Swine noninfectious diseases

What is porcine stress syndrome?

Porcine stress syndrome (PSS) refers to a cascade of physiologic events and clinical signs that occur in pigs that have a mutation in the calcium-release channel protein (ryanodine receptor [RYR]). This mutation

results in a hypersensitive triggering mechanism

of the calcium-release channel in skeletal muscle sarcoplasmic

reticulum in response to various stressors, such

as gas anesthetics or stressful environmental conditions.

The lack of proper calcium control within the membranous

portions of the sarcoplasmic reticulum and mitochondria

is thought to initiate the cascade of events that

results in the syndrome (O’Brien et al., 1991; Fujii et al.,

1991). Stress-susceptible pigs are also known to overrespond

to stressful stimuli, with excessive β-adrenergic

What type of receptor does porcine stress syndrome potentiate?

Calcium-release channel protein (ryanodine receptor [RYR]). This mutation results in a hypersensitive triggering mechanism

of the calcium-release channel in skeletal muscle sarcoplasmic

reticulum in response to various stressors. lack of proper calcium control within the membranous portions of the sarcoplasmic reticulum and mitochondria is thought to initiate the cascade of events

Major breeds affected by porcine stress syndrome?

The mutation is found in five major

breeds of swine: Landrace, Yorkshire, Duroc, Pietrain,

and Poland China and other breeds, including miniature

potbellied pigs

Is porcine stress syndrome recessive?

Autosomal recessive with variable penetrance.

What gene is affected for porcine stress syndrome?

a newly identified mutation (R1958W)

in the dystrophin gene has recently been shown to be

responsible for loss of animals due to transport stress

(Nonneman et al., 2012). This syndrome has also been

reported in humans, dogs, cats, and horses.

What risk factors predispose to porcine stress syndrome?

development of PSS has most commonly been associated with

exposure to halothane and succinylcholine; however,

methoxyflurane, enflurane, and isofluran

What are the clinical signs of procine stress syndrome?

Initial signs include tachycardia, tachypnea, muscle

rigidity, and hyperthermia. Clinicopathologic changes

include metabolic acidosis, myoglobinemia, hyperkalemia,

and hyperglycemia. Cardiovascular collapse and death.

Treatment of Porcine stress syndrome?

Anesthetic delivery should be discontinued

immediately and 100% oxygen delivered. Additional

treatment includes sodium bicarbonate to combat the

metabolic acidosis and hyperkalemia. Active cooling of

the animal may be done by ice packing and IV administration

of cooled fluids, or by gastric and/or rectal lavage

with iced saline. Dantrolene, an agent that prevents PSS

by decreasing release of calcium from the sarcoplasmic

reticulum while allowing calcium uptake to continue, is

highly effective in stopping the progression of the syndrome

when administered at the onset of signs.

What can you give as a pretreatment for porcine stress syndrome?

Dantrolene (3.5–5 mg/kg) can

also be given as preventive therapy in animals known to

be susceptible and to treat

Is salt poisoning common in pigs?

Salt poisoning, also known as sodium ion

toxicosis, is a condition that can easily occur in swine

What can you feed young pigs to increase risk of salt poisoning?

Feeding milk by products such as whey,

Most common cause of salt toxicity in pigs?

By far the most common initiator for the condition is water deprivation

Pathogenesis and clinical signs of salt toxicity?

Pathogenesis Salt poisoning is caused by hyperosmolarity

of the CNS. When the animal rehydrates, the osmotic pressure causes water to be drawn into the CNS, resulting in swelling and edema. Clinical Signs/Diagnosis Initially, the animal presents

as being very thirsty and constipated. CNS involvement,

which may be delayed for several days after the insult, follows.

The pigs will appear tense and apprehensive, with

ears pricked and staring ahead with the head slightly elevated.

The nose will then twitch, the eyes will close, and

a rhythmic chomping of the jaws follows. Animals may

also appear blind and deaf. Pigs near death may paddle

continuously.

Common histopathfinding of salt toxicity?

eosinophilic cuffing of the meningeal and cerebral vessels.

What part of the stomach are most affected by gastric ulcers in pigs?

Gastric ulceration in pigs refers to a condition in which ulceration of a specific region of the pig’s stomach, the pars oesophagea, occurs.

What type of feed is a predisposing factor for gastric ulcers in pigs?

under 700 nms in size. The diet should be more coarsely ground (not less than 700 µm in size), not contain excessive unsaturated fatty acids, and have the right balance of vitamin E and selenium.

Clinical signs of gastric ulcers in pigs?

In the peracute

form, apparently healthy animals are simply found dead.

In the acute form, pigs will become pale and weak, with

an increased respiratory rate. Vomiting of blood and

passage of bloody, tarry feces are seen. In the subacute

or chronic form, the animal will be anemic and anorexic,

with passage of dark feces that may be intermittent or

persistent

What can melamine be mixed with to cause toxicity in pigs?

Melamine and cyanuric acids, when fed together,

cause toxicity in animals

What age and sex are nephromas most common in?

Embryonal nephromas affect pigs under 1 year of

age, with predominance in females.

What age group is lymphosarcoma common in?

Lymphosarcomas affect primarily younger animals

but can affect mature animals of either sex. Most cases

What age and breed are melanomas most common in?

Melanomas occur as congenital lesions with exceptionally

high frequency in Sinclair miniature swine (85%

incidence at 1 year of age) and in Duroc, Iberian, and

Hormel breeds. Spontaneously regress

What breed is Thrombocytopenic purpura common in?

Thrombocytopenic purpura has been reported in

Gottingen pigs

Clinical signs of Thrombocytopenic purpura ?

extensive

multifocal subcutaneous hemorrhage. Vascular lesions are consistently present in renal

pelvis and coronary arteries. Type III hypersensitivity