenchyma. Some
cysts are derived from greatly dilated renal
tubules. Glomeruli can also develop dilated and
cystic Bowman spaces.
The cysts may be identified throughout one or
both kidneys. Some cases of renal cyst
development may be due to underlying chronic
inflammatory diseases. Tubules may become
markedly dilated if there is interstitial fibrosis
and inflammation.
Contd,…

6.  3.Hermaphrodites:
Hermaphroditism has been reported in a phenotypic
male common green iguana, but this condition should
be considered uncommon.
 4. Renal Tumors:
The principal renal tumors reported in wild animals
are adenocarcinoma, adenoma, and nephroblastoma.
Grossly, one or both kidneys may have irregular masses
within the parenchyma, whereas histologically the
tumors are comprised of irregular tubules.
Contd,…

7. Renal adenoma in a kingsnake. Fairly well differentiated
epithelial cells are forming tubular structures.

8.  5. Chronic Renal Disease:
The majority of reptiles that have renal disease
generally have chronic changes in which the etiology
can no longer be determined.
These chronic changes include variable degeneration
and/or necrosis of glomeruli and/or tubules.
Grossly, chronically diseased renal tissue may be
thickened, firm, and discolored.
Interstitial and glomerular fibrosis may be prominent
in histological sections of chronically diseased renal
tissue.
Contd,…

9. Dense connective tissue in the interstitium of the kidney.
Chronic renal disease with fibrosis causing thickening
and discoloration of the kidney of a snake (arrows).

10. Deposition Disorders
 1. Nephrocalcinosis:
Nephrocalcinosis is due to the deposition of calcium
salts (mineral) into the soft tissues and is a common
disease condition of reptiles.
The deposition of calcium salts may be identified within
the glomerular mesangium or basement membranes in
both the glomeruli and the renal tubules.
Grossly, multiple yellow white foci are observed.
Histologically, calcification is characterized by irregular
foci of dense basophilic (blue) material that can be
identified by special stains.

11. Multifocal areas of renal mineralization in a snake (arrows).

12.  2. Renal Gout:
Another common lesion in wild animals is renal gout,
which is associated with a deposition of uric acid in
the soft tissues.
The percentage excreted as uric acids is most likely
related to the animal’s natural habitat (e.g., desert
tortoises convert metabolized protein waste to the
insoluble salts of uric acid).
The cause of tissue urate deposition is renal
dysfunction.
Early gout lesions will have uric acid crystals
deposited within the tubular epithelial cells with a
gradual accumulation of more crystals around the
original deposition centers.
Contd,…

13. Grossly, linear yellow white streaks are observed
in diseased tissues . As the disease progresses, the
uric acid crystal deposits will break through the
basement membrane of the tubule, forming the
typical gouty tophi. The gouty tophi have radiating
uric acid crystals surrounded by inflammatory
cells.
Dietary factors have been implicated as a
predisposing factor to the development of renal
gout. An example of an improper dietary offering
that may lead to gout formation includes an
inappropriate diet fed to herbivorous reptiles (e.g.,
green iguanas fed high-protein dog and cat foods).
Contd,…

14. Linear deposition of urates in a snake kidney.
Severe chronic urate deposition in a snake kidney.

15. Chronic urate deposition
with basement membrane
breakdown and giant cell
reaction.
Early urate deposition in
renal tubules (arrows).

16.  3. Pigment Deposition:
Pigments identified as granular, golden-yellow to
brownish material have been identified in the
cytoplasm of the renal tubular epithelial cells of
reptiles.
Pigment deposition has also been associated with
aging, severe malnutrition, and cancer cachexia.
Other materials such as hemosiderin or bile
pigments may also be deposited in renal tissue, and
special stains are helpful to specifically identify the
substance in question.
Contd,…

17. Multiple variably sized pigment granules in renal tubule cells
of a horned lizard. These are probably hemosiderin, but special
stains are often necessary to determine the exact pigment.

