Advances in Diagnosis of Respiratory Diseases of Small Ruminants

Table 1

Common infectious respiratory diseases of small ruminants.

Sl. no.	Name of condition	Etiological agents	Affected species	Clinical signs	PM findings	Diagnostic tests	References
1	Peste des petits ruminants (PPR)	Morbillivirus (family Paramyxoviridae)	Goats and sheep	Mucopurulent nasal and ocular discharges, necrotising and erosive stomatitis, enteritis, and pneumonia	Congestion of mucosa of respiratory tract, exudates in tract, hardening of lungs mainly in anterior lobes, congestion hemorrhages, and erosion in intestinal mucosa	HA, HI, ELISA, PCR-ELISA, RT-PCR, real-time PCR LAMP	[29, 30, 37–43]
2	Bluetongue	Orbivirus (family Reoviridae)	Goats and sheep	Swelling of the lips and tongue and typical blue coloration of tongue, though this sign is confined to a minority of the animals. Nasal symptoms may be prominent, with nasal discharge and stertorous respiration	In sheep-oedematous face and ears, with dry, crusty exudate on the nostrils; hyperemic coronary bands of hooves; petechial or ecchymotic hemorrhages may be present and extend down the horn. Petechiae, ulcers, and erosions in the oral cavity, particularly on the tongue and dental pad. The oral mucous membranes may be necrotic or cyanotic. The nasal mucosa and pharynx may be edematous or cyanotic, and the trachea hyperemic and congested. Froth is sometimes seen in the trachea	AGID, RNA-PAGE, FIT, RT-PCR, ELISA, and real-time PCR	[44–58]
3	Parainfluenza	Paramyxovirus	Sheep and goats	Mostly associated with enzootic pneumonia	Generally followed by bacterial infection mainly secondary Mannheimia infection	Direct immunofluorescence, ELISA, RT-PCR, real-time PCR, and multiplex PCR	[11, 18, 59–65]
4	Caprine arthritis encephalitis virus	Retrovirus	Neurologic disease in kids and arthritis in adults	Lymphocytic mastitis and hard firm udders along with chronic wasting	Signs of secondary bacterial infection: thickening of interalveolar septa and lymphoid hyperplasia, chronic interstitial pneumonia	TaqMan quantitative PCR (qPCR)	[18, 66–71]
5	Ovine progressive pneumonia (maedi-visna)	Oncogenic retrovirus of subfamily Lentiviridae	Sheep	Chronic emaciation, weakness, dyspnea, lymphoproliferative pneumonia, meningeal arteritis with encephalitis, nonsuppurative arthritis, and lymphocytic mastitis	Characteristic firm lungs with grayish to brown discoloration, thickening of interalveolar septa, and lymphoid hyperplasia	Immunohistochemical (IHC), cELISA, AGID, IP, and real-time quantitative PCR (qPCR)	[18, 72–76]
6	Enzootic nasal tumors, ovine pulmonary adenomatosis (Jaagsiekte)	Retrovirus	Sheep and goats	Signs of inspiratory dyspnea along with seromucoid nasal discharge	Presence of uni- or bilateral tumor growth; firm, hard, grey colored lungs; lungs sink in water, and bronchi are found filled with white frothy fluid	ELISA, RT-PCR, real-time PCR, IHC, and nested PCR	[77–83]
7	Enzootic pneumonia (Pasteurellosis, shipping fever, and hemorrhagic septicemia)	M. haemolyticaand Bibersteinia trehalosi (Pasteurella trehalosi)	Sheep	Dyspnea, pyrexia, dullness, depression, mucopurulent nasal discharge, oculonasal blood, and tinged discharge	Serofibrinous fluid in lungs with fibrinous adhesions leading to consolidation of lungs	Counterimmunoelectrophoresis, ELISA, PCR, multiplex PCR, IHC, ISH, AFLP, AP-PCR, DNA fingerprinting, and Southern blot	[14, 84–96]
8		M. haemolytica and P.  multocida	Goats
9	Caseous lymphadenitis	Corynebacterium pseudotuberculosis	Sheep and goats	Chronic emaciation, dyspnea, exercise intolerance, dullness, forced full coughing, and weight loss	Enlargement of lymph nodes with greenish colored pus	Haemagglutination test, Counterimmunoelectrophoresis, IFN-𝛾 ELISA, and PCR	[14, 97–103]
10	Mycoplasma	M. ovipneumoniae, M. capricolum, M. mycoides subsp. mycoides, and M. agalactiae	Sheep and goats, kids may develop encephalitis	Anorexia, pyrexia, painful breathing, coughing, and sneezing	Peribronchiolar lymphocytic infiltrations are observed with diffused nonsuppurative pleuritis	Immunoblotting, immunobinding assay, growth inhibition, PCR-RFLP, and multiplex real-time PCR	[7, 18, 104–119]
11	Nasal myiasis	Oestrusovis	Sheep	Stamping of feet, efforts to hide nose, difficult breathing, and heavy sound in respiration	Swollen nasal membranes, plugged nostrils, and upper respiratory tract occluded with serofibrinous discharge	Double immunodiffusion (DD), indirect haemagglutination (IH) tests, ELISA, and PCR PCR-RFLP	[120–125]
12	Verminous pneumonia	Dictyocaulus filaria, Protostrongylus rufescens, and Muellerius capillaris	Young animals in the age group of 2–18 months	Pyrexia, coughing, rapid and painful breathing, nasal discharge, and emaciation with retarded growth	Presence of parasites and caseous exudates in lungs	ELISA and PCR	[14, 126–130]