small mammals 5 pt 2 "Rats" Flashcards
Mammary Tumors Etiology
- Mammary tissue from
neck to inguinal - BenignFibroadenoma
- 53% of cases, both sexes
- Often see changes of the reproductive tract – polyps, hyperplasia, cysts, metritis
- Adenocarcinomas
- 15%
<><><><><> - Distribution of the mammary tissue is extensive, neck to inguinal.
- Benign Fibroadenoma
- The most common subcutaneous tumor (53%) of the mammary glands.
- Can reach 8 to 10 cm in diameter and occur in both males and females.
- Often associated with changes in the reproductive tract, such as
endometrial polyps, hyperplasia, paraovarian cysts, and suppurative
metritis. - Adenocarcinomas
- Less common (15%)
Mammary Tumors prevention
- Prevention – early spaying (< 3 months best, < 7 months OK); subcutaneous deslorelin implants instead, questionable efficacy.
Mammary Tumors treatment
Treatment – surgical resection, often reoccur; spaying or deslorelin at this time questionable help.
Pituitary Adenoma etiology
- Common, increase
with age - Can secrete prolactin → lactation, fibroadenoma?
Pituitary Adenoma clinical signs
Hindlimb paresis/paralysis,
changes in vision
Pituitary Adenoma Dx
- CT/MRI
Pituitary Adenoma Tx
Cabergoline – blocks prolactin release
- regrowth possible
Chronic Renal Failure etiology, clinical signs
Very common, increase with
age, more severe in males
* Large, pale, irregular kidneys
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PU/PD, proteinuria,
biochemistries
Chronic Renal Failure Preventionand
Treatment
Low protein diet (4-7%, soybean)
Chronic Renal Failure in rats summary
- Chronic progressive nephrosis (CPN) is the best-known age-related disease in rats.
- Kidneys enlarged and pale and have a pitted, mottled surface that often contains
pinpoint cysts. - Lesions consist of a progressive glomerulosclerosis and myriad tubulointerstitial
disease primarily involving the convoluted proximal tubule. - The disease occurs earlier and is of greater severity in males than in females.
- Marked proteinuria, increases with age.
- Dietary factors have an important role in the progression of CPN; caloric
restriction, low-protein diets (4%-7%, soybean), and limiting the source of dietary protein reduce the incidence and severity of CPN; drugs and exposure to chemicals may exacerbate. - Diagnosis is based on clinical signs (polyuria/polydipsia), plasma biochemical results, and proteinuria.
- Treatment – supportive, low-protein diet.
Respiratory Disease in rats: principles
- Similar to dogs and cats
- History is critically important
- Previous illnesses and medications
- Exposure to toxins
- Interaction with other animals
- Handling
- Brief handling in unstable patients
- Physical examination may need to be performed in stages
resp disease in rats - husbandry
- Soft paper-based bedding, hay, and fleece blankets are good
choices - Pine and cedar shavings are not recommended
- Potential respiratory irritant
- Increased liver enzymes
- Cage cleaning
- Frequent cage cleaning very important
- High ammonia levels can worsen respiratory disease
resp disease in rats pathogens
- Respiratory disease is very common in pet rats
- Mycoplasma pulmonis is considered “ubiquitous” in pet rats, and can lead to oculonasal discharge, dyspnea, weight loss, and pulmonary abscessation * Chest x-ray can help determine severity of lesions and guide aggressiveness
and length of treatment
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Mycoplasma - Mycoplasma is very common in pet rats
- Difficult to kill due to lack of cell wall
- Can progress from upper respiratory infection to pneumonia,
abscesses, granulomas - Major component of chronic respiratory disease (CRD)
- Mycoplasma exacerbated by:
- Bacterial infections
- Viral infections
- Ammonia in the environment
- Genetics