18.  4. Amyloid deposition:
Amyloid is an insoluble pathologic proteinaceous
substance, deposited between cells in various tissues and
organs of the body. This amorphous, eosinophilic hyaline
extracellular substance encroaches on and results in
pressure atrophy of adjacent cells.
An amyloid type material has also been identified in the
renal interstitium and mesangium of the glomeruli in
Komodo dragon (Varanus komodoensis).
 5. Cholesterol deposition:
A deposition of cholesterol crystals and associated
inflammation have been described in round island geckos
(Phelsuma geuntheri).
In these geckos, the primary pathological lesions
identified were hepatic and splenic lipidosis.
Contd,…

19.  6. Nutrition-related Disorders:
Hypovitaminosis A can lead to squamous
metaplasia of the renal mucosal epithelium.
Squamous metaplasia can involve the renal
collecting ducts, and the accumulation of
desquamated cornified cells may result in a partial
blockage of the ducts resulting in the formation of
cystic spaces.
This will decrease the renal clearance of the urates
and there will be a precipitation of uric acid
crystals and the development of gout tophi in
multiple organs.
Contd,…

20.  7. Toxins:
A very serious side effect of antibiotics mainly
gentamicin administration in reptiles is
nephrotoxicity, particularly in snakes.
The lesions associated with toxicity progress from a
cloudy swelling of the proximal tubules to hydropic
degeneration and finally to tubular necrosis. Snakes
administered a high dose of gentamicin develop
visceral gout and extensive tubular necrosis.
The gout tophi in these snakes were identified on the
pericardium, the serosal membranes, and parenchyma
of the kidney, liver, spleen, and lungs.
Contd,…

21.  1. Metazoan Parasites:
Trematodes identified as Styphlodora renalis and S.
horrida have been described in the boa and python.
The ureters of infected snakes are dilated and filled
with the parasites, as well as urates, cellular debris,
and small amounts of calcium.
Trematodes have also been reported in king snakes,
cottonmouths, indigo snakes, tropical rat snakes, black
stripe snakes, bushmasters, and boa constrictors.
Spirorchid trematodes (blood flukes) have also been
identified in the ureters of painted turtles (Chrysemys
picta) and red-eared slider turtles (Trachemys scripta
elegans). The lesions associated with this parasite
infection occur because of microgranulomas forming
around the ova lodged within the blood vessels.
Infectious Diseases

22. Strongyloids, which have an alternating free
living and parasitic life cycle, are identified in
a Burmese python (Python molurus
bivitattus). The nematodes are identified in
the ureters, kidneys, and small intestine. The
ureters of the Burmese python were bilaterally
obstructed, and a ureteritis and enteritis are
identified.
Microfilaria have been reported in the great
vessels and renal vein of reptiles.
Contd,…

23. Nematode fragments, probably Strongyloides spp., in a
necrotic kidney of a boa constrictor.

24.  2. Protozoan Parasites:
a) Coccidia
Tortoises have intranuclear coccidial parasites in a
variety of epithelial tissues which results in
inflammation of the lung.
A similar coccidian organism(Tyzzeria boae) has been
described in the collecting ducts and ureters of a boa
constrictor.
b) Entamoeba invadens
Entamoeba invadens cause extensive renal necrosis
with inflammation of macrophages, heterophils, and
lymphocytes among some snake and chelonian species,
but rarely in lizards.
Contd,…

25. c) Microsporidia
The reports of wild animal microsporidia infections are
primarily systemic fatal infections diagnosed in bearded
dragons (Pogona vitticeps).
The primary lesion associated with microsporidia
infections is a severe hepatic necrosis with clusters of
light basophilic intracytoplasmic microorganisms packed
within distended hepatocytes, as well as being free in
areas of necrosis.
d) Renal Flagellates
Most reside in the lumen of the intestines; however, there
are flagellates associated with disease found in the
urogenital system of reptiles. Flagellates associated with
disease in reptile species are of the genus Spironucleus.
Tubulointerstitial nephritis and necrosis are the common
renal lesions accumulating within the lumen of the
tubules.
Contd,…

26. Spironucleus (Hexamita) infection of the renal tubules of
a tortoise. Note tubular necrosis and microorganisms (arrows).

27. e) Myxosporidia
They are common parasites of fish, but rarely identified
in amphibians and reptiles.
Histologically, renal intratubular myxozoan spores
have been associated with renal tubular necrosis,
tubular mineralization, and chronic interstitial
nephritis coupled with membranoproliferative
glomerulopathy.
f) Bacteria
Any number of bacterial infections can infect the
urinary system. The majority of bacteria found in
urinary system are Gram-negative bacteria (e.g.,
Pseudomonas spp., Aeromonas spp.).
Contd,…

28. Clusters of the bacterial organisms that arise in septic
conditions will cause blockage of the renal blood
vessels within the glomerular capillaries and the
interstitium. There may also be a peripheral
heterophilia in response to a bacteremia.
Grossly, there are multifocal to confluent yellow-white
areas that may be difficult to differentiate from large
urate deposits.
(g) Viruses (Inclusion Body Disease)
IBD can be responsible for clinical signs including
chronic regurgitation, ataxia, loss of righting reflexes,
paresis, and an increased incidence of secondary
infections such as stomatitis and pneumonia.
Contd,…

29. The cytoplasmic inclusions of boid Inclusion Body Disease
(IBD) (arrow heads). Probable hemosiderin pigments
(arrows).

30. Diseases of Urinary Bladder
 Any microscopic precipitates or polycrystalline
concretions found in the urinary tract of animals are
classified as urinary calculi.
 Urinary calculi or uroliths have been reported in
lizards, chelonians, snakes, and amphibians. Uroliths
of reptiles and amphibians appear to be composed of a
type of urate salt.
 Most uroliths are located in urinary bladder, but on
rare occasions in the ureters and cloaca. For species
without urinary bladders (e.g., snakes), the
concretions may be found where urine is frequently
stored, the distal ureters.
 Etiologies for urolith formation include nutritional
deficiencies (e.g., vitamin A and D), excessive dietary
protein, oxalates, bacterial infections, and suture
remnants.

31.  A common clinical finding associated with calculi
formation is dehydration.
 Generally, the majority of small calculi will not result
in significant lesions or clinical signs.
 Anorexia, constipation, egg binding, dysuria, and poor
growth are clinical signs that may be observed in
patients that have been diagnosed with urinary
calculi.
 Calculi with rough surfaces or increasing sizes may
irritate the lining of the urinary bladder, resulting in
hematuria, hypertrophy of the bladder wall, and/or
hyperplasia of the epithelial mucosa.
 Pressure necrosis to the bladder wall and internal
viscera have been reported, particularly with large
stones.
Contd,…

32. Transitional cell carcinoma of the urinary bladder of an
iguana. The mass is intraluminal.

33. Some Specific Diseases
In Wild Animals
Affecting Urinary
System...

34. 1. Anthrax:
 Mammalian herbivores have a higher susceptibility to anthrax
than carnivores.Wild mammals in North America that have
been confirmed to be susceptible to anthrax include:
 Wood bison;
 White-tailed deer (Odocoileus virginianus);
 Moose (Alces alces);
 Bobcat (Lynx rufus);
 Cougar (Felis concolor);
 Raccoon (Procyon lotor);
 Mink (Mustela vison).
 Humans are also susceptible to anthrax.
 Toxins produced by bacteria in the blood are transported
throughout the body. These toxins cause a reduction in oxygen
in the blood, edema, kidney failure, shock, and ultimately
death.

35. Bison killed by anthrax are often found on their back
or side with their legs in a "saw-horse position".

36. 2.Dioctophyme renale Infection :
 The giant kidney worm, Dioctophyme renale is one
of largest parasitic nematodes.
 Its complex life cycle requires an aquatic
oligochete or annelid as an intermediate host.
Fishes and frogs are paratenic hosts that serve to
infect the definitive hosts.

37. Contd,…
 Wild carnivores such as mustelids, canids, and
some domesticated animals are known
definitive hosts, with sporadic reports in
atypical hosts which include humans.
 Renal parasitism by D.renale can cause total
destruction of the renal parenchyma, atrophy
and fibrosis of renal tubules, dilation of the
renal pelvis, and urethral obstruction, and its
occurrence in the abdominal cavity can lead to
adhesions and peritonitis.