- Nutritional deficiencies
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Not all respiratory disease in rats is mycoplasmosis - Other bacterial infections: Streptococcus, Corynebacterium, Filobacterium (CAR bacillus), Hemophilus, Pasteurella
- Viral infections: Sendai (paramyxovirus), pneumonia virus of mice (paramyxovirus), SDA virus (coronavirus)
- Fungal infections: Pneumocystis carinii
- Non-infectious disease
- Cardiovascular disease
- Neoplasia
- Although it can be difficult to differentiate infection vs. neoplasia based on
chest x-rays in rats, chest x-rays can help rule out congestive heart failure - Streptococcus pneumonia
- Can occur acutely
- Young rats have more severe disease than older ones; sudden death may
occur - Mature rats: dyspnea, snuffling, abdominal breathing, purulent exudate
- Cytology: G+ diplococci
- Severe bacteremia can occur
- Corynebacterium pneumonia
- Corynebacterium kutschi pneumonia
- Rare
- Associated with debilitation/immunosuppression
- Pet rats usually develop bronchopneumonia and bronchiectasis
- Often have coinfection with other pathogens
- Common secondary pathogen
- Can also have balanitis, arthritis, abscesses
- Corynebacterium pseudotuberculosis
- Pneumonia in mice
Respiratory Disease viral
- Pneumonia virus of mice (paramyxovirus)
- Sendai (paramyxovirus)
- Sialodacryoadenitis [SDA] virus (coronavirus)
fungal resp disease agent
- Pneumocystis carinii
Respiratory Disease non-infectious causes
- Cardiovascular disease
- Neoplasia
- Environmental
> Cedar/pine
> Ammonia
Respiratory Disease Dx
- X-rays / CT
- Culture / PCR
- Mycoplasma PCR may have
higher sensitivity than culture - Serology
- CBC and biochemistries
- FNA?
Respiratory Disease Tx
Antibiotics
* Enrofloxacin, doxycycline, azithromycin, chloramphenicol
* Often need at least 3-4 weeks of treatment or longer
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* Antibiotics (enrofloxacin, doxycycline, azithromycin, chloramphenicol) * Often need at least 3-4 weeks of treatment or longer
* Oxygen
* Nebulization (saline, gentamicin)
* Bronchodilators (theophylline, nebulized aminophylline)
* Anti-inflammatories (NSAIDs vs. steroids)
* Sildenafil for pulmonary hypertension due to chronic respiratory disease
may prevent fibrosis * Antibiotics
* Mycoplasma
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* Tylosin, enrofloxacin + doxycycline, sulfamethazine, chloramphenicol
* Filobacterium (CARB)
* Sulfonamides, penicillin, ampicillin, chloramphenicol, neomycin,
streptomycin * Corynebacterium
* Ampicillin, chloramphenicol, tetracycline * Streptococcus
* Beta-lactamase-resistant penicillin (cloxacillin, oxacillin, dicloxacillin)
* 1st choice: amoxicillin-clavulanate
Respiratory Disease non-Ab treatments
- Oxygen
- Nebulization – saline,
gentamicin - Bronchodilators – theophylline, nebulized aminophylline
- Anti-inflammatories – NSAIDs vs. steroids
- Sildenafil for pulmonary hypertension due to chronic respiratory disease may prevent fibrosis
resp disease in rats conclusions
- Keep in mind that rats presenting with signs of mild upper respiratory disease
may have a severe pulmonary or thoracic disease! - Always offer radiographs for rats presenting with respiratory signs
- Rats may have flare-ups of mycoplasmosis secondary to immunosuppression
from other underlying diseases (such as neoplasia)
Posterior Paresis etiology
- Common, old animals
- Radiculoneuropathy – spinal nerve root degeneration
- Pituitary adenoma?
Posterior Paresis clinical signs
- Posterior paresis and paralysis
- Loss of tail control
- Incontinence
- Weight loss
Posterior Paresis Tx
- Supportive care
Chromodacryorrhea whats this
- Harderian glands, porphyrin
(fluoresces in UV c.f. blood) - Stress, chronic disease
ectoparasites in rats
- Fur mites
- Lice