38. 3. Inadequate Provision Of
Water :
 Adequate provision of water is essential for animal
welfare.
 Insufficient water intake can have various adverse
effects in wild and zoo animals mainly rabbits
(oryctolagus cuniculus), including reduced food intake,
increased risk of urinary tract infections and urinary
concretions, dehydration with subsequent
haemoconcentration, hyperthermia, exhaustion and
finally death.

39. 4. Chronic Kidney Disease:
 Mostly found in rats.
 It is called Chronic Renal Failure (CRF), Chronic
Progressive Nephropathy (CPN), Progressive
Glomerulo nephrosis (PGN), Rat Nephropathy, Chronic
Progressive Nephrosis, Chronic Glomerulonephropathy
,Spontaneous degenerative nephropathy
,Glomerulonephrosis , Glomerulonephritis ,Chronic
interstitial nephritis, Chronic nephrosis, Renal
insufficiency ,Chronic uremia, Protein Overload
nephropathy, Old Rat Nephropathy, etc.
 The gradual loss of kidney tissue in rats appears to be
primarily due to chronic inflammation. Chronic
inflammation gradually destroys the urine producing
glomeruli , the structural tissues that surround them
(interstitial nephritis), nephrons that convey the urine
out of the kidneys and eventually replace these
structures with nonfunctional scar tissue (fibrosis).

40. 5. Chlamydiosis
 Many reports of chlamydiosis appear in the
literature among both wild and captive populations
of anurans, including the African clawed frog,
Gunther’s triangle frog, the giant barred frog and
most recently in the European common frog (Rana
temporaria).
 Internally, organs such as the liver, spleen, and
kidney may have gross swelling and histological
evidence of marked histiocytic or granulomatous
inflammation.

41. 6. Proliferative kidney
disease (PKD)
 Proliferative kidney disease (PKD) is considered
one of the most serious parasitic diseases of
salmonids and is responsible for high mortalities
in fish farms and possibly also in populations of
wild fish.
 Fish with PKD are often lethargic and show a
darkening of the skin.

42. 7. Leptospirosis
 Leptospirosis can affect many wild and
domestic animals, including marine mammals.
The disease can affect cattle, sheep, goats, pigs,
horses, and dogs but is rare in cats.
 Causative agent is Leptospira interrogans - a
spirochete that has a hooked end and resembles
a question mark.
 Disease in cattle, sheep, goats and swine may
include a fever and reproductive problems (e.g.,
abortions). In horses, the eye is most commonly
affected. The eyelids may be reddened, the
horse will be sensitive to light and may blink
frequently or clouding of the eye may be seen.

43. 8. Lyme Disease
 Lyme disease is a tickborne illness that results from
infection with Borrelia burgdorferi.
 These organisms are maintained in wild animals,
but they can affect humans and some species of
domesticated animals including horses and cat.
 The illness is best characterized in the dog, where
arthritis and nephropathy appear to be the most
common sequelae.
 A syndrome of glomerulonephritis and interstitial
nephritis has also been reported in Bernese
Mountain Dogs.

44.  B. burgdorferi is associated with a form of kidney
disease called Lyme nephritis or Lyme nephropathy.
This syndrome is characterized by protein losing
nephropathy and a unique pathology consisting of
immune-mediated glomerulonephritis, lymphocytic
plasmacytic interstitial nephritis and diffuse tubular
necrosis with regeneration.
 Most dogs have signs of renal failure, which may
include dehydration, anorexia, lethargy, vomiting,
polyuria and polydipsia of varying degrees, and
weight loss.
 The kidney cortices may be diffusely light tan or red-
brown, and the cortical surface may contain pinpoint
red foci. The medulla often bulges on cut surface.
 Microscopically, the kidney lesions are characterized
by glomerulonephritis, tubular necrosis and diffuse
interstitial lymphoplasmacytic inflammation.
Contd,..